Testing a 100mA time delay RCD

[Podooser]

It is a TT supplyand a split CU and therefore the main MCB is a 100mA time delay RCD. No problem with testing the 30mA RCD. How does one test the main RCD.

 

[RF Lighting]

My tester has a setting for testing type S RCDs.

What make and model tester do you have?

 

[Lectrician]

Turn the test dial to 100mA and the type to 's'.

 

[Podooser]

Won't the 30mA RCD go first

 

[Lectrician]

Not if you test before it! RCD tests do not hve to be carried out using the plug-in lead

 

[RF Lighting]

Arn't you supposed to test RCD's in isolation anyway?

 

[Podooser]

Not if you test before it! RCD tests do not hve to be carried out using the plug-in lead

So using the 3 terminal lead

 

[ricicle]

Not if you test before it! RCD tests do not hve to be carried out using the plug-in lead

So using the 3 terminal lead

Yep

 

[Podooser]

Thanks chaps.

 

[securespark]

Arn't you supposed to test RCD's in isolation anyway?

Yes!!

And it's easier to my mind testing at the board that connecting a three-way test lead to some rose and you're trying to keep all probes connected while the test goes through.

Plus you need someone to be at the board resetting...

My Alphatek inserts a 30 sec delay on each of the tests...don't know quite why, yet.

 

[Jim2287]

perhaps it sets a fault and clear it to see if TD RCD trips ... waits 30secs for RCD to clear the fault then runs the test .... just a guess