CHOICE OF ELCB

PLEASE TURN OFF CAPS LOCK

ANSWER:

Yes, you can use.

There is nothing wrong in installing a 30mA RCCB in place of 100mA. In fact, a 30mA RCCB is more sensitive than a 100mA RCCB.

A 30mA RCCB is used when you require additional protection against direct contact with live part of the system and also if the earth loop impedance is high (upto 1667 ohm).

A 100mA RCCB is used for protection against indirect contact with live part of the system and for an earth loop impedance upto a maximum of 500ohm.

In your case, 30mA RCCB may cause nuisance tripping of the lighting feeder for small leakage currents.

Yes. But you have to use a 30mA RCCB if the earth loop resistance is high.

THANKS a lot.....one more question...is it possible to use a rccb for a dc system?

Dear all,

Not all Rccb's are not AC/DC type. Some Rccb, such as ABB F200B is for both AC and DC.

Regards

but is there any rccb for dc system available in merlin gerin or schneider?

Dear all,

I think, 30mA : 1667Ω 100mA : 500Ω is for TT system.

For TN system, the earth loop impedance can be much higher.

For instance, 230V / 30mA * 0.8 = 6100 Ω and 230V / 100mA *0.8 = 1800Ω.

Regards.