Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Single-Phase, Three-phase, Circuit Protection > Powerpoint - Circuit Protection > Flashcards

Powerpoint - Circuit Protection Flashcards

1
Q

A _____ is designed to be the weakest link in an electrical circuit

A

fuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fuses contain a metal strip of alloy that melts before the ________ do

A

conductors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Dual element fuses (time delay) operates with a built in time delay to allow for ________ overloads such as motor starting

A

temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Dual element fuses have _____ fuse elements, one for overloads and one for short circuits

A

two

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Overcurrent protection:

  • a current that exceeds some predetermined value that includes short circuits and ________
A

overloads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A _____ circuit is a current larger than normal which flows outside its normal path

A

short

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

An _______ is a current larger than normal but still flows within its normal path, normal range, within 3-6 times the FLA

A

overload

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Overload protection devices must respond rather ______

A

slow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Overcurrent and overload devices must be wired in ______ with the cat being protected

A

series

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name two forms of overcurrent protection

A

fuses, circuit breakers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

higher voltage means a _______ fuse

A

longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

__________ current rating is the maximum amount of current the fuse is designed to carry for long periods of time

A

continuous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Interrupting capacity is the max ______ circuit current an overcurrent device can safely interrupt

A

short

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Plug fuse colour coding

Blue __A
Pink __A
Red__A
Green __A

A

Blue - 15A
Pink - 20A
Red - 25A
Green - 30A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ferrule type cartridge fuses are used up to ___AMps

A

60 amps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Knife type fuses are used from 60A- ____A

A

60-600

17
Q

Standard code fuses have an interrupting capacity of _______amps

A

10,000amps

18
Q

High rupturing capacity fuses (HRC) have an interrupting capacity of _________

A

100,00 amps

19
Q

Two forms of HRC fuses:

Form 1: provides both short circuit and ________ protection

Form 2: provides for short circuit protection _____

A

form 1: overload

form 2: only

20
Q

The CEC defines a _________ as an electromechanical device designed to open a current carrying circuit under both overload and short cct conditions

A

circuit breaker

21
Q

CEC also requires circuit breakers be ___ free

A

trip

22
Q

Name three types of circuit breakers:

A

thermal

magnetic

thermal magnetic

solid state

23
Q

thermal circuit breakers are connected in ______ with the load it controls and its function is to protect the circuit against overloads

A

series

24
Q

Magnetic breakers have a magnetic connected in series with contacts and it protects against short _____

A

circuits

25
Q

The thermal magnetic breaker has a thermal element and electromagnetic in series with the contacts, it protects against both _______ and _________

A

short circuits and overloads

26
Q

GFCI detect a difference between the current flowing in the conductor to the load, and the current returning to the ______

A

device

27
Q

Relays are normally used to carry less than ___A of rated current flow through the contacts

A

20A

28
Q

Contactors are larger versions of a relay and normally carries between 20-60a through the _______

A

contacts

29
Q

Motor starters have built in means of ________ protection

A

overload

30
Q

Contactors and motor starts can control inductive and ________ loads

A

resistive

31
Q

Overload protection in a motor starter is rated at not more than ____% of the motor RLA

A

140%

32
Q

(motor starter) For over current protection with fuses on single phase or three phase it is required that all hot legs be ________

A

protected

33
Q

(motor starter) For overload protection only the two hot legs must be ______

A

protected

34
Q

Motor starter contacts are normally made of ______ or cadmium

A

silver

35
Q

Overload protection on motor starters may be magnetic, thermal or ______-________

A

thermal - magnetic

Single-Phase, Three-phase, Circuit Protection (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions