J MCC Motor Control Circuits Flashcards Preview

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Flashcards in J MCC Motor Control Circuits Deck (21)
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1

Horsepower is defined as

Moving a certain weight over a certain distance in one minute (e.g, 33,000 pounds lifted 1 foot in 1 minute equals 1hp)

2

It takes 746W of electric power to equal

1 HP

3

A over current protection device with a link that melts and opens the circuit on an over current condition

Fuse

4

A connection is made when 3 ends of separate phases are connected together creating a common wire

Wye

5

A...... is a metal enclosed distribution system of..... available in prefabricated sections

Busways, Busbars

6

Contain over current protection devices for lighting appliances and power distribution centers

Panel Boards

7

Receives incoming power and delivers it to control circuit and to loads

Motor Control center

8

Device that protects transformers and other electrical equipment from power surges caused by lightning

Lightning arrestor

9

Used first to stop and start motors...before magnetic motor starters

Knife switches

10

Two contractors that are connected in such a way that both sets of contacts cannot be closed at one time

Mechanical interlock contractors

11

A device used only periodically to remove electrical circuits from there supply source

Disconnect

12

Contractors with added overload protection device

Manual starter

13

An overload relay which resets automatically

Bimetallic relay

14

Solder-pot relay aka

Melting-alloy overload relay

15

When a device receives too little voltage to work and requires a manual restart

Low- voltage protection

16

When too much electricity is in the circui,t this happens, to save the wires, devices and limit the damage

Overload release
needs manual restart and wait for circuit to cool down

17

Rotary- action selector switch
Manually controls speed
changes the direction of motors

Drum Switch
(does not provide overload protection)

18

ON/Off With thermal overload is a ____ switch

Toggle switch (operates on a solder-pot principle)

19

Motors and circuits involves ____& ____ hazards

Mechanical and electrical hazards

20

Heather element and N.C. Contacts are wired in series with the line to the motor is what principle

Solder-pot principal

21

A device that operates on the reduction or failure of voltage, but not prevent a re-establishment of voltage

Low-voltage release