Code Standards Lesson 3

NEC 110.12(B) warns against the possible damage to electrical equipment due to paint, plaster, cleaners, abrasives, or corrosive residues.

Select one:

True

False

When the term voltage is used throughout the Code, it means the voltage at which the

circuit ? .

a. is approved

b. is protected from overcurrent

c. is rated

d. operates

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One of the ways that conductor sizes are expressed in the NEC is by using ? .

a. American Wire Gage or circular-mils

b. resistance or Ω

c. square-mils

d. color of conductor insulation

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Electrical equipment shall be installed in a neat and workmanlike manner.

a. True

b. False

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A piece of electrical equipment with a UL label on it shall be installed in accordance with any ? included in the listing or labeling.

a. field marks

b. hardware

c. instructions

d. lists

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When the word conductor is not identified with a material, it indicates the use of ? .

a. aluminum

b. aluminum or copper-clad aluminum

c. copper

d. copper, aluminum, or copper-clad aluminum

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Manufacturers are required to mark their products so the manufacturer can be identified.

The marking may consist of manufacturer’s ? .

a. information about the material the product is made of

b. name and information about the material the product is made of

c. trademark

d. trademark or name

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Which of the following is/are required relating to the general requirement for

identification of a disconnecting means that is not located and arranged so that its

purpose is evident?

a.Each disconnecting means must be legibly marked to indicate its purpose.

b.The marking must be of sufficient durability to withstand the environment involved.

c.Both a. and b.

d.Neither a. nor b.

Unused openings in boxes are generally required to be ? .

a. approved

b. closed

c. identified

d. used

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The width of the working space in front of electrical equipment 1,000 volts or less shall ? .

I. allow at least a 90° opening of equipment doors

II. allow at least a 180° opening of all equipment doors

III. not be less than 30" wide or the width of the equipment (whichever is greater)

IV. not be less than 36" wide or the width of the equipment (whichever is greater)

a. I. only

b. I. and III.

c. II. and IV.

d. III. only

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NEC 110.14(B) requires a splice in a conductor to be covered with an insulation ? .

a.as thick as the conductor’s insulation

b.equivalent to the conductor’s insulation or with an identified insulation device

c.of the same material as the conductor

d.thicker than the conductor's insulation

Which statement(s) is/are true according to NEC 110.14(A) for terminals?

a.Terminals for more than one conductor shall be so identified.

b.Terminals used to connect aluminum conductors shall be so identified.

c.Both a. and b.

d.Neither a. nor b.

Which statement(s) is/are true according to NEC 110.13(A) and (B)?

a.Electrical equipment provided with ventilating openings shall be installed so that the

ventilated openings are not obstructed.

b.Electrical equipment shall be firmly secured to the surface on which it is mounted.

c.Both a. and b.

d.Neither a. nor b.

The temperature rating associated with the ampacity of a conductor shall be so selected and coordinated as to not exceed the lowest temperature rating of any connected ? .

a. conductor

b. termination

c. device

d. all of the above

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On a 4-wire, delta-connected system where the midpoint of one phase winding is

grounded to supply lighting and similar loads, the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is ? in color or by other effective means.

a. green

b. light blue

c. orange

d. red

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Electrical equipment such as switchboards, switchgear, panelboards, industrial control

panels, meter socket enclosures, and motor control centers, that is in other than dwelling units, and is likely to require examination, adjustment, servicing, or maintenance while energized, shall be ? to warn qualified persons of potential electric arc flash hazards.

a. engraved

b. field or factory marked

c. identified

d. marked

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Each disconnecting means shall be legibly ? to indicate its purpose unless located and arranged so the purpose is evident.

a. engraved

b. field marked

c. identified

d. marked

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Why does the NEC specify that sufficient access and working space shall be provided and maintained about all electric equipment?

a. To permit cleaning crews safe access around the electrical equipment

b. To permit ready and safe operation and maintenance of such equipment

c. To permit safe operation at 1,000 V and above

d. To permit safe operation at 1,000 V, nominal, or less

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For equipment rated ? or more and over six feet wide, that contains overcurrent

devices, switching devices, or control devices, there shall generally be one entrance to and egress from the required working space not less than 24 inches wide and 6 / feet high at each end of the working space.

a. 200 A

b. 600 A

c. 1,200 A

d. 1,600 A

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All switchboards, switchgear, panelboards, and motor control centers shall generally be located in ? spaces and protected from damage.

a. accessible

b. dedicated

c. guarded

d. open

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For electrical equipment rated 1,000 volts, nominal or less, the space equal to the width and depth of the equipment and extending from the floor to a height of ? above the

equipment or to the structural ceiling, whichever is lower, shall generally be dedicated to the electrical installation.

a. 6'

b. 10'

c. 25'

d. 30'

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In general, the Code requires that live parts of electrical equipment operating at ? to

1,000 volts, nominal, shall be guarded against accidental contact.

a. 24 V

b. 50 V

c. 120 V

d. 600 V

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Service equipment at other than dwelling units shall be legibly marked in the field with the available fault current. The field marking(s) shall include ? and be of sufficient durability to withstand the environment involved.

a. the date the calculation was performed

b. the date the fault-current calculation was performed

c. the name of the engineer or engineering firm that performed the calculation

d. the name of the individual that performed the calculation

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