Regarding current ring circuit and adding a spur

[Scarum]

Hi

I would like to add a single socket spur on otherside of a plasterboard wall partition (from kitchen to lounge.) Before I get a sparkie in I wonder what you guys think of the set up.

In the kitchen there is an isolator switch to the freezer, my idea being to spur off that. This isolator switch is on a ring (has two live and two neutral) with a 32A RCB in the consumer unit. I discovered this ring also supplies the central heating (i.e. gas boiler, programer, thermostat) - btw... not protected by the RCD in the consumer unit (as are two socket rings and the oven circuit ring).

So would adding a spur off the isolator switch be possible?

And is it strange that the fridge and freezer share the central heating circuit ring?

Could / should a sparkie move the central heating ring in line with the RCD then adding the spur?

Thanks for any feedback.

 

[ban-all-sheds]

This isolator switch is on a ring (has two live and two neutral)

Do you mean 2 of each in the supply terminals, and the cable to the freezer in the load ones?

How is the freezer connected? Plug? FCU?

RCB

MCB.

I discovered this ring also supplies the central heating (i.e. gas boiler, programer, thermostat)

It remains to be seen whether it's a ring or not. Do they go off when you turn the isolator off?

the oven circuit ring).

You have a ring just for the oven? Are you sure?

So would adding a spur off the isolator switch be possible?

Not really - there's no RCD protection, and the Wiring Regulations now require that for sockets and for cables concealed in walls.

And is it strange that the fridge and freezer share the central heating circuit ring?

It remains to be seen whether it's a ring or not.

Are there two conductors in the MCB?

What size is the cable?

Could / should a sparkie move the central heating ring in line with the RCD then adding the spur?

Is there a spare way on the RCD side?

 

[Scarum]

Thanks for getting back.

This isolator switch is on a ring (has two live and two neutral)

Do you mean 2 of each in the supply terminals, and the cable to the freezer in the load ones?

How is the freezer connected? Plug? FCU?

Two of each in supply terminals and a fused switch to supply the plug socket for the freezer.

RCB

MCB.

Yes

I discovered this ring also supplies the central heating (i.e. gas boiler, programer, thermostat)

It remains to be seen whether it's a ring or not. Do they go off when you turn the isolator off?

The isolator switch to the freezer(?) - no, only freezer off. Isolator in the consumer unit (?), yes, freezer (and fridge) and central heating off. I should rewrite all that, thermostat is not on ring as it was replaced recently.

the oven circuit ring).

You have a ring just for the oven? Are you sure?

Yes. Is that a problem?

So would adding a spur off the isolator switch be possible?

Not really - there's no RCD protection, and the Wiring Regulations now require that for sockets and for cables concealed in walls.

So if suitable, a socket with built in RCD is feasable?

And is it strange that the fridge and freezer share the central heating circuit ring?

It remains to be seen whether it's a ring or not.

Are there two conductors in the MCB?

What size is the cable?

Can't answer that now without turning all off, will check tomorrow.

Could / should a sparkie move the central heating ring in line with the RCD then adding the spur?

Is there a spare way on the RCD side?

.

Yes, a blank cover.

Thanks.

 

[ericmark]

Problem 1 is lack of RCD. As you say you can have RCD's built into sockets but the cable would also need protecting so would have to be the special Ali-tube type which I have not seen sold in small quantities so could be a supply problem.

The normal house to British Standard will have both final rings and radials and even may can some conductors in parallel often found supplying grid switches in the kitchen. Identifying what you have is another problem however since you say your getting an electrician to do the work he will identify what you have.

The recommended method is to have fixed items over 2kW on their own dedicated supply. This would include items like immersion heater and oven. Items which are semi-fixed like washing machine and tumble drier are also often given a semi-dedicated supply where a row of switches will control items like a washing machine, tumble drier, fridge, freezer. It is often called a kitchen ring although strictly speaking often not a true final ring circuit.

As a result there are some grey areas where one electrician will and another will not add to some circuits. So if you really intend to get an electrician then that's the first move. Let him say what he will or will not do. If you are just worried about Part P police and really intend to do the work yourself then the first point is to work out what you have.

In theroy every installation should have a description or diagram which says exactly what does what. It is always a good idea to have one of these as all well and good while everything is working but once something stops working very hard to find out where it should be supplied from. So that is step one. By switching off the MCB's find out where every socket and FCU is supplied from. If possible then stick a copy with the consumer unit.

There are a few things that don't seem to quite make sense. Like if the boiler is from a final ring how can the thermostat be from anything else but final ring? So once you have sorted out what you have then start again with description of what you have and what you want.

 

[Scarum]

Problem 1 is lack of RCD. As you say you can have RCD's built into sockets but the cable would also need protecting so would have to be the special Ali-tube type which I have not seen sold in small quantities so could be a supply problem.

The normal house to British Standard will have both final rings and radials and even may can some conductors in parallel often found supplying grid switches in the kitchen. Identifying what you have is another problem however since you say your getting an electrician to do the work he will identify what you have.

The recommended method is to have fixed items over 2kW on their own dedicated supply. This would include items like immersion heater and oven. Items which are semi-fixed like washing machine and tumble drier are also often given a semi-dedicated supply where a row of switches will control items like a washing machine, tumble drier, fridge, freezer. It is often called a kitchen ring although strictly speaking often not a true final ring circuit.

As a result there are some grey areas where one electrician will and another will not add to some circuits. So if you really intend to get an electrician then that's the first move. Let him say what he will or will not do. If you are just worried about Part P police and really intend to do the work yourself then the first point is to work out what you have.

In theroy every installation should have a description or diagram which says exactly what does what. It is always a good idea to have one of these as all well and good while everything is working but once something stops working very hard to find out where it should be supplied from. So that is step one. By switching off the MCB's find out where every socket and FCU is supplied from. If possible then stick a copy with the consumer unit.

There are a few things that don't seem to quite make sense. Like if the boiler is from a final ring how can the thermostat be from anything else but final ring? So once you have sorted out what you have then start again with description of what you have and what you want.

Thank you for your insight, which obviously highlights the need to get a qulified electrician in to check everything out on this kitchen / boiler ring.

I have to say the house was built by Wimpy 14 years ago (I have lived in from new) and the MCBs were not labelled in the consumer unit. Although I did what you suggested years ago (finding out which MCBs supply what) but as you say, there is no clarity over what is happening in the kitchen (boiler & fridge/freezer supply).

Thanks again for your time to read and reply.