RCD

[avinalarf]

Back to this summerhouse supply...

I put a 20A breaker at the dwelling CU and installed a CU within the summerhouse that has a RCD main switch and MCBs for the circuits.

When RCD testing, is it correct for the RCD at the dwelling to trip as well as the one in the shed?

Cheers

 

[Apache]

yes

 

[ianmacd]

Only if you haven't taken discrimination into account.

Ian.

 

[Apache]

Only if you haven't taken discrimination into account.Ian.

Ian if she's using a main board with a 30mA to protect the sockets in the house (assume 16th ed board) then there's not a great deal of scope for discrimination?

Suppose if she'd split the tails and just had an isolator at house it wouldn't be a problem.

My shed it taken from a 20A breaker on a 100mA board to a sperate DB with a 30mA in the shed - sometimes both trip

:|

 

[ianmacd]

No need for an RCD on a "distribution" circuit (unless its not SWA/in steel conduit in a wall under 50mm etc.......) so could drop it off the RCD to allow for discrimination. That way the one in the house will not blow.

Also what size are the RCD's in tha garage?

Ian.

 

[Apache]

No need for an RCD on a "distribution" circuit (unless its not SWA/in steel conduit in a wall under 50mm etc.......) so could drop it off the RCD to allow for discrimination. That way the one in the house will not blow.Also what size are the RCD's in tha garage?

Ian.

What garage?

To quote Andyc

only needs one RCD - so if its RCD'd at house, then no further RCD req'd. or if run is in SWA, you could hae no RCD for SWA, and RCD at shed

this thread gives more detail

Nat did ask about this but we all wandered down the route of terminating the SWA :|

 

[ianmacd]

Don't you keep your cars in your summerhouses up there?

 

[Apache]

Don't you keep your cars in your summerhouses up there?

I don't know which University City she means?

I assumed she was down South?

 

[ianmacd]

My shed it taken from a 20A breaker on a 100mA board to a sperate DB with a 30mA in the shed - sometimes both trip

What else is on that RCD, Patch?

 

[ianmacd]

I don't know which University City she means?I assumed she was down South?

I meant where you are

 

[Apache]

What else is on that RCD, Patch?

everything except lights, cooker and immersion

:|

 

[ianmacd]

everything except lights, cooker and immersion :|

So sockets on a 100mA RCD? You could move the MCB for your shed off of the RCD if its not required for another reason.

 

[Apache]

So sockets on a 100mA RCD? You could move the MCB for your shed off of the RCD if its not required for another reason.

It is a split load board with two 100mA RCD's

http://i281.photobucket.com/albums/kk210/mikeywoodhouse/PICT0008-1.jpg

Yes sockets are on a 100mA breaker. CU changed to 16ed. Electrician thought it was TT (it was) so got this CU accordingly then turned out it had been upgraded to PME, but used it anyways

 

[Apache]

Or is that RHS RCD lower rated? I've never noticed

 

[Apache]

Looks like an 80mA

Handy having pics of the CU when I'm @ work

 

[ianmacd]

Looks like the one with all the mcb's on is the lower one too. Wierd why the left RCD is on the "other" side of the mcb's too.

 

[ianmacd]

OK now I see. It appears the sparks has replaced the main switch with a 100mA RCD. Is that not a time-delayed one? If it is then (assuming no other need for RCD), you could move the shed onto that one should satisfy discrimination for the RCD's.

Ian.

 

[Apache]

OK now I see. It appears the sparks has replaced the main switch with a 100mA RCD. Is that not a time-delayed one? If it is then (assuming no other need for RCD), you could move the shed onto that one should satisfy discrimination for the RCD's.Ian.

I suppose it would

Think I will leave be as I have only tripped RCD once in anger and the walk back to the house clamed me down

 

[avinalarf]

I don't know which University City she means?I assumed she was down South?

I'm in Cambridge

 

[Apache]

I'm in Cambridge

THAT University City

I always want Oxford to win the boat race

So what are the ratings of your two RCDs?