Yet another RCD discrimination thread ;)

[youngpadawan]

Hi peeps, just rewired a warehouse and had the simply genius idea of running an extra socket (spured off of one of the only circuits with an RCD in the entire building, of course) for the in-house technician to test faulty returns sent back by their customers. And naturally, one of the main reasons these products get sent back is due to tripping RCD's.

So basically I need a way for this single socket to trip without tripping the main RCD that feeds it (the web admin tells me he needs power for his computers to work, the killjoy) and am praying that I don't have to either replace the consumer unit for a split way board or run an independent supply for it. Does anyone know if there is an RCD out there set up for testing purposes or anything else that will trip before the mains 30mA? If I was being greedy I'd be asking for a 15mA rcd socket, but i'll settle for anything that will do the trick. Google has failed me and cities are... well, they try bless em.

Oh and it's an NIC job, so doing anything dirty with the cpc is out of the question

 

[RyanCheetham]

Can you not replace the socket for an RCD socket? Although it may still nuissance trip

 

[Octopus]

Wire the "special socket" back to a MCB in the board that isn't protected by an RCD??

Me thinks you'll need a 2nd CU

 

[not clever]

A dedicated circuit from db.

 

[ian.settle1]

As said a seperate RCD socket of it's own MCB.

Surely if the apparatus has been returned as tripping the RCD at the customers place the first thing to do is carry out a PAT test to see what the leakage current is of the apparatus returned to see if it is the apparatus at fault.

 

[youngpadawan]

Wire the "special socket" back to a MCB in the board that isn't protected by an RCD??

Me thinks you'll need a 2nd CU

This is how i currently see this playing out, sadly this is a pretty giant warehouse. The CU this circuit is on currently is a tiny 5 way RCD board for the shower (go figure) and kitchen, so it's either replace that for a split way or run 30 meters or so of singles with some new conduit to boot.

 

[Octopus]

I think you should run a sub main in SWA from the CU (obviously not RCD protected) to the "area" where the need it. In the area you'll need a 2 way board, 1 with a MCB and socket and 1 with RCBO and socket - then you've got yourself covered and the tester can "test" to his hearts content.

 

[youngpadawan]

As said a seperate RCD socket of it's own MCB.

Surely if the apparatus has been returned as tripping the RCD at the customers place the first thing to do is carry out a PAT test to see what the leakage current is of the apparatus returned to see if it is the apparatus at fault.

Hehe yeah, sadly this is how you and i might solve this, but i'd love to see his face when i try and sell him a PAT tester too

 

[Knobhead]

Just point out the saving to be made weeding out bogus claims.

 

[vjsmarwick]

Mmm what is feeding in to the 5way cu RCD ?
Can't you come from the incoming side of it and put just a dedicated RCD on that supply for your new socket ? Hard to tell when we can't actually see it but my guess is that would solve your problem.