What is the major cause of the failure of the circuit beaker?

The correct answer is option 4):(All of the above)

Concept:

• A  trip unit is the part of a circuit breaker that opens the circuit in the event of a thermal overload, short circuit or ground fault. An open circuit will not conduct electricity because either air or some other insulator has stopped or broken the flow of current in the loop.
• Trip Latch: The latch, rests on the trip latch roller when the breaker is closed. Trips the breaker when closed.
• The “closing spring” is mechanically charged by a motor and is held in its compressed position by a closing latch. When a close signal releases this latch, this spring pushes against a mechanical linkage to force the breaker contacts closed and, at once, charges the trip spring
• The trip circuit is open, the Trip latch is defective, Spring defective are the the major cause of the failure of the circuit beaker