Code Standards Lesson 6

A conductor having no covering or electrical insulation whatsoever is defined in the NEC

as a(n) ? conductor.

a.aluminum

b.bare

c.copper

d.grounded

A conductor meeting the definition of a covered conductor is not considered an insulated conductor.

Select one:

True

False

In order for a material to be recognized as an insulation, it must ? .

a.be made of material recognized as insulation by the Code

b.have the proper thickness as specified by the Code

c.both a. and b.

d.neither a. nor b.

Insulated conductors installed in a conduit, in a concrete slab, in contact with the earth,

would be considered to be installed in a ? .

a.damp location

b.dry location

c.semi-dry location

d.wet location

Electrical conductors installed in the office area of a building would be considered

located in a ? .

a.damp location

b.dry location

c.hazardous location

d.wet location

Electrical conductors installed in a cold storage warehouse could be considered located in a ? .

a.damp location

b.dry location

c.semi-dry location

d.wet location

Electrical conductors directly buried in the earth would be considered located in ? .

a.damp location

b.dry location

c.semi-dry location

d.wet location

One of the primary functions of insulation is to ? .

a.contain the heat

b.contain the voltage

c.make the conductors easier to pull

d.protect the resistance of the conductor

High heat will have a deteriorating effect on a conductor's insulation.

Select one:

True

False

Which of the following is/are characteristic(s) of good insulation?

a.Ability to withstand heat

b.Long life

c.Mechanical flexibility

d.Resistance to moisture

e.All of the above

Informational note guidance advises that thermoplastic insulation may stiffen at

temperatures lower than 14°F.

Select one:

True

False

Which of the listed heat sources does not normally contribute to the deteriorating of the conductor's insulation?

a.Adjacent load-carrying conductors

b.Ambient temperature

c.Heat from containment

d.Heat generated by current flow

e.All of the above contribute to the deteriorating of the conductor insulation

When current flows through a conductor, ?

a.heat will be generated within the conductor

b.the conductor will become hardened

c.the conductor will increase in size

d.the insulation will cool the conductor

NEC Table 310.4(A) and the Reference may be used for the following question.

Which statement(s) is/are true concerning the conductor insulation?

a.The insulation will have a temperature rating.

b.The insulation will have a voltage rating.

c.Both a. and b.

d.Neither a. nor b.

NEC Table 310.4(A) and the Reference may be used for the following question.

NEC Table 310.4(A) covers conductor ? and ? rated 600 volts.

a.applications / insulations

b.construction / application

c.construction / insulations

d.none of the above

NEC Table 310.4(A) and the Reference may be used for the following question.

The Code trade name for type THHN insulation is heat-resistant thermoplastic.

Select one:

True

False

Use NEC Table 310.4(A) and the Reference for the following question.

Match the following letter to the insulation characteristic or material for which it stands.

H

R

T

X

-possible answers-

Thermoplastic

Cross-link poly

Rubber covering

Heat Resistant

NEC Table 310.4(A) and the Reference may be used for the following question.

Which statement(s) is/are true when applied to conductor coverings?

a.Conductor covering materials are considered to have the same insulating properties as conductor insulating materials.

b.When the letter “L” is used, it indicates a linen covering over the insulation.

c.Both a. and b.

d.Neither a. nor b.

NEC Table 310.4(A) and the Reference may be used for the following question.

Type “MI” insulation is identified as ? .

a.magnetic insulation

b.metallic insulation

c.mineral insulation

d.none of the above

NEC Table 310.4(A) and the Reference may be used for the following question.

The Centigrade and Fahrenheit temperature ratings of THW conductor insulations used in a dry location are ? .

a.30°C (86°F)

b.60°C (140°F)

c.75°C (167°F)

d.90°C (194°F)

NEC Table 310.4(A) and the Reference may be used for the following question.

The Centigrade and Fahrenheit temperature rating of THHW conductor insulation used in a dry location is ? .

a.30°C (86°F)

b.60°C (140°F)

c.75°C (167°F)

d.90°C (194°F)

NEC Table 310.4(A) and the Reference may be used for the following question.

The maximum operating temperature of type USE insulation is ? .

a.30°C (86°F)

b.60°C (140°F)

c.75°C (167°F)

d.90°C (194°F)

NEC Table 310.4(A) and the Reference may be used for the following question.

Match each of the letters of Type THWN insulation with its insulation material or

characteristic.

T

H

W

N

-possible answers-

Nylon covering

Heat resistant

Thermoplastic

Wet locations

NEC Table 310.4(A) and the Reference may be used for the following question.

The thickness of the insulation on a conductor is measured in ? .

a.centimeters

b.inches

c.meters

d.mils

When conductors are to be spliced or terminated in a junction box, Section 300.14

generally requires at least ? of free conductor to be left available for splicing or

terminating.

a.4"

b.6"

c.8"

d.10"

Which statement(s) is/are true when applying Section 310.8 for marking electrical

conductors?

a.The maximum rated voltage for which the conductor is listed shall be durably marked on the surface of the conductor.

b.The size of the conductor shall be durably marked on the surface of the conductor.

c.Both a. and b.

d.Neither a. nor b.