Reversed polarity - who to blame?

[Gavin John Hyde]

Been on a job in Warmley this afternoon, customer told by Knowhow/curry's that she has reversed polarity so couldnt connect washing machine. worryingly all faceplates were metal so not ideal!
Go out and 230 between neutral and earth,nothing between line and earth. called western power who sent somebody out, result they took out cables between cutout outgoing ways and meter swapped them over to give the house correct polarity.
They say not the dno's fault as there supply is fine, but the cables from cutout to meter and then on to CU all followed through as correct polarity the problem appeared to me to be pre cut out. didnt test it from where i was stood.
Is it okay for them to simply swap the cables without checking the actual supply? walked in put a socket tester in and said everything is okay now and off they went.
Meter changed 2012 card says polarity okay, nothing been touched since!
consumer unit changed and rewired early 2006 by Mr electric franchise who decide to leave the tails hanging out the bottom on a 6+ meter run without a switched fuse. also put all sockets on one mcb due to tripping apparently.
all in the level of workmanship seems to be below what i would be happy with.
I have tightened the tails and advised them the tails need some attention,suggested to put a switched fuse in and extend the tails so they can be clipped and not hang down with stuff pushing against them and almost pulling them out. also should they be replaced in full?
Without the byb to hand as it is in van,so cant check regs. these tails run under the bathroom floor out to the meter and then inside, through out the run they have what appears just single layer of insulation and no 2nd sheath... shouldn't they be protected from mechanical damage somehow?

 

[telectrix]

What worries is where the fault is/was. if before cut-out and they have reversed the tails post cut-out, then is the Neutral DNO fused now, instead of the Line?

and those tails are a shitty mess.

 

[buzzlightyear]

those tails should be doubled sheathed. the DNO are a law to them self's .

 

[Gavin John Hyde]

I was in process of leaving as the dno arrived(only took them 30 mins from when I called- must have been a quiet day) so didn't stick around to long as I had another job to get to on way home.
Not 100% confident its right in all honesty. Much like you @telectrix - if they have just swapped cables around then they haven't really resolved the fault if it was pre cut out.
I identified the reversed polarity, called the DNO they came out and have said its sorted and is safe. I have covered my arse and ultimately the DNO have given it a clean bill of health.
Rather luckily for the customer, she changed a light fitting upstairs last week before aware of the fault, nice shiny metal one... flicked the mcb off and whole time good chance that the neutral was still live when fitting it!

 

[Midwest]

Seems to be a whole list of things wrong there, that have happened over the course of time. Even if someone was hurt because of criminal incompetence now, I suspect H&S would no doubt struggle to locate the offenders.

I know we often criticise Certsure, and Electrical Safety First are not 'directly' in that camp, but ESF have been banging about joe public using suitably qualified competent electricians for ages. This Part P thing again.

 

[mhar]

What earthing system? If a tncs wouldn't the earth be live as well if the fault was pre cutout?

 

[westward10]

Didn't it cross your mind that if they swapped things about to see if the head neutral is fused, first thing that crossed my mind as with Tel in #2.

 

[Gavin John Hyde]

Cut out was PME, and Cu changed pre Part P and the schemes coming into force.

 

[Wilko]

If PME then it must've been reversed after the cutout - otherwise the fridge etc would've been live (?). A not-so-smart-meter moment perhaps?

 

[mhar]

So, with pme the conductor that the earth would be linked to in the head would be live making the earth live and all metalwork bonded to it would also be live - taps, radiators, boiler etc, any metal light fittings, cooker case etc. In this scenario anything connected to a actual earth would create a fault current and operate an upstream device (300A fuse)

 

[telectrix]

something smells here. reversed polarity is generally the fault of meter fitter. are DNO covering someone's arse here?

 

[Squid]

I'd be more worried about the gas meter connection.........

 

[telectrix]

I'd be more worried about the gas meter connection.........

why, bypass not easy?

 

[Gavin John Hyde]

something smells here. reversed polarity is generally the fault of meter fitter. are DNO covering someone's arse here?

not a smart meter in sight thankfully, last meter according to a little card in the meter box was in 2012. incidentally ticked and signed saying polarity correct. so potentially been like this since then!! as she has been in the house 6 years and no work been done since.

So, with pme the conductor that the earth would be linked to in the head would be live making the earth live and all metalwork bonded to it would also be live - taps, radiators, boiler etc, any metal light fittings, cooker case etc. In this scenario anything connected to a actual earth would create a fault current and operate an upstream device (300A fuse)

Thats what made me think.. bloody heck.. as all the switches and sockets are metal face plates, bonding in place, i went round with the wonder lead doing a quick continuity check at sockets and switch fronts and all had continuity back to the CU so potentially could have been quite bad in event of a fault

 

[Pete999]

Seems to be a whole list of things wrong there, that have happened over the course of time. Even if someone was hurt because of criminal incompetence now, I suspect H&S would no doubt struggle to locate the offenders.

I know we often criticise Certsure, and Electrical Safety First are not 'directly' in that camp, but ESF have been banging about joe public using suitably qualified competent electricians for ages. This Part P thing again.

That's where Part P and suitably qualified competent electricians don't compute.

 

[Simonpotts1]

If circ in question is a radial with a load upstream then a broken neutral downstream will show up as reverse polarity with a plug in type tester .was it ever checked at incomer ?

 

[Pete999]

I was in process of leaving as the dno arrived(only took them 30 mins from when I called- must have been a quiet day) so didn't stick around to long as I had another job to get to on way home.
Not 100% confident its right in all honesty. Much like you @telectrix - if they have just swapped cables around then they haven't really resolved the fault if it was pre cut out.
I identified the reversed polarity, called the DNO they came out and have said its sorted and is safe. I have covered my arse and ultimately the DNO have given it a clean bill of health.
Rather luckily for the customer, she changed a light fitting upstairs last week before aware of the fault, nice shiny metal one... flicked the mcb off and whole time good chance that the neutral was still live when fitting it!

The clean bill of health the DNO gave the installation, goes as far as their equipment, in all honesty Gavin and I don't mean to be critical, it was your responsibility to check post DNO s visit, sorry but that's just as I feel, the excuse of another job to go to is a poor excuse, ask yourself would the DNO have checked polarity at the final circuits? no I don't think sold have stayed until everything was checked.

 

[Pete999]

I was in process of leaving as the dno arrived(only took them 30 mins from when I called- must have been a quiet day) so didn't stick around to long as I had another job to get to on way home.
Not 100% confident its right in all honesty. Much like you @telectrix - if they have just swapped cables around then they haven't really resolved the fault if it was pre cut out.
I identified the reversed polarity, called the DNO they came out and have said its sorted and is safe. I have covered my arse and ultimately the DNO have given it a clean bill of health.
Rather luckily for the customer, she changed a light fitting upstairs last week before aware of the fault, nice shiny metal one... flicked the mcb off and whole time good chance that the neutral was still live when fitting it!

The clean bill of health the DNO gave the installation, goes as far as their equipment, in all honesty Gavin and I don't mean to be critical, as you obviously care about your customers, it was your responsibility to check post DNO s visit, sorry but that's just as I feel, the excuse of another job to go to is a poor excuse, ask yourself would the DNO have checked polarity at the final circuits? no I don't think so I would have stayed until everything was checked. If it was my customer I would spend an hour checking, after the DNO had FOed.

 

[static zap]

Are family dynamics ok , or is he into antique power tools used in the garden (No RCD) ..! Been so dry this season .

 

[Gavin John Hyde]

The clean bill of health the DNO gave the installation, goes as far as their equipment, in all honesty Gavin and I don't mean to be critical, as you obviously care about your customers, it was your responsibility to check post DNO s visit, sorry but that's just as I feel, the excuse of another job to go to is a poor excuse, ask yourself would the DNO have checked polarity at the final circuits? no I don't think so I would have stayed until everything was checked. If it was my customer I would spend an hour checking, after the DNO had FOed.

fair comment @Pete999 , the DNO used a plug in tester on the sockets and cooker socket outlet both now showed correct polarity. Customer had phoned me to tell me what they said and did. These being the only circuits with socket outlets. I had satisfied myself the issue was before the customers wiring and as such limited to what i could do to start checking the cut out etc...
I had already checked the circuits inside for polarity through dead testing and established that the polarity issue was not internal. so handed over to the DNO once I was certain the polarity testing at consumer unit tails showed that the incoming supply was responsible be it either the dno supply or mixed up tails somewhere.

 

[buzzlightyear]

I was at a job to day and watched the DNO change a main cut out
2 people was their .talking to the wait for it .a young lady .
she told me that a contractor fitted a cut out wrong polarity sacked their and then .

 

[Squid]

why, bypass not easy?

Bend on the copper looks a tad tight...

 

[Midwest]

That's where Part P and suitably qualified competent electricians don't compute.

Pete, this is a continuing argument or opinion you have, there's lots of so you call 'Part P qualified electricians' out there. Just because they've chosen to join one of these schemes, doesn't make them less qualified, as is does not make them more qualified.

 

[Toneyz]

Pete, this is a continuing argument or opinion you have, there's lots of so you call 'Part P qualified electricians' out there. Just because they've chosen to join one of these schemes, doesn't make them less qualified, as is does not make them more qualified.

Pete, you need to see the video by that Ninga bloke.

 

[Toneyz]

Pete, this is a continuing argument or opinion you have, there's lots of so you call 'Part P qualified electricians' out there. Just because they've chosen to join one of these schemes, doesn't make them less qualified, as is does not make them more qualified.

Forget this rubbish Part P qualified or PartP approved.

 

[Marvo]

I'm sure this is probably a dumb question but the setup in the UK is different than it is here. What exactly do you call the 'cut-out' and what exactly do you call the 'head' on a typical domestic supply?

 

[snowhead]

So, with pme the conductor that the earth would be linked to in the head would be live making the earth live and all metalwork bonded to it would also be live - taps, radiators, boiler etc, any metal light fittings, cooker case etc. In this scenario anything connected to a actual earth would create a fault current and operate an upstream device (300A fuse)

NO.
Assuming the polarity into the cutout/head was correct on the DNO side all that was wrong was the neutral was on the red cable through the meter to the C.U Live side.
And the Live was on the black through the meter to the C.U Neutral side.
The Earth was still Earth.

The O.P states no voltage Line (Red) to Earth

 

[Toneyz]

Pete, you need to see the video by that Ninga bloke.

new ECS card video.

 

[johnduffell]

OP- Any photo of the cutout from before you left?

 

[westward10]

I'm sure this is probably a dumb question but the setup in the UK is different than it is here. What exactly do you call the 'cut-out' and what exactly do you call the 'head' on a typical domestic supply?

Head and cut-out are generally the same thing, it is the final point at which the suppliers cable connects with the service fuse/s and the means of earthing if provided.

 

[PEG]

I was in process of leaving as the dno arrived(only took them 30 mins from when I called- must have been a quiet day) so didn't stick around to long as I had another job to get to on way home.
Not 100% confident its right in all honesty. Much like you @telectrix - if they have just swapped cables around then they haven't really resolved the fault if it was pre cut out.
I identified the reversed polarity, called the DNO they came out and have said its sorted and is safe. I have covered my arse and ultimately the DNO have given it a clean bill of health.
Rather luckily for the customer, she changed a light fitting upstairs last week before aware of the fault, nice shiny metal one... flicked the mcb off and whole time good chance that the neutral was still live when fitting it!

They are very limited on what they can give a clean bill of health...

 

[Gavin John Hyde]

OP- Any photo of the cutout from before you left?

No i didnt take one as the other pics were so the customer could send to the landlord. As them tails out the bottom need sorting. I also take a picture of a cu when ever i open it and test so i have record of how it was when i left it. That way if somebody alters it and messes up i got evidence etc... takes seconds but potentially saves a lot of aggro later on.

 

[Toneyz]

I remember years ago at the first company I worked for a so-called electrician installed the polarity of the L & N in the main consumer unit switch reversed (split 1 rcd board lights protected by mcb) didn't do any testing just self-connected and on this day went home came in the next day well there was an L to E fault (I think) and as the mcb was now in the neutral did not trip all the 1.0mm T & E pvc cable from the C.U to the fifth light was all burnt.

 

[mhar]

NO.
Assuming the polarity into the cutout/head was correct on the DNO side all that was wrong was the neutral was on the red cable through the meter to the C.U Live side.
And the Live was on the black through the meter to the C.U Neutral side.
The Earth was still Earth.

The O.P states no voltage Line (Red) to Earth

Exactly.

I was pointing out the consequence of reverse polarity on the DNO side (as had been suggested) and why it was extremely unlikely

 

[Pete999]

Pete, this is a continuing argument or opinion you have, there's lots of so you call 'Part P qualified electricians' out there. Just because they've chosen to join one of these schemes, doesn't make them less qualified, as is does not make them more qualified.

Perhaps I was being a bit harsh, I should have said "Part P qualified and Competent Electricians doesn't always compute, it was not my intention to lump all Part P electricians in the same boat" so point taken, but you are correct I do have a bee in my bonnet about this issue, probably always will. Thanks for the reply.

 

[Pete999]

Pete, you need to see the video by that Ninga bloke.

Do you have a link as Sparky Ninja has lots of videos

 

[Toneyz]

Do you have a link as Sparky Ninja has lots of videos

I'll try to post it here.sorry say's too large it is The new ECS Registered electrician status.

 

[Pete999]

I'll try to post it here.sorry say's too large it is The new ECS Registered electrician status.

I'll ave a look

 

[Midwest]

Perhaps I was being a bit harsh, I should have said "Part P qualified and Competent Electricians doesn't always compute, it was not my intention to lump all Part P electricians in the same boat" so point taken, but you are correct I do have a bee in my bonnet about this issue, probably always will. Thanks for the reply.

Would you be happy if they described themselves as 'Part P scheme registered, as well as competent'?

 

[Pete999]

Would you be happy if they described themselves as 'Part P scheme registered, as well as competent'?

If they could prove that they were competent, because gaining a non qualification and describing themselves as Part P qualified is laughable imo. How many people do you see or hear about saying I have the 17th, Part P and PAT and class themselves as electricians and to top it all they are registered with some CP Scheme, Certsure have said that they loose 10% of their membership annually and when pressed to clarify how many are lost due to non conformity it is 2% of that 10% so in realty it's 0.02% of the membership, and a lot of the members have 1 or more of the 3 qualifications I mentioned earlier, not all because of course there are exceptions to the rule, and are very competent electricians to boot, so please don't say I am referring to all short course people because I'm not.

 

[Percyprod]

DNO's responsibility ends at outgoing side of cut-out. If wrong polarity in installation, they would check at cut-out. The reason they turned up quickly is that they take reversed polarity very seriously. We were expected to be on site in 1 hour. If incoming polrity is wrong it needs to be corrected by dno. This would be taken seriously. If it was the installation connected wrong way round then I would have not corrected it, that would be down to supplier or electrician. Dno operatives are not allowed to do any work on the installation for obvious reasons.