Fuses and circuit breakers

Question 1

Air circuit breakers are commonly used in which of the following situation:

– low voltage applications
– high current or voltage service application
– extra high voltage application with standard ratings up to 765,000 V
– applications up to 750,000 kVA at 13,800 v

Answer 1

Low voltage application (under 600 V)

Question 2

Circuit breakers carry a current rating indicating how much current they will carry continuously and circuit breakers are designed to open___.

Answer 2

At a value of current over this rated current

Question 3

How are circuit breakers rated?

Answer 3

By their interrupting do Ute and how long it takes to interrupt the cycle

Question 4

Which of the following is rated up to 60 A at 125 V, 250 V, and 600 V?

– non-contact fuse
– contact fuse
– knife blade fuse
– ferrule fuse

Answer 4

Ferrule fuse

Question 5

Which of the following is NOT a type of commonly used circuit breaker?

– air circuit breaker 
– oil circuit breaker 
– water circuit breaker 
– gas circuit breaker 
– magnetic air circuit breaker 
– compressed air circuit breaker

Answer 5

Water circuit breaker

Question 6

Many circuit breakers have two sets of contacts, these contacts are called___and___contacts.

Answer 6

Arc; load