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Discuss Is it a 2 or 4 Pole RCD? in the DIY Electrical Forum area at ElectriciansForums.net

Jon7

DIY
Hi,

New to the forum and not an electrician so be gentle .

I'm looking to install an outside electrical supply to my shed for lighting and some sockets etc and have the armoured cable ready to go. However on looking at my consumer unit there isn't room. However the MK RCD is taking up 4 spaces in the box. When I have looked up the RCD it seems to be a 2 pole but modern 2 pole RCD's are much smaller. Can someone confirm this is a 2 pole RCD and if it's ok to be replaced with a modern smaller type please (image attached to post)?

Cheers

Jon

IMG_20181012_131608.jpg
 

Murdoch

Electrician's Arms
Maybe consult a spark ........ lots to think about apart from what you mention and there's BS 7671 and Part P compliance too...
 

TJ Anderson

Forum Mentor
Electrician's Arms
Trainee Access
DIY
Hi,

New to the forum and not an electrician so be gentle .

I'm looking to install an outside electrical supply to my shed for lighting and some sockets etc and have the armoured cable ready to go. However on looking at my consumer unit there isn't room. However the MK RCD is taking up 4 spaces in the box. When I have looked up the RCD it seems to be a 2 pole but modern 2 pole RCD's are much smaller. Can someone confirm this is a 2 pole RCD and if it's ok to be replaced with a modern smaller type please (image attached to post)?

Cheers

Jon

View attachment 44821

Yes, it is a 2 pole unit but it's an older style type that takes up more space (4 ways in consumer unit)

As you rightly say, modern RCD'S are smaller. The current 80A/30ma MK Sentry 2 pole RCD only takes 2 ways which would free up 2 for other devices.

https://www.screwfix.com/p/mk-sentry-80a-30ma-dp-type-ac-rcd/35907?tc=AA1&ds_kid=92700019938271463&ds_rl=1248181&ds_rl=1245250&ds_rl=1249484&gclid=EAIaIQobChMItf-r4P6A3gIVK7vtCh3w7gZzEAQYAiABEgL5FPD_BwE&gclsrc=aw.ds&dclid=CJHxuuv-gN4CFQ8o0wodtIsGRw
 

davesparks

Forum Mentor
Electrician's Arms
Trainee Access
Yes that is operating as a two pole RCD, but no you can’t just swap it for a 2 module wide equivalent.
That CU is designed and built to work with the four module unit you have, a new two pole unit will not be a direct swap and trying to fit it in will create a significant fire risk.
 

davesparks

Forum Mentor
Electrician's Arms
Trainee Access
I'm looking to install an outside electrical supply to my shed for lighting and some sockets etc and have the armoured cable ready to go.
Do you have the correct cable glands to go with the armoured cable and know how to fit them?
Do you understand how the armour provides the necessary protection to the cable and how it will be dangerous if it’s not correctly terminated with glands and earth connection?
And for that matter what conductor size is the armoured cable and how did you calculate the size required?
 

TJ Anderson

Forum Mentor
Electrician's Arms
Trainee Access
DIY
Do you have the correct cable glands to go with the armoured cable and know how to fit them?
Do you understand how the armour provides the necessary protection to the cable and how it will be dangerous if it’s not correctly terminated with glands and earth connection?
And for that matter what conductor size is the armoured cable and how did you calculate the size required?
Why ask him that? He didn't ask you that did he?

He only asked about the RCD.

He probably drives a car too. Why don't you ask him if he has a driving licence and understands the risks of the road? Lol
 

Murdoch

Electrician's Arms
Why ask him that? He didn't ask you that did he?

He only asked about the RCD.

He probably drives a car too. Why don't you ask him if he has a driving licence and understands the risks of the road? Lol
I've given you a disagree - mainly because the OP states he's not a spark so extremely unlikely to understand what is required
 
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Jon7

DIY
Hi everyone,

Thanks for your replies. I'm only looking for a few sockets and a light in the shed, it's not going to run any high loads like in a workshop.

I will consult an electrician when it comes to installation etc as I'm not going to risk my family's life for the sake of a few sockets in my shed.

At this stage I just wanted to know if I could replace the current RCD with a modern small one as that will effect cost, i.e. if I need to replace the Consumer Unit.

Thanks,

Jon
 

Murdoch

Electrician's Arms
1 thing for sure is that having a single up front RCD is NOT a good idea, less so if you connect circuits outside the house

1 fault and everything goes off

Where in Wales are you ?
 

TJ Anderson

Forum Mentor
Electrician's Arms
Trainee Access
DIY
I've given you a disagree - mainly because the OP states he's not a spark so extremely unlikely to understand what is required

It's not a step by step guide is it. I just a answered his question regarding an RCD type. I didn't give him an install guide on how to replace it.

Also. Telling everyone who asks a question to get an Electrician in on every question, no matter what, is ridiculous, unhelpful, boring and damaging to the forum. I do appreciate you are self employed and rely on domestic customers for your living. You chose to do that. To be blunt, your business situation is not everyone else's so you can't steer everyone else that way.
 
Last edited by a moderator:

Murdoch

Electrician's Arms
Telling everyone who asks a question to get an Electrician in on every question, no matter what, is ridiculous, unhelpful, boring and damaging to the forum.
So you don't think giving a self admitted non electrician a recommendation to consult a competent spark is bad advice then ?

That would be ridiculous
 

Jon7

DIY
First of all I didn't want to start any arguments so apologies for this and secondly I'm not DIY'ing this, I just wanted advice as if it can't be done I'll need to cost up a CU replacement with my spark!

Just wanted advice that is all.
 

Murdoch

Electrician's Arms

TJ Anderson

Forum Mentor
Electrician's Arms
Trainee Access
DIY
So you don't think giving a self admitted non electrician a recommendation to consult a competent spark is bad advice then ?

That would be ridiculous
You are taking it out of context. Not every question requires "Get an Electrician" as the answer. The OP of this thread asked a straight forward question about an RCD.
 

Murdoch

Electrician's Arms
You are taking it out of context.
No .......... then its how can I do this? My spark is on holiday? My spark is asking me to buy .................

Cynical - maybe .............. but so often happens...............
 

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