Radial Circuit - Comments pleas

[JohnW2]

Most houses today have two circuits (RCD is a over current device)....

No, it's not (an 'overcurernt device') - neither in the the normal sense nor per the BS7671 definition of 'overcurrent'. OK, so it operates when the L-N current imbalance exceeds a certain threshold, but that is not what we (or BS7671) mean by overcurrent.

Even if it were not for that, I would suggest that no sensible person would interpret the regs as saying that all 'final circuits' protected by a common RCD were a 'single circuit' - so I think you are probably just confusing the issue! No sensible person would attempt to argue that a new set of wiring/loads connected to a new (or previously unused) MCB/fuse was not a 'new circuit' (just because it was protected by a pre-existing RCD), would they?

Kind Regards, John

 

[deadshort]

I have come across problems with EICR's in the past where the inspector has given the circuit a code but I can't see why the code has been given. Code 2 - 415.1.1 is great even if it should not have been code 2 at least you know why it has failed.

The same with comments on the forum not permitted - 522.6.6 OK we all know the reason why and we can give why we feel it's not permitted.

No it doesn't. How did you comply with Part 6?

At least does show where he is looking and quite valid a plug in EZ150 tester only shows better than 1.50Ω and so does not give a 100% answer as to if it passes. Can't remember new limit for a ring final but not talking about a ring final and 16A spur is around the 2.73Ω mark so good enough.

OK the 40 mS tripping time needs a special meter but he did say except for RCD testing. What we must remember is enquiry is a permitted method so to get some one else to test and then use those results on the paper work you have raised is permitted.

I see nothing wrong in getting an EICR done then copying the test results onto an EIC and signing it. Neither is there anything wrong with using a three signature form.

As to LABC accepting the paperwork I will agree I did myself have problems. But the Liverpool inspector was very helpful and the Cheshire one was not too bad it was only the Flintshire one who raised objections. It does vary council to council and not even sure if notifiable anyway.

We have argued again and again as to what is a new circuit. Until some one is taken to court we do not have the answer. It would seem adding a FCU does not make a new circuit under Part P but it does with BS7671 so if adding a FCU does not form a new circuit then why would adding a MCB form a new circuit they both do the same thing after all.

If I was asked is it a new circuit if so you need to pay £5 I would say yes it's a new circuit, but if they want £100 then I would answer no it's not a new circuit as I would not want to pay £100 for a rubber stamp. And until the minimum charge is dropped to a reasonable figure I am sure most people who would need to register the work with the LABC would say the same until a test case shows other wise which is unlikely to happen with owner occupied property.

Most houses today have two circuits (RCD is a over current device) which are further split into more circuits (MCB's) but with a populated CU non of those circuits will be new.

Yes I will agree this is not what was intended by the law but it will require case law to clarify. If the house was being rented out then I would not take a chance we have seen how courts are very quick to find land lords guilty so the tenant can claim compensation. The Mrs Whittall case is a good example. But for owner occupier DIY I know of no cases where the grieving husband has been taken to court for killing his wife.

Since he was able to show a reasonable drawing and work out he has a TN-C-S supply I would not class Jackson as an idiot and if we expect every regulations to be followed both in spirit and word then may as well get rid of the Electrics UK section of DIYNOT.

Well said Eric, I agree 100%.

 

[ericmark]

An RCD measures current differential across a number of conductors with a current transformer and if that current goes over the permitted limit then it trips. It therefore has to be an over current device. I know that is not likely the meaning envisaged when the team wrote BS7671 but never the less simple English must consider this as over current so therefore their use must form circuits. In fact 314.1 (iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced seems to point to BS7671 considering RCD's form circuits.

The problem is not with BS7671 or Part P the problem lies with the scheme operators who have deemed FCU's as not forming a circuit when clearly they do. This has also been the case with duel RCD's with consumer units the scheme operators have deemed it needs 2 RCD's to comply and in real terms it depends on the size of the dwelling. We all know narrow boats and caravans can run on two 30 mA RCD's in series without a problem yet we still say that should not be done in other dwellings and clearly some bed sits are no larger than a caravan.

But Part P does not just say circuit it says "New Circuit" and this also leaves a problem. In my house I have a 16A MCB feeding a double socket below the distribution unit/fuse box (although now fitted with MCB's it was produced before the type testing came out so is not a consumer unit). Since already a circuit it in England I could extend this as much as I wanted as long as it did not go into the bathroom. I can also plug in different sizes of MCB up to the carrier maximum.

But again in real terms it does not matter what the regulations or law says we all know in real terms any DIY person is unlikely to do the work correctly as the equipment required is so expensive. So the option is give advice to make it safer even if it does not completely follow regulations or law. Or say no point in having DIYNOT UK electrics section. If you consider the latter to be best option then why did you register?

If the question was asked on the IET forum then following Part P and BS7671 to letter is expected but that's not the case with a DIY site.

 

[deadshort]

Sad to say, in answer to your final question, it would appear that a few register to belittle and bully and bamboozle the poster leaving them confused and scared stiff. The classic is the post about making a table lamp,that is typical of this forum. The new look site looks great and obviously a lot of time and effort has gone in to the 'new look' but i fear unless attitudes change Diynot will not be for much longer as the few regular contributors are going to get p…. off.

DS

 

[bernardgreen]

One or two RCDs ?

Doesn't it come down to common sense and the over all safety of the occupants of the "protected" property.

If there is one RCD and it is tripped by a kettle of scalding water that has also scalded a person then the lighting circuit should NOT be on that RCD and neither should the socket that powers the base station of the cordless phone. First aid in the dark is difficult and 999 calls still need the cordless phones base station to have power. Try and find your mobile phone in the dark.

BS7671 is designed to try and achieve safety in the electrical installation. BS7671 was written with little if any regard or consideration of what can happen if one of the safety devices required by BS7671 operates to remove power from an electrically hazardous situation or fault.

 

[bernardgreen]

The fact is that people will continue to do DIY electrical work until the day it is declared to be a criminal offence. That will reduce the amount of DIY electrical work but not stop it.

Therefore any source of sensible information and advice that can be accessed by a DIYer doing electrical work is for the most part a good idea.

Perhaps the DIY work cannot be fully and comprehensively tested. Perhaps the RCD is slightly out of spec as regards it tripping time. May be the MCB is a bit slow in tripping compared to time it should take at a specific overload. But look at the specifications and they are very tight. Probably much tighter than is necessary in order to allow for some slackness in the quality of the installation.

That said all DIY work should be carried out to meet or exceed the quality required by B7671 and this forum can be valuable in encouraging DIYers to work to that standard. At the same time explain to the un-informed DIYer why that quality of work is required as many of the reaons for certain requirement are not clear, ( some electricians do not fully understand the reasons behind some of the requirements of BS7671 )

 

[JohnW2]

An RCD measures current differential across a number of conductors with a current transformer and if that current goes over the permitted limit then it trips. It therefore has to be an over current device. I know that is not likely the meaning envisaged when the team wrote BS7671 but never the less simple English must consider this as over current so therefore their use must form circuits.

With respect, as I said, IMO that is a silly argument that serves no purpose other than to confuse, particularly to confuse and potentially mislead DIYers. Even were it not for the BS7671 definition. I don't think there would be many people other than yourself who would seriously suggest that an RCD should be regarded as an Overcurrent Protective Device, or that everything protected by a common RCD (the entire electrical installation in some cases) should be regarded as 'one circuit' (so than nothing new protected by a pre-existing RCD would be a 'new circuit').

This forum exists primarily to assist and inform DIYers - not, IMO, to confuse and potentially mislead them.

Kind Regards, John

 

[JohnW2]

Sad to say, in answer to your final question, it would appear that a few register to belittle and bully and bamboozle the poster leaving them confused and scared stiff. The classic is the post about making a table lamp,that is typical of this forum.

I think you have probably chosen just about the worst possible example to support your (valid) point. I agree that it is not unusual for OPs to be 'confused and (sometimes unnecessarily) scared stiff' by responses here. However, in the case of the table lamp thread, the OP specifically wanted to know about all the legal, regulatory and liability issues/pitfalls/concerns associated with manufacturing electrical items for sale to the public - so, AFAICS, he really was looking to be 'scared stiff' if that were appropriate. He wrote:

... where do I stand with regards to the law and selling elictraical goods to the puplic. What safety measures/tests do I need to do (if any) or would i be ok if using low wattage bulbs and using ce certified parts, would I be able to sell with a plug fitted or not fitted? I have had a look at the govenment website and it seems to be very unclear. ... It seems to be a bit of a minefield ...

Kind Regards, John

 

[DocScrewdriver]

The fact is that people will continue to do DIY electrical work until the day it is declared to be a criminal offence. That will reduce the amount of DIY electrical work but not stop it.

Therefore any source of sensible information and advice that can be accessed by a DIYer doing electrical work is for the most part a good idea.

Perhaps the DIY work cannot be fully and comprehensively tested. Perhaps the RCD is slightly out of spec as regards it tripping time. May be the MCB is a bit slow in tripping compared to time it should take at a specific overload. But look at the specifications and they are very tight. Probably much tighter than is necessary in order to allow for some slackness in the quality of the installation.

That said all DIY work should be carried out to meet or exceed the quality required by B7671 and this forum can be valuable in encouraging DIYers to work to that standard. At the same time explain to the un-informed DIYer why that quality of work is required as many of the reaons for certain requirement are not clear, ( some electricians do not fully understand the reasons behind some of the requirements of BS7671 )

That's the most sensible response I've read on here or on any other 'DIY' forum. Keen and skilled DIY'ers are more than capable of working to and often above the standards needed.

 

[Taylortwocities]

Keen and skilled DIY'ers are more than capable of working to and often above the standards needed.

That is true, but the problem is that many DIYers - no matter how keen and skilled they may think they are in a DIY environment - are not aware of what the standards are.
Most contributors here will respond on the basis that the OP has no idea on the requirements of the Wiring and Building Regulations, nor what the legal requirements are.
Otherwise they would not post their query on a "DIY" forum, turning instead to forums that are aimed at folk who do have measurable levels of competence.

 

[JohnW2]

That's the most sensible response I've read on here or on any other 'DIY' forum. Keen and skilled DIY'ers are more than capable of working to and often above the standards needed.

I agree, but a few here don't. I personally feel that, within reason, it is better to try to offer assistance/advice to DIYers than to leave them to muddle along without any help, even if their level of knowledge/understanding/skill is clearly limited, and even though we accept that what they do will often in some ways be non-ideal, and strictly non-compliant with regulations (commonly because of limited facilities for testing). One problem is that, whilst you are right in saying that many 'skilled' DIYers are more than capable of working to adequate standards, some are clearly totally out of their depth, and even those of us who 'try to help when we can' feel unable to advise anything other than that they should not attempt the work they are talking about.

KInd Regards, John

 

[jbirschner]

Thank you for all comments. Much appreciated.

I would say that I got some experience in my background... not much related with residential but mostly industrial.
All residential electrics seem pretty easy only knowing the norms should suffice to make a perfect wiring system.

I do built industrial panels with MCBs, rellays, thermal overloads, plcs and also work with 3 phase 800A main panels and sub panels and so on... I do feel that my wiring diagram is not very good but to a perfect scenario I would do a proper Radial with 4mm (ring is not the best option in my view only if I under a 32a RCBO for a 4mm twin plus earth, 2.5mm would heat if one end splits and it could cause fire on a ring) and not using junction boxes at all. All circuits should be protected against over-current and also against earth leaks to prevent harm in case of a live phase contact. That's why we have MCBs and RCDs of a mix using RCBOs.

Everyone got different concepts regarding a subject and I think we should respect other opinions.

I do protect all my machines at work, without proper qualification, mostly for self learning and experience.

I will progress to my city guilds 2365, already studying to get qualified... but again by myself.

What ever I am doing I will get a qualified person to recheck all my work and certify it.

Thank you so much erikmark and others for all comments.

 

[Belboz]

Sad to say, in answer to your final question, it would appear that a few register to belittle and bully and bamboozle the poster leaving them confused and scared stiff. The classic is the post about making a table lamp,that is typical of this forum. The new look site looks great and obviously a lot of time and effort has gone in to the 'new look' but i fear unless attitudes change Diynot will not be for much longer as the few regular contributors are going to get p…. off.

DS

I have said this before but my belief is that Electrical work ought to be treated in the same way as Gas. IMHO, the amount of DIY gas work has decreased considerably since the inception of Corgi and Gas Safe registration and the world is a safer place for that. Surely time to treat electrical work in the same manner? After all, electricity can kill just as much as gas. I am not saying that very minor electrical work cannot be undertaken by the DIYer but that should be the exception and not the rule. Time to give Electrics the respect it deserves.

Personally, I don't think the issues about belittling and bullying are a major issue. Most posters on here who are electrical experts are actually trying to give good advice which is intended to prevent injury or death by potential electrical bodgers. Their concerns are well-meaning and, more often that not, founded on experience and a knowledge of the pitfalls.

The one issue here is that posts asking about electrical issues quickly descend into an expert debate and become so full of technical terminology that posters cannot 'see the wood for the trees'. William Hill (there are other bookmakers available!) should give odds as to how many posts on an electrics topic it will take before the original points is lost and the debate about BS1234 and the inner workings of a multi-amp hokey-cokey 2000 radial ring consumer unit take over.

 

[jbirschner]

That's true Belboz, simple question require a simple answer.

I do agree that all areas are dangerous and should be done by a registered expert, like Gas, Steam, Electrical, industrial Gas Burners and so on... I deal with all with only knowledge acquired online and own experience and always had an expert to check my work and never had a problem.

Everybody is imperfect and registered or not a person will make mistakes and whoever has more knowledge is less prone to errors and your comment is valid.

By the way, what do you say about that diagram?

Regards, Jackson.

 

[riveralt]

What ever I am doing I will get a qualified person to recheck all my work and certify it.

I think this is most frustrating thing about your post(s) - You are still not listening to what is being said or probably you do not want to hear what is being said.
So I will try again. This is predicated on the belief that this is a new circuit as per your drawing and putting aside all the issues of testing.
Your drawing is fine - the way in which you have designed the circuit - while okay - unnecessarily adds weaknesses to the radial circuit - which should be rectified.
Despite what you say no qualified Competent Person Scheme member will legally be able to recheck your work nor will they legally certify it and register it with your LABC as is required by law.
If that makes me a PITA then so be it - the advice has been offered - its up to you whether you heed it.