New Consumer Unit Installation - L&N Reverse at the sockets

[Des 56]

I asked because it is the first time in 50 years that I have heard of an installation being left with a known reverse polarity issue
Its the first time I have known of a customer, having been made aware of the problem, then sourcing electricians test equipment to check an installation constructed by another
I asked.you answered,thank you for the response

 

[Andy-1960]

I take it the isolation of the supply to the property wasn't carried out by the DNO ?

 

[mache]

To answer you question on relative safety at this time. The line and neutral reversal is a problem if you have a secondary fault occur before the situation is resolved. As an example should your washing machine develope a fault. It is possible the plug fuse will blow but this will only disconnect on the now neutral line. There will remain live power feeding into the machine. My advice until the situation rectified would be to unplug any metal cased equipment you have where ever possible. E.g. washing machine, dish washer etc any any equipment you do not required powered up. No one can guess if or when a fault may occur.
I am not a professional electrician by the way but I believe I am correct in my thought process. I am sure others can confirm or correct if necessary.

 

[Wilko]

Pete999, I think it is Muppets all round in this case, him and me.

Vol, no way this is your fault ... End of.

 

[gazdkw82]

He is not an electrician if he left you with reversed polarity after changing your CU.

It's not a difficult problem to figure out and most likely is something to do with the installation process of the CU.

The fact that he only noticed reversed polarity after plugging in a tester says to me he's not even done the basic testing required for this type of work.

Just can't believe it's been left like that

 

[Andy-1960]

To answer you question on relative safety at this time. The line and neutral reversal is a problem if you have a secondary fault occur before the situation is resolved. As an example should your washing machine develope a fault. It is possible the plug fuse will blow but this will only disconnect on the now neutral line. There will remain live power feeding into the machine. My advice until the situation rectified would be to unplug any metal cased equipment you have where ever possible. E.g. washing machine, dish washer etc any any equipment you do not required powered up. No one can guess if or when a fault may occur.
I am not a professional electrician by the way but I believe I am correct in my thought process. I am sure others can confirm or correct if necessary.

Fuses will only blow in the event of overcurrent fault, faults to earth will not cause fuse to blow because they are effectively not in circuit. RCD's will continue to operate in the event of a live to earth fault, but some RCD's only break on one pole, so in this situation the circuit would still remain live.
Circuits not protected by an RCD will only have to fuse in the cut out (100A?) as protection, which could cause a major fault, fire, etc.
Also remember any Edison screw light fittings will be backwards so the threaded part will now also be live.
I cannot believe this 'electrician' has cleared off for the weekend and left this.. it needs to be addressed now

 

[Pete999]

Vol, no way this is your fault ... End of.

Correct not your fault.

 

[Bob Geldoff1234]

With the correct test instruments then its pretty easy to determine where the live neutral reverse has taken place.Even if the bloke had an appointment then fixing this kind of fault wouldn't have taken long to find if you have the experience.I agree with everyone else's opinion ,that it needs sorting asap.

 

[gazdkw82]

It has to be all the sockets reversed or else there would a short circuit somewhere. I'd say the wholes system is reversed at the tails or the RFC is wired incorrectly at the board.

Again, proper testing would easily determine the issue.

 

[Octopus]

Out of interest when was the CU changed?