Is a borrowed earth allowed?

[buzzlightyear]

What I am saying is that he has done nothing wrong, it is permitted provided it is adequate for a cpc to serve more than one circuit. What he has done may seem unorthodox but I was asking for those who disagree with his actions to back it up with a Regulation.

so Westy is like borrowing a neutral .

 

[buzzlightyear]

for the op .

 

[westward10]

Ok I give up, I'm orrffh to cook a curry is my excuse.

My thoughts were that the cpc must remain effective throughout the life of the install. Therefore, if the RFC is altered or removed subsequently, the installer altering/removing may not know the other circuit is reliant on its cpc.

You could argue if the problem cpc has only one break it is now effectively connected to earth from either end. I think it would be prudent to fit some form of info at the CU.

 

[Andy-1960]

I agree with Westy, the circuits cannot now be independently isolated, anyone working on the RFC in the future could potentially get a shock from the cooker circuit in the event of a fault on the cooker.
It is as BL says like borrowing a neutral, as soon as that link is disconnected there could be a potential difference between the two earth conductors.
Big problem with temporary repairs is that they have a nasty habit of become permanent repairs!
Also, what has now been done must surely screw the test results for the RFC, so how do you document that in the EICR?
Correct thing to do would be to isolate the cooker circuit and label it saying it is not to be used until remedial action has been carried out and document that to the client.

 

[Kamikaze]

2) lowish IR readings 1.75M L-E and N-E on light circuits and one rfc but possibly in hindsight due to some bulbs, fan and appliances still plugged in. Could this account for it?

If you got those readings of the same lighting circuit, then I would say there is a fault on that circuit. Did you disconnect the earth and neutral for that circuit out of the board before testing?

 

[Midwest]

I agree with Westy.

Think he disagrees with you?

 

[westward10]

Think he disagrees with you?

I didn't like to point out the error

 

[westward10]

so Westy is like borrowing a neutral .

Different scenario Buzz.

 

['mr2'gd4u]

Trouble is the diffence in size of cpc. 1.5mm on a 2.5mm ring (essentially 3mm) the cooker if in a 10mm t&e.. With a 4mm cpc... 6mm t&e is fine at 2.5mm cpc

 

[HappyHippyDad]

As some of the more experienced have said... It is fine to use a CPC common to two or more circuits, and it complies with a regulation 543.1.2 (as long as it's CSA is sufficient).

I do find it worrying when members, some are even trusted members, give the wrong advice and give it out so quickly without giving proper thought. We all get it wrong at times, but at least lets give it some thought before we get it wrong.

 

[buzzlightyear]

It is as BL says like borrowing a neutral, as soon as that link is disconnected there could be a potential difference between the two earth conductors.
Big problem with temporary repairs is that they have a nasty habit of become permanent repairs!

Different scenario Buzz.

how can it be a different . are you saying its ok to borrow a earth knowing if their is fault to earth It want clear quicker. IMO the op needs to ring his scam and get clarification.

 

[Midwest]

As some of the more experienced have said... It is fine to use a CPC common to two or more circuits, and it complies with a regulation 543.1.2 (as long as it's CSA is sufficient).

I do find it worrying when members, some are even trusted members, give the wrong advice and give it out so quickly without giving proper thought. We all get it wrong at times, but at least lets give it some thought before we get it wrong.

Thats told me then. Still think its so wrong though.

 

[Andy-1960]

I agree with Westy, the circuits cannot now be independently isolated, anyone working on the RFC in the future could potentially get a shock from the cooker circuit in the event of a fault on the cooker.
It is as BL says like borrowing a neutral, as soon as that link is disconnected there could be a potential difference between the two earth conductors.
Big problem with temporary repairs is that they have a nasty habit of become permanent repairs!
Also, what has now been done must surely screw the test results for the RFC, so how do you document that in the EICR?
Correct thing to do would be to isolate the cooker circuit and label it saying it is not to be used until remedial action has been carried out and document that to the client.

I agree with Westy.

I meant Midwest... sorry Westy!

 

[Midwest]

I meant Midwest... sorry Westy!

He needs to change his name. Something more befitting a Moderator.

 

[Andy-1960]

I agree with Westy.

I meant Midwest... sorry Westy!

 

[Midwest]

Who said that

 

[Deleted member 9648]

It is permitted for a protective conductor to be common to two or more circuits, I do not have the BBB to hand, only the BRB....where it is 543.1.2.
Edit...sorry, I see that's already been said.

 

[Nigel]

Nothing different than a conduit sytem being used as a cpc for multiple circuits.

 

[ruston]

I didn't like to point out the error

Not like you . Promotion has mellowed you.

 

[Midwest]

Nothing different than a conduit sytem being used as a cpc for multiple circuits.

But it ain't a conduit system, its in someone's house.

So so so wrong.