Deck 13: The Electric Service and Grounding

Question 1

GFPE monitors are designed to sense ____ faults only.

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

Answer 1

B

Question 2

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

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

Answer 2

A

Question 3

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

Answer 3

B

Question 4

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 5

What are the advantages of proper bonding and grounding?

Question 6

____ 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 7

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 8

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 9

When is ground-fault protection of equipment not required?

Question 10

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 11

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

Question 12

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

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

Question 13

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

Question 14

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

Question 15

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

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

Question 16

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

Question 17

What is an effective ground-fault current path?

Question 18

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 19

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 20

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