Nusiance Rcd Tripping

[toml]

Been toa job this morning and the customer (well gaffer) is complaining about nusiance tripping. Meggered it all, all fine (over 150meg for a10yr old installation). 2 rcd tested on auto 1 tested at 1x 17 and 5x 8ms. But the other one doesn't trip at all for the tester but trip about 3 or 4 times a day for no reason) I plan to replace it tomorrow (if I can get hold of a legrande rcd from anywhere)

But if it's not thus then what can it be. Also next door is suffering from the same problem which I've looked at and again the wiring is fine

Any ideas?

 

[steptoe]

have you tried ramping them?

why replace without doing basic testing first?

 

[SLIPSHOD & SLAPDASH]

I had a 0 sec result, only on one of the  x1 tests today, never had that before . Will check it out further when i next visit

 

[toml]

Ramp tested. One trips at 17mA and the dodgy one trips at >33mA. So I'm hoping it's that

 

[SPECIAL LOCATION]

Are you testing them with loads disconnected?

2x RCD's...  one working one tripping... 

why not swap them over first to see if the problem stays with the RCD or with the circuits?

Next door having problems as well.....

What is the earting arrangement ...

Whats your  Ze / Ra?

Could you have something from outside your installation causing problems..?

opcorn

 

[toml]

It's a tt system, ra is 23.9 ohms. I'm replacing the rcd for the piece of mind of me gaffer. Then if it ain't then I will suggest that central power or whoever they are these days comes and has a look

 

[Doc Hudson]

So is there also a front end 100ma td RCD, has there been any tripping issues with that? 

Doc H.

 

[Steve3948]

Sounds liike 2 X 30mA Doc.