Deck 14: Lamps and Ballasts for Lighting

Question 1

The ____ is defined in NEC Article 100 as the point of connection between the facilities of the serving utility and the premises wiring .

A)open delta
B)singular phase
C)service point
D)transformer

Answer 1

C

Question 2

NEC 250.64(C)states that grounding electrode conductors generally are not permitted to be ____.

A)stranded
B)spliced
C)covered
D)integrated

Answer 2

B

Question 3

What liquid was used in the past in liquid-filled transformers? Is it still in use?

Answer 3

Years ago, the most widely used liquid was askarel, a mixture of polychlorinated-biphenyls (PCBs)and trichlorobenzene-found to be highly toxic. Askarel was good for indoor installations because it was not flammable, it had excellent insulating characteristics and cooling features, and the cost was attractive. The Toxic Substance Control Act of 1976 and further regulations set forth by the Environmental Protection Agency (EPA)pretty much made askarel a thing of the past. These older transformers have either been replaced over the years or have had the askarel (the PCB liquid)removed and then replaced with noncontaminating liquids.

Question 4

What are the advantages of proper bonding and grounding?

Question 5

The two basic methods of metering are primary high-voltage metering and ____.

A)intermediate-voltage metering
B)pulsed metering
C)secondary high-voltage metering
D)low-voltage metering

Question 6

When and how does primary high-voltage metering take place?

Question 7

Utilities make up the connections on the line side and load side of their transformers according to the ____ requirements.

A)NFPA
B)NESC
C)TEK
D)UL

Question 8

Dry-type transformers are widely used because they are ____ than comparably rated liquid-filled transformers.

A)better dielectrics
B)better conductors
C)heavier in weight
D)lighter in weight

Question 9

When is ground-fault protection of equipment not required?

Question 10

In this country and throughout the world, ____ is(are)the common reference point for all electrical systems.

A)the atmosphere
B)a standard metal plate
C)the earth
D)individual building walls

Question 11

____ occur when an ungrounded "hot" conductor comes in contact with a grounded surface or grounded equipment.

A)Circuit breakings
B)Ground faults
C)Open circuits
D)Arc blasts

Question 12

The temperatures of an electrical arc, such as might occur on a 480/277-volt solidly grounded, wye-connected system, are ____.

A)at the boiling point of water
B)not hot enough to melt metals
C)safe for humans
D)hotter than the surface of the sun

Question 13

The ____ connection scheme has the advantage of being able to provide either 3-phase or 3-phase and single-phase power using only two transformers.

A)three-wire delta
B)4-wire wye
C)open delta
D)single-phase

Question 14

GFPE monitors are designed to sense ____ faults only.

A)phase-to-phase
B)phase-to-ground
C)3-phase
D)phase-to-neutral

Question 15

NEC 110.16 has a requirement for placing a notice on certain equipment to warn qualified persons of the serious hazard of ____ flash events.

A)arc
B)current
C)lightning
D)voltage

Question 16

GFCI protection can be attained using GFCI circuit breakers or GFCI ____.

A)switchboards
B)monitors
C)receptacles
D)panelboards

Question 17

NEC 230.71 permits not more than ____ disconnects to serve as the building disconnecting means.

A)6
B)10
C)14
D)18

Question 18

What is an effective ground-fault current path?

Question 19

The lower (or shorter)the ____ of the grounding path, the greater the ground-fault current.

A)length
B)elevation
C)magnetic permeability
D)impedance

Question 20

Today's liquid-filled transformers have their windings immersed in highly refined mineral oil (combustible), silicone fluid, edible seed oil-based dielectric coolant, or other acceptable nontoxic liquids that have ____ properties.

A)high dielectric
B)high conductance
C)low dielectric
D)photoactive