can you give me info about earth leakage circuit breaker?

Answer 1

the earth leakage ciruit breaker is a transformer with three windings
the phase and neutral are connected to one winding each and the trip circuit is connected to the third winding.
as long as the phase and neutral currents are balanced there is no trip.
if some current passes through earth it creates an imbalance between the phase and neutral windings which creates a corresponding current in the trip winding (tripping the circuit breaker).
the important thing to remember is that this type of circuit breaker offers no protection against an short circuit overload current, unless combined with a conventional circuitbreaker.

Answer 2

The circuit breaker would be of a specific current rating.
A leak to ground would result in a breaker overload and shut the system down.

Answer 3

You're probably talking about a ground fault isolator. By using a differential transformer, it measures the difference in the current flowing through it wire and trips at a difference if I believe 5 ma.

Answer 4

The idea is to prevent current flow in your safety ground. In reality the safety ground and the neutral should only tie together at the transformer.