ELR Tripping

[poji]

Hello,
I'm in TT world. I got ELR tripping here. ELR having protection the several small circuit which have RCCB. When i test using RCCB tester at downward circuit which has RCCB, the ELR will tripped. What is the problem here? Using discrimination it should RCCB that should trip.

 

[Christech]

Hi
Are your devices of equal ma ?.If not is the upstream device "Time Delayed" ?

 

[ian.settle1]

Whats a ELR?

 

[Christech]

Earth Leakage Relay

 

[poji]

Yup, the circuit coming from main switchboard which has ELR at the sensitivity of 0.5A at time delay 50ms. At the bulding sub-switchboard, there is ELR at the sensitivity of 0.3A at time delay 50ms. From the sub-switchboard there are several circuit going out which having protection of RCCB of sensitivity 0.3A and 0.1A at instanteneous time. The problem here when I having RCCB test at downstream circuit at each circuit having the RCCB protection, the ELR at sub-switchboard tripped. Shouldn't be happen as the current & time discrimination are already there.

The ELR also tripped even at no trip test of RCCB test.

ELR also tripped even at no trip test of RCCB.

Already replace the ELR,tripping is still there. But, when i test the terminal at zct using test pen, there is voltage there. In my knowledge, there shouldn't be a voltage there as in normal circuit there should be a balance current. So should not have a voltage.It is possible the tripping is due to the faulty zct???