Lesson 4: NEC Chapter 4: Using the Electricity

High-voltage is defined as a potential difference of more than ? , nominal.

1000V 490.2

An embedded deicing unit of the resistance type shall not exceed ? of heated area.

120 watts/ft2 426.20(A)

How many parts exist in Article 410?

17

Low-voltage lighting systems shall not be supplied by a branch circuit rated greater than ? .

20A 411.8

The voltage of a storage battery having 12 lead-acid type cells connected in series will be ? .

24V

The full-load current of a 25-horsepower, 480-volt, 3-phase, squirrel-cage induction motor is ? .

34A Table 430.250

The maximum distance between two pieces of electrical equipment that are considered to be in sight of each other is ? .

50' 100

When a capacitor that operates at 1,000 volts or less is removed from an energized circuit, the charge on the capacitor shall be drained to ? or less within ? .

50V / 1 minute 460.6 (A)

The ampacity of 18 AWG fixture wire is ? .

6A Table 402.5

A luminaire measuring 12 inches in diameter and weighing six pounds is supported by a screwshell of a lampholder.

Acceptable 410.30(A)

Which of the following conditions must be met before two or more 120-volt, one-horsepower or less motors are permitted to be installed on the same 20-ampere branch circuit?

Both B & A 430.53 (A)

The means of emergency shutdown used for a generator's prime mover shall comply with which of the following provisions?

Both B and C 445.18(B)

What type(s) of phase converters are covered by the NEC?

Both B and C 455.2

Which of the following locations would not require a 15-ampere, 125-volt nonlocking-type receptacle to be listed tamper resistant?

Conference room of a business office 406.12

Fixed, industrial-process heating equipment and motors shall be considered ? .

Continuous loads 425.4(B)

Industrial control-panel enclosures shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices or other equipment, unless the conductors fill less than 50% of the cross-sectional area of the wiring space.

False 409.104(A)

Under no condition is the attachment plug cap for a 240-volt room air conditioner in a residential occupancy permitted to be used as the disconnecting means for the room air conditioner.

False 440.63

Each autotransformer 1,000 volts, nominal, or less shall be protected by an individual overcurrent device installed with each ungrounded input conductor and installed in series with the winding common to both the primary and secondary (shunt winding) of an autotransformer.

False 450.4(A)

? duty is defined as intermittent operation in which the load conditions are regularly recurrent.

Periodic 100

Insulated conductors used within a switchboard or switchgear shall be listed, flame retardant, and voltage rated.

True 408.19

A panelboard containing a 4-wire, delta-connected system shall be permanently field marked to identify the voltage to ground on the high leg.

True 408.3(F)(1)

In a residential occupancy, two fixed electric space-heating units are permitted to be supplied by a 30-ampere branch circuit.

True 424.4(A)

When pipelines are electrically heated, the pipelines must be identified by caution signs or markings.

True 427.13

An overhead projector is mounted below a suspended ceiling of a classroom. The power supply cord serving the projector is run through a hole in the suspended ceiling and is plugged into a receptacle outlet above the ceiling.

Violation 400.12(2)

Three-way switches are installed with the grounded conductor being switched in order to control a lighting fixture from two locations.

Violation 404.2(A)

A cord-and-plug-connected kitchen waste disposer is installed below the kitchen sink, with the receptacle accessible. A four-foot length of Type SJ cord not subject to physical damage is used.

Violation 422.16(B)(1)(1)

A 100-ampere resistor bank is connected to a controller with conductor insulation rated 75°C. The resistors are not used in conjunction with the starting current of a motor.

Violation 470.4

Type SJ flexible cord is recognized ? .

as a hard usage cord Table 400.4

A panelboard is designed to be placed in a ? .

cabinet 408.38

A single-throw knife switch shall not be installed in a manner that will ? .

tend to close the switch with gravity 404.6(A)