Adding a FCU to a ring main.

[mark222]

I work for a company installing boilers. As a qualified electrician for the company my main work is adding onto an existing circuit and putting FCU next to the boiler.

Am i right in thinking that as of 1st July when the 17th edition comes into force, I will need to ensure RCD protection of the addition to the circuit?

And would the use of a RCD FCU be acceptable? Bearing in mind some of the boilers we fit are in bathroom airing cupboards and kitchens?

Any help would be gratefully recieved as i have been getting conflicting answers off fellow sparks at work.

 

[Mr Sworld]

I work for a company installing boilers. As a qualified electrician for the company my main work is adding onto an existing circuit and putting FCU next to the boiler.Am i right in thinking that as of 1st July when the 17th edition comes into force, I will need to ensure RCD protection of the addition to the circuit?

And would the use of a RCD FCU be acceptable? Bearing in mind some of the boilers we fit are in bathroom airing cupboards and kitchens?

Any help would be gratefully recieved as i have been getting conflicting answers off fellow sparks at work.

Hi Mark, rcd protection on circuits is to be used when the cables are buried in walls, the idea is to trip the circuit if the houseowner puts a nail through the cable. So if the boiler was in the kitchen and you ran the cable in surface mounted conduit you wouldn't need to rcd it. Also if the cable is buried and in a earthed metal conduit or trunking (yeah, right!) you wouldn't need to rcd it either.

As for a bathroom airing cupboard then, yes, you would rcd it which ever way its run.

I wouldn't use a rcd fcu as the rcd is there to protect the cable (except for the bathroom where it is used to protect you as well!). So I would run the circuit from a rcd'ed side of the CU or run it from a rcbo. Then use a fcu to bring the cord out to the boiler.

Hope this helps.

 

[SPECIAL LOCATION]

I work for a company installing boilers. As a qualified electrician for the company my main work is adding onto an existing circuit and putting FCU next to the boiler.Am i right in thinking that as of 1st July when the 17th edition comes into force, I will need to ensure RCD protection of the addition to the circuit?

And would the use of a RCD FCU be acceptable? Bearing in mind some of the boilers we fit are in bathroom airing cupboards and kitchens?

Any help would be gratefully recieved as i have been getting conflicting answers off fellow sparks at work.

Hi mark

welcome M8..

this is one of those grey areas at the moment...

at an NCEIC 17th ed seminar earlier this year a similar question was asked but re an additional socket spurred of a ring.

The NICEIC didn't have a definitive answer then either??

spose one option is to put the cost of the RCD FCU, toward an RCBO instead?

wouldn't make to much of an additional cost on the job!

and your backs covered all angles.

but you would need to know the board type and etc.. before getting to site??

and some older boards wouldn't be compatible anyway??

This is the similar problem that will be encountered with almost every alteration & addition to a circuit July onwards..??? ?:| ? :|

think its going to be a wait and see.. :|

keep an eye on electrical journals etc..

& of course electrical forums

to try to get more definitive answers.

But ultimately me thinks it is going to be RCBO's all round even with alterations

 

[steptoe]

cant remember the CODE number, IS IT 3 .?

but surely its a normal FCU and just a

'DOES NOT COMPLY WITH "current" BS 7671'

in the box.?

its not an 'UNSATISFACTORY', AFAIK.

how is anything ever going to comply again? down to changing a light in the kitchen?

dunno much else, but i think this is the route I will have to take with my 30 odd faults on every PIR....

 

[kme]

cant remember the CODE number, IS IT 3 .?but surely its a normal FCU and just a

'DOES NOT COMPLY WITH "current" BS 7671'

in the box.?

its not an 'UNSATISFACTORY', AFAIK.

how is anything ever going to comply again? down to changing a light in the kitchen?

dunno much else, but i think this is the route I will have to take with my 30 odd faults on every PIR....

Nah m8, it`s a 4. Yes, it isn`t an "unsatisfactory", but you couldn`t install it, then fill out your own cert, saying that the work you`d just done didn`t comply???

Well, I suppose you COULD technically, but I wouldn`t personally.