Separate RCD circuit for fridge and freezer

[bonebill]

I am planning on having a split-load CU.

I though it might be an idea to put in a separate circuit to power two separate single 13A sockets, one for a fridge/freezer, and one for a freezer.

I thought it could go on the non-RCD side of the CU, but fed out through an RCBO.

So the fridge and freezer would still be behind an RCD but wouldn't be killed by a trip on the main RCD.

Since it's only powering a fridge and a freezer, I thought I could do it on a radial circuit using 2.5mm cable with a 16A RCBO.

Is that allowed?

Even if it is allowed, would I be better off making a ring circuit instead and using a 32A RCBO?

Another quick question: looking at the MK RCBOs on tlc-direct, the 16A RCBO is 2 modules wide but the 32A one is only 1 module wide. It seems strange that the higher rated one would be smaller. The MK specs document only mentions 1 module wide versions. Is the 2 module wide version old stock?

 

[andy]

make a 2.5mm radial on a normal 16A MCB on the non-RCD side

 

[plugwash]

I am planning on having a split-load CU.

I though it might be an idea to put in a separate circuit to power two separate single 13A sockets, one for a fridge/freezer, and one for a freezer.

I thought it could go on the non-RCD side of the CU, but fed out through an RCBO.

So the fridge and freezer would still be behind an RCD but wouldn't be killed by a trip on the main RCD.

Since it's only powering a fridge and a freezer, I thought I could do it on a radial circuit using 2.5mm cable with a 16A RCBO.

Is that allowed?

Even if it is allowed, would I be better off making a ring circuit instead and using a 32A RCBO?

Another quick question: looking at the MK RCBOs on tlc-direct, the 16A RCBO is 2 modules wide but the 32A one is only 1 module wide. It seems strange that the higher rated one would be smaller. The MK specs document only mentions 1 module wide versions. Is the 2 module wide version old stock?

TLCs picutures are somewhat dubious in general.

a 16A cuitcuit with 2.5mm cable is fine.

no real need to RCD the fridge and freezer though of course there is nothing stopping you using a RCBO if you wan't to.

 

[ban-all-sheds]

no real need to RCD the fridge and freezer

Good idea not to, IMHO

 

[breezer]

fridges / freezers have been known to trip an rcd when there is nothing wrong, which is why it is suggested you put them on the NON rcd side of your CU

that way you can go on 'oliday and come back to find fridge & freezer still on

 

[bonebill]

fridges / freezers have been known to trip an rcd when there is nothing wrong

hmmm. perhaps there was something wrong...

Anyway thanks for the advice guys. I guess I'll have a separate circuit for the fridges on the non-RCD side. I'll probably stick it on a plain 16A MCB and be done with it.

 

[plugwash]

there is quite some difference between will trip an rcd and dangerous.

the main reason we fit 30ma rcds is for supplementry protection against direct contact between the human body and the mains.which with large mostly static appliances is extrmely unlikely in the first place.

there was a stage of rcd madness when it was normal to use a 30ma rcd as the main incomer. Gradually people have realised this is not so smart.

 

[kai]

Have Two B16amp MCB circuits for them, One for the Freezer and One for the Fridge - that's the best way.

 

[andy]

Have Two B16amp MCB circuits for them, One for the Freezer and One for the Fridge - that's the best way.

isnt that going a little OTT? i mean most places have a seperate ring for the kitchen, but not to extra radials for the fridge and freezer!

 

[ban-all-sheds]

I think a separate circuit for the F/F, or the fridge and the freezer is a good idea, as it allows you to leave the kitchen sockets, which could reasonably be expected etc, with RCD protection.

And with only 1 or 2 loads there's not much point making that circuit a ring.

But I think that one circuit would be enough.

AFAICR, the idea of nuisance trips to RCD circuits in this respect relates to people who have overhead supplies - TT or converted PME, as close lightning strikes can trigger a trip of a whole-house RCD. Whether this same vulnerability applies to a split-load board, or an RCBO, IHNI, but given that a F/F does not need RCD protection, and given that the consequences of a nuisance trip could be the loss of several hundred pounds worth of stuff, I can see no good reason for ever putting one on an RCD circuit.

 

[bonebill]

fridges / freezers have been known to trip an rcd when there is nothing wrong

hmmm. perhaps there was something wrong...

Just been sniffing around for what might cause earth leakage.

Stumbled across section 607 and standing protective conductor currents.

I will probably have at least two PCs, and a printer, and an LCD monitor (c/w SMPSU), and probably some other SMPSU devices that I haven't thought of, so a bunch of SMPSU devices.

So it looks like I might want to be thinking about section 607 compliance for my main socket ring...