Electrical: NEC Level 4, Entire Second Semester

Heating cable for snow-melting is typically installed in a serpentine pattern with loops spaced at _____.

1 foot (30 cm) on center

How far below the finished surface should snow-melting and anti-icing systems be installed?

1-1/2 to 2 inches (4 to 5 cm)

The power rating of a voltage regulator should be based on the maximum power outputcapability of the tester multiplied by a factor of about _____.

1.3

In general, how much endplay should ball-bearing motors have?

1/32" to 1/16"

For floating structures that are installed to rise and fall in response to the water level without lateral movement, the electrical datum plane is 30" above the point at which the floating structure touches the water and a minimum of how many inches above the deck level?

12"

Which of the following is the recommended abrasive cloth used to clean cable during a splice?

120-grit abrasive cloth

For outdoor electric de-icing installations, branch circuits and overcurrent devices supplying the equipment shall be sized at not less than what percentage of the total heater load?

125%

Wall-mounted underwater luminaires must be installed so that the top of the lens is at least how many inches below the water level?

18

The recommended minimum polarization index for an AC motor is _____.

2.0

The polarization index is commonly used for motors that exceed _____.

200hp

The maximum branch circuit rating for footlights, border lights, and proscenium sidelights when using standard lampholders is _____.

20A

The main overcurrent protective device that feeds a marina must have ground-fault protection of no more than _____.

30mA

NEMA's usual service conditions include a frequency variation of not more than what percentage of the nameplate frequency?

5%

Any fixed or stationary electric sign that is installed within a fountain must be at least how many feet inside the fountain, as measured from the outside edge of the fountain?

5'

Unless there is a permanent barrier installed between the receptacle and a storable pool, a receptacle cannot be located any closer to a storable pool than _____.

6 feet

Proof tests are made at what percentage of the original factory voltage?

60%

Heater elements on electric pool-water heaters must be subdivided into loads not exceeding 48A each and be protected by overcurrent protective devices not greater than _____.

60A

According to the NEC®, cables on agricultural buildings must be secured within how many inches of any box, cabinet, or fitting to which they connect?

8"

Acceptance testing calls for a maximum value of what percentage of the factory test voltage?

80%

How are future service connections handled when installing heat tracing on domestic hot-water supply systems?

A service loop of extra heating cable is provided at connections.

Which of these devices can retain a high-voltage charge after power has been removed?

Capacitors used in motor circuits

Which of the following termination classes is the only one that provides a seal against external elements?

Class 1

Which of the following is the best instrument for testing for a grounded coil?

Continuity tester

To finish a splice and ensure complete protection, it should be covered with how many layers of vinyl electrical tape?

Four

Which of the following principles states that heat is created in one place and carried to another by means of air or water?

Heat-transfer principle

When conducted properly, which of the following will indicate faults such as cracks, discontinuity, thin spots, and faulty terminations?

Hi-pot test

Thermostats with bimetal sensing elements typically use a combination of copper or brass and _____.

Invar®

Which of the following is an approved wiring method allowed in fire-rated construction?

Metal-clad cable

When refrigeration compressors are driven by conventional (nonhermetic) motors, the motors and controls are subject to the requirements in _____.

NEC Article 430

In agricultural buildings that require equipotential planes, the equipotential plane must be bonded to the grounding system with a bare or insulated solid copper wire no smaller than _____.

No 8 AWG

Assuming that a worker is qualified to do a job and is otherwise an effective craft professional, which of the following could be a reason for turnover for such a worker?

Not being given any opportunity for advancement

The thermostat terminal that connects to the reversing valve control in a heat pump is _____.

O

The form used to report work-related injuries and illnesses is _____.

OSHA Form 300

Materials typically used for cable jackets include neoprene, lead, and _____.

PVC

Which of the following may be used to detect unusual bearing noise during rundown when the motor is powered down?

Stethoscope

Which of the following statements regarding the consequences of willful safety violations is true?

Superintendents and crew leaders can be held financially and criminally liable.

Which of the following describes a finned air-over motor that powers and is cooled by the slipstream from a large fan?

TEAO motor

Which of the following is used to check the rotating speeds of motors?

Tachometer

Which of the following occurs as soon as a heating thermostat is closed?

The inducer fan starts.

Which of the following is an NEC Article 427 requirement for the installation of electrical heat tracing cables on pipelines and vessels in unclassified areas?

The presence of electric heating equipment must be identified using permanent caution signs or markings at the specified intervals.

Which of the following is an example of an external analog device?

Thermistors

Which of the following is true with regard to fixed stage switchboards?

They are permitted to supply both stage and non-stage equipment.

Which of the following is not a factor in determining the appropriate type of heating cable for a pipe heat-tracing application?

Type of process fluid

On a roof de-icing system, secure cables to each other using _____.

UV-resistant cable ties

Which of the following best describes continuity monitoring?

Verifies that voltage is present at the end termination of a heat-tracing cable run

A knee in a leakage current-versus-voltage plot indicates a _____.

breakdown current

To eliminate air voids when preparing a splice, pencil the insulation and then _____.

buff it using abrasive cloth

Two methods used to provide stress control for medium-voltage cable terminations are geometric and _____.

capacitive

If a mercury thermostat seems out of adjustment, the first thing to do is _____.

check for accurate leveling

The component labeled 2 in Figure 2 is a(n) _____.

controller

A suitable connector for medium-voltage cable splices is a compression or _____.

crimp type

Automatic changeover thermostats have a minimum interlock setting, also known as the _____.

deadband

Multi-stage thermostats provide energy savings by cycling on stages of heating or cooling based on _____.

demand

The temperature at which a liquid first condenses when vapor is cooled is known as the _____.

dew point

As the temperature surrounding a self-regulating heating cable decreases, the _____.

electrical resistance decreases

Absorption current consists of polarization current and _____.

electron drift

The component labeled 7 in the figure above is a(n) _____.

end seal

NEC Section 555.19(A)(1) states that proper shore power receptacles for marinas shall be _____.

equipped with strain relief for the cable when it is plugged in

The loss of a single phase of a polyphase motor can cause _____.

failure of the remaining phase windings

Electric heat tracing of pipe is done for freeze protection and _____.

for temperature maintenance of the process fluids

A quick test that can be made to determine if an installation is good is known as a(n) _____.

go/no-go test

Splices made with conductors of different sizes can be most easily accommodated using a(n)_____.

heat-shrink kit

OSHA regulations require that employers _____.

identify and keep records of safety hazards

If a lockout relay becomes defective, it should be replaced with an exact duplicate, sometimes called a(n) _____.

impedance relay

Companies traditionally offer craft-professional training _____.

in a hands-on setting, where they learn from an experienced worker

In both new and retrofit construction situations, a hydromassage or whirlpool tub must have power supplied by a(n) _____.

individual branch circuit

The useful life of a squirrel cage induction motor depends largely upon the condition of its _____.

insulation

A conventional thermostat should not be thrown into the regular trash because it _____.

may contain mercury

Connecting a 120V heating cable to a 240V circuit will _____.

melt the cable

Which of the following factors affects the frequency and thoroughness of motor maintenance and testing?

nature of service

A freezestat is a _____.

normally closed bimetal switch

To extend the melting time of a snow-melting system, controllers can use a(n) _____.

off-delay timing function

If two separate receptacles having different voltages and amperage ratings are installed in a single boat slip, the total load calculation must include _____.

only the receptacle with the higher VA demand

Self-regulating cables are referred to as _____.

parallel resistance heating cables

Insured costs for occupational injuries or deaths include _____.

pensions for dependents

In an air-to-air heat pump, defrost is accomplished by _____.

placing the unit in the cooling mode

When installing heating cable, fasten the cable to the pipes using fiberglass tape or _____.

plastic cable ties

The component labeled 1 in the figure above is a(n) _____.

power connection

The purpose of the defrost cycle in a heat pump is to _____.

prevent ice buildup on the outdoor coil

An autotransformer is one of the methods used to _____.

reduce startup current

NEC Article 440, Part V covers _____.

requirements for motor compressor controllers

The frequency of motor lubrication depends on the type of bearing, motor application, and _____.

service environment

The main way for crew leaders to encourage crew safety is to _____.

set a good example for them

A carnival ride properly powered through a disconnect switch within 6 feet (1.8 m) of the operator can also be opened from the operator's console using a _____.

shunt trip

Bearing misalignment within a motor can result when one or two of the mounting feet of a motor are spaced away from an uneven mounting surface and are then anchored down against the surface without proper shimming. This condition is referred to as _____.

soft foot

The most effective approach to the inability of two employees to work together would be to _____.

speak directly to the individuals and to others to learn what the problems are

According to NEC Article 424, embedded floor heating cable may be spliced with _____.

splices identified in the manufacturer's instructions

When two or more wired partitions are electrically connected together, the cord must be terminated at an attachment plug-and-cord connector equipped with a _____.

strain relief device

The tubing that carries heat-laden refrigerant gas from the evaporator to the compressor is known as the _____.

suction line

The component labeled 6 in the figure above is a(n) _____.

tee kit

Which of the following qualifies as an assembly occupancy?

the auditorium of a civic center

Footlights in a stage that are designed to disappear into a storage recess when not in use must be designed so that _____.

the power supply is automatically disconnected when the lights are retracted

When delegating, the crew leader should make sure the crew member understands what to do and _____.

their level of responsibility

A device that uses dissimilar metals to control electron flow is known as a(n) _____.

thermocouple

Individual freestanding partitions or groups of them secured together can be powered using a single flexible cord, provided that there are no more than _____.

thirteen 125V, 15A receptacles

To increase furnace efficiency, the startup of the furnace blower is delayed using a _____.

time delay relay

Prohibitions on the abuse of drugs apply _____.

to any inappropriate use of drugs or other substances that cause impairment

In temporary installations, single insulated feeder and branch circuit conductors may be used to supply power for temporary testing, emergencies, experiments, and developmental work where accessible _____.

to qualified persons only

Insulation must protect from flashover damage and _____.

tracking damage

To transmit information, systems using power-line carrier technology make use of _____.

wiring