Breakers And Fuses

Question 1

Definition of overcurrent

Answer 1

Very large current Over short time

Question 2

How many times the rated current give me over current range be

Answer 2

Many hundreds of times

Question 3

What damage to circuit can an overload cause

Answer 3

Heat

Question 4

Three typical causes of overload

Answer 4

Too much equipment plugged in

In proper sized equipment

Ceased or worn out bearings

Question 5

What is temporary overcurrent

Answer 5

Necessary for normal starting the motor

Question 6

What is short-circuit current

Answer 6

Current that flows in a circuit during a fault

Question 7

Too bad things that happen with a short circuit current

Answer 7

Mechanical stress

Thermal energy

Question 8

What formula used to calculate amount of thermal energy

Answer 8

J= I squared r x T

Question 9

Besides a current that exceeds the rating what other two conditions may cause the fuse to open

Answer 9

Hi ambient temperature and excessive vibration

Question 10

What is interrupting rating expected of HRC fuse

Answer 10

200,000

Question 11

Maximum current and voltage for plug fuse

Answer 11

30 A 150 V

Question 12

Maximum interrupting capacity rating for standard fuse

Answer 12

10,000 amps

Question 13

Definition of overload

Answer 13

Moderate increase to above normal current overtime