Power to loft - Adding spur to MCB / fuse that carries ring

[coops1975]

Hi

I was wondering if it is okay to add a separate 2.5mm cable to the MCB, on the fuse that carries the "upstairs sockets - this carries the ring for upstairs sockets" and take the single 2.5mm direct to a FCU (13amp) to power a two twin sockets that would have a load less than 13amps.

Thanks all you help in advance.


Cheers


Coops

 

[PrenticeBoyofDerry]

Why don't you either extend the ring final circuit to the loft or take a fused spur from a conveniently located socket outlet?
Will save you the hassle of routing cable from the CU.

 

[xr4x4]

That's not what he asked.

Maybe it's easier to do it as he said.

I'd like to know as well, as I didn't think it was normal practice.

 

[PrenticeBoyofDerry]

That's not what he asked.

Offering alternatives that the OP may not of thought of!

Maybe it's easier to do it as he said.

Could well be depending on the location of the CU with relationship to loft? If the CU is in the loft, could be much easier!

I'd like to know as well, as I didn't think it was normal practice.

It's not good practice, I would always recommend extend the circuit, rather than spurring, but in essence that's what it would be if you parked the cable directly in to the protective device of an existing circuit. Could be issues with MCB rating and current carrying capacity of the 2.5mm T&E though!

 

[xr4x4]

Ah of course, 2.5mm t&e in a 32a mcb, not good.

 

[slup]

Practically speaking, that's no different to a spur. It's still 2.5mm cable on a 32A MCB which ever way you do it.

 

[coops1975]

Thank you for your replies.

I have a small roof loft over the garage ( that sticks out a little from the front of the house - part integral) and I have access to the loft from the small roof loft and in turn to the CU. Most of the house wiring goes through the small loft to the CU below. I have access to the main loft via the cavity wall.

The nearest socket is within the small loft, but this is a spur from a twin socket from within the garage part conversion, and would be very difficult to access, and to try to include the socket in the small loft and then the main loft socket onto the ring main. I will be looking at the wiring on this tomorrow.

Otherwise I know it not ideal sticking 2.5mm wire direct to the MCB but it is the easiest, at least it would be a radial type connection and a ring main into the same mcb. I assume, based on the replies that it is okay to do this?

The FCU with 13amp fuse is for extra safety so the cable is not overloaded, by somebody in the future - if we were to sell the house.

Cheers


Coops

 

[Electrifying]

Hi

I was wondering if it is okay to add a separate 2.5mm cable to the MCB, on the fuse that carries the "upstairs sockets - this carries the ring for upstairs sockets" and take the single 2.5mm direct to a FCU (13amp) to power a two twin sockets that would have a load less than 13amps.

Thanks all you help in advance.


Cheers


Coops

Take no notice of some of the replies - yes, what you are suggesting is perfectly acceptable - and no, it's not bad practice.
As long as you have a 13A FCU installed, you can also add as many sockets as you like. (after the FCU, of course)

 

[PrenticeBoyofDerry]

Hi

I was wondering if it is okay to add a separate 2.5mm cable to the MCB, on the fuse that carries the "upstairs sockets - this carries the ring for upstairs sockets" and take the single 2.5mm direct to a FCU (13amp) to power a two twin sockets that would have a load less than 13amps.

Thanks all you help in advance.


Cheers


Coops

Take no notice of some of the replies - yes, what you are suggesting is perfectly acceptable - and no, it's not bad practice.
As long as you have a 13A FCU installed, you can also add as many sockets as you like. (after the FCU, of course)

In this situation why would a 13A FCU be needed?
I would personal stick an 13A FCU prior to the double socket in the garage feeding the spur to small loft and add from that, if I could not extend the RFC!

 

[PrenticeBoyofDerry]

Practically speaking, that's no different to a spur. It's still 2.5mm cable on a 32A MCB which ever way you do it.

but a RFC is sharing the load, were this could be considered a 32A radial with 2.5mm T&E

coops1975, what is the rating of the protective device of this circuit and are you sure the cables CSA is 2.5mm?

 

[RF Lighting]

But the load on the cable is limited to 13A by the upstream fuse in the FCU, and sufficient fault protection is provided by the 32A device in the CU, so there's no problem with it at all. It's a spur off a ring. It doesn't matter which point of the ring it happens to be supplied from.

 

[PrenticeBoyofDerry]

Might be me that's got a little muddled here

power a two twin sockets

now what does that mean?
a double socket
a four socket outlet
or two doubles?
I understood the post to mean a double socket.

 

[coops1975]

Practically speaking, that's no different to a spur. It's still 2.5mm cable on a 32A MCB which ever way you do it.

but a RFC is sharing the load, were this could be considered a 32A radial with 2.5mm T&E

coops1975, what is the rating of the protective device of this circuit and are you sure the cables CSA is 2.5mm?

PrenticeBoyofDerry: the protection is in the form of a MCB 32A. The cable I am using is 2.5mm T&E. I hope this helps in clarifying. Let me know if your answer changes based on the new information.

Cheers


Coops

 

[coops1975]

Might be me that's got a little muddled here

power a two twin sockets

now what does that mean?
a double socket
a four socket outlet
or two doubles?
I understood the post to mean a double socket.

Looking to add 2x double sockets

 

[coops1975]

But the load on the cable is limited to 13A by the upstream fuse in the FCU, and sufficient fault protection is provided by the 32A device in the CU, so there's no problem with it at all. It's a spur off a ring. It doesn't matter which point of the ring it happens to be supplied from.

RF Lighting, Does this mean, that based on the same rules of adding a spur to a ring via a socket you should only do it once - unless using an FCU.

Does the same apply to the fact that I am planning to add the cable direct to the 32A MCB in the consumer unit and that this should only be done once as well.

I hope the above makes sense.

Cheers


Coops