Are you replacing type AC RCD's with Type A?

[HappyHippyDad]

Just looking for a bit of clarification regarding RCD's.

A type AC RCD is no longer acceptable for offering additional protection for socket outlets. If you are (for example) adding one socket to an existing circuit are you all updating the RCD to a type A? I can see this being a bit tricky sometimes. It's ok if its a brand of consumer unit that does type A RCD's but this will not always be the case.

Do the regulations mean that if you are extending an existing socket circuit you cannot use an existing type AC RCD?

 

[Electro-tech]

I think it would depend on the circuit or circuits & what equipment the RCD is protecting. I guess changing it will cover further additions or changes of equipment that would need DC protection.

 

[Julie.]

Technically yes, it should be replaced, it's no different from before, if you needed to add an additional outlet or circuit, and the existing protection wasn't up to spec you would change the existing, or add something such as a rcd where there wasn't one previously.

It isn't something I quite agree with as there are always circumstances where this ups the price beyond what the customer is willing to pay.

For example, grandson finds granny fallen due to tripping over an extension lead (for the Xmas tree), so suggests adding a socket near the corner where the tree goes, - but, it needs rcd, none available for the existing cu etc - basically a single socket results in a new cu etc.

The end result is that nothing gets done to improve the situation, and granny goes back to using and tripping over extension leads!

I do sometimes think the distance we have to go in order to be compliant is a bit too far at times, I would much rather a half way there improvement to none at all - although of course we have to make sure this isn't abused

 

[Cagethethird]

You could always list it as a departure on the certificate. Not great but I think for a small job, the addition of a socket etc its okay, as long as you have offered the RCD change

 

[HappyHippyDad]

I think I may use a degree of common sense.

If I am able to change the existing type AC to a type A (fairly easily) I will factor this into the quote.

If it means a board change I may choose to give them that as an option rather than make it mandatory.

 

[HappyHippyDad]

You could always list it as a departure on the certificate. Not great but I think for a small job, the addition of a socket etc its okay, as long as you have offered the RCD change

I used to think the departures box was for this sort of use (ie get out of jail free). However, thanks to one @davesparks posts I realise this is not it's intended use.

The departures box is simply if you have done something that departs from BS7671, but (and this is the crucial bit) "The resulting degree of safety of the installation shall not be less than that obtained by compliance with the regulations" (120.3)

It would be less safe by using a type AC than a type A, so this isn't suitable for the departures box.

 

[Mike Johnson]

Same with all BS, if you depart from the content of the BS it must be to go "above and beyond" the requirements in that standard, this is quite clear from the HSE and has been tested in Court on a number of occasions.

 

[timhoward]

If replacing the device in the CU isn’t viable then I suppose changing a point on the ring for an RCD spur for the addition is a possibility now they are back in the regs.
Of course, either/both may trip but no one can say the addition doesn’t comply with latest regs.

 

[Cagethethird]

I used to think the departures box was for this sort of use (ie get out of jail free). However, thanks to one @davesparks posts I realise this is not it's intended use.

The departures box is simply if you have done something that departs from BS7671, but (and this is the crucial bit) "The resulting degree of safety of the installation shall not be less than that obtained by compliance with the regulations" (120.3)

It would be less safe by using a type AC than a type A, so this isn't suitable for the departures box.

Yes, I agree.
I was just thinking what could/would i do. This is going to be something we will all have to deal with over the next few years

 

[Vortigern]

I absolutely replace with A type RCBO. In fact you can't really get any other now. But aside from regs, if something can produce a safer installation then of course use it. I am a bit concerned that places like screwfix, b&q are selling dual rcd cu at pretty cheap prices. Recently I was asked to do a cu installation and the guy had bought two dual rcd which were the old AC type and I said he would have to take them back and get a refund as they don't meet regs now. I wonder how many have a go DIY are fitting these. And should such stores even be selling them. It does seem rather irresponsible of them to do so.

 

[westward10]

There is nothing stating type AC rcds do not meet 'the Regs'.

 

[Pretty Mouth]

I think I may use a degree of common sense.

If I am able to change the existing type AC to a type A (fairly easily) I will factor this into the quote.

If it means a board change I may choose to give them that as an option rather than make it mandatory.

I'll be taking the same approach. It makes sense to install type A on new installations etc, but I don't feel that existing circuits protected by type AC are going to be a great deal safer by installing type A.

 

[Pretty Mouth]

I absolutely replace with A type RCBO. In fact you can't really get any other now. But aside from regs, if something can produce a safer installation then of course use it. I am a bit concerned that places like screwfix, b&q are selling dual rcd cu at pretty cheap prices. Recently I was asked to do a cu installation and the guy had bought two dual rcd which were the old AC type and I said he would have to take them back and get a refund as they don't meet regs now. I wonder how many have a go DIY are fitting these. And should such stores even be selling them. It does seem rather irresponsible of them to do so.

I think amendment 1 will be withdrawn on 28th September, so AC still valid for the time being

 

[westward10]

I think amendment 1 will be withdrawn on 28th September, so AC still valid for the time being

Nothing to state they are precluded.

 

[happysteve]

NAPIT did a FAQ video, accessible from their installer portal (where you do the notifications) addressing this scenario, and their view is that if you're doing additions and alterations to a circuit, and where the new Regs would require a Type A RCD (i.e. unless it's a fixed load that could not leak DC under fault conditions) then a Type A RCD is required, i.e. if there is an existing Type AC RCD then this is not sufficient, and you need to do something about it.

A lot of my work involves minor works - additions and alterations to existing circuits.

A lot of the consumer units I come across were manufactuered by the likes of GET, Vytec, Steeple, GE, F&G, Contactum (the old ones with the brown MCB levers), MEM, CED, Legrand, "Plug-in-Systems", Tenby; or old Wylex/Crabtree boards with BS4293 RCDs and BS3871 MCBs. Chances of getting an RCBO or even a Type A RCCB to fit in those boards is pretty much nil (with the possible exception of the MEM RCBO pods). With a few notable exeptions, getting information from manufacturers about whether they approve the fitting of current (Type A RCBO/RCD) devices into older boards is like pulling teeth. Sometimes they're happy to talk to you on the phone, but they're rarely - if ever - willing to put anything in writing, and writen enquiries are ignored.

So if a new board is not wanted/economically unfeasible, then it's either a Type A RCD spur if it's lights, or I guess an external metal enclosure with a Type A RCCB if it's sockets (like doing minor works on a circuit off an old BS3036 fuse board).

It's a lot harder to explain to clients why it's necessary, too. When RCDs in general were introduced, and became required in more and more circumstances, it was easier to point out the difference in how an RCD will protect you where a fuse or circuit breaker won't. I suppose you could go along the lines of, "Well, it's not that the old RCDs are not safe any more, it's more that the things we plug into the circuits have changed," route, but then they point out that LED lights, and power supplies etc have been around for many years so why didn't they do this sooner, it feels a bit like the sort of uncomfortable conversation you'd have with someone in the 1990's who'd bought a garage with an asbestos roof a few years earlier.

One of the things that the CPSes could actually do that's useful is to collectively go round all the manufacturers of all the devices, and get written documentation about what is compatible with what. Their advice to "contact the manufacturer to confirm compatibility" is all very well but my own experience is enquiries go unanswered; and there must be so much duplicated waste of time when everyone's asking the same questions.