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Flashcards in Ch 4 Deck (62)
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1

If there is a neutral-to-case connection on the load side of f the GFCI protection device, the sensors detect the imbalance of the current returning on the _______ and prevents the GFCI device from being turned on

ECG or Equipment Grounding Conductor

2

A current-limiting type fuse is a fuse designed for operations relating to only what?

Short circuits

3

The electrical connection between any two conductors of the electrical system from line-to-line- or from line-to-neutral is called:

Short Circuit

4

What are the two ways in which power is transferred from the utility distribution transformer?

Overhead service drop : underground service lateral

5

The NEC requires a listed AFCI-protection device to be installed to protect the branch-circuit wiring for ______

Dwelling unit bedrooms

6

A GFCI operates on the principle of monitoring the imbalance of ____ between the circuits _____ and _____

Current : Ungrounded : Neutral

7

The opening time for an overcurrent protection device is _____ proportional to the ______ of the current

Inversely : Magnitude

8

A fault must quickly be removed by doing what?

Opening the circuit's overcurrent protection device

9

Would you use a GFCI or AFCI to clear a Ground Fault Parallel Arc?

Either

10

What happens to a fuse when a sustained overload occurs?

A portion of the element is overheated and breaks, which prevents current from going through the fuse.

11

Electromagnetic circuit breakers open on the principle of ________ and _______

Thermal Energy and Electromagnetism

12

Ground-fault protection of equipment is a system intended to provide protection of equipment from damaging ground-fault currents by _____ all ungrounded conductors of the faulted circuit.

Opening

13

What kinds of protection do Instantaneous breakers offer?

Short circuit and ground fault. Not overload

14

This type of circuit breaker depends upon temperature rise in the sensing element for actuation. It has a predetermined calibration temperature.

Thermal Trip Element

15

The purpose of overcurrent protection is to protect equipment and the conductors from what?

Dangerous temperatures

16

What is a more dangerous arc fault, parallel or series?

Parallel

17

Typically, when a GFCI protection device fails, the switching contacts remain closed and the device will continue to provide power _____ GFCI protection

Without

18

What does "AIR" stand for?

Ampere Interrupting Rating

19

The most effective way to reduce conductor voltage drop and power loss is to:

Lower the current flowing through the conductors by increasing the circuit voltage

20

What are the two ways parallel arcing faults occur?

Short circuit or ground fault

21

Typically, circuit breakers and fuses are designed to open or clear short-circuit and ground-circuit fault current in how many cycles?

Less than 1

22

The electrical connection between any ungrounded conductors of the electrical system and any non-current-carrying metal object is called:

Ground Fault

23

Typically, a steam turbine is directly connected to an electrical generator, which produces _______ kV, three-phase power

13.80

24

What are the two most common types of overcurrent protection?

Fuses and Circuit Breakers

25

A series arc-fault current is ____ limited; the arc's current cannot be greater than the load current the conductor serves.

Load

26

What temperature do electric arcs operate at?

Between 5,000 and 15,000 F

27

Conductor power losses are directly proportional to the length of the conductor and the ______ of the current

Square

28

Various distribution feeders transfer the primary distribution voltage from step-down substations to ________ ________

Distribution transformers

29

Metal parts of premises wiring are bonded to a low-impedance path designed and intended to carry fault current from _______ to _______

The point of a line-case fault on a wiring system : the neutral conductor at the electrical supply source

30

This type of breaker operates on the principle that as the current increases, the time it takes for the device to open decreases

Inverse time breaker