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Flashcards in Review Deck (18)
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1

Define circuit breakers

A device designed to open and close by non-automatic means, and to open the circuit automatically on a pre-determined condition

2

What is another name for a pilot light that comes in different colors?

Indicator lamp

3

In the case of magnetically opened contacts, the normal state occurs when the operating coil is ______.

deenergized

4

A common use of a latching relay is in the rotor circuit of a wound rotor motor.

False

5

OSHA does not require that a person whose work requires them to work on energized equipment to have specialized training.

False

6

Name three types of fuses

1. Standard one time fuse
2. Time delay or dual element
3. Current limiting

7

Name three types of circuit breakers

1. Non automatic
2. Magnetic
3. Thermal
4. Thermal-magnetic
5. Ratings molded case

8

What does ambient temperature affect?

the trip setting of the device

9

List three types of operators in oil tight units

1. Standard flush head
2. Extended head
3. Mushroom head
4. Key lock

10

Why is a low voltage indicating light bulb preferred?

due to vibration normally present in machines

11

What is the difference between a drum switch and a selector switch?

The drum switch is bigger in size, number of contacts and positions.

12

What is basically a communication carrier that is also used as a power amplifier?

A relay

13

The ______ is really nothing but a memory relay.

latching relay

14

The ______ has a distinct advantage when changing relays without disturbing the circuit wiring.

plug-in relay

15

What is generally constructed in a similar fashion to a relay?

a contactor

16

The coil of the contactor is generally what voltage?

120 V

17

What is the difference between a contactor and a motor starter?

A starter has a separate overload protection provided.

18

What device has a timing function after the timer has been energized or de-energized?

A time delay relay