IMPEDANZ ERTC
INSTITUTE OF INTEGRATED ELECTRICAL ENGINEERING
SOUTHERN CAVITE CHAPTER
Engineering, Review, Training & Consultancy
SPEAKER:
ENGR. JAIME A. PACO
, PEE, MM-EM, CPM, CEM
DIRECTOR, IMPEDANZ ERTC
www.impedanzengineering.com
|
impedanz.safety@gmail.com
|
PCAB & DOLE Accredited
About the Speaker
ENGR. JAIME A. PACO
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Professional Electrical Engineer
ASEAN Certified Energy Manager, CEM
Master of Engineering Management
Certified Plant Mechanic
Director/Lecturer, Impedanz Engineering Review, Training & Consultancy
Electrical Consultant of Several Companies in CALABARZON
IIEE Lifetime and Senior Member
IIEE RME Affairs Committee Member (2012, 2013)
IIEE Electoral Process Committee Member (2016)
President, IIEE Central Laguna Chapter (2015)
Adviser, IIEE Central Laguna Chapter (2016 to present)
Member, Rotary Club of Calamba
Member, Mechatronics and Robotics Society of the Phils. (MRSP)
Member, PSME (Phil. Society of Mechanical Engineers) – Central Laguna
Member, Institute of Electrical and Electronics Engineer (IEEE - USA)
Member, VP for Internal, Phil. Integrated Fire Protection Org. (2020 Laguna)
FEATI University, BSEE Batch 87, University Scholar
Former Faculty Member (Letran, Lyceum, Malayan-MAPUA of Laguna)
Former Faculty Member (De La Salle University Lipa, Perpetual)
“PEC PROVISIONS FOR ELECTRICAL SYSTEM DESIGN”
ABSTRACT
The Electrical System of any facilities must be designed and installed in
accordance with the latest edition of Philippine Electrical Code for it to
become safe and reliable.
This webinar will tackle significant provisions of PEC for Electrical System
Design. This includes not only sizing of CB or feeders but also requirements
on installation of panelboards, GFCI circuit breakers, electrical equipment
space requirements, services, grounding, etc.
This is an interesting 3-hour presentation of PEC Provisions with the sharing
of Lecturer’s experiences; Join us!
PHILIPPINE ELECTRICAL CODE 2017
2017 edition:
The purpose of this Code is the practical
safeguarding of persons and property from
hazards arising from the use of electricity.
This Code is intended as a design
specification or an instruction manual to
qualified persons.
PHILIPPINE ELECTRICAL CODE
(PEC) 2017
THE KEY WORD IS:
SAFETY
KNOWLEDGE
CHECK ✔
When is the
Electrical Safety
month?
READING PEC PROVISIONS
Chapter
Chapter
Article
Part
Section
2.50.1.4
General Requirements for
Grounding and Bonding
Section 2.50.1.4
Article
6.95
Fire Pumps
Article 6.95
SECTION 1.2.1.1
Electrical Permit Needed Before
Work is Started
What is the latest version
Of Philippine Electrical Code?
TOTAL CONNECTED LOAD
____________ KVA
Design: PEE
“REE/RME must have PTR”
In-charge: PEE/REE/RME
Source: Municipal Government
PEC ARTICLE 1.2 – PERMITS AND INSPECTION
CERTIFICATES
Section 1.2.1.2 – Requirements
for Electrical Permit
Signature and Submittals
(A) Electrical Permit shall include the ff
minimum information:
1. Applicant
2. PEE who signed and sealed plans
and specification with photocopy of
PTR and valid PRC license.
3. Licensed Electrical Practitioner incharge of electrical works, with
photocopy of PTR and valid PRC
license.
4. Building Owner
5. Lot Owner
6. Building Official
 All Plans and Permit must be signed by the OWNER.
 All Plans and Permit must be signed and sealed by
PEE.
Submit copy of PEE’s valid PRC license with PTR.
 Submit copy of REE/RME valid PRC license with PTR.
( for in-charge of Electrical Works)
KNOWLEDGE
CHECK ✔
How many copies
of Plans must be
submitted for
permit application?
(B) Five 5 sets of electrical plans and specs signed
and sealed by PEE
to maximum of 7 sets,
1 copy for Contractor
1 copy for Owner
We need to submit documents to Office
of the Building Official (OBO) for permit
approval.
(before start of Construction, so that)
We will know if our design is correct and
in compliance with PEC.
(Documents – Electrical Permit and set of Plans)
Use cable with “W” in Insulation
W – Moisture Resistant
SECTION 1.2.1.4 POSTING OF
ELECTRICAL PERMIT
A copy of electrical permit, upon issuance, shall be posted at a
conspicuous location at the job site and shall not be removed until
final inspection and approval of the work shall have been made.
LEP in-charge of design and in-charge of installation shall post a copy
of their valid PRC license together with the electrical permit at all
times.
Must indicate the
following:
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Building Permit Number
Contractor
Engineering Professionals
PEE Design Engineer
PEE/REE/RME In-Charge
of Electrical Installations
ARTICLE 1.3 ELECTRICAL PLANS AND
SPECIFICATIONS
1.3.1.1 Drawing Sheets
(A)Electrical plans and drawings shall be drawn on drawing
sheets of the following standard sizes:
760mm x 1000mm
600mm x 900mm
500mm x 760mm
297mm x 420mm
- 24 in x 36 in - A1
- 16 in x 24 in - A2
- 12 in x 16 in - A3
(A)For dwelling unit having a floor area of not more
than 50 sq. meters with a total load not exceeding
3680 VA, a drawing sheet of A3 is permitted.
297mm x 420mm
- 12 in x 16 in - A3
REMINDER:
PLANS SHOULD BE
READABLE
KNOWLEDGE
CHECK ✔
Where to put
Design Analysis?
ARTICLE 1.3, PART 1.3.2 PLANS AND
SPECIFICATIONS
Part 1.3.2 (F) Design Analysis
Design Analysis shall be included on the drawings or shall be
submitted on a separate sheets of standard size, and shall show:
(1) Branch circuits, sub-feeders, feeders, busways and service
entrance;
(2) Types, ratings, and trip settings of overload
protective devices;
Brand:
Type:
Rating:
kAIC Rating:
Air Circuit Breaker
2000 A
85
(3) Calculation of
voltage drops
VD = 𝟑 𝑰 𝒁
𝒍𝒆𝒏𝒈𝒕𝒉 𝒊𝒏 𝒎𝒆𝒕𝒆𝒓𝒔
𝟏
(
)(
)
𝟑𝟎𝟓 𝒎𝒆𝒕𝒆𝒓𝒔
𝒏𝒐.𝒐𝒇 𝒔𝒆𝒕𝒔
SAMPLE VOLTAGE DROP CALCULATION
Given: 10 HP, 230V, 3PH Squirrel Cage Induction Motor,
Distance from Power Panel = 15m
Computation:
From PEC: VD = 1.732 (Amps) ( Z ) ( L / 305m ) ( 1 / no. of parallel paths )
VD = 1.732 (28A) (1.1 ohms) (15m / 305m) ( 1 / 1 set)
VD = 2.62 V
%VD = (VD / 230 V)(100%) = (2.62 V / 230 V)(100%)
%VD = 1.14 %
(4) Calculation of short circuit current for
determining the interrupting capacity of
overcurrent protective device for residential,
commercial, and industrial establishment;
We do short circuit calculation by manual
computation or using Software.
kAIC RATING
KNOWLEDGE
CHECK ✔
What is the meaning
of FPN in PEC?
FPN means FINE-PRINT NOTES
– It supplements the article rules,
they are not part of the
requirements but for information
and explanation purposes only.
N
FPN No. 1: This analysis is not required for dwelling
units but required for service equipment and other electrical
equipment not part of individual dwelling units of residential
condominiums and individual detached dwelling units
15 Amp Residential CB
usually has 8 to 10kAIC
rating
(5) Protection
coordination of
overcurrent protective
devices;
Time Current Curve of
Circuit Breaker (TCC)
(6) Arc-Flash Hazard Analysis to determine the
required Personal Protective Equipment (PPE) in
other than dwelling place – (see Appendix H for PPE)
FPN No. 2: Arc-flash Hazard Analysis required is intended
for concerned parties to be informed and made aware of the
importance of Personal Protective Equipment (PPE) and
its type for the flash hazard risk category determined by the
analysis
Calculation of Incident Energy
PPE CATEGORY
PPE CATEGORY
ARTICLE 1.10 REQUIREMENTS FOR ELECTRICAL
INSTALLATIONS
The Criteria for Examination of Electrical Inspection:
1. Suitability for the installation
2. Mechanical strength and durability
3. Wire bending and connection space
4. Electrical insulation
5. Heating effects produced by the equipment
under normal and abnormal condition of use.
6. Arcing effects
7. Class, type, size, voltage, ampacity, specific use of equipment.
NEMA 3R
STAINLESS
ENCLOSURE
LEARNINGS:
1.
2.
3.
4.
5.
6.
Electrical permit is required before start of construction.
Plans and Permit must be signed by Owner and PEE
Aside from Electrical Plans, Short Circuit Analysis is required
Short Circuit Analysis is not required for dwelling units
Short Circuit Analysis is conducted to determine kAIC rating of CB
Voltage Drop Calculation and Cable color coding is new addition to
Schedule of Loads
7. Arc-flash analysis is used to determine PPE required
8. Arc-flash sticker is required on Electrical Panel
9. Protection Coordination reduces downtime hence increase productivity.
REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
Section 1.10.2.1 Spaces About Electrical Equipment
• Width of Working Space
The work space shall permit
at least 90 degree opening of
equipment doors or hinged panels.
REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
Section 1.10.2.1 Spaces About Electrical Equipment
• Entrance to Working Space
a) Large equipment - equipment rated 1200 amperes
or more shall have at least one entrance. 600 mm
wide and 2000 mm high.
b) Headroom - The minimum headroom of working
spaces about service equipment, switchboards, panel
boards, or motor control centers shall be 2000 mm.
1.10.2.1 Spaces About
Electrical Equipment:
Sufficient access and working
space shall be provided and
maintained about all electric
equipment to permit ready and
safe operation and
maintenance of such
equipment
CHAPTER 2. WIRING AND PROTECTION
Means of identifying Grounding Conductors
A.) Sizes 14mm2 or Smaller
- Continuous white
- Continuous gray outer finish
- Three continuous white or gray stripes along the
conductor’s
entire length on other than green
insulation.
Equipment Grounding
Conductors are NON-CURRENT
carrying conductors
CHAPTER 2. WIRING AND PROTECTION
Means of identifying Grounding Conductors
B.) Sizes Larger than 22mm2
- Continuous white or gray outer finish.
- Three continuous white stripes along it entire length
other than green insulation
- At the times of installation, distinctive white or gray
marking at its terminations. This marking shall encircle
the conductor or insulation.
ARTICLE 2.10 BRANCH CIRCUITS
RATING:
A.) IN GENERAL – The rating for other than individual
branch circuits shall be 15,20, 30, 40, and 50 A.
B.) OVER 50 AMPERES – Multi-outlet branch circuits
greater than 50A shall be permitted to supply nonlighting over outlet loads.
Ground Fault Circuit Interrupter Protection (GFCI)
a) Dwelling Units - All 125/250 volts, single phase, 15-20
amperes receptacles installed in the following locations
shall be of GFCI protection:
1. Bathrooms
2. Garages
3. Outdoors
4. Crawl spaces - at or below grade level
5. Unfinished basements
6. Kitchen
7. Laundry circuits, and wet bar sinks
8. Boathouses
PART 2.10.2 BRANCH-CIRCUITS RATINGS
1. In General - Branch-circuit conductors shall
have an ampacity not less than the maximum load
to be served. Branch circuit conductors which
supplies continuous load and combination thereof
shall have an ampacity not less than 125% of the
continuous load.
LEARNINGS:
1. Door opening for Electrical Panel must be 90 degrees
2. Electrical Panelboards must be readily accessible with enough
working space for safety.
3. Equipment grounding conductor is colored green
4. System grounding conductor is colored white
5. GFCI type of CB is required for damp or wet location
6. Branch circuit conductor shall have ampacity of 125% of the load
7. Branch circuit conductor shall be loaded up to 80% of it’s ampacity
PART 2.10.2 BRANCH-CIRCUITS RATINGS
2. Household Ranges and Cooking
Appliances – Fore ranges of 8 ¾ kW or more
rating, shall have a minimum-branch circuit
rating 40 amperes.
Branch Circuits requiring at least 20A
Overcurrent Protection
1. Small Appliance Branch Circuits
2. Laundry Branch Circuits
3. Bathroom Branch Circuits
4. Dwelling Unit (50 m2) not more than 3680VA
20A (80%) = 16A
16A (230V) = 3680 VA
Section 2.10.2.6 A (1)
Cord-and-Plug- Connected Equipment Not
Fastened in Place.
The rating of any one cord-and-plug-connected utilization
equipment not fastened in place shall not exceed
80 percent of the branch-circuit ampere rating.
c\
80% of 20A is 16A
ARTICLE 2.15
FEEDERS
Minimum Rating and Size
a) In General - Feeders shall have an allowable
ampacity not less than the noncontinuous
load plus 125% of the continuous load
Continuous load - a load where the maximum current is expected to
continue for 3 hours or more.
Improper Cable
Grouping
“BE CAREFUL NOT TO
DAMAGE THE CABLE
INSULATION DURING
CONSTRUCTION”
FEEDERS
must have proper
cable groupings.
Each conduit must
have L1, L2, L3, (plus
N or G depending on
requirements)
Example:
Dwelling units with 50 sq.
meters area,
The general lighting load is:
50 sq.mx 24VA/ sq.m.
= 1200 VA
:
KNOWLEDGE
CHECK ✔
What is the
meaning of Demand
Factor?
Demand Factor is defined as the ratio of
maximum demand over connected load
Connected load = 6000VA
Maximum demand = 3000VA
Demand Factor = (3000/6000) = 0.5 or 50%
KNOWLEDGE
CHECK ✔
What is the
advantage of
applying correct
demand factors?
Correct demand factors
allows you to use a smaller
size of cable.
Table 2.20.3.15
Optional Feeder and Service Load Calculations
Heating and Air-Conditioning Load
a) 100% - Air-Conditioning and Cooling
b) 100% - Heat Pump without any Supplementary Electric Heating
c) 100% - Electrical Thermal Storage
d) 100% - Heat Pump Compressor and 65%
- Supplemental Electric Heating
e) 65% - Electric Space Heating less than 4 Controlled Units
f) 40% - Electric Space Heating for 4 or more Controlled Units
Conductor Size and Supports
a) Overhead Spans - Individual conductors shall not be
smaller than the following:
1. For 600 volts, nominal, or less
1. 15m Length - 5.5 mm2 (2.6 mm. dia.) copper and 8.0
mm2
(3.2 mm. dia.) aluminum
2. Longer than 15m - 8.0 mm2 (3.2 mm. dia.) copper and 14
mm2 aluminum
OUTSIDE BRANCH CIRCUITS & FEEDERS
2. For over 600 volts
1. Open Individual Conductors - 14 mm2 copper and 22
mm2 aluminum
2. Conductors in Cable - 8.0 mm2 (3.2 mm. dia.) copper and
14 mm2 aluminum
b) Festoon Lighting - Overhead conductors for festoon lighting
shall not be smaller than 3.5 mm2 unless the conductors
are supported by messenger wirings.
OPEN CONDUCTOR SPACING (CLEARANCES) –
FEEDERS AND CONDUCTORS
Conductor on Poles
- Shall have a separation of not less than 300 mm where not placed on
racks or brackets.
a) Power conductors below communications conductors - 750 mm
b) Power conductors alone or above communications conductors:
1. 300V or less - 600 mm
2. Over 300V- 750 mm
c) Communications conductors below power conductors - Same
OVERHEAD SERVICE
Buildings or Structures requiring Additional Feeders/Service Entrance:
a) Special Conditions - Additional feeder or branch circuits shall be
permitted to the ff.
1. Fire pumps (high pressure) for the building
2. Emergency systems
3. Legally required standby systems
4. Optional standby systems
5. Parallel power production systems
6. Multiple sources of supply for the purpose of enhanced reliability
b) Special Occupancies - By special permission, additional feeder or branch circuit shall be
permitted:
1. Multiple-occupancy buildings where there is no available space for service
equipment accessible to all occupancies.
2. A single building/structure sufficiently large to make two or more supplies necessary.
c) Capacity Requirements - Where the capacity requirements are in excess of 2000
amperes at a supply voltage of 600V or less
d) Different Characteristics - Additional services shall be permitted for different voltages,
frequencies, or phases, or for different uses, such as for different rate schedules.
e) By Identification
Clearance of Service Lateral:
a) 600 mm - directly buried cable
b) 150 mm - RMC or IMC installation
c) 450 mm - PVC approved for direct burial without
concrete encasement
d) 450 mm - other approved raceway for direct burial
KNOWLEDGE
CHECK ✔
What is the general
rule in the installation
of SERVICES?
ARTICLE 2.30 - SERVICES
General Rule:
ONE service to ONE building
ARTICLE 2.30 - SERVICES
SERVICE
The conductors and
equipment for delivering
electric energy from the
serving utility to the wiring
system of the premises
served.
ARTICLE 2.30 - SERVICES
A building must be served by only one
service except the following:
(a) Special Conditions
1. Fire pumps
2. Emergency systems
3. Legally required standby systems
4. Optional standby systems
5. Parallel power production Systems
6. Multiple sources of supply for the
purpose of enhanced reliability
What type
of
conduit
is
in
the
picture?
What is the PEC
KNOWLEDGE
CHECK ✔
COMMENT YOUR ANSWERS
Article number
of FIRE Pumps?
ARTICLE 6.95 FIRE PUMPS
FIRE PUMP CONTROLLER has
NO thermal overload relay.
ARTICLE 2.30 - SERVICES
(b) Special Occupancies
1. Multiple occupancy building Where no available space for
service equipment accessible
to all occupants
ARTICLE 2.30 - SERVICES
(b) Special Occupancies
2. Single building or group of
single detached buildings large
to make two or more service
necessary
ARTICLE 2.30 - SERVICES
(c) Capacity requirements
1. Where the capacity requirements are in excess of 2000 A at a
supply voltage of 1000 volts or less
2. Where the load requirements of a single-phase installation are
greater than the serving agency normally supplies through one
service
ARTICLE 2.30 - SERVICES
(d.) Different characteristics
- For different voltages, frequencies, or phases, or for
different uses, such as for different rate schedules
As defined by PEC:
OVERHEAD – service
conductors between the service
point and the first point of
connection to the service entrance
conductors at the building or other
structure.
As defined by PEC:
UNDERGROUND – service
conductors between the
service point and the first point
of connection to the service
entrance conductors in a
terminal box, or other enclosure
inside or outside the building
wall.
Part 2.30.2 Overhead Service
Conductors
Service Drop - The overhead
conductors between the utility
electric supply system and the
service point.
(B) Vertical Clearance for Overhead
Service Conductors
3000mm -
above finished grade, sidewalks, pedestrians
property where voltages does not exceed 150V.
3700mm – over residential property, driveways, and
commercial areas where voltages does not exceed 300V to ground.
4500mm – for those areas listed in 3700mm classification
where exceed 300V to ground.
4500mm – over public streets, alleys, roads, parking areas
subject to truck traffic, driveways other than
residential, other land such as cultivated, grazing, forest and orchard
7500mm – over tracks of railroads
Part 2.30.3 Underground Service Conductors
SERVICE LATERAL
The underground service
conductors between the
utility electric supply system
and the service point.
Minimum Size
8.0 mm2 Copper or
14.0 mm2 Aluminum or Copper-clad
aluminum
SERVICE CABLE - conductors
made up in the form a cable.
SERVICE CONDUCTORS –
conductors from the service point to
the service disconnecting means.
(F) Drip loops. It shall be formed on
individual conductors.
Part 2.30.5 Service
Equipment
The necessary equipment usually
consisting of a circuit breakers or
switches and fuses and their
accessories, connected to the
load end of service conductors to
a building or other structure.
Intended to constitute the main
control and cutoff the supply.
SERVICE POINT
The point of connection
between the facilities of
the serving utility and the
premises wiring.
DISCONNECTING MEANS
General:
Disconnecting Means shall be
provided to disconnect all conductors
in a building or other structure from the
service – entrance conductors.
2.30.6.3 GROUPING OF
DISCONNECTS
MAXIMUM (SIX) 6 DISCONNECTING MEANS
The general rule is a maximum of six
(6) service disconnecting means can
be installed in one location - without
the need of a main service
disconnecting means ahead of these.
SERVICE
ENTRANCE
INSTALLATION
ARTICLE 3.0 GENERAL REQUIREMENTS FOR WIRING METHODS AND
MATERIALS
TYPES OF WIRING METHODS
1.
2.
3.
4.
5.
6.
Rigid Steel Conduit (RSC)
Intermediate Metallic Conduit (IMC)
Electrical Metallic Tubing (EMT)
Flexible Metallic Conduit (Armored Cable)
PVC Conduit
Flexible Non-Metallic Conduit
Minimum size of Conduit
= 15mm dia.
Maximum size of Conduit
= 100 mm dia.
PEC Table 3.10.2.6(B)(16): Cable Ampacity
Source: PEC 2017, page 174
CONDUCTOR
INSULATION
DESCRIPTION
TEMPERATURE RATING
TW
Moisture Resistant Thermoplastic
60°C
THW
Moisture & Heat Resistant Thermoplastic
75°C
THHN
Thermoplastic High-Heat Resistant NylonCoated
90°C
THWN
Thermoplastic Heat and Water Resistant
75°C
THWN - 2
Thermoplastic Heat and Water Resistant
90°C
Source: PEC 2017, page 174
Source: PEC 2017, page 174
PEC Table 2.40.1.6(A):
Standard Ampere
Ratings for Fuses and
Inverse Time Circuit
Source: PEC 2017, page 86
It is very important in the design
of branch circuit.
A continuous load shall not
exceed 80% of the rating of
the branch circuit.
This means that for a 20A rated
circuit at 80% = 16A would be the
maximum load on the circuit if it
was continuously loaded for 3
hours or more.
PEC Table 3.10.2.6(B)(16):
Ampacity Adjustment
Factor
When there are more than three
current-carrying conductors in a
raceway or cable, the ampacity of
each conductor must be reduced as
indicated in the given table to
compensate for heating effects and
reduced heat dissipation due to
reduced ventilation of individual
conductors.
Sample Computation to determine the
number of Outlets
Number of Outlets = (Nominal V)(CB x 80%)
Volt-Ampere
Number of Outlets = (230V)(20A x 80%)
180VA
Number of Outlets = 20 outlets
Sample Computation to determine the
number of Lamps
Number of lamps = (Nominal V)(CB x 80%)
W
Number of lamps = (230V)(15A x 80%)
100W
Number of Lamps = 27 lamps
Article 3.10 – Conductors for General Wiring
(H) Conductors in Parallel
For FEEDER installation,
We start paralleling at 50mm2
Stranded Conductors
- The conductors installed in raceways, size 8.0 mm and larger shall be
stranded.
2
Conductors in Parallel
- Conductors that are 50 mm sq. and larger (aluminum, copper-clad
aluminum, copper) are permitted to be in parallel. Parallel conductors in
each phase, polarity, neutral/grounded circuit conductors shall comply with
the ff:
1. Be the same length
2. Have the same conductor material
3. Be the same cross sectional area of the conducting material
4. Have the same insulation type
5. Be terminated in the same manner
ARTICLE 2.50
GROUNDING AND BONDING
ARTICLE 2.50 GROUNDING AND BONDING
GROUNDING – connecting to earth
or to some conducting body that
serves in place of the earth.
BONDING – connected to establish
electrical continuity and conductivity.
Section 2.50.1.4 - General Requirements for
Grounding and Bonding
a) Electrical System Grounding - Shall have connections that limit the voltage
imposed by lightning, line surges, or unintentional contact with higher-voltage
lines that will stabilize the voltage to earth.
b) Grounding of Electrical Equipment - Non-current carrying conductive materials,
electrical conductors, or equipment shall be connected to earth so as to limit the
voltage to ground.
c) Bonding of Electrical Equipment - Non-current carrying conductive materials
forming part of such equipment connected together establishing an ―effective
ground-fault current path”.
Connection of Grounding and
Bonding Equipment
a) Connected by exothermic welding,
listed pressure contactors, listed
clamps.
b) Connection devices or fittings that
depend solely on solders shall not be
used.
c) Sheet metal screws shall not be used.
d) Non-conductive coatings shall be
removed such as paint, lacquer, and
enamel.
exothermic welding
PEC Table
2.50.3.17
Grounding Electrode
Conductor
For AlternatingCurrent Systems
SIZING OF MOTOR’S
OVER CURRENT
PROTECTION
KNOWLEDGE
CHECK ✔
COMMENT YOUR ANSWERS
KNOWLEDGE
CHECK ✔
COMMENT YOUR ANSWERS
HOW TO SIZE CB AND
FEEDERS FOR GROUP
OF MOTORS?
TRANSFORMER PROTECTION
PRIMARY PROTECTION
(BASED ON PRIMARY
CURRENT GREATER THAN 9
AMPS)
CB = 125% X Primary Current
ARTICLE 4.40 AIR-CONDITIONING AND
REFRIGERATING EQUIPMENT
Branch Circuit Conductors
Single Motor-Compressor - Compressors shall have a rating of 125%
ampacity of the full-load current.
Wye-Start, Delta-Run Connected Motor-Compressor - Shall have a
rating of 72% ampacity of the full-load rated current.
AIRCONDITIONING
AND
REFRIGERATING
EQUIPMENT
OUR LEARNINGS
- Electrical permit is required before the start of electrical installation
- Building wiring installations must be in compliance with the latest edition of
the Philippine Electrical Code
- Proper clearances must be observed in installing service entrance
- General Rule: One Service is to One Building only
- Size 50mm2 and larger shall be permitted to be connected in parallel.
- Wires and cables must be loaded up to 80% of its ampacity
- Wires and cables must be installed inside a conduit, cable tray or ducting for
protection
OUR LEARNINGS
- Derating factors must be applied on cable ampacity based on wiring methods
and ambient temperature
- Proper color coding must be observed and placed on schedule of loads voltage drop is required on design and must be placed on schedule of loads
- Proper enclosure specifications must be used on the required environment
- Conduits and panel boards must be properly supported and must have
mechanical strength
- Grounding and Bonding is required on electrical installations
KNOWLEDGE
CHECK ✔
COMMENT YOUR ANSWERS
Who initiated
the revisions of
PEC 2009?
REFERENCES
- Philippine Electrical Code (2017 Ed.)
- National Electrical Code Handbook
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JOIN OUR SAFETY
TRAININGS!
JOIN OUR SAFETY TEAM!