RCD tripping times

[afswift]

Hi

When testing an RCD circuit to get tripping times, with a split load board should i expect all circuits on the RCD side to trip at exactly the same time?

I have just tested mine and i get a varied reading for each circuit, only about 5ms between times but does this sound ok?

Cheers, Adam

 

[Spark123]

You are meant to test the RCD in isolation from the circuits.
Assuming you are talking about a bog standard 30mA device, it shouldn't trip @ 15mA, should trip at 30mA in less than 300ms for a BSEN or 200ms for the old BS and less than 40ms at 150mA. Do both + and - cycles for all tests.

 

[GaryMo]

I have just tested mine and i get a varied reading for each circuit, only about 5ms between times but does this sound ok?

As above for correct method to test an RCD.
By testing each individual circuit you're including differing impedances so you figures may well differ slightly.

 

[Click-Sure]

Yep, test RCD's in isolation. testing from part of a circuit that is connected will give flase/misleading results.

 

[securespark]

Don't forget, 5x test not needed for 100mA units or above.

 

[kevrevv]

Hi

When testing an RCD circuit to get tripping times, with a split load board should i expect all circuits on the RCD side to trip at exactly the same time?

I have just tested mine and i get a varied reading for each circuit, only about 5ms between times but does this sound ok?

Cheers, Adam

you only need to check if the rcd trips within the specified time. if it does then it is ok. if it trips on any circuit within 40ms x delta 5 then u are ok. there are 7 tests for an rcd altogether. u are not checking the impedance of the circuit u are checking if the rcd trips within a time when a current of 30milli amps passes it.

 

[Spark123]

Posted: Mon 09 Jun, 2008 8:47 pm Post Subject: RCD tripping times