2014
ELECTRICAL INSPECTOR
INSTRUCTORS’ MANUAL
LEVEL III
NC Code Officials Qualification Board
322 Chapanoke Road
Raleigh, NC 27603
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
1
ARTICLE
90
100
110
220
230
240
250
280
300
310
314
326
328
336
392
400
408
427
430
445
450
460
470
490
500
501
502
503
504
505
513
515
516
517
530
610
660
665
668
TITLE
INTRODUCTION TO THE NEC
DEFINITIONS
REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
BRANCH CIRCUIT, FEEDER AND SERVICE CALCULATIONS
SERVICES
OVERCURRENT PROTECTION
GROUNDING AND BONDING
SURGE ARRESTOR
WIRING METHODS
CONDUCTORS FOR GENERAL WIRING
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES;
FITTINGS; AND HANDHOLE ENCLOSURES
ARTICLE 326 INTEGRATED GAS SPACER CABLE: TYPE IGS
ARTICLE 328 MEDIUM VOLTAGE CABLE: TYPE MV
POWER AND CONTROL TRAY CABLE: TYPE TC
CABLE TRAYS
FLEXIBLE CORDS AND CABLES
SWITCHBOARDS AND PANELBOARDS
FIXED ELECTRIC HEATING EQUIPMENT FOR PIPELINES AND VESSELS
MOTORS, MOTOR CIRCUITS, AND CONTROLLERS
GENERATORS
TRANSFORMERS AND TRANSFORMER VAULTS
CAPACITORS
RESISTORS AND REACTORS
EQUIPMENT OVER 600 VOLTS NOMINAL
HAZARDOUS (CLASSIFIED) LOCATIONS, CLASSES I, II AND III
DIVISIONS 1 AND 2
CLASS I LOCATIONS
CLASS II LOCATIONS
CLASS III LOCATIONS
INTRINSICALLY SAFE SYSTEMS
CLASS I, ZONE 0, 1 AND 2 LOCATIONS
AIRCRAFT HANGARS
BULK STORAGE PLANTS
SPRAY APPLICATION, DIPPING, AND COATING PROCESSES
HEALTH CARE FACILITIES
MOTION PICTURE AND TELEVISION STUDIOS
AND SIMILAR LOCATIONS
CRANES AND HOISTS
X-RAY EQUIPMENT
INDUCTION AND DIELECTRIC HEATING EQUIPMENT
ELECTROLYTIC CELLS
Electrical
Instructors
Manual
and Student Worksheets -- Level 3
Revision 20082014
Electrical
Instructor
Manual
Level III
PAGE TM
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149
2 2
669
ELECTROPLATING
70-600 152
705
INTERCONNECTED ELECTRICAL POWER PRODUCTION SOURCES
70-662 155
708
CRITICAL OPERATIONS POWER SYSTEMS
70-667 158
THE PAGE NUMBER LISTED ABOVE CORRESPONDS TO THE ARTICLE LOCATION IN THE NORTH
CAROLINA ELECTRIC CODE BOOK (THE NEC 2008). THE “TM” NUMBERS TO THE RIGHT OF THE ARTICLE
NUMBERS CORRESPONDS TO THE PAGE NUMBERS IN THE TRAINING MANUAL FOR THE STARTING PAGE
FOR EACH ARTICLE LISTED.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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INTRODUCTION TO THE NATIONAL ELECTRIC CODE
ARTICLE 90
LEVEL III
OBJECTIVES:
Each student should become familiar with:
1. The purpose and scope of the National Electrical Code.
2. The definitions and fundamental rules covered by the Code.
MATERIALS NEEDED:
National Electrical Code (NEC) 2014 edition
INTRODUCTION:
By this level of instruction each student should have had both Level I and II. Any student
who hasn’t had Levels I and II should be given the work sheets from those levels as a study
guide. This student will need a lot of special attention...
This lesson should give the students a clear picture of how the Code is organized so they may
find information more easily in later assignments and on the job. The Code is not a set of
laws; it is a set of rules. It is intended for use by governmental bodies exercising legal
jurisdiction over electrical installations and for use by insurance inspectors.
PRESENTING THE LESSON:
The National Electrical Code, Article 90, Introduction, outlines the purpose and explains the
scope, arrangement, enforcement, and formal interpretations of the Code. It also contains
details of safety examinations of equipment, future wiring expansion and units of
measurement used in the Code.
The purpose of this Code is to safeguard people and property from electrical hazards by
outlining provisions that are necessary for safety. Many hazards that occur are due to
overloading wiring systems or exceeding the provisions of this Code; therefore, it is
important to plan for future increases in the use of electricity.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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This Code is not an instruction manual for untrained persons. Many areas are covered by this
Code, but there are also a lot of areas not covered. Pay close attention to the requirements
listed in Section 90.2.
90.2 Scope
90.2(B) (5) Explain-controlled by electric utilities
90.2(C) See definition Article 100
90.5 Mandatory Rules etc.
90.6 See Vol. I-A, NC State Bldg. Code, post this link on the board for the students to reference,
http://www.ncdoi.com/OSFM/Engineering/Interpretations.asp
Remind the students that the Chief Electrical Inspectors usually exercise legal jurisdiction
over electrical installations through city or county ordinances or laws based on the NEC. The
instructor should lead a class discussion of the material contained in the appropriate
sections of the Code. After each section distribute the worksheets for the students to
complete and answer any questions they may have.
APPLICATION:
If time allows, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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INTRODUCTION TO THE NATIONAL ELECTRIC CODE
ARTICLE 90
LEVEL III
1. The purpose of this Code is which of the following?
a. The safeguarding of persons and property from hazards arising from the use of
electricity.
b. The practical safeguarding of persons and property from hazards arising from the use of
electricity.
c. The safeguarding of property and persons from hazards arising from the improper use
of electricity.
d. The health safety and welfare of the general public
2. A rule that is characterized by the use of the terms shall be permitted or shall not be
required is which of the following?
a. Mandatory rule
b. Permissive rule
c. Explanatory rule
d. None of the above
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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INTRODUCTION TO THE NATIONAL ELECTRIC CODE
ARTICLE 90
Level III
ANSWER KEY
1.
2.
b. Practical safeguarding
b. Permissive rule
90.1(A)
90.5(B)
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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DEFINITIONS
ARTICLE 100
Level III
OBJECTIVE:
Each student should become familiar with Article 100, definitions essential to the proper use of
the NEC.
INTRODUCTION:
The definitions in Article 100 are terms normally found more than one Article of the Code. We
will cover Part II of Article 100 briefly. Determine if students have questions about Part I, and
then discuss if needed.
PRESENTING THE LESSON:
Briefly review Part I of Article 100, then discuss Part II (Over 600 Volts, Nominal). Students
will be returning to Article 100 constantly to look at a definition of particular terms in code
articles.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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DEFINITIONS
ARTICLE 100
Level III
WORKSHEET
1. By definition, which of the following is correct concerning disconnecting means for
equipment?
I. The disconnecting means is used to disconnect the circuit conductors from their source
of supply.
II. A disconnecting means must be at no more than 50 feet from the equipment it serves.
a.
b.
c.
d.
I only
II only
Both I and II
Neither I nor II
2. A volatile flammable liquid is a liquid having a flash point below which of the following?
a.
b.
c.
d.
60C
70C
38C
36C
3. To be in sight from or within sight of means to be within which of the following?
a.
b.
c.
d.
100 ft.
75 ft
50 ft
25 ft.
.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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DEFINITIONS
ARTICLE 100
Level III
ANSWER KEY
1.
2.
3.
a, I only
c, 38C
c, 50 ft.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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ELECTRICAL
ARTICLE 110
Level III
OBJECTIVE:
To assure that student is familiar with Article 110, Part III, installations over 600 volts,
nominal; indoors and outdoors.
INTRODUCTION:
Explain to class that you will cover Article 110, Part III, in detail, as this is important
because more installations of this type are being installed.
Also Part IV Tunnels and Part V Manholes will be
covered
PRESENTING THE LESSON:
Discuss Article 110, Part III in detail, giving illustration on board, use handouts.
Also discuss both indoor and outdoor installations.
Discuss Table 110.34 (A) in 110.34 (A), pointing out the difference from the
Table 110.26 (A) (1).
Discuss Part IV covering raceways, bonding and ventilation.
Discuss Part V and point out that this has been moved from Article 314 pointing out that
this covers all voltages.
APPLICATION:
If time will allow let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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ELECTRICAL
ARTICLE 110
Level III
WORKSHEET
1. In general at least one entrance shall be provided to give access to the working space
about electric equipment over 600 V. This space shall be a minimum width of:
a.
b.
c.
d.
12 inches
18 inches
24 inches
30 inches
2. Electrical equipment, using 2400 volts, with exposed live parts on one side and no live or
grounded parts on the other side of the working space shall have a minimum working
space in front of the equipment of:
a.
b.
c.
d.
3 feet
4 feet
5 feet
6 feet
3. Unguarded live parts operating at 1,200 volts between phases shall be elevated above a
working space by a least which of the following?
a.
b.
c.
d.
8 ft.
9 ft.
10 ft.
no requirement
4. The entrances to a room containing exposed live parts operating at over 600 volts shall
be:
a.
b.
c.
d.
5.
Kept Locked
Unlocked at all times
Provided with signs “Danger-High Voltage-Keep Out”
Both a and c
A wall, screen, or fence used to enclose an outdoor electrical installation to keep out
persons who are not qualified shall not be less than which of the following in height?
a.
b.
c.
d.
6 ft.
7 ft.
8 ft.
5 ft.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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6. Where electrical equipment operating at 240 volts is located in a room with equipment
operating at 12,000 volts, the high voltage equipment shall be separated from the low
voltage equipment by:
a.
b.
c.
d.
a partition
a screen
a fence
any of the above
7. Electrical controls for the ventilation system shall be arranged in which of the following
manners?
a.
b.
c.
d.
So that the airflow can be reversed.
So that the airflow cannot be reversed.
In a manner that will allow access.
So that the motors can be reached.
8. Manhole covers shall be over which of the following weights or otherwise designed to
require the use of tools to open.
a.
b.
c.
d.
100 kg
45 pounds
100 kPa
100 pounds
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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ELECTRICAL
ARTICLE 110
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
8.
c, 24 inches
a, 3 feet
b, 9 ft.
d, both a and c
b, 7 ft.
d, any of the above
a. so airflow can be reversed.
d. 100 pounds
110.33(A)
Table 110.34(A), condition1
Table 110.34(E)
110.34(C)
110.31
110.34(B)
110.57
110.75(D
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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BRANCH CIRCUIT AND FEEDER CALCULATIONS
ARTICLE 220
Level III
OBJECTIVE:
Each student should become familiar with the requirements for determining the number
of branch circuits required and for computing branch circuit and feeder loads using
different voltages, and ratings in commercial applications.
INTRODUCTION:
This lesson should review the basic electrical formulas and methods used to determine sizes
of branch circuits and feeders. Explain to class that this is a brief review of Level I and II
materials. Make sure that class knows the difference in residential and commercial
applications.
PRESENTING THE LESSON:
Briefly review Article 220 for residential and commercial requirements for Level I and II
feeders and branch circuits and their calculations.
Point out 210.19 (page 49 on the NEC) for continuous and noncontinuous loads.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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BRANCH CIRCUIT AND FEEDER CALCULATIONS
ARTICLE 220
Level III
WORKSHEET
1. A multi-family dwelling unit complex, consisting of nine units is supplied by a 120/240
volt single-phase, 3 wire service. Each unit has 900 square feet and a calculated load of
37,000 volt amperes. Using Article 220.84 (optional method to calculate the service for
this complex), which of the following is the minimum volt amperes to size the
ungrounded service entrance conductor?
a.
b.
c.
d.
139,860
143,190
233,100
333,000
2. A 3600 square foot store building is supplied by a 120/208 volt, 4-wire, three phase
service with 60 linear feet of non-continuous show window lighting. Which of the
following is the minimum number of 120 volt, 2-wire, 20 amp branch circuits to serve
both the general lighting load and show window load?
a.
b.
c.
d.
8
9
10
11
3. A 25 KW, 480 volt, 3-phase, continuous load is to be supplied with THHW copper.
Which of the following is the minimum ampacity to size the load?
a.
b.
c.
d.
30 amperes
38 amperes
75 amperes
87 amperes
4. A 25 KW, 240 volt, single phase continuous load for electric heat is to be supplied with
THW aluminum conductors. Which of the following is the minimum size conductor
permitted for the load?
a
b
c
d
.
.
.
.
#1
#1/0
#2/0
#3/0
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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5. A school building is supplied by a 120/208 volt, 3-phase, 4-wire service and it has been
determined to have a total connected load of 150 KVA for the previous one year period.
The existing 3-phase service consists of two separate sets (in parallel) of 350 KCmil,
THW copper conductors protected by 700 amp fuses. Which of the following is the
maximum connected load permitted to be added to this service?
a.
b.
c.
d.
6.
79 amps
99 amps
183 amps
223 amps
A 120/240 volt, single phase, 3-wire service is to supply a 1000 square foot single-family
dwelling. This dwelling has a 120/240 volt 12 KW range, a 120/240 volt 5 KW dryer, 240
volt 4.5 KW water heater, a 240 volt 10 KVA central electric space heating load, and a
240 volt 2 KW AC unit. Using the optional method (220.82), the total compiled load for
sizing the ungrounded service entrance conductor in Volt Amps is:
a.
b.
c.
d.
16,000
21,600
24,100
27,600
7. A 277/480 volt, 3-phase, 4-wire feeder is supplying 100 KVA of noncontinuous load and
185 KVA of continuous load. The neutral conductor will have the full capacity of the
phase conductors because of the presence of harmonic currents in the system. What is the
minimum size overcurrent device allowed to protect this feeder?
a.
b.
c.
d.
300 Amperes
400 Amperes
225 Amperes
350 Amperes
8. What ampacity would be used in determining the proper size conductor for the load in
question #7?
a.
b.
c.
d.
600 amp
350 amp
400 amp
499 amp
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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9. What is the minimum size feeder conductors required to supply the following 208 volt, 3phase commercial kitchen appliances?
(1) 20 KVA deep fat fryer
(1) 50 KVA dishwasher
(1) 14 KVA water heater
(1) 30 KVA range
(1) 30 KVA oven
(2) 4 KVA steamers
a.
b.
c.
d.
250 Kcmil TRW copper
300 Kcmil TRW copper
300 Kcmil TRW aluminum
250 Kcmil TRW aluminum
10. A high school home economics classroom has (10) 208 volt, single phase, 12 KW ranges
connected to a 208 volt, 3-phase feeder. What is the minimum ampacity of the feeder
conductors?
a.
b.
c.
d.
85 amps
125 amps
65 amps
96 amps
11. Size the minimum ampacity of the service conductors for a school with a 277/480 volt, 3phase, 4-wire supply. It has been decided to size the service conductors for this school
under the optional calculation allowed in Section 220.86. The building is 40,000 square
feet in area and has the following connected loads:
Interior and exterior lighting
Kitchen equipment
Space heating
Air conditioning
Other loads
a.
b.
c.
d.
75 KVA
65 KVA
250 KVA
190 KVA
102 KVA
480 amperes
600 amperes
720 amperes
310 amperes
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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12. A new restaurant has total electric power. The total connected load is 476 KVA. Using the
optional method, what is the minimum allowable KVA that will be used to size the
service equipment?
a.
b.
c.
d.
400 KVA
238 KVA
325 KVA
425 KVA
13. If a 120/208 volt, 3-phase service is used, what is the minimum ampacity of the service in
question (12) above, using a single main circuit breaker?
a.
b.
c.
d.
800 amps
600 amps
700 amps
1200 amps
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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BRANCH CIRCUIT AND FEEDER CALCULATIONS
ARTICLE 220
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
b, (37,000 x 9 x .43) = 143,190 VA
d, (3600 x 3 x 1.25) + (60 x 200) / 120 / 20 = 10.6 = 11 circuits
b, (25,000 x 1.25) / 1.732 / 480 = 37.6 amps = 38 amps
c, (25,000 x 1.25) / 240 = 130.2 amps [drop minor fraction - Table 310.16, 130 amps;
use 2/0 THW Al.]
b, Total amps of conductors = 310 x 2 = 620 amps; additional
load = 620 - (150,000 / 360 x 1.25) = 99 amps [220.86]
c, [220.82] Heat = 10,000 x .65 = 6500 VA
* The instructor should explain heat calculation at percentage versus A/C calculation at
100 percent to determine largest load.
Other Loads:
General Lighting
Small Appliance
Laundry
Range
Dryer
Water heater
Subtotal
1000 x 3 =
1500 x 2 =
1500 x 1 =
(Nameplate)
(Nameplate)
(Nameplate)
1st 10,000 x 1.00 =
Remainder = 19,000 x .4 =
Electric Heat =
Total Load
10,000 VA
7600 VA
6500 VA
24,100 VA
3000 VA
3000 VA
1500 VA
12,000 VA
5000 VA
4500 VA
29,000 VA
7.
b, 400 amperes [210.19] Calculate the continuous load at 125% and the noncontinuous
load at 100%. 185,000 X 1.25 = 231,250 VA. Plus 100,000 VA = 331,250/831= 398.61
amperes, rounded to 399 amperes.
8.
c, 399 amp
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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9.
b, 300 Kcmil THW copper [220.56]
Step 1: Find the total connected load: 20+50+14+30+30+4+4 = 152 KVA
Step 2: Find the demand factor from the table (220.56) for 7 appliances-this is: 65% of
connected load.
Step 3: 152 X .6 = 98.8 KVA
Step 4: Compare the two largest pieces of equipment to the 65% demand,
obtained in Step 3. Select the larger of the two, which in this case is 98.8 KVA.
Step 5: Calculate the ampacity required, 98.800/360 = 274.4 amperes
Step 6: Selection of conductor from the wire tables (310.16)
10. d, 96 amps [220.55]
Step 1: 220.55 requires the load to be computed on twice the number of ranges connected
between any two phases. Each range equals 2/3 of the three phases, for 10 ranges
this occurs four times. Double this and use 8 ranges to select the minimum
demand, form table 220.55 for (8) ranges (table 220.55 is based on 12 kw.). This
selected value is 23,000 VA.
Step 2: Find the current per phase: 23,000/2 = 11,500.
Step 3: Find the 3-phase equivalent circuit: 11,500 X 3 = 34,500 VA.
Step 4: Find the minimum ampacity of the feeder: 34,500/360 = 96 amperes. Use 96
amperes
11. a, 480 amperes [220.86]
Step 1: Find the total continuous load, omitting the smaller, the heat or the air
conditioner. 75+65+250+102 = 492 KVA connected.
Step 2: Find the demand VA per square foot for the building:
492,000/40,000 = 12.3 VA per square foot.
Step 3: Use the table 220-86 to calculate the demands. The first 3 VA per square
foot has a demand of 100%. This is 40,000 X 3 = 120,000 VA.
Step 4: Use the table for the remaining 9.3 VA at 75%.
40,000 X 9.3 X .75 = 279,000 VA.
Step 5: Total demands 120,000 + 279,000 = 399,000 VA
Step 6: Find the minimum ampacity, 399,000/831 = 480 amperes. Use 480
amperes.
12. b, 476 KVA x 50% = 238 KVA
13. c, 700 238,000/360 = 661 = 700Amp
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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SERVICES
ARTICLE 230
Level III
OBJECTIVE:
Each student should understand requirements for services over 600 volts nominal.
INTRODUCTION:
Explain to class that we will cover services in Part VIII of Article 230. Briefly discuss
previous sections of 230, under 600 volts.
PRESENTING THE LESSON:
Go over Article 230, Part VIII in detail; discuss wiring methods, warning signs, supports,
disconnecting means, overcurrent protection. (Refer to Article 240.100) for overcurrent
protection.
APPLICATION:
If time will allow, let the class time answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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SERVICES
ARTICLE 230
Level III
WORKSHEET
1. Above ground Service Entrance conductors over 600 V shall be installed in which of the
following:
a.
b.
c.
d.
Rigid Metal Conduit
Intermediate Metal Conduit
Rigid Non-metallic Conduit
All of the above
2. In general, service Entrance Conductors over 600 V, not in cable, shall be a minimum
size of:
a.
b.
c.
d.
#8 copper
#6 copper
#4 copper
#3 copper
3. When using fuses to protect service entrance conductors over 600 volts, which of the following
is the maximum fuse permitted to protect a conductor that is rated at 145 amps.
a
b
c
d
.
.
.
.
400
450
500
600
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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SERVICES
ARTICLE 230
Level III
ANSWER KEY
1.
2.
3.
d, all of the above
b, #6
a, 400;
145 x 3 = 435 400 < 435
230.202(B)
230.202(A)
230.208
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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FUSES AND CIRCUIT BREAKERS
GREATER THAN 600 VOLTS
ARTICLE 240
Level III
OBJECTIVE:
Each student should be familiar with the requirements for overcurrent protection for over
600 volts nominal applications.
MATERIALS NEEDED:
Show pictures and literature of over 600 volt fuses and circuit breakers.
PRESENTING THE LESSON:
The approach to the design and manufacture of the over 600 volt fuses and circuit breakers
is quite different than that take for protective devices of lower voltages. Consequently different
requirements for the protection of feeder and branch circuit conductors have been included in
sections 240.100 and 240.101.
In order to illustrate the above it is suggested that conductors and code allowed overcurrent
devices be selected for a typical 200 ampere branch circuit at both voltage levels-- 600 volts and
say 5000 volts in rigid metal conduit and copper conductor.
Ex. 600 V 3/0 THW
200 amperes OC device
Ex. 5000 V 2/0 XLPE - 90o C 400 amperes OC device
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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FUSES AND CIRCUIT BREAKERS
GREATER THAN 600 VOLTS
ARTICLE 240
Level III
WORKSHEET
1. A 4160 volt feeder consisting of #2 conductors, with an ampacity rating of 140 amps, is to be
protected with fuses. Which of the following is the maximum size fuse permitted to protect
this feeder?
a
b
c
d
.
.
.
.
200
300
400
450
2. A 4160 volt feeder consisting of #4 conductors, with an ampacity rating of 97 amps is to be
protected with a circuit breaker. Which of the following is the maximum size breaker
permitted to protect this feeder?
a
b
c
d
.
.
.
.
300
400
500
600
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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FUSES AND CIRCUIT BREAKERS GREATER THAN 600
VOLTS ARTICLE 240
Level III
ANSWER KEY
1 . c, 400
140 x 3 = 420 420 > 400
2 . c, 500
97 x 6 = 582 582 > 500
240.101(A)
240.101
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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GROUNDING OVER 1000 VOLTS
ARTICLE 250
Level III
OBJECTIVE:
Each student should understand the requirements for grounding of systems over 1000 volts
nominal, part X of Article 250.
INTRODUCTION:
Make the class aware that you will be covering Article 250. Part X, High Voltage, make them
aware that more installations of this type are being installed.
PRESENTING THE LESSON:
Discuss Article 250, Part X in detail; briefly review grounding requirements of previous
Sections of 250.
Explain that 250.50 of the Code is a North Carolina amendment. Be sure the students have the
amendments in their Code book or hand out the amendments. You can also give them the web
site for DOT, www.ncdoi.com
APPLICATION:
Tf time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
Tf time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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GROUNDING OVER 1000
VOLTS ARTICLE 250
Level III
WORKSHEET
1. When using insulated conductors, in a solidly grounded neutral system over 1 KV,
without exception, the minimum insulation level for neutral conductors is:
a.
b.
c.
d.
150 volts
250 volts
300 volts
600 volts
2. When grounding equipment, grounding conductors not an integral part of a cable
assembly shall not be smaller than:
a.
b.
c.
d.
#6 Copper
#4 Copper
#3 Copper
#2 Copper
3. A high voltage, Impedance grounded neutral system is operating at 13.8 KV. The phase
conductors are insulated for 15 KV. The systems neutral conductor must have a
minimum insulation level of:
a.
b.
c.
d.
600 volts
0 volts, it can be bare
1000 volts
15,000 volts
4. The ampacity of a neutral conductor operating at over 1kv shall be of sufficient ampacity for
the load imposed on the conductor but not less than which of the following percentage of
the phase conductors.
a.
b.
c.
d.
100 percent of the ampacity
70 percent of the ampacity
33 1/3 percent of the ampacity
Two trade sizes smaller
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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5. An impedance grounded neutral high voltage service shall have the grounding impedance
connected at which of the following points?
a. Ahead of the insertion of the grounding impedance
b. Between the supply grounding electrode and the neutral point of the supply
transformer or generator
c. At the center point of the wye
d. None of the above
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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GROUNDING OVER 1000 VOLTS
ARTICLE 250
Level III
ANSWER KEY
1.
2.
3.
4.
5.
d, 600 volts
a, #6 Copper
d, 15,000 volts
c, 33 1/3 percent of the ampacity
b, beyond the point of the ground impedance
250.184(A)(1)
250.190(C)
250.187(B)
250.184(A)(2)
250.187(A)
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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SURGE ARRESTOR
ARTICLE 280 Level
III
OBJECTIVE:
Each student should be familiar with a surge arrestor, what its purpose is, where and why it is
normally used, and the minimum size of connecting conductors required.
INTRODUCTION:
Explain to class that you will cover Article 280, Parts I, II, and III. Types and sizes of
conductors utilized depend on KV of circuit.
PRESENTING THE LESSON:
Cover Article 280 where arrestors are to be connected, one to each ungrounded conductor, to
the grounded service conductor, or grounding electrode conductor. Conductor size will differ in
circuits of 1 KV and over. Arrestors may be located inside or outside.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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SURGE ARRESTOR
ARTICLE 280 Level
III
WORKSHEET
1.
Which of the following is correct concerning the installation of surge arrestors?
I. Unless listed for installation in accessible locations, surge arrestors shall be made
inaccessible to unqualified persons.
II. Surge arresters shall be installed outdoors only.
a.
b.
c.
d.
I only
II only
Both I and II
Neither I nor II
2. For circuits of I KV and over, the conductor between the surge arrester and the line and
surge arrester and the grounding connection shall not be smaller than:
a.
b.
c.
d.
#8 Copper
#4 Copper
#6 Copper
#3 Copper
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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SURGE ARRESTOR
ARTICLE 280 Level
III
ANSWER KEY
1.
2.
a, I only
b, #6 Copper
280.11
280.23
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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WIRING METHODS -OVER 1000 VOLTS
ARTICLE 300
Level III
OBJECTIVE:
Each student should understand requirements for wiring methods over 1000 volts.
INTRODUCTION:
We will cover Part II in its entirety.
PRESENTING THE LESSON:
Go over Part II, Article 300 briefly; discuss conductors, conductor bending radius, and
protection against heating. Note that Section 300.40 requires that metallic shielding
components such as tapes, wires, or braids, or combinations thereof, shall be connected to a
grounding conductor, grounding busbar, or a grounding electrode. Also note the changes to
footnote 3 part d, Table 300.50
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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WIRING METHODS-OVER 1000 VOLTS
ARTICLE 300
Level III
WORKSHEET
1. When using non-shielded conductors, the conductor shall not be bent to a radius less
than:
a.
b.
c.
d.
4 times the overall diameter of the conductor
6 times the overall diameter of the conductor
8 times the overall diameter of the conductor
12 times the overall diameter of the conductor
2. Where direct burial conductors that are shielded and rated above 2000 volts, and the
circuit voltage over 1000 volts. The cable shall be buried a minimum of which of the
following?
a.
b.
c.
d.
36 inches
30 inches
18 inches
6 inches
3. Over 350 Kcmil through 500 Kcmil copper installed in vertical raceways shall be
supported at which of the following distances?
a.
b.
c.
d.
75 feet
50 feet
100 feet
25 feet
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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WIRING METHODS-OVER 600 VOLTS
ARTICLE 300
Level III
ANSWER KEY
1.
2.
3.
c
b
b
300.34
300.50(A)
T300.19(A)
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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CONDUCTORS FOR GENERAL WIRING – OVER 600
VOLTS ARTICLE 310
LEVEL III
OBJECTIVE:
Each student should be familiar with conductors for general wiring in high voltage
applications.
Review Article 310 in Level II. Note Section 310.4 (E) that states; Where
parallel
equipment grounding conductors are used, they shall be sized in accordance with 250.122.
Sectioned equipment grounding conductors smaller than 1/0 AWG shall be permitted in
multiconductor cables in accordance with 310.13, provided the combined circular mil area
in each cable complies with 250.122.
Review the shielding requirements. The purpose of shielding is to confine the
voltage
stresses to the insulation. Insulation shields shall be connected to a grounding
electrode
conductor, grounding busbar, or a grounding electrode.
APPLICATION:
If time will allow, let the class answer questions on the
worksheet. CHECKING AND FOLLOW UP :
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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CONDUCTORS FOR GENERAL WIRING
ARTICLE 310
LEVEL III
WORKSHEET
1.
The minimum size-awg for a conductor operating at 12000 Volts is:
a
b
c
d
.
.
.
.
8
6
2
1
2. The maximum voltage permitted for a direct buried, non-shielded, multiconductor cable
with an overall metallic sheath or armor is:
a.
b.
c.
d.
2000 Volts
2001 Volts
5000 Volts
8000 Volts
3. The required minimum insulation thickness of a 500 Kcmil XHHW conductor to be
operated at 1500 volts is:
a.
b.
c.
d.
65 mils
95 mils
100 mils
110 mils
4. The ampacity of a 3/0 THW insulated conductor operating at 1 KV where three conductors are
installed in a raceway at an ambient temperature of 38 degrees C is 310.16 with amp
correction factor applied:
a.
b.
c.
d.
176 amps
188 amps
145 amps
189 amps
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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5. The allowable ampacity of a 1/0 insulated single aluminum conductor is isolated in air with a
conductor temperature of 90 degrees C and an ambient air temperature of 40 degrees C,
operating at 23 KV is:
a.
b.
c.
d.
175 amps
200 amps
230 amps
270 amps
6. The allowable ampacity of 4/0 single copper conductor cables triplexed in air with a conductor
temperature of 90 degrees C and ambient temperature of 40 degrees C, operating at 12,000
volts is:
a.
b.
c.
d.
335 amps
345 amps
270 amps
395 amps
7. Three 500 Kcmil Aluminum conductors operating at 15,000 volts are installed in a one circuit
underground electrical duct. Based on the conductors operating in an ambient earth
temperature of 20 degrees C, 100% load factor, RHO of 90,and conductor temperature of
90 degrees C, the allowable ampacity of the conductor is:
a.
b.
c.
d.
8.
230 amps
290 amps
370 amps
465 amps
A six circuit underground electrical duct contains 1/0 copper conductors operating at 5,000
volts. Based on the following factors, what is the allowable ampacity of the conductors?
Ambient earth temperature of 20 degrees C, 100% load factor, RHO of 90, and conductor
temperature of 90 degrees C.
a.
b.
c.
d.
135 amps
165 amps
200 amps
155 amps
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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9. An insulated 90 degrees C 1/0 three conductor aluminum triplex cable supplies the primary
voltage to a 25,000 volt transformer. The cable is installed outside in free air. The
allowable ampacity of the triplex is:
a.
b.
c.
d.
145 amps
170 amps
185 amps
215 amps
10. A single #1 insulated non-shielded solid dielectric copper conductor rated at 3,500 volts
suitable for dry locations (without a jacket) shall have an insulation thickness of:
a.
b.
c.
d.
45 mils
90 mils
110 mils
125 mils
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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CONDUCTORS FOR GENERAL WIRING
ARTICLE 310
LEVEL III
ANSWER KEY
1. c
310.106 (A)
2. c
310.10 (F) exception No 2
3. b
Table 310.104(A)
4. a
Table 310.15(B)(16) and Table 310.15(B)(2)(a)
5. b
Table 310.60(C)(70)
6. b
Table 310.60(C)(68)
7. c
Table 310.60(C)(78)
8. a
Table 310.60(C)(77) See six circuits bottom of table
9. b
Table 310.60(C)(72)
10 .c
Table 310.104(D)
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
42
OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES
AND FITTINGS OVER 600 VOLTS NOMINAL
ARTICLE 314
Level III
OBJECTIVE:
Each student should understand requirements of article 314 applying to over 600 volts.
(under 600 volts have been covered in Level I.)
MATERIALS NEEDED:
Samples of outlet boxes, pull and junction boxes, conduit bodies and fittings. Handouts
with examples of sizing pull and junction boxes.
INTRODUCTION:
Article 314 covers the installation and use of all boxes, conduit boxes and fittings as required
by Section 300.15 used as outlet, junction, or pull boxes, depending on their use. Cast, sheet
metal, nonmetallic, and other boxes such as FS, FD, and larger boxes are not classified as
conduit bodies. Review Section 314.4, Note that metal boxes shall be grounded and bonded
in accordance with Parts I, IV, V, VI, VII, and X of Article 250 as applicable, except as
permitted in 250.112(I).
PRESENTING THE LESSON:
Article 314 requirements are very important when considering safety of electrical
installations. Time should be spent reviewing the requirements covered in the Level I course.
Emphasis should be placed on Part IV of the article which deals with pull and junction
boxed on systems of over 600 Volts nominal.
APPLICATION:
If time will allow, let the class answer questions on the
worksheet. CHECKING AND FOLLOW UP :
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES
AND FITTINGS OVER 600 VOLTS NOMINAL
ARTICLE 314
Level III
WORKSHEET
1. What length box is required for three #1 lead-covered conductors at 1600 volts for a straight
pull? #1 outside diameter is .585.
a
b
c
d
15”
19”
22”
29”
.
.
.
.
2. What length box is required for seven #1 nonshielded conductors at 1600 volts for a
straight pull? #1 outside diameter is .585.
a
b
c
d
15”
22”
22”
29”
.
.
.
.
3. What size box is required for two #2 and two #4 lead covered conductors at 1600 volts for
an angle pull? #2 outside diameter is .505 and #4 is .445.
a.
b.
c.
d.
14”
19”
20”
25”
4. What size box is required for two #2 and two #4 nonshielded conductors at 1600 volts for an
angle pull? #2 outside diameter is .505 and #4 is .445.
a.
b.
c.
d.
14”
19”
20”
25”
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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5. Warning signs for boxes exceeding 600 volts shall have the following wording:
a.
b.
c.
d.
DANGER KEEP OUT
DANGER 600 VOLTS
DANGER HIGH VOLTAGE KEEP OUT
DANGER HIGH VOLTAGE
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT
BODIES AND FITTINGS OVER 600 VOLTS NOMINAL
ARTICLE 314
Level III
ANSWER KEY
1
2
3
4
.
.
.
.
d,
b,
c,
a,
5.
c.
29”
19”
20”
14”
314.71(A) .585 X 48 = 28.08 = 29”
314.71(A) .585 X 32 = 18.72 = 19”
314.71(B) .505 X 36 = 18.18+.050+.445+.445 = 19.58
314.71(B)Ex. No. 2
.505 X 24 = 12.12 + .050 + .445 + .445 = 13.06 = 14”
=
20”
DANGER- HIGH VOLTAGE -KEEP OUT 314.72(E)
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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INTEGRATED GAS SPACER
CABLE ARTICLE 326
Level III
OBJECTIVE:
Each student should know the requirements included in the Article for this wiring method.
MATERIALS NEEDED:
Pictures and manufacturing literature of IGS cable.
PRESENTING THE LESSON:
This wiring method is comparatively quite expensive and unlikely to be encountered except
in very special applications requiring thorough engineering. It is suggested that the time
spent on this Article be limited.
APPLICATION:
If time will allow, let the class answer questions on the
worksheet. CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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INTEGRATED GAS SPACER CABLE
ARTICLE 326
Level III
WORKSHEET
1. An underground run of 3" IGS cable with two 90 degree bends is to be installed. The
minimum bending radius permitted is:
a
b
c
d
.
.
.
.
12"
24"
35"
48"
2. The ampacity of a 1500 KCMIL cable and conduit is:
a.
b.
c.
d.
168 amperes
238 amperes
292 amperes
357 amperes
2014 Electrical Instructors Manual and Student Worksheets -- Level 3
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INTEGRATED GAS SPACER CABLE
ARTICLE 326
Level III
ANSWER KEY
1.
2.
c
c 292 amperes
326.24 Table 326.24.
326.80 Table 326.80
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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MEDIUM VOLTAGE CABLE
ARTICLE 328
Level III
OBJECTIVE:
Each student should be familiar with the uses permitted and not permitted for MV cable.
INTRODUCTION:
Explain to the class that this is not a very popular installation, and that a small amount of
time will be spent on this article.
PRESENTING THE LESSON:
Briefly explain and discuss Article 328, particularly section 328.2 “Definition”, 328.10
“Permitted Uses”, and 328.14 “Installation.”
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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MEDIUM VOLTAGE CABLE
ARTICLE 328
Level III
WORKSHEET
1. Type MV Cable shall be permitted for systems rated up to:
a.
2001 Volts
b.
4160 Volts
c.
7200 Volts
d.
35,000 Volts
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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MEDIUM VOLTAGE CABLE
ARTICLE 328
Level III
ANSWER KEY
1.
d, 328.10
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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POWER AND CONTROL TRAY CABLE TYPE TC
ARTICLE 336
Level III
OBJECTIVE:
Each student should be familiar with the definition of this cable, where it can and cannot
be used, and the normal sizes of conductors.
INTRODUCTION:
Explain to the class that you will briefly cover Article 336. This is seen very seldom in the
field, and a small amount of time should be spent on this Article.
PRESENTING THE LESSON:
Discuss Article 336 with class; cover permitted use and non-permitted use of cable, sizes
of copper and aluminum conductors. Explain that Type TC Power and Control Cable is for
the use in industrial power or control circuits where small diameter cables are used.
Primary installations include cable trays, raceways and outdoor locations where supported
by a messenger wire. Discuss the eight (8) listed permitted used in 336.10.
APPLICATION:
If time will allow, let the class answer questions on the worksheets.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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POWER AND CONTROL TRAY CABLE
ARTICLE 336
Level III
WORKSHEET
1. Normally, the minimum size of copper conductor permitted for TC cable is:
a.
#18
b.
#16
c.
#14
d.
#12
2. Which of the following is correct concerning the use of TC cable?
I.
II.
TC Cable is permitted to be used in Cable Tray.
TC Cable is approved for power, lighting, control and signal circuits.
a.
I only
b.
II only
c.
Both I and II
d.
Neither I nor II
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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POWER AND CONTROL TRAY CABLE
ARTICLE 336
Level III
ANSWER KEY
1. a, 18
2. c, Both I and II
336.104
336.10
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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CABLE TRAYS
ARTICLE 392
LEVEL III
OBJECTIVE:
Each student should be familiar with the requirements for cable tray wiring systems.
MATERIALS NEEDED:
Photos of cable tray, conductors samples if available.
INTRODUCTION:
Cable tray systems are a widely used wiring method and are used primarily in industrial
applications though not limited to such use. They offer a practical and flexible solution
to electrical power distribution when used for electrical services, feeders, and branch
circuits, especially when larger size conductors and cables are used. Note the additions
that may be included in cable trays to Table 392.10(A) Wiring Methods.
PRESENTING THE LESSON:
Point out minimum single conductor sizes [392.10(B)(1)(a)]. Emphasize the restrictions
that apply when cable tray is used for equipment grounding [392.10(B)(1)(c)] and
reference the metal requirements and other provisions that apply for cable trays used as
equipment grounding conductors (392.60).
Discuss 392.22 and the accompanying tables. Work an example using these tables in
conjunction with Table 5 in Chapter 9 to demonstrate proper procedure in regard to
conductor fill. Also note 2014 change in section 392.18(H) that the danger marking(s) or
labels shall comply with 110.21(B).
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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CABLE TRAYS
ARTICLE 392
LEVEL III
WORKSHEET
1. The maximum allowable rung spacing for a ladder cable tray where 1/0 and 4/0
single conductor cable is used?
a.
b.
c.
d.
6”
7”
8”
9”
2. Which of the following is an acceptable means of bonding a cable tray used as an
equipment ground?
a.
b.
c.
d.
Bonding jumpers
Bolted mechanical connectors
both A and B
neither A nor B
3. The minimum cross sectional area of an aluminum cable tray used for equipment
grounding and housing conductors protected by 500 amp circuit breaker is: a. .20 sq. in.
b. .30 sq. in.
c. .40 sq. in.
d. .60 sq. in.
4. Where ventilated channel cable trays contain single-conductor cables are which of
the following width, the sum of the diameters of all single conductors shall not exceed
the inside width of the channel.
a.
b.
c.
d.
75 mm (3 in.)
100 mm (4 in.)
150 mm (6 in.)
all of the above
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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5. Where cable trays are continuously covered for more than which of the following,
with solid unventilated covers, the ampacities for No. 1/0 through 500 kcmil cables
shall not exceed 60% of the allowable ampacities in Tables 310.17 and 310.19.
a
b
c
d
.
.
.
.
4’
6’
10’
8’
6. The ampacities for Nos. 1/0 and larger single conductor cables rated 2001 volts or
larger in uncovered cable trays shall not exceed which of the following percentage of
the allowable ampacities in Table 310.69 and 310.70.
a.
50%
b.
80%
c.
60%
d.
75%
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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CABLE TRAYS
ARTICLE 392
LEVEL III
ANSWER KEY
1.
2.
3.
4.
5.
6.
d
c
c
d
b
d
392.3(B)(1)(a)
392.7(B)(4)
Table 392.7(B)(2)
392.10(B)
392.11(B)(2)
392.13(B)(1)
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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FLEXIBLE CORDS AND CABLES
ARTICLE 400
Level III
OBJECTIVE:
Each student should be acquainted with the installation and use requirements for Flexible
Cords and Cables.
INTRODUCTION:
This article covers the requirements for use and installation of Flexible cords and Cable and
including the requirements for portable cables over 600 V, nominal.
PRESENTING THE LESSON:
Review Level I Article 400. Cover the requirements in Part III on Portable Cables over 600
volts, nominal.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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FLEXIBLE CORDS AND CABLES
ARTICLE 400
Level III
WORKSHEET
1. What is the allowable ampacity rating for # 4 types SO cord when nine conductors are
carrying current?
a.
b.
c.
d.
42 amps
60 amps
70 amps
85 amps
2. What is the allowable ampacity rating for # 18 types SO cord when three conductors are
carrying current?
a.
b.
c.
d.
5 amps
7 amps
10 amps
not permitted
3. Under what conditions, if any, may a cord be spliced?
a.
b.
c.
d.
4.
SJO cord is to be marked, on the cord, at intervals not to exceed?
a.
b.
c.
d.
5.
Not permitted
hard-service and junior hard service cords only
#14 and larger only
repair of b & c together
12 inches
18 inches
24 inches
36 inches
Unless specifically permitted in 400.7, flexible cords and cables shall not be used for
which of the following:
a.
b.
c.
d.
as a substitute for the fixed wiring of a structure.
where run through holes in walls, ceilings, or floors.
where concealed behind building walls ceilings or floors.
all of the above
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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6.
The minimum size for conductor for portable cables over 600 volts shall be?
a.
b.
c.
d.
# 8 AL
# 1/0 Cu
# 6 AL
# 12 Cu
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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FLEXIBLE CORDS AND CABLES
ARTICLE 400
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
a, 42 amps [Table 400.5(A)(1) and Table 400.5(A)(3)] # 4 SO = 60 amps [400.5] nine
conductors at 70% 60 amps X 70% = 42 amps
b, 7 amps
Table 400.5(A)
d, repair of b and c together
400.9
c, 24 inches
400.6
d, all of the above
400.8
d, # 12 Cu
400.31(A)
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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SWITCHBOARDS AND PANELBOARDS
ARTICLE 408
Level III
OBJECTIVE:
Each student should be familiar with the installation requirements of Switchboards and
Panelboards.
INTRODUCTION:
This article covers the requirements for use and installation of Switchboard and Panelboards.
PRESENTING THE LESSON:
Review Level I Article 408. See Level I Article 408 Lesson plan for reference. Emphasize the
requirements for installing switchboards and panelboard in hazardous locations.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 Electrical Instructors Manual and Student Worksheets – Level 3
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SWITCHBOARDS AND PANELBOARDS
ARTICLE 408
Level III
WORKSHEET
1. On a switchboard or panelboard supplied from a 4-wire delta-connected system, the high-leg
conductor is identified by which color?
a.
b.
c.
d.
Blue
Red
Orange
White
2. The phase arrangement on a three phase bus as viewed left to right shall be?
a.
b.
c.
d.
bca
abc
cba
any of the above
3. The dedicated space in Section 110.26 shall extend from the floor to a height of ____ above
the equipment or to the structural ceiling to a height of which of the following?
a
b
c
d
6’
10’
6’ 6”
6’ 4”
.
.
.
.
4. Minimum distances between the top of switchboard to combustible ceiling if not totally
enclosed is:
a.
b.
c.
d.
0 feet
1 foot
2 feet
3 feet
5. The conduit or raceways shall not rise more than what distance above the bottom of
switchboard enclosures?
a.
b.
c.
d.
1 inch
2 inches
3 inches
4 inches
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6. A panelboard shall be provided with physical means to prevent the installation of more
overcurrent devices than which of the following?
a.
b.
c.
d.
That number for which the panelboard was designed, rated, and listed.
Not more than 42 overcurrent devices.
Not more than the panelboard directory allows.
Not more than the Authority Having Jurisdiction will allow.
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SWITCHBOARDS AND PANELBOARDS
ARTICLE 408
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
c
b
a
d
c
a
408.3(E) FPN – see 110.15
408.3(E)
110.26(E)(1)(a)
408.18(A)
408.5
408.54
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FIXED ELECTRIC HEATING EQUIPMENT FOR PIPELINES AND VESSELS
ARTICLE 427
Level III
OBJECTIVE:
Each student should be familiar with electrically energized heating system and the installations
of the systems used with pipelines or vessels.
INTRODUCTION:
This Article covers electrically energized heating systems and the requirements for installing
them when used with pipelines or vessels such as (1) resistance heating elements, (2)
Impedance heating, (3) induction heating, and (4) skin effect heating.
PRESENTING THE LESSON:
Cover definitions, application of other Articles and branch-circuit sizing (427.2, 3, & 4).
Review the installation requirements, emphasizing the need of posting appropriate caution
signs. (Part II)
Cover requirement for resistance heating elements, emphasizing power supply bends, electrical
connections, grounding and equipment protection. (Part III)
Cover requirements for impedance heating, emphasizing voltage limitations, the use of an
isolation transformer, and grounding. (Part IV)
Cover requirements for induction heating, emphasizing the need for personnel protection. (Part
V)
Cover the requirement for skin effect heating, emphasizing grounding. (Part VI) Cover
the requirement for disconnecting means, controls, and overcurrent protections.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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FIXED ELECTRIC HEATING EQUIPMENT FOR PIPELINES AND VESSELS
ARTICLE 427
Level III
WORKSHEET
1. Branch circuit conductors supplying fixed electric heating equipment for pipelines shall
have an ampacity not less than what percentage of the total load of the heaters?
a
b
c
d
.
.
.
.
125%
100%
250%
110%
2. Which of the following may be used for protection of power supply loads to resistance heater
elements where they emerge from electrically heated pipe lines?
a.
b.
c.
d.
rigid metal conduit
intermediate metal conduit
electrical metallic tubing
all of the above
3. Ground fault protection of equipment shall not be required where there is alarm
indication of ground faults and:
I.
conditions of maintenance and supervision ensure that only qualified person
will service the installed system.
II. Continued circuit operation is necessary for safe operation of equipment or process.
a.
b.
c.
d.
I only
II only
I and II
Neither I nor II
4. The maximum voltage for impedance heating of a pipeline if a ground fault circuitinterrupter for personnel protection is provided is which of the following?
a.
b.
c.
d.
150 volts
30 volts
24 volts
80 volts
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FIXED ELECTRIC HEATING EQUIPMENT FOR PIPELINES AND VESSELS
ARTICLE 427
Level III
ANSWER KEY
1.
2.
3.
4.
125%
d.
c,
d
427.4
427.18(B)
427.22
427.27
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MOTORS, MOTOR CIRCUITS, AND CONTROLLERS
ARTICLE 430
Level III
OBJECTIVE:
Each student should be familiar with the installation requirements of motor, motor circuits and
controllers.
INTRODUCTION:
This Article covers the requirements for the installation of motors, motor circuits, and
controllers with additional requirements for over 600 volts, nominal.
PRESENTING THE LESSON:
Review Level I and II Article 430. See Level I and II Article 430 lesson plan for reference.
Cover the requirements for conductors, overcurrent protection, overload protection, faultcurrent protection and disconnecting means for over 600 volts, nominal installations. Note to
the students that motor overload protection that is separate from the motor shall be based on
the motor nameplate rating and not the Electrical Code sections. (430.6)(A)(2)
APPLICATION:
If time will allow, let the class time answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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MOTORS, MOTOR CIRCUITS, AND CONTROLLERS
ARTICLE 430
Level III
WORKSHEET
1. Motor controller disconnecting means for motors over 1000 volts shall be capable of
which of the following?
a.
b.
c.
d.
Being locked in the closed position.
Being locked in the open position.
Being serviceable from the open position.
Being capable of being locked out
2. The ampacity of conductors for motors over 1000volts shall not be less than the current at
which of the following is set to trip?
a.
b.
c.
d.
The motor overload device.
The thermal overcurrent device.
The motor controller trip-set device.
The circuit breaker overcurrent rating.
3. The full-load rating of a motor found on the nameplate is 30.4 amperes and that found in Table
430.250 is 30.8 amperes. Which value is required to be used when determining the minimum
size branch-circuit conductor permitted?
a.
b.
c.
d.
The figure in 430.248
The figure in 430.250
The figure on the motor.
The nameplate rating.
4. Branch-circuit conductors that supply a single motor used for continuous duty shall have
an ampacity not less than which of the following percentage of the motors full-load
current rating?
a
b
c
d
.
.
.
.
140%
125%
175%
250%
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5. Feeder tap conductors shall be enclosed by a controller or raceway not more than which of
the following lengths.
a.
b.
c.
d.
25 feet
5 feet
6 feet
10 feet
6. Without exception, what is the maximum percentage allowed when using an inverse time
circuit breaker for the motor branch-circuit short circuit and ground-fault protective
device?
a
b
c
d
.
.
.
.
125%
150%
250%
350%
7. When fuses are used for motor overload protection, a three phase motor shall have an
overload protection inserted in which of the following?
a.
b.
c.
d.
In each main breaker.
In each breaker in the panel.
In all feeders.
In each phase conductor.
8. Complete the following requirements for a 15 HP, 230 volt, 3-phase, induction type, A-C
motor with a service factor of 1.15, no code letter and without separate overload
protection.
Full Load Current _________________________ (Table 430.250)
Branch-circuit Ampacity ____________________ (Section 430.22)
Disconnecting Means _______________________ (Section 403.110)
Overcurrent Protection ______________________ (Table 430.52)
(Time delay fuse)
Heater Size _______________________________ (Section 430.32) (430.6)(A)(2)
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9. A motor is to be connected to a feeder tap not over 25 feet in length: Which of the
following is correct?
I. Tap conductors must have an ampacity at least one-third that of the feeder
conductor.
II. Be protected from physical damage.
a. I only
b. II only
c. both I and I
d. neither I nor II
10. Three motors are supplied by the same feeder, one with a full load ampacity of 28 amps
protected by a 50 amp dual element fuse, the other two with a full load ampacity of 22
amps each, protected by 30 amp dual element fuse each. Which of the following is the
maximum size fuse permitted to protect the feeder?
a.
b.
c.
d.
70 amps
80 amps
90 amps
100 amps
11. The branch-circuit conductors for a motor are protected by time-delay (Dual element)
fuses. If the fuses are not holding on the line, they may be increased to a maximum of:
a
b
c
d
.
.
.
.
150%
175%
200%
225%
12. A feeder is to supply two motors, with a full load ampacity of 28 amps each and a noncontinuous lighting load of 100 amps. Which of the following is the minimum size
conductor permitted for this feeder, using THHN copper?
a
b
c
d
.
.
.
.
#
#
#
#
2
1
1/0
2/0
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13. A 7 1/2 HP, 230 volt, 3-phase motor, has it’s control circuit conductors tapped from the line
side of the magnetic starter. This motor has multiple start-stop stations, located at different
locations, to control this motor. The motor is protected by a 60 ampere circuit breaker. What is
the minimum size of the control circuit conductors, when protected by the branch circuit short
circuit device?
a.
b.
c.
d.
16 AWG, copper
14 AWG, copper
12 AWG, copper
10 AWG, copper
14. Which of the following statements is/are true about the disconnecting means for
stationary motors rated at 2 hp or less and 300 volts or less?
(1) A general-use switch having an ampere rating not less than twice the full-load
current rating of the motor
(2) A listed manual motor controller having a horsepower rating not less than the
rating of the motor and marked “Suitable as Motor Disconnect”
a.
b.
c.
d.
1 only
2 only
Both 1 and 2
Neither 1 nor 2
15. When sizing a motor circuits protective components, the motor ampacity listed in tables
430.247 through 430.250 shall always be used instead of the full load ampacity given on
the motor nameplate EXCEPT for:
a.
b.
c.
d.
branch circuit conductors
motor overloads
short circuit device
single phase motor
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16. A 460 volt, 3-phase feeder is supplying the following continuous duty, squirrel cage
induction motors, (1) 50 HP, (1) 60 HP, (1) 75 HP, (1) 100 HP, (1) 125 HP. All of the above
motors are full voltage start, code letter “F”, with a service factor of 1.2. Answer all of the
following questions about this motor feeder.
A. Using THW copper, size each of the motor supply conductors
(a) 50 HP _______________________________________
(b) 60 HP _______________________________________
(c) 75 HP _______________________________________
(d) 100 HP _______________________________________
(e) 125 HP ______________________________________
B. What are the proper size overloads for each of the motors?
(a) 50 HP _____________________________________
(b) 60 HP _____________________________________
(c) 75 HP _____________________________________
(d) 100 HP ____________________________________
(e) 125 HP ____________________________________
C. Using inverse time circuit breaker, size the breaker for all the motors of the group:
(a) 50 HP _______________________________________
(b) 60 HP _______________________________________
(c) 75 HP _______________________________________
(d) 100 HP _______________________________________
(e) 125 HP ______________________________________
D. Using THHN copper conductors, what are the minimum size feeder conductors
required for the above 460 volt, 3-phase motors? Use (2) conductors in parallel per
phase, install all (6) current carrying conductors in the same raceways. The ampacity
correction factors of 310.15(B)(2) [310.15(B)(3)(a)] must be applied.
(a)
(b)
(c)
(d)
2 X 300 Kcmils
2 X 350 Kcmils
2 X 400 Kcmils
2 X 500 Kcmils
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E. Size all the feeder taps for all the motors of the above group. The maximum tap
length between the feeder and the motors, short circuit protective device is between 16
and 24 feet. (Use 75°C conductors)
(a)
(b)
(c)
(d)
(e)
50 HP
60 HP
75 HP
100 HP
125 HP
F. Using an inverse time circuit breaker, what is the minimum size of this feeder’s short
circuit protective device?
a. 700 amperes
b. 800 amperes
c. 600 amperes
d. 100 amperes
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MOTORS, MOTOR CIRCUITS, AND CONTROLLERS
ARTICLE 430
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
b. being locked in the open position
430.227
a. a motor overload device
430.224
b. the figure in 430.250
430.6(A)(1)
b. 125%
430.22
d. 10 feet
430.28
c. 250
T 430.52
d. In each phase conductor
430.36
Full load current - 42
Branch-circuit Size - 52.5 (42 X 125% = 52.5)
Disconnecting Means - 48 (42 X 115% = 48.3)
Overcurrent Protection - 80 (42 X 175% = 73.5;
go up to 80 ampere) Time delay fuse - 80 amps
Heater Size - 52.5
(42 X 125% = 52.5)
c, both I and II
430.28
c, 90 amps, 50 + 22 + 22 = 94 amps = 90 amps
430.62
d, 225%
430.52 exc.2(b)
d, #2/0, (28 X 125%) + 28 + 100 = 163 amps
430.25
(110.14(C) conductor was chosen from the 75 degree column)
b, 14 AWG, copper
430.72(B)
c, both 1 and 2
430.109(C)
b, motor overloads
430.6(A)(2)
16. FEEDER QUESTIONS
16. A. Motor Branch Circuit Conductors
(a)
(b)
(c)
(d)
(e)
65 amps X 125% = 81.25 amperes, use #4 Cu.
77 amps X 125% = 96.25 amperes, use #3 Cu.
96 amps X 125% = 120 amperes, use #1 Cu.
124 amps X 125% = 155 amperes, use #2/0 Cu.
156 amps X 125% = 195 ampere, use #3/0 Cu.
16. B. Overloads
(a)
(b)
(c)
(d)
(e)
430.22(A)
430.32(A)
65 amps X 125% = 81.25 amperes, use 81.25
77 amps X 125% = 96.25 amperes, use 96.25
96 amps X 125% = 120 amperes, use 120
124 amps X 125% = 155 amperes, use 155
156 amps X 125% = 195 ampere, use 195
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16. C. Inverse Time Circuit Breakers
(a)
(b)
(c)
(d)
(e)
430.52 & Table 430.52
65 amps X 250% = 162.5 amperes, go up to a 175 amp.
77 amps X 250% = 192.5 amperes, go up to a 200 amp.
96 amps X 250% = 240 amperes, go up to a 250 amp.
124 amps X 250% = 310 amperes, go up to a 350 amp.
156 amps X 250% = 390 ampere, go up to a 400 amp.
16. D. Feeder Conductors
430.24
(See correction factors of Table 310.15(B)2(a) 310.15 (B)(3)(a)
Answer: b, (156 X 1.25 = 195) + 124 + 96 + 77 + 65 = 557 amps
Find the minimum parallel ampacity, adjust this ampacity to compensate for (6) current
carrying conductors in the same raceway. 557/2 = 278.5 amps/.8 (correction factor) =
348 amperes.
Select a 90º C conductor capable of carrying 348 amperes, a 350 Kcmil, 90º C can carry
350 amperes. Select the 350 Kcmil conductor each.
Answer: 2 x 350 Kcmil, 90 degree c conductors in parallel per phase
16. E. Feeder Taps
430.28
Find the adjusted ampacity of 2 x 350 Kcmil in parallel, when (6) current carrying
conductors are in the same raceway. 350 amps X .8 (correction factor) = 280 X 2, for a
feeder adjusted ampacity of 560 amperes.
Find the minimum tap, which must have 1/3 the ampacity of the feeder conductors, in
this application. 560/3 = 186.67 amperes. Select a 3/0, 75º C conductor for the
minimum tap conductor allowed by 430.28
(a) 3/0
(d) 3/0
(b) 3/0
(e) 3/0
16. F. Select the Feeder Overcurrent Device
(c) 3/0
430.62
Answer: a, select the largest branch overcurrent device (400) plus the full load current of
all other motors of the group. 400 + 124 + 96 + 77 + 65 = 762 amperes, go down to a 700
amp circuit breaker
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GENERATORS
ARTICLE 445
Level III
OBJECTIVE:
Each student should be familiar with the installation requirements for generators.
INTRODUCTION:
This Article covers general requirements for generators but the applicable provisions of
Articles 230, 250, 700, 701, 702, and 705 must also be met.
PRESENTING THE LESSON:
Cover location requirements as found in 445.10, requirements for overcurrent protection as
found in 445.12 and 445.13 for conductor ampacity.
APPLICATION:
If time will allow, let the class answer the questions on worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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GENERATORS
ARTICLE 445
Level III
WORKSHEET
1. The ampacity of the phase conductors from the generator terminals to the first
overcurrent device shall not be less than what percentage of the generator nameplate
current?
a
b
c
d
.
.
.
.
125%
115%
50%
150%
2. Where wires pass through an opening having sharp edges which of the following shall be used
to protect the conductors?
a.
b.
c.
d.
3.
Constant-voltage generators, except ac generator exciters, shall be protected from
overloads by which of the following?
a.
b.
c.
d.
4.
Bushing
Shim
Grounding Bushing
Shielded Circuit Conductor
inherent design
circuit breakers
fuses
any of the above
Overcurrent devices protecting a three-wire, direct current generator shall consist of:
a.
b.
c.
d.
fuses only
three pole circuit breaker
double pole circuit breaker
any of the above
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5. Live parts of generators operated at more than which of the following voltages to ground shall
not be exposed to accidental contact?
a
b
c
d
.
.
.
.
25
50
600
1000
6. Each generator shall be provided with a name plate containing which of the following?
a.
b.
c.
d.
rated frequency
power factor
KVA rating
all of the above
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GENERATORS
ARTICLE 445
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
b. 115%
a. Bushing
d, any of the above
c, double pole circuit breaker
b, 50
d, all of the above
445.13
445.16
445.12(A)
445.12(E)
445.14
445.11
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TRANSFORMERS AND TRANSFORMER VAULTS
ARTICLE 450
Level III
OBJECTIVE:
Each student should be familiar with the requirement for installations of transformers.
INTRODUCTION:
This Article covers the requirement for the installation of transformers and transformer vaults
including installations over 600 volts, nominal.
PRESENTING THE LESSON:
Review Level II Article 450. See Level II Article 450 lesson plan for reference.
Cover the overcurrent protection requirements for transformers over 600 volts, nominal
[450.3(A)]
Cover the requirements for dry-type transformers rated over 35,000 volts. [450.21(C)]
Cover the requirements for liquid filled transformers. [450.23, 24 & 25]
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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TRANSFORMERS AND TRANSFORMER VAULTS
ARTICLE 450
Level III
WORKSHEET
1. A 500 KVA, 3-phase transformer has a 25 KV, delta primary and a 4.16 KV wye connected
secondary. The transformer is located in an unsupervised location and has 4%
impedance. Size the fuses for primary and secondary.
a. primary: ___________________
b. secondary: __________________
2. A 100 KVA, 3-phase transformer has a 480 volt, delta connected primary and a 120/208 volt,
wye connected secondary. The secondary overcurrent device is set at 125%. What is the
maximum permitted inverse time circuit breaker, for the secondary?
a.
b.
c.
d.
200 amps
300 amps
350 amps
400 amps
3. A transformer rated at 600 volts or less and equipped with coordinated thermal overload
protection by the manufacturer and arranged to interrupt the primary current shall be
permitted to have primary overcurrent protection rated or set at a current value that is not
more than________ the rated current of the transformer for transformers having not
more than 6 percent impedance and not more than________ the rated current of the
transformer for transformers having more than 6 percent but not more than 10 percent
impedance.
4. What is the maximum number of overcurrent devices permitted on the secondary side of a
transformer, in lieu of a single overcurrent device?
a.
b.
c.
d.
not permitted
6
8
2
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5. A 112.5 KVA, 480 volt, 3-phase transformer is tapped from a 300 ampere feeder. The
secondary of the transformer is 120/208 volts, 3-phase. The transformer is protected at
125% on the secondary side. Answer the following questions about the above
arrangement.
1. Can the 300 amp overcurrent device protecting the feeder also protect the primary
side of the transformer?
2. What is the maximum size of the secondary current device?
6 A 300 KVA, dry type transformer is installed outdoors, adjacent to a building of
combustible construction. What is the minimum clearance between the transformer and
the building?
a.
b.
c.
d.
18 inches
12 inches
24 inches
36 inches
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TRANSFORMERS AND TRANSFORMER VAULTS
ARTICLE 450
Level III
ANSWER KEY
1.
25000 X 1.732 = 43250 and 4160 X 1.732 = 7,205
a: 35 amps, [Table 450.3(A)] 500,000 VA/43,250 = 11.56 amperes X 300% [Table
450.3(A)] = 34.65 amps. Select a 35 ampere fuse.
450.3(A) Note 1] = 34.68 amps. Select a 35 ampere fuse.
b: 175 amps, [Table 450.3(A)] 500,000 VA/7,205 = 69.39 amperes X 250% [Table
450.3(A)] = 173.47 amps. Select a 175 ampere fuse.
c: 175 amps, [Table 450.3(A)] 500,000 VA/7,205 = 69.39 amperes X 250% [Table
450.3(A) Note 1] = 173.47 amps. Select a 175 ampere fuse.
Note the question is asking for fuse size which is different for breaker size
2.
c, 350 amps, [Table 450.3(B)] 100,000/360 = 277.77 amperes X 1.25 = 347.21
amperes.
Select a 350 amp circuit breaker. See 240.6, and read Note 1 to Table 450.3(B).
3.
six times, four times table 450.3(B) note three
4.
b. 6, [450.3(A)] Note: 2 & 450.3(B) Note: 2
5.
1. yes, [Table 450.3(B)]Compare feeder protection to 250% of the full load of the
transformer. 112,500/831 = 135.38 amperes X 250% = 338.44 amperes. The feeder
is within allowed limits.
2. 112500/360 = 312.5, 312.5 X 125% = 390.625> 350
6.
d. 12 inches, [450.22]
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CAPACITORS
ARTICLE 460
Level III
OBJECTIVE:
Each student should be familiar with installation requirements for capacitors over 600 volts.
INTRODUCTION:
This article covers requirements for capacitor installations. It should be noted that the
inspector will not often encounter such installations and surge capacitors or capacitors included
as a component part of other apparatus and conforming to the requirements of such apparatus are
excluded from these requirements.
PRESENTING THE LESSON:
Review Level II Article 460. Briefly cover requirements for capacitors over 1000 volts as found
in Part II of Article 460.
APPLICATION:
If time will allow, let the class time answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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CAPACITORS
ARTICLE 460
Level III
WORKSHEET
1. For capacitors over 1000 volts, Nominal a means shall be provided to reduce the residual
voltage of a capacitor to which of the following?
a.
b.
c.
d.
30 volts or less within 5 minutes of disconnection.
50 volts or less within 5 minutes of disconnection.
24 volts or less within 30 seconds of disconnection.
12 volts or less within 10 seconds of disconnection.
2. Capacitor cases if grounded shall be grounded in accordance with which Article?
a.
b.
c.
d.
Article 250
Article 230
Article 210
Article 460
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CAPACITORS ARTICLE 460
Level III
ANSWER KEY
1.
2.
b. 50 volts; 5 minutes
a. 250
460.28(A)
460.27
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RESISTORS AND REACTORS
ARTICLE 470
Level III
WORKSHEET
1. Resistors over 1000 volts shall have a clearance of not less than which of the following
distances from combustible materials?
a.
b.
c.
d.
12 inches
24 inches
6 inches
18 inches
2. Insulated conductors used for connections between resistance elements and controllers
shall be suitable for an operating temperature of not less than:
a.
b.
c.
d.
3.
Clearances from resistors and reactors to grounded surfaces shall be:
a.
b.
c.
d.
4.
60º C
75º C
90º C
110º C
adequate for the voltage
at least 12 inches
at least 24 inches
no requirements
To protect personnel from accidental contact with energized parts of reactors, the reactors
shall be:
a.
b.
c.
d.
isolated by enclosure
isolated by guarding only
isolated by elevation
either A or C
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5. Without exception, which of the following statements about the grounding of resistor and
reactor cases or enclosures is correct?
I. Shall be connected to the grounded circuit conductor.
II. Shall be connected to the equipment grounding conductor.
a.
b.
c.
d.
I only
II only
both I and II
neither I nor II
6. Installation of oil-filled reactors, in addition to other requirements, shall comply with
applicable requirements of which Article of the Code?
a.
b.
c.
d.
450
800
430
chapter 9
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RESISTORS AND REACTORS ARTICLE 470
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
a, 12 inches
c, 90° C
a, adequate for the voltage
d, either A or C
b
a, 450
470.18(C)
470.4
470.18(D)
470.18(B)
470.19
470.20
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EQUIPMENT OVER 1000 VOLTS
ARTICLE 490
Level III
OBJECTIVE:
Each student should be familiar with the general requirements for equipment operating at over
1000 volts.
INTRODUCTION:
This Article covers requirements for equipment operating at more than 1000 volts.
See 490.2 Definition of “High Voltage”
PRESENTING THE LESSON:
Discuss Part II. Note the requirements for circuit breakers and fuses installed indoors.
Emphasize requirements for warning signs.[490.21(B)(6)], [490.21(B)(7)], [490.21(C)(2)],
[490.21(E)(3)]. Show examples of Table 490.24 – minimum clearances. Discuss accessibility
rules: [490.35]
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW - UP:
If time will allow, correct the worksheets and discuss the results.
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EQUIPMENT OVER 1000 VOLTS
ARTICLE 490
Level III
WORKSHEET
1. Power fuses of the vented type shall not be used in which of the following positions unless
identified for that use.
a.
b.
c.
d.
in a vertical position
where exposed to the weather
outdoors
indoors
2. Cover plates intended to be removed for inspection of energized parts or wiring shall
be equipped with lifting handles and shall not exceed 12 square feet in area or which
of the following in weight, unless they are hinged and bolted or locked.
a.
b.
c.
d.
60 pounds
100 pounds
50 pounds
6 pounds
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EQUIPMENT OVER 1000 VOLTS
ARTICLE 490
Level III
ANSWER KEY
1. d, indoors
2. a. 60 pounds
490.21(B)(1)
490.38
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HAZARDOUS (CLASSIFIED) LOCATIONS
ARTICLE 500
Level III
OBJECTIVE:
Each student should be familiar with the three basic classifications of hazardous
installations, Class I, Class II, and Class III. Be sure student is familiar with the differences
in the three Locations, and also how the locations are also similar in some cases.
INTRODUCTION:
Explain to students that you will cover Article 500 in detail, also sections 500.1, 500.2,
and 500.3, difference in class locations, and wiring methods permitted and not permitted.
PRESENTING THE LESSON:
Discuss Article 500 of NEC very thoroughly. Talk about Class I, Class II, and Class III.
Explain the differences in three locations, such as gases, dust, fibers. Use pictures of
location if available, and samples of equipment used in each location. Samples of material
and handouts are available from manufacturer. Classification and listing of equipment in this
location is extremely important.
APPLICATION:
If time will allow, let the class answer questions on the
worksheet. CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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HAZARDOUS (CLASSIFIED) LOCATIONS
ARTICLE 500
Level III
WORKSHEET
1.
Which of the following is correct concerning hazardous (classified) locations?
I. Article 501 deals with the hazard involved normally with gases or vapors.
II. Article 502 deals with the hazard involved with easily ignitable fiber or flying
particles.
a.
b.
c.
d.
I only
Both I and II
II only
Neither I nor II
2. All of the following locations are normally involved in Class I location except:
a.
b.
c.
d.
Gasoline dispensing units
Commercial garage pits, below floor level
Spray booths of paint room
Textile manufacturing plants
3. Which of the following would be a Class I Group A CLASSIFICATION?
a.
b.
c.
d.
acetone
methanol
acetylene
gasoline
4. Hazardous location equipment identified as T2 shall have a maximum temperature of:
a.
b.
c.
d.
40° C
300° C
842°C
104° C
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5.
Which of the following is/are correct regarding Class II locations?
I. A Class II Division I location contains quantities of combustible dust in the air under
normal operating conditions will ignite.
II. A Class II Division 2 location dust is never present
a.
b.
c.
d.
6.
I only
II only
Both I and II
Neither I nor II
A class III Division I location contains:
a.
b.
c.
d.
combustible dust
ignitable fibers
flammable vapors
any of the above
7. Equipment approved for Hazardous location use shall be marked with:
a.
b.
c.
d.
(a ) class
(b) group
(c) temperature range
(d) all of the above
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HAZARDOUS (CLASSIFIED) LOCATION ARTICLE
500
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
a, I only
d, Textile manufacturing plants
c, acetylene
b, 300 degrees C
a, I only
b, ignitable fibers
d, all of the above
500.1
500.5
500.6(A)(1)
Table 500.8(B)
500.5(C)(1),
500.5(D)
500.8(B)
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CLASS I LOCATION HAZARDOUS
ARTICLE 501
Level III
OBJECTIVE:
Each student should be acquainted with requirements for selecting wiring methods and
equipment necessary for these locations.
MATERIALS NEEDED:
Manufacturer’s literature covering the equipment required in such hazardous locations is
readily available and is a "must" to supplement samples and selected pictures.
INTRODUCTION:
This Article only includes requirements used in the selection of suitable equipment for use in
Class I locations. Point out that material included in other Articles must initially be used to
classify the area prior to use of Article 501.
PRESENTATION OF LESSON:
Review the several definitions that apply specifically to hazardous locations. Briefly review
requirements included in Article 500 which apply to the classification of Class I area.
Emphasis must be placed on the importance of requiring listed equipment when applying the
requirement applicable to wiring methods and specific equipment installed in such areas. This
is equally true for both standard and intrinsically safe equipment.
As the various sections included in this article are covered, incorporate specific examples,
diagrams, and or pictures to clearly illustrate intent. Whenever possible, enumerate reasons for
the specific requirements.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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CLASS I HAZARDOUS LOCATION
ARTICLE 501
Level III
WORKSHEET
1.
In a class I, Division I location all of the following are approved wiring methods except:
a. Threaded Rigid metal conduit
b. Threaded steel intermediate metal conduit
c. MI cable
d. Electrical metallic tubing
2.
When installing seal-off fittings in a Class I , Division I location, the minimum thickness
of sealing compound shall not be less than which of the following?
a.
b.
c.
d.
3.
When installing sealing compound in a seal-off fitting in a Class I, Division II location,
the compound shall have a melting point of not less than:
a.
b.
c.
d.
4.
1/8 inch
3/8 inch
1/2 inch
5/8 inch
93° C
125°F
175° F
200°C
In a Class I Division I location, conduit seals for enclosures shall normally be installed
within a distance from the enclosure of:
a.
b.
c.
d.
12 inches
15 inches
18 inches
24 inches
5. For Class I, Division I pendant fixture stems longer than 12 inches, permanent bracing shall
be provided at a level not more than which of the following above the lower end of the
stem.
a.
b.
c.
d.
18 inches
6 inches
24 inches
12 inches
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6.
In a conduit run passing from a Class I, Division 2 location into an unclassified location,
the seal-off fitting(s) shall be:
a.
b.
c.
d.
7.
installed on either side of the locations
installed in the Class I division location only
permitted on either side of the boundary
permitted in the unclassified side only
Wiring methods for non-incendive circuits in a Class 1, Division 2 location shall be:
a.
b.
c.
d.
rigid conduit only
I.M.C. only
type PLTC cable only
any method suitable for ordinary locations
8. All of the following are permitted to be installed between a seal fitting and an enclosure in a
Class I Division I location except:
a.
b.
c.
d.
explosion proof junction boxes
explosion proof couplings
explosion proof conduit bodies
explosion proof elbows
9. A metal conduit which does not contain any fittings, boxes, etc. and passes through a Class
I Division 1 location will not be required to contain seal-offs provided the conduit
extends at least how far beyond the hazardous location into an unclassified location.
a.
b.
c.
d.
18 inches
10 feet
20 feet
12 inches
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CLASS I HAZARDOUS LOCATION
ARTICLE 501
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
8.
9.
d, electrical metallic tubing
d, 5/8
a, 93 degrees C
c, 18 inches
d, 12 inches
c, permitted on either side of the boundary
d, any method suitable for ordinary locations
a, explosion proof junction boxes
d, 12 inches
501.10(A)(1)
501.15(C) (3)
501.15(C)(2)
501.15(A)(1)(2)
501.130(A)(3)
501.15(B)(2)
501.10(B)(3)
501.15(A)(1)
501.15(A)(4)Ex.1
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CLASS II HAZARDOUS LOCATIONS
ARTICLE 502
Level III
OBJECTIVE:
Each student should be acquainted with the particular class location in Article 502, the
difference in Class II, Division I and Class II, Division II, and wiring methods permitted.
INTRODUCTION:
Explain to the class that you will cover Article 502 in detail; also refer back to Article 500.
Refer back to Article 100. Definitions, this is a very important installation, not often seen in
field, but very important when encountered.
PRESENTING THE LESSON:
Cover Article 500 briefly, Article 100, definition of Hazardous equipment, then article 502 in
detail. Cover places normally involved in 502, such as flour mills, grain bins.
Discuss wiring methods for Division I and Division II of Class II location. Show samples and
pictures of equipment in class. Manufacturer listing and labeling of equipment for Class II
location is extremely important.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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CLASS II HAZARDOUS LOCATIONS
ARTICLE 502
Level III
WORKSHEET
1.
In a Class II, Division I location, all of the following are approved wiring methods
except:
a.
b.
c.
d.
2.
In a class II, Division II location Dry-type transformers shall operate at not over:
a.
b.
c.
d.
3.
Threaded rigid metal conduit
MI cable
Threaded steel intermediate metal conduit
Rigid non-metallic conduit
120 volts
240 volts
300 volts
600 volts
In a Class II, Division II location, all of the following are approved wiring methods
except:
a.
b.
c.
d.
Rigid metal conduit
UF cable
Intermediate metal conduit
Electrical metallic tubing
4. Unless identified for such locations, explosionproof equipment and wiring in which of the
following locations shall not be required and shall not be acceptable?
a.
b.
c.
d.
Class I locations
Class II locations
Class IV locations
Class III locations
5. No transformer shall be installed in a location where all of the following dusts are present
except:
a.
b.
c.
d.
magnesium
aluminum bronze powders
aluminum
wood
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6.
Boxes located in Class II, Division 2 locations which contain taps or connections shall:
a.
b.
c.
d.
7.
be provided with telescoping or close-fitting covers
be a minimum size of 20 cubic inches
have no openings which after installation would allow escape of sparks
be dust tight
Which of the following is correct regarding Bonding in a Class II location?
I. Double locknut types of contact shall be allowed as a means of bonding
II. Locknut-bushing type of contact shall be allowed as a means of bonding.
a.
b.
c.
d.
8.
In a Class II, Division 2 location, flexible conduit shall be installed with internal or
external bonding jumpers except:
a.
b.
c.
d.
9.
I only
II only
Either I or II
Neither I nor II
The flexible conduit is 6 ft. or less
overcurrent protection in the circuit is limited to 10 amps maximum.
the load is not a power utilization load.
all the above
Flexible cords used in Class II locations shall:
a.
b.
c.
d.
be of extra-hard usage
not be allowed
be of a junior-hard service type
the lamp temperature rating
10. Each lighting fixture approved for Class II locations shall be clearly marked to indicate:
a.
b.
c.
d.
the manufacturer
the ampacity
the maximum wattage of the lamp
the lamp temperature rating.
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CLASS II HAZARDOUS LOCATIONS ARTICLE 502
Level III
ANSWER KEY
1. d, rigid non-metallic conduit
2. d, 600 volts
3. b, UF cable
4. b
5. d, wood
6. d
7. d, neither I nor II
8. d, all of the above
9. a, be of extra-hard usage
10. c, the maximum wattage of the lamp
502.10(A)(1)
502.100(B)(3)
502.10(B)(1)
502.5
502.100(A)(3)
502.10(B)(4)
502.30 (A)
502.30 (B)Ex.
502.140(B)(1)
502.130(A)(1)
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CLASS III HAZARDOUS LOCATIONS
ARTICLE 503
Level III
OBJECTIVE:
Each student should be acquainted with hazards involved in Class III locations, requirements in
the NEC for this type location, wiring methods for Div. I and Div. II locations, and where you
would normally see a Class III location.
INTRODUCTION:
Explain to the class that you will cover Article 500 briefly, then on to Article 503 in detail. Refer
to Article 100 Definition briefly. You will explain the difference in a Class III, Division I, and a
Class III, Division II location.
PRESENTING THE LESSON:
Briefly cover Article 100 (related parts only) Article 500, then Article 503. Discuss in detail
location difference in a Division I and a Division II location in Class III installations. Discuss
wiring methods in a Class III, Division I and Division II location. You would see this type of
installation in a Textile mill for example. Manufacturer listing and labeling instructions for
equipment in Class III locations are very important.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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CLASS III HAZARDOUS LOCATIONS
ARTICLE 503
Level III
WORKSHEET
1. In a Class III, Division I location, all of the following are approved wiring methods
except:
a.
b.
c.
d.
2.
Rigid Metal Conduit
Intermediate Metal Conduit
Electrical Metallic Tubing
UF Type Cable
In a Class III, Division II location, in areas used solely for storage and containing no
machinery, which of the following are approved wiring methods:
a.
b.
c.
d.
open wiring on insulators
Rigid metal conduit
Electrical metallic tubing
all of the above
3. In a Class III, Division I, location, pendant luminaires supported by stems consisting of
threaded rigid metal conduit must be braced, if the stems are longer than:
a.
b.
c.
d.
6 inches
8 inches
10 inches
12 inches
4. Under normal conditions, fixed lighting luminaires installed in a Class III location shall
not exceed an exposed surface temperature of which of the following under normal conditions
of use?
a
b
c
d
5.
.
.
.
.
165°C
175°C
90°C
40°C
Boxes and fittings in Class III, Division I locations shall be:
a.
b.
c.
d.
of any type
dusttight
anodized aluminum only
none of the above
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CLASS III HAZARDOUS LOCATIONS
ARTICLE 503
Level III
ANSWER KEY
1.
2.
3.
4.
5.
d, UF Type Cable
d, all of the above
d, 12 inches
a, 165ºC
b, dusttight
503.10(A)
503.10(B) Exception
503.130(C)
503.130(A)
503.10(A)(2)
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INTRINSICALLY SAFE SYSTEMS
ARTICLE 504
Level III
OBJECTIVES:
Each student should be acquainted with the requirements included in this Article, which cover
the installation of intrinsically safe (I.S.) apparatus, wiring, and systems for Class I, II, and III
locations.
INTRODUCTION:
The use of some wiring methods in hazardous locations can be extremely expensive. For
economical reasons, more and more I.S. wiring was being used which brought about the need
for specific regulations covering such installations.
PRESENTING THE LESSON:
1.
Thoroughly cover the requirements included in the scope, equipment approval, and
the definitions included within the Article.
2.
Point out the importance of complying with installation limitations that may be in the
instructions included with the equipment listing and/or included in Section 504.10 as to
location.
3.
Cover the remaining material included in the Article which provides installation
specifics.
4.
Use manufacturer's literature, pictures, and samples to more thoroughly illustrate the
intended application and installation methods.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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INTRINSICALLY SAFE SYSTEMS
ARTICLE 504
Level III
WORKSHEET
1.
All of the following terms are included in the definitions in Section 504.2 except:
a.
b.
c.
d.
Different Intrinsically Safe Circuits
Associated Apparatus
Intrinsically Safe System
Cold Arc Circuit
2. Within enclosures, conductors of intrinsically safe circuits shall be separated from
conductors of any non-intrinsically safe circuit, a minimum distance of:
a.
b.
c.
d.
2 inches
4 inches
6 inches
8 inches
3. The maximum spacing between labels used to identify "Intrinsic Safety
Wiring" is:
a.
b.
c.
d.
6 inches
24 inches
6 feet
25 feet
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INTRINSICALLY SAFE SYSTEMS
ARTICLE 504
Level III
ANSWER KEY
1.
2.
3.
d, Cold Arc Circuit
a, 2 inches
d, 25 feet
504.2
504.30(A)(2)(1)
504.80(B)
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CLASS I, ZONE 0, 1, AND 2
LOCATIONS ARTICLE 505
LEVEL III
OBJECTIVE:
Each student should be knowledgeable of an alternate method of classifying hazardous gases and
liquids for grouping and classification.
INTRODUCTION:
Explain the different group classifications. Reference the 2012 edition of NFPA 497 –
Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of
Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas.
PRESENTING THE LESSON:
Explain the zone group classification and group wiring methods and other hazardous location
articles as applied to zone locations, according to the design standards and specifications as
required by the registered design professional.
APPLICATION:
If time will allow, let the class answer questions on the
worksheet. CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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CLASS I, ZONE 0, 1, AND 2 LOCATIONS
ARTICLE 505
LEVEL III
WORKSHEET
1.
An atmosphere containing acetylene is classified in which Group?
a. Group II A
b. Group II B
c. Group II C
d. None of the above
2.
In which area are ignitable concentrations of flammable gases or vapors which may be
present for long periods of time being found?
a. Class I, Division I
b. Class I, Zone 0
c. Class I, Zone 1
d. Class I, Zone 2
3.
Equipment shall be marked to show the class, zone, gas, and temperature classification
referenced to an ambient temperature of which of the following?
a. 40°C
b. 60°C
c. 90°C
d.100°C
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CLASS I, ZONE 0, 1, AND 2 LOCATIONS
ARTICLE 505
LEVEL III
ANSWER KEY
1.
c, Group II C
505.6(A)
2.
b, Class I, Zone 0
505.5(B)(1)
3.
a, 40°C
505.9(C)(1) and (D)(1)
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AIRCRAFT HANGARS
ARTICLE 513
Level III
OBJECTIVE:
Each student should be familiar with the wiring and equipment methods pertaining to aircraft
hangars.
INTRODUCTION:
This Article applies to locations used for storage or servicing of aircraft in which gasoline, jet
fuels, or other volatile flammable liquids or flammable gases are used.
PRESENTING THE LESSON:
Explain the various classifications as outlined in 513.3 and what is required to declassify
adjacent locations.
Make sure the student is aware that equipment and wiring methods utilized in Class I areas
must comply with Article 501 (previously covered). All other fixed wiring in a hangar shall be
installed in metallic raceways or shall be Type MI, TC, or Type MC cable.
Particular emphasis should be placed on:
a) Grounding equipment not within Class I areas
b) Arcing equipment above Class I areas
c) Warning signs on mobile stanchions
d) Restrictions on battery chargers and required signs on mobile chargers
e) Restrictions for external power sources for energizing aircraft.
f) mobile servicing equipment requirements
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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AIRCRAFT HANGARS
ARTICLE 513 Level III
WORKSHEET
1.
All fixed wiring in a hangar but not installed in a Class I location as classified in 513.3
shall be installed in metal raceways or shall be which of the following?
a.
b.
c.
d.
Type MI
Type TC
Type MC
All of the above
2. External power sources for energizing aircraft shall be a minimum of which of the
following inches above floor level.
a.
b.
c.
d.
6 inches
18 inches
24 inches
12 inches
3. Mobile equipment to be used in hangars shall be marked and kept at least which of the
following distance clear of aircraft engines and fuel tanks.
a.
b.
c.
d.
3 ft.
5 ft.
8 ft.
10 ft.
4. All wiring installed in or under the hangar floor shall comply with the requirements for
which of the following locations?
a.
b.
c.
d.
Class 1, Division 2
Class 1, Division 1
Class 1, Division 3
Class 2, Division 2
5. All wiring located within 10 ft of an aircraft in a hanger used for painting shall be
classified how?
a.
b.
c.
d.
Class 1, Division 1
Class 1, Division 2
Class 2, Division 1
Class 2, Division 2
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AIRCRAFT HANGARS
ARTICLE 513 Level III
ANSWER KEY
1.
2.
3.
4.
5.
d. all of the above
b, 18 inches
b, 5 feet
b. Class 1, Division 1
a, Class 1, Division 1
513.7(A)
513.10(C)(1)
513.10(D)(1)
513.3(A)
513.3(C)(2)
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BULK STORAGE
PLANTS ARTICLE 515
Level III
OBJECTIVE:
Each student should be familiar with the wiring and equipment methods pertaining to bulk
storage plants.
INTRODUCTION:
This Article applies to areas where flammable liquids are received, stored, or blended for bulk
distribution. For further information see NFPA 30-2012.
PRESENTING THE LESSON:
Inform the students that all wiring and equipment in the Class I locations defined in this Article
shall comply with applicable provisions of Article 501.
Cover the various Class I locations in Table 515.3. Remind the students that these areas are
outlined in NFPA 30 Chapter 5. Any areas deviating from these requirements must be
classified by the inspector (authority) having jurisdiction.
Cover the various underground wiring methods (515.8) and those permitted above the Class I
area (515.7).
If gasoline dispensing is carried on at the bulk location, the applicable provisions of Article
514 shall apply.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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BULK STORAGE PLANTS
ARTICLE 515 Level III
WORKSHEET
1. A Class I Division I area shall extend how far from the edge of all indoor equipment
installed in accordance with NFPA 30 2012, extending in all directions.
a.
b.
c.
d.
3 feet
5 feet
10 feet
25 feet
2. A Class I Division II area shall extend how many feet from roof of a storage tank.
a.
b.
c.
d.
3.
3 feet
5 feet
10 feet
25 feet
A bulk storage plant is:
a.
b.
c.
d.
that portion of a property where flammable liquids are stored.
that portion of a property where flammable liquids are stored or blended.
that portion of a property where flammable liquids are stored or blended in bulk.
that portion of a property where flammable liquids are stored or blended in bulk
and are received and distributed by pipelines, tank car, or tank vehicle.
4. How would office and/or restroom without opening into a classified location be
classified?
a.
b.
c.
d.
Class I, Division I
Class I, Division II
Unclassified (ordinarily)
None of the above
5. Threaded steel intermediate metal conduit shall be used for which of the following
distances where rigid nonmetallic conduit is used underground at a bulk storage plant?
a.
b.
c.
d.
The last 2 feet
The last 4 feet
The last 6 feet
The last 10 feet
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6. All fixed wiring above Class I locations at a bulk storage plant shall be in?
a.
b.
c.
d.
metal raceways
PVC schedule 80
neither a or b
both a and b
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BULK STORAGE PLANTS
ARTICLE 515
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
b, 5
Table 515.3
c, 10
Table 515.3
d, that portion of a property where flammable liquids are stored
or blended in bulk and are received and distributed by pipelines,
tank car,
or tank vehicle
515.2 515.1
c, Unclassified (ordinarily)
Table 515.3
a, 2
515.8(A)
d, both a and b
515.7(A)
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SPRAY APPLICATION, DIPPING, AND COATING PROCESSES
ARTICLE 516
Level III
OBJECTIVE:
Each student should become familiar with the wiring methods and equipment associated with
spray application, dipping, coating processes and printing processes.
INTRODUCTION:
This Article covers the specific hazards associated with applying various finishes or coatings to
material. Call attention to the various NFPA manuals and Volume 5 “Fire Protection” which
provides additional information.
PRESENTING THE LESSON:
Cover the classification of the following areas.
1. Class I or Class II, Division I
2. Class I or Class II, Division II
3. Adjacent locations
4. Non-hazardous locations
Emphasize that equipment must be installed according to its listing and labeling. The problem
of paint residue build up renders most explosion proof light fixtures unsuitable for spray areas.
(516.4(B))
Portable equipment shall not be used in the spray area during spray operations. Cover the two
exceptions [516.4(D)]
Bring out that interlocking the ventilation system with the spraying equipment reduces the
Class I or Class II Division II area from the openings in spray booths or rooms. 516.3 (D)2
informational note
Cover Electrostatic equipment and state the differences between this and other methods of
application.
a) Fixed equipment [516.10(A)]
b) Hand spraying equipment [516.10(B)]
c) Powder coating [516.10(C)] emphasize that this involves combustible dusts and
equipment must comply with Article 502.
Cover the problems associated with wiring and equipment above Class I and Class II locations.
Cover the problems associated with wiring and equipment above Class I and Class II
Locations.
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APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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SPRAY APPLICATION, DIPPING, AND COATING PROCESSES
ARTICLE 516
Level III
WORKSHEET
1. Which of the following space(s) shall be considered Class I, Division 1, or Class I, Zone 0,
as applicable:
(1) The interior of any open or closed container of a flammable liquid
(2) The interior of any dip tank or coating tank
a.
b.
c.
d.
(1) only
(2) only
Both (1) and (2)
Neither (1) nor (2)
2. The space between 10 feet vertically and 20 feet horizontally of unenclosed spraying
shall be classified as:
a.
b.
c.
d.
Class I division 2
Class 1 division 1
Class 2 division 2
unclassified
3. When in open spray areas and outside the Class I division 1 location, the vertical height of
the Class I division 2 location is:
a
b
c
d
20’
10’
15’
5’
.
.
.
.
4. Which of the following statements is/are true concerning portable electric lamps used in
Class I division 1 locations?
I- The plug in terminates outside of the Class I division 1 locations
II- The Portable Electric lamp is approved for Class I division 1 locations.
a.
b.
c.
d.
I only
Both I and II
II only
Neither I nor II
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5. Fixed wiring where cables are used above Class I division 2 locations includes which of
the following?
a.
b.
c.
d.
NM
AC
MC
UF
6. Switches which arc and spark above Class I division 2 locations must:
a.
b.
c.
d.
Be guarded
Totally enclosed
Elevated
Not allowed
7. When shall metal raceways, metal-jacketed cables, and all noncurrent-carrying metal
parts of fixed or portable equipment be grounded?
a.
b.
c.
d.
regardless of voltage
over 300 volts to ground
over 250 volts to ground
480 volts phase to phase
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SPRAY APPLICATION, DIPPING, AND COATING PROCESSES
ARTICLE 516
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
c, Both (1) and (2)
b, Class 1 division 1
b, 10’
c, II only
c, MC
b, totally enclosed
a, regardless of voltage
516.3(A)
516.3(D) 1
516.3(D) 1
516.4(D)Ex. 1
516.7(A)
516.7(B)
516.16
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HEALTH CARE FACILITIES
ARTICLE 517
Level III
OBJECTIVE:
Each student should be acquainted with the various types of facilities in Article 517, such as
hospitals, nursing homes, residential custodial cares facilities, doctor's offices, and dental
offices.
MATERIALS NEEDED:
Overhead projections of FPN figures:
517.30, No. 1
517.41(B), No. 2
517.30, No. 2
517.41, No. 1
INTRODUCTION:
Explain to students that you will cover Article 517 in detail, definitions are very important.
You will cover different types of facilities in this Article, and the requirements for each one.
Emphasis will be placed on essential electrical systems in clinics, medical and dental offices,
out patient facilities, nursing homes, residential custodial care facilities, hospitals, and other
health care facilities serving patients.
PRESENTING THE LESSON:
Discuss facilities, such as a hospital, nursing home, and residential custodial care facility.
Cover wiring requirements for each type, to include services, branch circuits, and emergency
services for facilities.
Discuss where certain types or numbers of circuits are required in specific locations or areas of
a facility.
Discuss the areas that are more critical than others, such as an operating room in a hospital.
It will also be necessary to cover requirements for essential electrical systems in hospitals.
Divide the emergency system into two mandatory branches: 1) Life Safety 2) and the critical
branch. Connection to alternative power sources along with essential electrical systems for
nursing homes and residential care facilities as well as systems for clinics need to be covered in
this lesson.
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HEALTH CARE FACILITIES
ARTICLE 517
Level III
WORKSHEET
1. To be classified as a nursing home, a facility is used for lodging, boarding and nursing
care on a 24 hour basis, with a minimum number of:
a.
b.
c.
d.
4 persons
6 persons
8 persons
10 persons
2. In General Care areas (without exceptions), each patient bed location shall be provided
with a minimum of:
a.
b.
c.
d.
2 receptacles
3 receptacles
8 receptacles
6 receptacles
3. In Critical Care areas, each patient bed location shall be provided with a minimum of:
a.
b.
c.
d.
2 receptacles
4 receptacles
6 receptacles
8 receptacles
4. In a location where flammable anesthetics are employed, the entire area shall be
considered to be Class I, Division I location which shall extend upward to a level
above the floor of:
a.
b.
c.
d.
3
4
5
6
feet
feet
feet
feet
5. When wiring above hazardous anesthetizing locations all of the following are approved
wiring methods except:
a.
b.
c.
d.
Rigid metal conduit
Intermediate metal conduit
Electrical metallic tubing
Type NMC Cable
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6. Which of the following is the minimum number of independent power sources for
essential electrical systems in hospitals?
a.
b.
c.
d.
7.
1
2
3
4
Wiring of the life safety branch and the critical branch shall be permitted to occupy the
same raceways, boxes, or cabinets of other circuits not part of the branch where such
wiring complies with one of the following?
a. Is in transfer equipment enclosures
b. Is in exit or emergency luminaires (lighting fixtures)supplied from two sources
c. Is in a common junction box attached to exit or emergency luminaires (lighting
fixtures) supplied from two sources
d. Is for two or more emergency circuits supplied from the same branch
e. All of the above
8. The life safety branch shall be installed and connected to the alternate source of power so that
functions shall be automatically restored to operation within how much time of the failure
of normal power?
a.
b.
c.
d.
9.
10 seconds
20 seconds
30 seconds
60 seconds
Part II of article 517 applies to which types of health care facilities?
a.
b.
c.
d.
hospitals
dental offices
all health care facilities
nursing homes
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10. Which of the following wiring methods is not permitted in the patient care areas of a
medical doctor’s offices?
a. rigid metal conduit with an insulated copper equipment grounding conductor
installed in the conduit.
b. intermediate metal conduit with an insulated copper equipment grounding
conductor in the conduit.
c. electrical metallic tubing with an insulated copper equipment grounding
conductor installed in the conduit.
d. rigid nonmetallic conduit with an insulated copper equipment grounding
conductor installed in the conduit.
11. A service to a hospital is 277/480, 3-phase. The main is 4,000 amperes and there are 12
feeders off of this service, 3 of which are 1,000 amperes or larger. Which of the
following statements are true about Ground Fault Protection of Equipment for this
system?
a.
b.
c.
d.
Only the 4,000 ampere main requires GFPE protection.
Only the (3) feeder 1,000 amps or larger require GFPE protection.
The main and all (12) feeders require GFPE protection
The main and the (3) feeders of 1,000 amps or larger require protection.
12. All of the following loads may be connected to the Life Safety Branch, EXCEPT:
a.
b.
c.
d.
nurse call systems
elevators
fire alarms
exit signs
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HEALTH CARE FACILITIES ARTICLE
517
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
a, 4 persons
517.2 definitions
c, 8 receptacles
517.18(B)
c, 14 receptacles
517.19(B)(1)
c, 5 feet
517.60(A)(1)
d, Type NMC
517.61(B)(1)
b, 2
517.35(A)
1. In transfer switches
2. In exit or emergency lighting fixtures supplied from two
sources
3. In a common junction box attached to exit or emergency
lighting fixtures supplied from
two sources
517.30(C)(1)
8. a. 10 seconds
517.42
9. c, all health care facilities
517.10(A)
10. d, rigid nonmetallic conduit with an insulated copper equipment
grounding conductor installed
in the conduit.
517.13(A)
11. c, the main and all (12) feeders require
GFPE protection.
517.17(A)(B)
12. a, nurse call systems
517.32
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MOTION PICTURE AND TELEVISION STUDIOS AND SIMILAR LOCATIONS
ARTICLE 530
Level III
OBJECTIVE:
Each student should be familiar with the requirements of Article 530 for places where film or
tape over 7/8 inch (22mm) in width is exposed, developed, printed, cut, edited, rewound,
repaired, or stored.
INTRODUCTION:
This Article covers wiring normally associated with motion picture and television productions.
PRESENTING THE LESSON:
These installations are not regularly encountered in inspection work. Discuss the contents of
article 530 and make the students aware of requirements that exist. Inform them of what to
look for when a field installation occurs.
Cover special wiring requirements, sizing of feeder conductors [Table 530.19(A)] and wiring
in film storage vaults.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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MOTION PICTURE AND TELEVISION STUDIOS AND SIMILAR LOCATIONS
ARTICLE 530
Level III
WORKSHEET
1. What permanent wiring methods are permitted on stage or sets of motion picture studios?
a.
b.
c.
d.
MC
MI
approved raceways
a, b, and c
2. A demand of what percentage of the maximum possible connected load shall be
permitted for all portable feeders.
a
b
c
d
3.
100%
60%
75%
50%
Stage cable for stage lighting shall be protected by means of overcurrent devices set at
not more than?
a
b
c
d
4.
.
.
.
.
.
.
.
.
125%
200%
300%
400%
Lamps in cellulose nitrate film storage vaults shall be controlled by a switch:
a.
b.
c.
d.
Located outside the vault.
Located inside the vaults.
Located outside the vault and provided with a pilot light.
Located inside or outside if keyed.
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MOTION PICTURE AND TELEVISION STUDIOS AND SIMILAR LOCATIONS
ARTICLE 530
Level III
ANSWER KEY
1.
2.
3.
4.
d, a, b, and c
d, 50%
d, 400%
c, located outside the vault and provided with
a pilot light.
530.11
530.19(B)
530.18(A)
530.51
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CRANES AND
HOISTS ARTICLE 610
Level III
OBJECTIVE:
Each student should be familiar with the requirements for wiring cranes, monorail hoists, hoists
and all runways.
PRESENTING THE LESSON:
Briefly mention that all equipment operating in hazardous locations shall comply with Articles
500 through 503.
Cover wiring methods and conductors; emphasizing that ampacity is as stated in Table
610.14(A) not 310.16.
Contact conductors are usually factory assembled and field installed as listed units. Briefly
acquaint the students with the terminology involved and state that no other loads can be
supplied 610.21(H).
Point out the requirements for runway conductor disconnecting means and the exception that
permits the motor circuit switch to be omitted.
Overcurrent protection is basically the same as other motor overcurrent requirements except
that the demand factors of Table 610.14(E) are applied.
Point out that cranes and hoists controls include limit switches (610.55) to limit travel and 2 1/2
feet of working space is required where live parts must be accessed (610.57).
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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CRANES AND HOISTS
ARTICLE 610 Level III
WORKSHEET
1. Conductors shall be enclosed in raceways or what type cable?
a.
b.
c.
d.
MC or AC
NM or NMC
AC or SNM
USE or UF
2. #8 THWN conductors used to supply a 15 minute motor on a crane are rated at:
a.
b.
c.
d.
3.
60 amps
55 amps
67 amps
69 amps
The smallest conductor allowed to be used for electronic circuits:
a.
b.
c.
d.
#16
#14
#18
#20
4. Four cranes are supplied by a common conductor system with a total computed load of 50
amps. What size conductor would be needed if the longest time-rated motor is 60
minutes?
a. #8
b. #14
c . #18
d . #20
5. Where bridge wire contact conductors have a span exceeding 80 feet, insulating saddles
shall be placed at intervals not exceeding:
a.
b.
c.
d.
25’
50’
10’
40 ’
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6. The continuous ampere rating of a switch or circuit breaker used as a disconnect switch
shall not be less than what percentage of the combined short-time ampere rating of the
motors or not less than what percentage of the sum of the short-time rating of the motors
required for any single motion?
a
b
c
d
.
.
.
.
100%-75%
50%-75%
50%-50%
75%-50%
7. Control circuits shall have overcurrent protection not more than what percentage of the
ampacity of the control conductors?
a
b
c
d
.
.
.
.
100%
200%
300%
400%
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CRANES AND HOISTS ARTICLE
610 Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
7.
a, MC or AC
c, 67 amps (see note under table)
d, #20
a, #8
50 X 87% = 43.5 < 55
b, 50 ft.
b, 50%-75%
c, 300%
610.11
610.14(E) & Table 610.14(A)
610.14(C)(2)
610.14(E)(3) &
Table 610.14(A) and (E)
610.21(D)
610.33
610.53
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X-RAY EQUIPMENT
ARTICLE 660
Level III
OBJECTIVE:
Each student should be familiar with the requirements for all x-ray equipment used for
industrial or other nonmedical or nondental use.
INTRODUCTION:
Explain that medical and dental x-ray equipment is covered in Article 517-V and that Article
660 is not applicable for those installations.
PRESENTING THE LESSON:
Explain that this Article is concerned with electrical safety and not health hazards or radiation
from the equipment.
Proper application of this Article depends upon understanding the definitions outlined in 660.2.
Cover all of these.
Explain that fixed equipment can only be cord and plug connected if it can be properly
supplied by a branch circuit rated 30 amperes or less. Portable, mobile and transportable
equipment of any capacity shall be permitted to be connected by hard service cable or cord.
Explain that the rating of the disconnecting means, conductor ampacity, and overcurrent
protection are different from normal equipment because of the short duration of service. Be
sure to emphasize calculations using momentary ratings may result in smaller sizing of
conductors; however, voltage regulation may require larger conductors for proper equipment
operation.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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X-RAY EQUIPMENT
ARTICLE 660
Level III
WORKSHEET
1. Article 660 covers x-ray equipment in which of the following locations?
a.
b.
c.
d.
Hospitals
Dental offices
nursing homes
none of the above
2. A momentary rating is a rating based on an operating interval that does not exceed which of
the following?
a.
b.
c.
d.
5 seconds
1 minute
30 seconds
5 minutes
3. An x-ray disconnecting means is required to provide adequate capacity for:
a.
b.
c.
d.
50% of the input required for momentary input
100% of the input for the long time rating
Both A and B
Whichever is greater of A or B
4. The minimum ampacity of the branch circuit conductors for an x-ray machine with a
momentary rating of 100 amperes and a long time rating of 50 amperes is:
a.
b.
c.
d.
50 amperes
100 amperes
200 amperes
225 amperes
5. Transformers and capacitors that are part of x-ray equipment must comply with:
a.
b.
c.
d.
Transformers must comply with Article 450
Capacitors must comply with Article 460
Both a and b
Neither a nor b
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6. A feeder supplies four x-ray machines. The x-ray machines have the following momentary
ratings: 100 amperes, 60 amperes, 30 amperes, and 32 amperes. What is the minimum
ampacity of the feeder conductors?
a.
b.
c.
d.
92.4 amperes
100.21 amperes
160.4 amperes
125 amperes
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X-RAY EQUIPMENT
ARTICLE 660
Level III
ANSWER KEY
1.
2.
3.
4.
5.
6.
d, none of the above
a, 5 seconds
d, Whichever is greater A or B
a, 50 amperes
d, neither a nor b
a, 92.4 amperes
660.1
660.2
660.5
660.6(A)
660.35
660.6(B)
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INDUCTION AND DIELECTRIC HEATING EQUIPMENT
ARTICLE 665
Level III
OBJECTIVE:
Each student should be familiar with the requirements of Article 665 for induction and
dielectric heating equipment.
INTRODUCTION:
Explain that this Article does not cover heating equipment for medical or dental applications,
appliances, or line frequency pipelines and vessels heating.
PRESENTING THE LESSON:
Start off by explaining the difference between the two types of heating systems. Dielectric
heating is heating a nominally insulated material as compared to heating a nominally
conductive material.
Warning labels or signs shall be attached to the equipment in such a manner as to be fully
visible even when doors are open or panels are removed. Compliance with Article
110.21(B) is required.
Cover interlocks requirements as outlined in 665.25.
Explain that motor-generator equipment is basically a motor load and that supply conductors,
overcurrent protection and disconnecting means shall be as specified in Article 430. The
generator output is normally isolated from ground.
Cover the safety precautions necessary when using remote controlled switching.
Heating equipment other than motor-generator types shall have overcurrent protection in
accordance with Article 240.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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INDUCTION AND DIELECTRIC HEATING EQUIPMENT
ARTICLE 665
Level III
WORKSHEET
1. Article 665 covers what type of applications?
a. Induction and dental applications.
b. Industrial and scientific applications.
c. Welding and heating applications.
d. Guarding and grounding applications
2. Warning labels or signs shall be attached on equipment and be plainly visible even when
doors are open or panels are removed if the voltage is over which of the following?
a.
b.
c.
d.
125 Volts AC or DC
600 Volts AC or DC
150 Volts AC or DC
Not required
3. Equipment other than motor generator shall have overcurrent as specified in which Article?
a.
b.
c.
d.
430
665
240
310
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INDUCTION AND DIELECTRIC HEATING EQUIPMENT
ARTICLE 665
Level III
ANSWER KEY
1.
2.
3.
b. Industrial and scientific applications
c. 150 volts ac or dc
c. 240
665.1
665.23
665.11
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ELECTROLYTIC CELLS
ARTICLE 668 Level III
OBJECTIVE:
Each student should be acquainted with the requirements for installation of electrical
components of electrolytic cells and cell lines.
INTRODUCTION:
Article 668 applies to the installation of electrical components of electrolytic cells and cell
lines. It does not apply to cells used as a source of electrical energy (storage batteries).
PRESENTING THE LESSON:
Cover scope of Article (668.1) to make students familiar with where this article applies.
Emphasis should be placed on Informational Notes to 668.1.
Go over definitions found in 668.2.
Cover applications of other articles as found in 668.3.
Discuss space requirements for cell line working zone as covered in 668.10 and differences in
grounding practices from those normally used as found in 668.11, 668.15, 668.20, 668.21,
668.30, 668.32(A). Cover requirements for Cranes and Hoists found in 668.32.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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ELECTROLYTIC CELLS
ARTICLE 668 Level III
WORKSHEET
1.
The provisions of Article 668 applies to the installation of electrolytic cells except for
which of the following?
a.
b.
c.
d.
A source of electric energy.
The production of copper.
The production of aluminum
The production of chlorine.
2. A tank or vat in which electrochemical reactions are caused by applying electrical energy for
the purpose of refining or producing usable materials is which the following?
a.
b.
c.
d.
Cell
Electrolytic cell
Cell Vat
Vat
3. The frames and enclosures of portable electrical equipment used within the cell line
working zone shall not be required to be?
a.
b.
c.
d.
Bonded
Grounded
Electrically continuous
Shielded
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ELECTROLYTIC
CELLS ARTICLE 668
Level III
ANSWER KEY
1.
2.
3.
a. energy source
b.
b. Grounded
668.1
668.2 Definitions
668.20(A)
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ELECTROPLATING
ARTICLE 669
Level III
OBJECTIVE:
Each student should be acquainted with the requirements for electroplating installations.
INTRODUCTION:
This Article applies to electroplating, anodizing, electro polishing, and electro stripping. The
term electroplating is used to identify any or all of these processes in this Article.
PRESENTING THE LESSON:
Cover requirements for branch circuit conductors (669.5), wiring methods (669.6) and warning
signs (669.7).
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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ELECTROPLATING
ARTICLE 669 Level
III
WORKSHEET
1. Branch circuit conductors supplying electroplating equipment shall have an ampacity of not
less than which of the following percentage of the total connected load.
a
b
c
d
.
.
.
.
125%
175%
50 %
80 %
2. Where bare conductors are present in electroplating applications, which of the following is
required?
a.
b.
c.
d.
Warning alarms
Warning language
Warning lights
Warning signs
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ELECTROPLATING
ARTICLE 669 Level III
ANSWER KEY
1.
2.
a. 125%
d. warning signs
Section 669.5
Section 669.7
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INTERCONNECTED ELECTRICAL POWER PRODUCTION SOURCES
ARTICLE 705
Level III
OBJECTIVE:
Each student should be acquainted with the requirements for interconnected electrical power
production sources installations.
INTRODUCTION:
This Article applies to interconnected electrical power production sources. This article covers
the installation of one or more electric power production sources operating in parallel.
PRESENTING THE LESSON:
Cover the definitions outlined in 705.2. Explain in detail that other articles such as 445
Generators, 690 Solar Photovoltaic Systems, 692 Fuel cell systems, apply to the use of this
section.
Cover in detail 705.12 Point of attachment, inverters and overcurrent.
705.20 Through 705.22 for disconnecting means of sources and equipment and their
prospective locations.
705.30 overcurrent protection of solar photovoltaic systems, transformers, fuel cell systems,
utility interactive inverter and generators.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
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INTERCONNECTED ELECTRICAL POWER PRODUCTION SOURCES
ARTICLE 705
Level III
WORKSHEET
1. The point at which the power production and distribution network and the customer
interface occurs in an interactive system is which of the following?
a.
b.
c.
d.
Point of attachment
the weather head
point of common coupling
none of the above
2. A dedicated overcurrent and disconnect shall be made at a dedicated:
a.
b.
c.
d.
circuit breaker
fusible disconnecting means
nonfused disconnect
either a or b
3. Which of the following statements are true concerning the loss of one phase of a three
phase interconnected power production sources?
I.
II.
a.
b.
c.
d.
When one phase opens an audible and visual warning must come on
Shall automatically disconnect the system
I only
II only
both I and II
neither I nor II
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INTERCONNECTED ELECTRICAL POWER PRODUCTION SOURCES ARTICLE
705
Level III
ANSWER SHEET
1. d
705.2
2. d
705.12(D)(1)
3. b II only
705.42
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CRITICAL OPERATIONS POWER SYSTEMS
ARTICLE 708
LEVEL III
OBJECTIVES:
Each student should be familiar with and understand the nature of Article 708 as it relates to
systems necessary for emergency operations of governmental systems.
INTRODUCTION:
Explain the background and reasoning behind instituting guidelines and requirements for
maintaining certain public electrical and utility systems during extreme conditions caused by loss
of services due to weather related or human caused events
PRESENTING THE LESSON:
Discuss different aspects and concerns based on the Authority Having Jurisdiction and who that
may be to take control and maintain order during catastrophic events where loss of power and
other systems lead to extreme environmental conditions for the inhabitants of the affected
community.
Explain the comparisons between emergency systems covered in Article 700 and how those
requirements there are necessary in addressing similar conditions under Article 708.
Relate the needs for planning by emergency management and proper governmental agencies
responsible for enduring the event and the recovery afterwards to move toward normal
conditions.
APPLICATION:
Allow the class time to complete worksheet
CHECKING AND FOLLOW-UP:
Correct the worksheets and discuss the answers with the class.
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CRITICAL OPERATIONS POWER SYSTEMS
ARTICLE 708
LEVEL III
WORKSHEET
1. Critical Power Operations Systems are those systems classed by which of the following?
a.
b.
c.
d.
Municipal agency
State agency
Federal Agency
Any of the above
2. When establishing critical operations systems, a Commissioning Plan shall be:
a.
b.
c.
d.
planned and approved
developed and documented
commissioned by the governing agency
made by the local authority having jurisdiction
3. Hazards to be considered at a minimum shall include, but shall not be limited to which of the
following:
I.
Naturally occurring hazards (geological, meteorological, and biological)
II.
Human-caused events (accidental and intentional)
a.
b.
c.
d.
I only
II only
Neither I nor II
Both I and II
4. Physical security shall be provided for critical operations power systems in accordance with
which of the following?
I.
II.
Risk Assessment
Restricted Access
a.
b.
c.
d.
I only
II only
Both I and II
Neither I nor II
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5. The feeder-and branch-circuit overcurrent devices shall be accessible to which of the
following?
a.
b.
c.
d.
qualified persons
only government officials
only military personnel
authorized persons
6. Alternate power sources shall be capable of operating the COPS for a minimum of:
a.
b.
c.
d.
24 hours
72 hours
48 hours
96 hours
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CRITICAL OPERATIONS POWER SYSTEMS ARTICLE 708
LEVEL III
ANSWER KEY
1.
2.
3.
4.
5.
6.
d, any of the above
b,
d, both I and II
c, both I and II
d, authorized persons
b, 72 hours
708.1
708.8(A)
708.4(B)
708.5
708.50
708.22(C)
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