Rcd/rcbo

[pig]

Hi all,
There is a 'utility' circuit in an outbuilding which feeds three 1 gang sockets in turn, one for a fridge freezer, one for a tumble dryer and the last one for a washing machine. What I am wondering is whether to put the circuit on a 20A RCBO and then use switched 1 gang sockets, or use a 20A MCB and then a RCD socket for the fridge freezer. My question is would this way better as it would ensure that the tumble dryer or washing machine couldn't trip the RCD as the fridge freezer would be on its own RCD? If this is the case would the tumble dryer and washing machine also require RCD protection? If doing this with a RCBO then I would install a neon socket for the fridge freezer so it is easy to see at a glance that the power is present. The sockets are located next to the three appliances so the neon would be clearly visible at all times.
Regards.

 

[Pete999]

Is your consumers unit in the house a modern type, more to the point does the consumers unit have RCDs installed already?

 

[telectrix]

if these sockets are each labelled for a specific use. e.g. washer, tumble dryer,freezer, and the cables are not buried in walls < 50mm deep, then RCD protection can be omitted.

 

[pig]

Yes it's almost brand new. The consumer unit has a RCD protected side so I was going to put this circuit onto the non-RCD protected side so the food in the fridge freezer isn't lost if the RCD trips. What i'm not sure about is whether to put this circuit on a RCBO or a MCB with a RCD socket for the freezer. Reason I'm thinking is because the tumble dryer or washing machine could trip the RCBO, but then using a MCB, only the fridge freezer would be RCD protected (using a RCD socket)
Thanks.

 

[pig]

if these sockets are each labelled for a specific use. e.g. washer, tumble dryer,freezer, and the cables are not buried in walls < 50mm deep, then RCD protection can be omitted.

Yes the sockets are wired with SWA so the cable and accessories are surface mounted. I had already thought of labelling each socket so it can be seen that those sockets are for the appliances that it is labelled for only. Thanks

 

[andyb]

Why do you want to omit rcd protection for sockets supplying a washing machine and tumble drier?

 

[Richard Burns]

Why not just fit RCD protected sockets at each location.

This then avoids the fairly low grade specific socket idea and provides individual additional protection to each appliance.

 

[gazdkw82]

Wouldn't it best to just RCD the lot? Have a trial period and if it keeps tripping then move the freezer onto its own RCD?

 

[Pete999]

Yes it's almost brand new. The consumer unit has a RCD protected side so I was going to put this circuit onto the non-RCD protected side so the food in the fridge freezer isn't lost if the RCD trips. What i'm not sure about is whether to put this circuit on a RCBO or a MCB with a RCD socket for the freezer. Reason I'm thinking is because the tumble dryer or washing machine could trip the RCBO, but then using a MCB, only the fridge freezer would be RCD protected (using a RCD socket)
Thanks.

Not much chance of discrimination when you install RCDs in the same circuit, Pig ask the Mods for permission to post in the trainee forum,

 

[Octopus]

Wouldn't it best to just RCD the lot? Have a trial period and if it keeps tripping then move the freezer onto its own RCD?

And then if it trips have a freezer full of defrosted food?

What's the cable size?

 

[Leesparkykent]

My freezer has been on an RCD for the last 10years and I've never had a problem with it being on an RCD or lost a freezers worth of food....

 

[gazdkw82]

And then if it trips have a freezer full of defrosted food?

What's the cable size?

Is is there no way to trial the freezer for a week without food in it?

 

[Davisonp]

And then if it trips have a freezer full of defrosted food?

If the RCBO is tripped by a tumble drier or washing machine, then it should be noticed long before a problem with defrosting food.
Individual RCD sockets would prevent anything other than a problem with the freezer itself causing food to defrost.

 

[ipf]

My freezer has been on an RCD for the last 10years and I've never had a problem with it being on an RCD or lost a freezers worth of food....

Yeah...I'm still baffled by all this lot, too.

 

[gazdkw82]

We had an a freezer in our garage and it tripped the RCD quote a few times. Ended up scrapping it in the end

 

[pig]

And then if it trips have a freezer full of defrosted food?

What's the cable size?

Cable size is 4mm XLPE SWA.

 

[Octopus]

Cable size is 4mm XLPE SWA.

Is this for you or a client?

 

[Leesparkykent]

whats the earthing arrangement?

 

[pig]

Is this for you or a client?

It is indeed for me so myself and the rest of my inhabitants will know about the arrangement.

 

[pig]

whats the earthing arrangement?

TN-S earthing

 

[Leesparkykent]

TN-S earthing

Thought id ask incase it was TT.

 

[Octopus]

It is indeed for me so myself and the rest of my inhabitants will know about the arrangement.

Maybe a cu in the shed with a rcbo for the sockets, a mcb for the freezer and a mcb for the lights