RCD TEST Question

[mark22]

Help Please

I have installed a new supply to a garage. It is fed from a split board consumer unit in the house and is protected by an 80amp RCD.

I have installed a consumer unit in the garage which has a 40 amp RCD. (cu earthed via earth rod).

I carried out an RCD test and got the following results :

x1 27ms at 0 tripped garage
17ms at 180 tripped garage
x5 4ms at 0 tripped garage
7ms at 180 tripped house

My question is why does it only trip in the house on x5 at 180 and is the only way to resolve this by removing the circuit away from the rcd on the main board.
thanks
Mark

 

[Octopus]

No sympathy. What makes you think you designed and installed a sensible solution????

 

[D Skelton]

^^^ I second that.

What did you expect after only 5 weeks worth of training!?

Get an electrician in!

 

[plugsandsparks]

Its a combination of what each RCD is seeing at the time of your test. As the house will see a different load to the garage your results are really meaningless. If you try and test 2 RCDs in series like that it will only end up one way, - disappointing. Might be worth starting again with the design. cheers P&S

 

[telectrix]

Help Please

I have installed a new supply to a garage. It is fed from a split board consumer unit in the house and is protected by an 80amp RCD.

I have installed a consumer unit in the garage which has a 40 amp RCD. (cu earthed via earth rod).

I carried out an RCD test and got the following results :

x1 27ms at 0 tripped garage
17ms at 180 tripped garage
x5 4ms at 0 tripped garage
7ms at 180 tripped house

My question is why does it only trip in the house on x5 at 180 and is the only way to resolve this by removing the circuit away from the rcd on the main board.
thanks
Mark

you have the answer in the last part of the post.

 

[Octopus]

Hope the OP has his tin hat on!

 

[D Skelton]

Hope the OP stops fraudulently charging people for the services of an electrician when he clearly isn't one!

 

[Andy78]

tut tut

 

[MDJ]

Double post

 

[MDJ]

And a bullet proof vest as well murdoch lol

 

[D Skelton]

Mike, empty your inbox

 

[MDJ]

Mike, empty your inbox

Okay M8 I have cheers

 

[sarusystems]

Is the house also TT
and if the house trips on X5 only why is there a problem you still need to protect the cable to your new Unit

 

[uksparks]

Mark,

A couple opossessions...

1. Is the garage down the garden from the house or connected to it?
2. What earthing arrangement do you have at the house? TT, TN-S, TN-C-S
3. Is the RCD in the main board a time delay RCD or just normal?
4. This earth rod, is it a screwdriver jabbed in the ground or a proper rod, details please, size etc...
5. On the basis you used SWA to feed to sub board, did you ground the steel wire and if so, which end?

Do you have any knowledge or understanding of sine waves or how RCD's work? I am going to guess and say no.

 

[Engineer54]

Here we go yet again!! The dreaded garage ''I can't 'export PME'' and the ''tripping of series connected RCD's'' !! When will they ever learn??

No-one ever seems to search on here for similar threads, it would save these OP's a lot of time and, ....stay well under cover of the barrage of well deserved abuse!! lol!!