rcd too sensitive

[unclebubble]

Can anyone help?I've just done a consumer unit change over at work and gone to do the RCD test on 30ma setting and its tripping out at 1/2 at 0.0 and the same reading for x1 and x5.
Maybe the RCD needs changing?The RCD is fine working though with a load on it!Any help would be appreciated Cheers

 

[Spark123]

Did you check it in isolation?

 

[unclebubble]

No Haven't tried isolating it,will try monday morn if it's fine then what do you think,I've done insulation resistance and all circuits on RCD side are acceptable being >500.Cheers for the help

 

[Spark123]

If that is fine then swop it.

 

[Click-Sure]

Have you got a ramp test function on your tester?

Mine has got me out of a few scrapes in the past, and provided undisputable evidence when returning faulty goods, sometimes even to the customer, that said I could show anything that said (say) 19 on a screen to most when it should be around 30 and it wouldn't mean much to 'em

 

[securespark]

19mA would be passable for a ramp, surely?

 

[Click-Sure]

Yes, depends on the IR of the circuit(s) connected to it. Seen a 30 get 2 on the ramp, and seen a ramp reach its conclusion, which turned out in an RCD that turned out to be a switch (bloody imports)

 

[securespark]

The IR is unimportant if measuring in isolation, as one should.