RCBO Testing

[Rumacoai]

I know this keeps cropping up but I'm just interested to see if its me or the equipment !

I have a 6 amp Wylex RCBO on a lighting circuit that tests OK at the farthest point of circuit and mid way point, but will not test at CU. It will not trip. I am using a Fluke 1654B on Auto.

I have two other RCD's on board that both test at CU ok

I done this due to a post in another forum, and I was interested to see the outcome.

Are there any reasons or tricks I am missing.

 

[steptoe]

use DP RCBOs.

 

[tom1]

what terminal are you sticking your live probe on the rcbo top or bottem

 

[Rumacoai]

Tried both

I have gone back to RCBO as someone said it might be my probes, I have put a piece of wire coming from top Line connection and used croc clips on earth bar and line wire. Works perfectly. Doesn't look right though I have to say.

Can't believe I didn't pick up on this, what a numpty.

Thanks for help though, I will see if I can think of any other silly questions.

 

[Doc Hudson]

RCD's & RCBO's should be tested as near to the device as practical, not at the end of a circuit they are protecting. That is written somewhere in the on site guide.

Doc H.

 

[steptoe]

Tried bothI have gone back to RCBO as someone said it might be my probes, I have put a piece of wire coming from top Line connection and used croc clips on earth bar and line wire. Works perfectly. Doesn't look right though I have to say.

Can't believe I didn't pick up on this, what a numpty.

Thanks for help though, I will see if I can think of any other silly questions.

so you havent actually been testing it then?

 

[Rumacoai]

It transpires my probe was not reaching and connecting, DOH!, so I wasn't testing anything, still I am only human and I certainly won't make that msitake again..

Thanks for help though.