New Consumer Unit Installation - L&N Reverse at the sockets | Page 7 | on ElectriciansForums

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Some information to add, On May 16th the electricity company (the main electricity infrastructure company not the name on the electricity bills) comes to upgrade the supply side meter at the close mouth (for those that don't know, close is the entrance way to a Glasgow tenement). That will be upgraded in order for me to have SMART gas and electricity meters installed. This, with the CU replacement, is part of the general upgrade of systems in the house.
The supply side upgrades will include a new isolation unit as the existing fuse box with the big ceramic cartridge fuses is well out of date. I obviously don't actually know what they will be changing/installing as they don't share that information with me, of course! :)
Hi Vol, The electricity company, Scottish Power, have obviously noticed that the tap service supply to your flat needs upgrading, as do most tenement flats in Glasgow. This should not be at any cost to yourself.
If Scottish Power is also replacing your consumer unit, this will incur a charge, a quite hefty charge!
Regards, AldoTheHaldo.
 
The RCD does not "trump" reversed polarity the danger of reversed polarity trumps the RCD. If we leave aside the RCD for a moment, the danger lies between L-N. This means the installation can still be live even when the breaker operates (or is switched off) in the consumer unit for any particular circuit. The ramifications of that are quite exhaustively numerous.
While I think that the subject has been "beaten to death" I would like to address your suggestion vis a vis the trolls, it is only natural we will confer among ourselves in order to orientate ourselves to the facts presented against the facts not presented which are garnered by inference (we all sometimes have to fill in the blanks). I think any electrician knows there is no way you can leave a client with the situation you have described, I know I could not leave until I had rectified or issued a danger notice and isolated the supply and possibly called the DNO or maybe REC as @MrLights has suggested, (and if you look at his qualifications, I am sure you will attach significance to his statements)
An electrician would (must!) be aware this would break the law and leave the client in a hazardous situation. Personally I find a deep lack of congruency in the assertion that an electrician left you in such a potentially dangerous situation. It leads me to feel that there is something missing. I am not suggesting you are obscuring vital facts, I can accept you may have missed or not be able to know the true situation. The idea that RCD can obviate a reversed polarity is dangerously misleading. Again I can not imagine an electrician could have made such an assertion. Hence the sense of incongruency. Sorry to go on but there it is.
 
The RCD does not "trump" reversed polarity the danger of reversed polarity trumps the RCD. If we leave aside the RCD for a moment, the danger lies between L-N. This means the installation can still be live even when the breaker operates (or is switched off) in the consumer unit for any particular circuit. The ramifications of that are quite exhaustively numerous.
While I think that the subject has been "beaten to death" I would like to address your suggestion vis a vis the trolls, it is only natural we will confer among ourselves in order to orientate ourselves to the facts presented against the facts not presented which are garnered by inference (we all sometimes have to fill in the blanks). I think any electrician knows there is no way you can leave a client with the situation you have described, I know I could not leave until I had rectified or issued a danger notice and isolated the supply and possibly called the DNO or maybe REC as @MrLights has suggested, (and if you look at his qualifications, I am sure you will attach significance to his statements)
An electrician would (must!) be aware this would break the law and leave the client in a hazardous situation. Personally I find a deep lack of congruency in the assertion that an electrician left you in such a potentially dangerous situation. It leads me to feel that there is something missing. I am not suggesting you are obscuring vital facts, I can accept you may have missed or not be able to know the true situation. The idea that RCD can obviate a reversed polarity is dangerously misleading. Again I can not imagine an electrician could have made such an assertion. Hence the sense of incongruency. Sorry to go on but there it is.

Totally agree Vortigern. Again, if the polarity is reversed inside the cut-out, other flats in his tenement WILL more than likely be in the same very dangerous electrical condition. Immediate emergency response numbers in this situation are...
08000 92 92 90 OR 033 10 10 222 (Free from mobiles). Or dial 105.
More to say on this and others another time. Scary stories!
 
If the electrician doing the job was working in compliance with the 17th edition of the wiring regulations then he would have carried out two tests on every circuit before switching the power on. These tests would confirm that the CPC (earth) is present and at a suitably low resistance and the correct polarity at every point, also that the insulation resistance (integrity of the insulation) is acceptable on each circuit.
He would also have tested the polarity of the supply and the integrity of the incoming earth supply before switching on.
After switching on he would have tested every circuit with a live test for the integrity of the earth, this also confirms the polarity. He will also have tested each RCD to measure the time it takes to trip after a fault occurs at its rated tripping current and at 5x it's rated tripping current.

If the electrician has tested the rcds by the integral test button only then he has only proved that they work mechanically and not proved that they will provide electric shock protection.

Based on the polarity fault being present on every circuit it is most likely that it is on the incoming supply or the tails.
In my opinion it can now only be considered as being no better protected than it was before he started.
 
This is a rant. Don't read it if it's going to bore you. I realise that I run the risk of antagonising many with this but I feel bad about the accusations.

OK Vortigern, I'll bite. Your cosy rationalisation of unfounded speculation on the basis of easily refutable logic needs to be challenged. To all others, my apologies, for in this particular post, we have moved from my original two questions (is it dangerous? what could have caused it?) to an argument about the lazy assumption that "I must be lying". How does Vortigern and others arrive at that conclusion? - well it is based on the Notion of Infallibility of REAL electricians who would NEVER repeat never make a mistake and even if they did it just could not be a mistake of such catastrophic and dangerous proportions. Therefore, if it wasn't the electrician in the hallway whodunnit, who could it have been? Mmmmmm (ponders weightily).

The accusation you are presenting (which you lazily disguise as inference) is as sound as that used to dunk presumed witches. In other words, it isn't evidence at all. I originally raised the issue of trolling because I seriously doubted the motivation of some of the contributors, which in my opinion goes against the stated community orientation of the forum. And you virtue-signal this as "conferring amongst yourselves".

Here are the facts, believe them or not.

1. I contracted with an electrician after querying his qualifications and experience as much as reasonably can (for reasons best known to the electricity regulators and the electricians community, there isn't an easy online reference such as Gas Safe which can tell me instantly whether an individual, who carries photographic identification on a lanyard at all times, is registered and in which disciplines he has qualified). And as some on this and other threads have stated, registration on any of the existing (voluntary registration) electricians bodies is no guarantee of competence and vice versa.

2. I had already agreed a schedule with the Power Companies involved to get my meters changed to SMART meters in advance of the CU change. However, due to the need to change some of the electricity supply infrastructure before changing the meter, the CU change went ahead prior to the meter changeover. Both the supply company electrician who was on site to survey the meter change and the electrician who came to change the CU - both agreed the change in schedule wasn't significant.

3. Unfortunately, the electrician who came to change the CU did not test the sockets IN ADVANCE of the changeover from fuse box to the EN 61439-3, BS 7671 Amendment 3 compliant CU from British General. Everybody without exception has assumed that the electrician created the problem - perhaps he just continued an existing problem? As the infrastructure upgrade and the meter changeover have not yet taken place, we cannot be absolutely certain that the cause of the problem does not exist elsewhere from the CU installation. The issues about testing are mentioned later.

4. From what I could see, and I did watch from time to time, the electrician did the changeover from the old fuse box to CU diligently and neatly. The meter tails were upgraded as he suggested they should be. As I mention below, I'm not sure what testing was done, if any.

5. The property is old with both old and mixed old/new wiring, lots of surface cabling etc. I was pleasantly surprised when the double RCD units stayed positive when the system was switched on. I didn't expect the system to fail but it wouldn't have greatly shocked me (punny!) if it had.

6. I have to agree that, all the other issues notwithstanding, the electrician demonstrably failed in the adequate testing of the system, especially after the reversed polarity was discovered. Yes, he used a socket tester only at that stage (I can't say he hadn't done any other testing at the CU only that I didn't see that testing happen), one of the reasons I bought a similar and good reputation socket tester from Amazon - would another device of the same type replicate the problem?. [Here's another logical conundrum, for me anyway. If these devices are so crap, why believe their results? It is ONLY these devices that have uncovered the fault that has led to this long and meandering thread, why has everybody believed the output of these crap devices rather than perhaps challenging their results. Remember, the only testing which has shown reversed polarity, comes from these little plug in devices. Why are they so right even when they are so crap?]

7. Electricians disagree about things even on this excellent forum. Many on the thread say that reverse polarity is a potentially dangerous situation only under certain specific circumstances and the problem should be remedied as soon as possible. Others say, cut the electricity supply now, touch nothing and call this emergency number. Some say yeah, a bit of risk management is OK while waiting for the electrician to come ASAP and remedy the situation, others say that cannot happen, all must be cut now, no exceptions. This is a common feature it seems of electricians forums, disagreements about faults or solutions - either there is a hell of a lot of ambiguity in the regulations or there is a huge disparity in the skills levels involved (but it cant be that, cos electricians cannot make these kinds of mistakes according to Vortigern and others).

8. As soon as I contacted the electrician and told him of my concerns, he cleared his diary for Monday to come back and resolve the situation, free of charge. He has already said he will test every single socket for faults if there is no "central" or common fault/ solution. Me? I am worried that the fault somehow lies with the supply company's system and will mean even greater delays and upheaval. We can all agree that the situation should not have been allowed to exist but given it has, I think he is giving a fair response under the circumstances. This view will never satisfy the vitriolic critics but I prefer to live on my planet. NB We all agree he should never have left the reverse polarity situation in the first place.

9. Perhaps I still fundamentally misunderstand the overall processes about RCDs and safety, perhaps not. However, I can't shake the feeling that if the presence of RCDs cannot detect or protect against a reversed polarity situation, then there is some kind of design failure, or at least a missed opportunity. Given that there is so much safety literature out there about the need for correct wiring - and given that at least one qualified electrician has allowed a reverse polarity situation to exist :) - surely the 17th Ed mandated protections on the CU should cover the (remote) possibility of reverse polarity?

Because I live in an older flat and I am planning other electricity change projects, I read a lot about it. The number of forums where electricians just plain disagree with each other, both sets quoting the 17th Edition etc regulations (which some claim are still only advisory not compulsory anyway!) is scary.

That's enough from me, no more biting or ranting. Sorry to take up so much of your time.

As a courtesy to those who have given me pragmatic advice and information, I will update after the electrician has resolved/tried to resolve the problems tomorrow.

My sincere thanks again to those who have helped make my first venture to this Electricians Forums a pleasant and informative experience.
 
Vol sorry to see that you feel you have been vilified on this forum, but the truth is there have and will be hundreds of similar threads, where people have purported to have electric work carried out by electricians, when in fact they have carried out the work themselves and something has gone wrong.

Lets give you the benefit of doubt, and accept you have been subjected to poor electrical experience.

Without going through everything again, I think davesparks #98, encapsulates what most have said. The socket testers you speak of are not, test equipment per say, but are just a piece of equipment used on the completion of work, as a kind of double check on everything else that has been tested. Indeed, if the correct tests have been carried out, there is perhaps little use for them.

So therefore to 'discover' this fault with such a socket tester, at this stage is somewhat surprising. As regards disagreement between members, the wiring regulations BS7671, is a very large document, with vague sounding definitions & recommendations, so its not a surprise that we cannot all agree on the interpretation of every regulation.

Hope all go's well tomorrow, and let us know how you get on.

Kind Regards
 
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Hi Vol thanks for the reply. You did say in post no. 56
If you have a real suspicion of something germane, then speak up and give your evidence.
I offered something germane to the conversation. At no point have I stated or inferred you have lied. But if the cap fits then indeed wear it. In fact I took pains in stating I accepted this may be something beyond your ken. But no matter I have had worse insults on this forum and elsewhere. There is no evidence as there is no accusation. I will stand by my assertion that something is missing. You have been told the cause may be on the DNO side as opposed to the electricians. I would not venture opinion on such a set of vague facts without personally inspecting the installation myself (which I guess will not happen til hell freezes over!) However the fact you are left in this situation is a breach of the law. That is incontravertible. I suggest you take heed of the cautions you have been offered.
As regard differing opinions...you never heard your father debate engineering principles? Clergy debating interpretation of scriptures, politicians policies on and on. It is this very debate that reveals what is commonly accepted arriving at consensus opinion. We are not all automatons who regurgitate the "law" we are thinkers and like to mull on the possibilities. If the kitchen is too hot....
As regards socket testers, would you use a bicycle pump to pump up your car tire?
 
Well this really has turned into an epic, one that I wasn't going to get involved in.
But after reading Vols rant, there are a few things that come to mind.

@Vol:
1) Nobody said that we were infallible & don't make mistakes but in our industry, Your "Electrician" leaving you in the situation he has: To us that doesn't class as a mistake, it classes as sheer bloody incompetence.

2) I believe you said your electrician is NIC registered, you could have checked with them.

3) Don't remember you mentioning before this, that a scot power engineer was also on site.

4) Your "Electrician" should have tested prior to the CU change without question.

5) A socket tester provides a quick test only, Proper testing must be carried out using the Correct Calibrated test equipment, otherwise you don't know things are safe & whatever certificate he provides is worthless.

6) You say the "Electrician" cleared his diary as soon as you informed him of your concerns, Yet by your initial statement he already knew about the problem, and was quite happy to walk away and leave you to it.

7) If as you say, your worried you may have a supply problem, then take the advice you've already been given, including by a Scot power engineer. Put in an Emergency call to Scott power.

8) You think your "Electrician" is giving a fair response under the circumstances, Sorry but we'd all disagree with that.

You wonder why we're getting sceptical, maybe it's that there seem to be inconsistencies in the story, even for a householder that likes to keep informed you appear to know too much regarding the 17th & exactly what the pertinent regs are, on several occasions you've been asked to provide a picture of what has been installed , on each occasion you've chosen to ignore the requests.

As for myself, I think your rant shows total Disrespect to the Qualified & Highly experienced Electricians on this forum, that Freely gave their time to try to advise you.

OK that's it, I'm done & out of this farce.

Dan: If you don't find the above in keeping with Forum rules, I apologise.
 
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In all fairness chaps the OP has consistently denied this allegation. Judging from afar is somewhat thwart with danger.

Whilst I have had my suspicions, we should give the OP the benefit of doubt. Hopefully the fault, if it does exist, will be rectified tomorrow, which at the end of the day is the major concern.

Lets look forward to the OP reporting back, with the result. :)
 

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