100ma RCD on sockets

[Lillpete]

I have carried out some repairs to a small cottage (TT suplply all covered by a 100ma rcd and services bonded in 10mm) today which entailed relacing a damaged cable to an outide light and while I was there I installed a mains powered smoke alarm, all the cableing I worked on was run either in the loft or surface and the Zs was 7.2 ohms so the lack of a 30ma RCD is not a problem (I beleive) for this curcuit however the sockets (which have not been altered since the early 80's) have a Zs of around 7 ohms. Obviously this ideally would have a 30ma RCD, however as there is no outside space for them to use equipment outside (thinking back to old regs) is it safe for this to be left as is?

It is an elderly couple and they are not very well off so a new consumer unit would be hard for them to afford.

 

[Andy™]

i would recommend adding a 30mA, but at least they have some protection from the 100mA

 

[Evans Electric]

Could you add a 30mA RCD remote from the board , shouldn't cost too much.

 

[spinlondon]

Can you replace the 100mA with a 30mA?

 

[Lillpete]

That would make it safer but is the "its better than when I found it" acceptable? as it would obviously be an alteration to the installation that would not meet current discrimination rules??

what do you think??

 

[Andy™]

safer than it was. just make a note that you have deviated slightly by installing one RCD for all circuits

 

[binky]

By the time you've bought the RCD, an enclosure is only @

 

[Evans Electric]

Binky, Interesting that you say " he shouldn't have started the work if it doesn't comply" . When we return to 2nd fix a kitchen we started, the new c/unit will be a split-load as in the 16th edition . Our new work will be covered by the RCD but the rest of the house won't . It will be an improvement from the old Wylex Rewirable but as you say , doesn't comply with 17th . Its what the customer wants.

I have to say, it doesn't bother me in the least, our work is covered and we havn't made anything worse.

 

[a1spark]

These phrase " Have not made anything worse" or its "Safer than it was" confuse me !

All additions or alterations should comply with the current Ed of B.S 7671.It is not an option to pick and choose which parts of the Regs to adhere to suit personal preferences !

I am aware of these phrases being used in the context of the building Regs when carrying out Electrical work which is an accepted practice, but it refers to Fire Ratings--Acoustic Ratings..Drilling holes in joists etc NOT the Design of the Electrical Installation

a1spark

 

[Evans Electric]

A1 I appreciate what you say, but we don't live in a perfect world. The cusomer had stated categorically that he didn't want the Wylex rewirable taken out. I said we would have to fit a new board next to it then, for the kitchen work. Didn't want that either. So the compromise is the split-load .

A year ago the split-load would comply and raise no adverse comment on here . The new regs do not make all the work carried out to the 16th suddenly unacceptable. As I have said before ,we are not The Electric Police , I can't make the customer have a 17th ed. board if he doesn't want one.

 

[SPECIAL LOCATION]

A1 I appreciate what you say, but we don't live in a perfect world. The cusomer had stated categorically that he didn't want the Wylex rewirable taken out. I said we would have to fit a new board next to it then, for the kitchen work. Didn't want that either. So the compromise is the split-load . A year ago the split-load would comply and raise no adverse comment on here . The new regs do not make all the work carried out to the 16th suddenly unacceptable. As I have said before ,we are not The Electric Police , I can't make the customer have a 17th ed. board if he doesn't want one.

?

:| ?:|

So you ARE taking out the wylex and putting those circuits onto part of a new CU?

Some of your modified kitchen work will be on an RCD on that same board...?

Yet ONE additional RCD for the rest of the original circuits would only be about

 

[a1spark]

A1 I appreciate what you say, but we don't live in a perfect world. The cusomer had stated categorically that he didn't want the Wylex rewirable taken out. I said we would have to fit a new board next to it then, for the kitchen work. Didn't want that either. So the compromise is the split-load . A year ago the split-load would comply and raise no adverse comment on here . The new regs do not make all the work carried out to the 16th suddenly unacceptable. As I have said before ,we are not The Electric Police , I can't make the customer have a 17th ed. board if he doesn't want one.

I know its a dilemma and I know you have covered your part of the work with the RCD protected side of the board..my post wasnt really referring to your situation....it was referring to the posters who freely turn a blind eye to ommisions in Safety on an existing installation when carrying out additions or alterations.

In the case of your Kitchen job I think you could put on the EIC . Change of C.U. due to "Distress condition" of the existing unit...stating customers reluctance to install dual rcd board.....I think that would cover you in any issues arising from future P.I.Rs etc.

Regards a1spark

 

[Evans Electric]

Its not my choice, Specs, the customer doesn't want an RCD on his existing wiring , he didn't want one on the new work but I had to say that we couldn't connect it (a) to his Wylex and (B) without an RCD . He has done alterations to it , we have already removed a switch drop wired in telephone cable , ( 2 pair twisted) that we came across . He says it has worked for 10 years ,what is the fuss, and he,s not even paying us for doing it because he deems it unnecessary.

I know there are guys on here who will say they would walk away from it, they may think different after a long spell of only working 2 days a week , sometimes one.

The existing wiring goes down as "Not inspected, reconnected as existing"

 

[Lillpete]

By the time you've bought the RCD, an enclosure is only @

 

[Andy™]

i would make sure the new part is RCD'd. not the existing. (but still recommend it)

 

[spinlondon]

Two schools of thought here.

One states that if work is done to an existing circuit, then the whole circuit right back to the board has to comply with the current Regs.

The other is that only the part that is worked on must comply with the current Regs.

In Evans Electric's case It could be argued that there is no Reg. requiring that RCDs are housed in the CU, so by placing only the new circuits on the RCD protected part of the board, you can note under observations on existing installations the lack of RCD protection.

In the OP's case, it is a requirement that all socket outlets must be protected by a 30mA RCD. One could replave the 100mA RCD, and then note that there is no discrimination as an observation about the existing installation.

There used to be a Reg. in the 16th. 721-01-02

"It shall be verified that every alteration or addition complies with the Regulations and does not impair the safety of an existing installation."

I don't know if that Reg. has been retained by the 17th.

 

[binky]

Binky, Interesting that you say " he shouldn't have started the work if it doesn't comply" . When we return to 2nd fix a kitchen we started, the new c/unit will be a split-load as in the 16th edition . Our new work will be covered by the RCD but the rest of the house won't . It will be an improvement from the old Wylex Rewirable but as you say , doesn't comply with 17th . Its what the customer wants. I have to say, it doesn't bother me in the least, our work is covered and we havn't made anything worse.

Non compliance isn't an acceptable position - we install to the 17th (and certify accordingly)and can't back track (I had this discussion with my assessor this year). However there are ways of complying, like mini CU for kitchen and leave the rest, its cheaper than 16th CU if customer is that awkward headbang . I tend to agree that RCDing lights seems overkill but that is now the requirement so you can comply or leave circuit alone. Our legal liability is to the regs not the customer, afterall the customer probably wants the job for

 

[wozz]

i cant see the problem with this one (i may be missing something)

why should you have to RCD a existing circuit if you are extending it? as long as you RCD (if required) your work i think you are ok. As long as your recommendations are noted on MWC.

The OP hasnt installed anything thats needs RCD protection has he?

 

[binky]

i cant see the problem with this one (i may be missing something) why should you have to RCD a existing circuit if you are extending it?

Extending is modifying a circuit - all works therefore should be to 17th which includes RCD light circuit. That's the official position. However IMHO for 1 smoke alarm I probaly wouldn't bother, because it seems overkill to me, start adding more stuff, then I probably would, becuase level of involvement is higher. At this years assessment, I had marked a MWC in the way discussed here with a comment in the non-compliance box - I was told off.

 

[wozz]

if you are getting told off for it you have to go with what your scheme says although this seems to say different

http://www.esc.org.uk/forum/forum_ed_thread.html

EDQ3

In the answers it states the extended part of the circuit must be RCD not the existing.