Reverse Polarity

[housewife59]

Apologies for intruding on your website - I am NOT an electician!! I would like some advice - a couple of weeks ago a MeterPlus employee came to fit a new meter in my house - he spotted a fault - said it was reverse polarity - the whole house was affected & told me to get an electrician to sort the problem. To cut a long story sort the problem was identified yesterday as aNEDL problem arising from underground cabling in the village 5 years ago. Basically I was told that the tails to the box on the outside of my house had been wrongly connected causing the reverse polarity. I would like to know what if any risks this has posed to me & my family over the last 5 years but more worryingly if the instalation was wrong to my property what about the rest of the village? Any comments or observations would be most welcome

 

[rocker]

Sorry just to add - have your suplier sorted this out yet? I was under the impression they had. This needs to be sorted out immediately if it hasn't been already.

 

[housewife59]

Thanks for all your replies - websites like this are brilliant! If you ( all of you have been kind enough to reply to me) read my initial posting NEDL resolved the problem yesterday. My mind is at rest now but I am furious that a negligent NEDL engineer has apparently put my family at risk to a potentially hazardous situation for the past five years!! If we had not had a request from the meter reader to meterplus to install a new meter we would have been none the wiser of the danger that we were in, I am the type of person who gets shocks off baby buggies, supermarket trolleys etc my family just laugh at me so the mini shocks from the taps were just regarded as 'mum being electric'!! Am I supercharged because of my house?!?!

 

[housewife59]

I should have added this in my last posting - I contacted NEDLs customer complaints dept last night - I would have assumed that they would view a situation like this as a priority - lunchtime now & no reply or comment from them yet - I am rather disappointed, to say the least, in their lack of communication!! As I said in original posting - if my house was connected wrongly during the underground cabling job how many others in the village are at risk too!

 

[acat]

So long as you are safe now that is the mai thing next step is put your complaint in writing and if it is not resolved to your satisfaction the next step is the electricity regulator and the press.

On behalf of all the forum members wish you well


Chris

 

[pushrod]

. If you were suffering from that sort of thing then you would notice for instance the hoover would be blowing instead of sucking.

I've seen this written by a few people on here as a symptom of reversed polarity and thought that it was wrong for most motors, particularly anything running on rectified AC. Anyway just reversed the polarity on my vacuum and it still sucked

And lights are not polarity dependent for functioning ( For safety yes)

(tin hat on )

TBH it doesn't surprise me at all that a reverse polarity can go undetected for such a long time as isn't it only in fault conditions that it would become apparent and then it would be extremely serious as protective devices, eg MCBs, would not operate.

 

[Scud]

Housewife, I train for a DNO and can tell you in all seriousness that you need as a matter of urgency to call, in the first instance, your DNO's emergency helpline, and failing an immediate resolution, call Consumer Direct on 08454 04 05 06. I cannot stress highly enough how important this could be. If your supply is TN-C-S, this is potentially a very dangerous situation. If you happen to have an outside tap in your garden, please keep everyone away from it. In a reverse polarity situation, this tap could be a potential killer. I'm not trying to panic you, but I feel your DNO is treating this situation nowhere near seriously enough.

 

[Golden_Boy]

Thanks for your reply - can you tell me what appliances would be polarity dependent?

How can AC equipment be polarity dependant ??? Can someone explain this please...

 

[Des 56]

You have a pme instllation,the metalwork is bonded back to the earth terminal to ensures there is no potential diffenece between the pipework and other metalic parts
You have reverse polarity,which means all metalwork that has been corectly bonded back to the earth terminal has now become live

The situation you have is that all metalic parts of the installation are now at 230 volts with regard to true earth
Any metalic part that you touch then rises your potential to 230 volt above true earth

If you then also come into contact with an actual true earth this oould be fatal
There doesn't need to be a fault situation,the systen is an explosion waiting for or a victim

You should ask for explanations as to why7 your familly was allowed to be left at risk for such an important problem and why it was not resolved as an emergency at the outset

 

[Des 56]

Ac being polarity dependantv
An insignificant number of appliances may need correct polarity to function correctly,but on the whole polarity does not have any impact on the function of an appliance
Vacuum cleaners dont blow instead of suck etc
polarity is more important with regard to protection and safety

 

[ezzzekiel]

dno do take this seriously, they check polarity about 5 times before during after working on a system, in fact its prob the only test they carry out, usually will result in the sack for some one although they will try and keep it low key.

 

[pushrod]

You have a pme instllation,the metalwork is bonded back to the earth terminal to ensures there is no potential diffenece between the pipework and other metalic parts
You have reverse polarity,which means all metalwork that has been corectly bonded back to the earth terminal has now become live

The situation you have is that all metalic parts of the installation are now at 230 volts with regard to true earth
Any metalic part that you touch then rises your potential to 230 volt above true earth

If you then also come into contact with an actual true earth this oould be fatal
There doesn't need to be a fault situation,the systen is an explosion waiting for or a victim

You should ask for explanations as to why7 your familly was allowed to be left at risk for such an important problem and why it was not resolved as an emergency at the outset

Still trying to get my head around this a bit - isn't what you are describing above is if the reverse has taken place probably some distance from the installation and you have ended up with the earthing connected to the live. But then as you said all metal work would belive and the real live would effectively be linked directly to earth via the water pipes - wouldn't that take out the local substation? (as the main fuse would be in the neutral) Difficult to imagine how that could go undetected for such a long time.

Isn't it more likely that the polarity reverse took place at the installation with the neutral and earth being correctly linked but then fed to the " live" wires of the installation and the real live being fed to the neutral? If it is like this you could imagine it going undetected for a long as it is only in an earth fault situation that you would become aware of it as all the protective devices of the installation would be effectively in the neutral (so the fault path would be neutral of the installation to cpc bypassing the protective devices - still very dangerous!)

 

[housewife59]

To update all you kindly folks who have offered advice etc. When the meterplus man who came to fit the new meter identified the problem as reverse polarity & would not fit a new meter, he left me with the impression that there was nothing to worry about - 'get an electrician to sort ot out' was his advice. The electrician we called, last thursday, established that the fault lay on the NEDL side of the meter. Our village had the cables put underground 5 years ago and it transpires that the person who connected us during the works made a grave error. We had 3 NEDL visits last thursday & the men were amazed that such a mistake could possibly be made but they saw it for themselves! Something to do with concentric cables being wrongly connected to the new box they put on the outside wall of the house. I contacted NEDL via email that night & have heard nothing to date - I would have thought they would take this very seriously but no! I have also written to them with a copy to meterplus for their comments as I have said in prevoius postings - if our house was 'wrong' how many other properties are at risk??!! We have not had any elecrical work done in the house since the cabling was done so were none the wiser to the problem Thankfully my situation has ended without damage to life or property but I would still want NEDL to explain how something like this can happen.
Thanks again for all your advice & comments

 

[pushrod]

To update all you kindly folks who have offered advice etc. When the meterplus man who came to fit the new meter identified the problem as reverse polarity & would not fit a new meter, he left me with the impression that there was nothing to worry about - 'get an electrician to sort ot out' was his advice. The electrician we called, last thursday, established that the fault lay on the NEDL side of the meter. Our village had the cables put underground 5 years ago and it transpires that the person who connected us during the works made a grave error. We had 3 NEDL visits last thursday & the men were amazed that such a mistake could possibly be made but they saw it for themselves! Something to do with concentric cables being wrongly connected to the new box they put on the outside wall of the house. I contacted NEDL via email that night & have heard nothing to date - I would have thought they would take this very seriously but no! I have also written to them with a copy to meterplus for their comments as I have said in prevoius postings - if our house was 'wrong' how many other properties are at risk??!! We have not had any elecrical work done in the house since the cabling was done so were none the wiser to the problem Thankfully my situation has ended without damage to life or property but I would still want NEDL to explain how something like this can happen.
Thanks again for all your advice & comments

from what you said earlier it sounds as if it was just your house that was connected "the wrong way around" and was not a group fault as such, unless the person doing the connection managed to mess it up with other people's houses as well . No doubt the supplier will be checking the other houses that the person worked on. As you say thankfully there has not been no serious accidents and at least it has promoted lots of healthy debate on here ( that may well continue)

 

[Golden_Boy]

Ac being polarity dependantv
An insignificant number of appliances may need correct polarity to function correctly,but on the whole polarity does not have any impact on the function of an appliance
Vacuum cleaners dont blow instead of suck etc
polarity is more important with regard to protection and safety

Have you an example please ?

I still cant understand why polarity of a singe phase A.C. supply can make any diffrence at all to the operation of an appliance.

 

[davelerave]

polarity doesn't affect the operation of an AC appliance