RCBO Question...

[Dean Williams]

Hi
when i try to test an RBCO at the DB it trips as soon as the test probes touch the terminals, this only seems to happen with Bill/MEM RCBOs, it doesnt happen with Merlin or Square D. I'm using a standard Robin RCD tester. Any idea why???

 

[telectrix]

seem to remember a thread a while ago that some RCBOs needed the fly lead disconnecting . not too sure exactly what it was . i don't use many RCBOs, myself.

 

[Dean Williams]

its so annoying, its ok if i test at a socket but when your working alone testing in long corridors going back and forward on 1x and 5x, 0 degrees and 180 degrees....its a bit of a pig!

 

[telectrix]

so's the ex-wife. glad i don't have to reset that any more.

 

[Dunc]

Try disconnecting the outgoing cable from the RCBO and put a short length of wire in the terminals and test from there. Had the opposite problem on a MEM RCBO where I couldn't get it to trip at all so may be a similar issue. Worth a go anyway.

 

[nickblake]

It could well be due to the electronics in the meter if you are putting one probe on at a time it may cause an imbalance when the second probe is connected ,try switching off the RCBO putting both your leads on then switching back on and then testing just a thought