RCD on radial for fused spurs?

[MrPupsi]

Hi all,

Half way through an installation as a subby on someone else’s electrical contract.

It’s for a church, in which they’ve asked me to run 2 radial circuits.

Circuits 1 and 2 split a total of 10 fused spurs, 5 on each radial, each with a 3a fuse and on a 20a mcb.
Cables are run under floor boards and through the joists.
Run in 2.5mm twin and earth, each run no longer than 25m.

I’m under the impression that this needs to be RCD protected but the site manager has said that MCBs are fine. I’ve flicked through the regs but haven’t sat my 18th yet, which is booked in for next month.
As the cables aren’t in walls or supplying any sockets, he may be right?

Can anyone shed any light on this please?

 

[Ian1981]

If the circuits do not need additional protection in accordance with 415.1.1 or earth fault protection by an rcd say 100mA etc and they are not supplying sockets then yes he is correct going from your information provided.
As they are fused spurs then they are just supplying fixed current using equipment by the sounds of it.
That’s all I can say given your information.

 

[Barnaby Stedman]

Are they buried in walls at all
regs state cables less than 50mm into a wall need RCD protection i think

 

[Ian1981]

Are they buried in walls at all
regs state cables less than 50mm into a wall need RCD protection i think

They are not in walls.
Don’t know how the come out of the floor though

 

[Ian1981]

where do the cables go when they appear from the floor void?
How are the fused spurs fixed and to what, location etc?

 

[Pete999]

Hi all,

Half way through an installation as a subby on someone else’s electrical contract.

It’s for a church, in which they’ve asked me to run 2 radial circuits.

Circuits 1 and 2 split a total of 10 fused spurs, 5 on each radial, each with a 3a fuse and on a 20a mcb.
Cables are run under floor boards and through the joists.
Run in 2.5mm twin and earth, each run no longer than 25m.

I’m under the impression that this needs to be RCD protected but the site manager has said that MCBs are fine. I’ve flicked through the regs but haven’t sat my 18th yet, which is booked in for next month.
As the cables aren’t in walls or supplying any sockets, he may be right?

Can anyone shed any light on this please?

You might want to check if PVC/PVC cables are suitable for Churches, seem to recall there are certain rules regarding Churches, could be wrong but worth checking, was this work designed and planned prior to 2019?
Wiring churches: the engineer's perspective - https://electrical.------.org/wiring-matters/issues/53/wiring-churches-the-engineers-perspective/
You may find this useful

 

[MrPupsi]

Sorry, should have added, where cables are not under the floorboards, they are in pvc trunking, fixed in securely with D clips.

The spurs supply power to a radiator fan, so fixed equipment and won’t be used for anything else.
Spurs are fixed to the walls and are located in the main hall along the sides of the walls.

Unsure of when the work was planned.

 

[buzzlightyear]

https://d2z8ufzpcqvblm.cloudfront.net/sites/www.voltimum.co.uk/files/fields/attachment_file/gb/others/6/200907291488200905086110200905065629.pdf,
READ THIS ,MR PUPPY.

 

[Pete999]

https://d2z8ufzpcqvblm.cloudfront.net/sites/www.voltimum.co.uk/files/fields/attachment_file/gb/others/6/200907291488200905086110200905065629.pdf,
READ THIS ,MR PUPPY.

Can't see it Buzz

 

[buzzlightyear]

Can't see it Buzz

I tried to up load it Pete ,but is cloud front . .

 

[buzzlightyear]

delete

 

[Pete999]

I tried to up load it Pete ,but is cloud front . .

Right, never mind

 

[A032701]

why not put it on an rcd if there is a rcd there already ?
then no one can kick a fuss
better safe than sorry.

 

[Andy78]

why not put it on an rcd if there is a rcd there already ?
then no one can kick a fuss
better safe than sorry.

If you don't know what you're doing I can see why adding RCDs when they are not required could seem like a good idea.

 

[Pete999]

I posted up concerns from Engineers regarding wiring in Churches, what to avoid processes to follow, Authorities responsible, etc the OP hasn't responded I can only imagine He/ She is at work, the OP is a subby but it's still the OP's responsibility to take note of the advice given in the linked document, look forward to the response.