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
