Is it a 2 or 4 Pole RCD?

[Jon7]

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

 

[Octopus]

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]

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-sentr...gclsrc=aw.ds&dclid=CJHxuuv-gN4CFQ8o0wodtIsGRw

 

[davesparks]

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]

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]

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

 

[Octopus]

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

 

[Jon7]

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

 

[Octopus]

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]

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.

 

[Octopus]

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]

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.

 

[Octopus]

New people posting is what makes it interesting on here and gives it some variety.

hum ......................................

 

[TJ Anderson]

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.

 

[Octopus]

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...............

 

[The Ghost]

https://www.screwfix.com/p/mk-sentry-2-module-63a-30ma-rcd/86634
It does say that it is a replacement from an MK bod on the Q&A part and can be used to replace the existing one. But not to worry you can always split the tails to a henley block and put an RCD for something else like garage etc. independently. Sure your chosen spark will tell you of this alternative.

 

[Dave OCD]

No that's a 63a, the original 4 module RCD is 80A rated.

 

[TJ Anderson]

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...............

I agree, I know a lot of them are doing it themselves

https://www.screwfix.com/p/mk-sentry-2-module-63a-30ma-rcd/86634
It does say that it is a replacement from an MK bod on the Q&A part and can be used to replace the existing one. But not to worry you can always split the tails to a henley block and put an RCD for something else like garage etc. independently. Sure your chosen spark will tell you of this alternative.

That is not an equivalent. That is 63A. The existing is 80A.

 

[Spoon]

Damaging? It can only serve to improve the forum if it discourages diyers from posting.

I have to disagree with you here mate. We have a DIY section to help them out. We just can't give out step-by-step instructions. It is up to each forum member if they want to help or not. Simple.

 

[Spoon]

I just wanted advice as if it can't be done I'll need to cost up a CU replacement with my spark!

As @Vortigern has already mentioned. If the RCD can't be replaced your electrician could add another small CU next to the existing one. This can feed the garage.

 

[littlespark]

I guess a few forum members have had a bad week to be this tetchy on a Friday.

To change the 4-module sized RCD to one that only takes up 2 would mean sourcing another busbar that feeds the MCBs. The one you have will be 2 pins short.
The idea of Henley blocks on the tails to feed a separate RCD isolating switch to supply the new outside installation is the sensible choice.

 

['mr2'gd4u]

I think Murdoch was merely pointing out that its a new circuit addition and changes to cu so basically make sure you get a spark in? Just... Kinda like a note.

 

[Jon7]

Thanks all, some very sensible advice and just to re-iterate I'm not doing this myself. I've spoken to my spark and the wheels are in motion for a professional and most importantly safe installation.

 

[TJ Anderson]

After your discussion, what have you decided to actually do then?

 

[Sintra]

@Jon7 We have given you diy status and moved your thread to the diy section of the forum as this section of the forum is for members that will give you constructive advice.

 

[mossep]

You can buy a 2 pole MK RCD, a new bit of bus bar and a split load kit that will give a flexible neutral link cable. Get an electrician to do it though, it’s not a DIY job

 

[Midwest]

First of all I didn't want to start any arguments so apologies for this

I dunno, somebody comes to the forum to seek some guidance, then ends up trying to break up a fight, and then apologies for starting it