Contactum RCBO won't trip during test

[Smugley]

Hi again, just considering whether I'm going crazy or I've got a duff RCBO. Perhaps someone will help me see the light either way. Quite prepared for the former!

Installed it yesterday and when I got to doing the certificate I couldn't get it to trip. It's one of the ones with no earth wire. Took it home to test at my place and same.

L&N IN connected correctly, but whether I do a 0.5xI, 1xI, 5xI or ramp test, it doesn't trip at all (Megger 1552).

This behaviour whether load connected or not. Also noted that voltage at the input terminals is 236V and at the output terminals is 228V. Test button works as expected.

Just want to know I'm not doing something stupid before taking it back for a replacement.
Cheers

 

[Deleted member 9648]

Sounds to me like i'ts duff.Bit odd if it works on the test button though.

 

[bugsy]

Fails ramp test but works on test button , Sounds like a bit of duff kit to me , take it back and also worth a call to their tech guy's

 

[Smugley]

Thanks guys, won't section myself just yet! I think the VD of 8v from input to output in a bit of a worry too..

edit: Bugger. Seems like it's my Megger at fault. Tried it on an RCD and it didn't trip that either. Pain in the usual place.

 

[robsparx]

my megger was a bit funny with a Contactum rcd recently. It only seemed to be that and one other make though. Sent it back and they sorted it very quickly