nothing like being thrown a curve ball

[martin mcguinness]

I was asked to change a light fitting in a neighbours house easy job help out a neighbour I thought. I had my 2nd oldest son with me so thought it would be good to show him how to work safely ie how to use a voltage indicator and work safe.
normal procedure
prove indicator using proving unit
check voltage at light fitting
demonstrate fitting dead (lock mcb off)
prove indicator with proving unit
get young lad to disconnect light and he said I've just had a shock from wiring (single twin and earth at light ) I thought I just checked and its dead so I checked it again and no voltage so I decided to do it. I got a cracker of a shock made me look like a total plank in front of young lad so I checked again, no voltage between L+N but 240 between L+E.
turns out when there smart meter fitted the installer made a small mistake (don't know how to find sarcastic emoji)
turns out the MCB switched the neutral as L+N reversed
anyone else had something like this
and DNO contacted to rectify issue

 

[loplug]

That’s why safe isolation you test between all live conductors and all live conductors to earth

 

[Dillb]

Not a curve ball, but you doing thing imcorrectly. Single phase you test L-E, L-N and N-E when doing safe isolation.

 

[martin mcguinness]

that is a lesson learnt had voltage indicator on l+n when switching off tbh I didn't check between l+e for some reason on this occasion but as I said season learnt
anyone else had this issue after a meter change

 

[Andy78]

Doh !
I have only once followed safe isolation procedure and ended up with live parts, so it is not an infallible method at all.
In this instance though you just did it wrong.

 

[Spoon]

turns out when there smart meter fitted the installer made a small mistake (don't know how to find sarcastic emoji)
turns out the MCB switched the neutral as L+N reversed
anyone else had something like this

There is another thread on there about a new 'smart meter' being wired up wrong.

 

[martin mcguinness]

maybe should have headed thread how to look like a total ---- to one of your kids

 

[MJPD29]

Surely there is some sort of action people can take in this situation of you hadn't have spotted that then nothing would have had proper protection for God knows how long I think it's ridiculous I've heard of this happening a few times now

 

[Spoon]

Crossed Polarity smart meter into mains - https://www.electriciansforums.co.uk/threads/crossed-polarity-smart-meter-into-mains.137432/

 

[MJPD29]

Wonder how it ended for him

 

[Andy78]

Meter fitter wants ripping a new one by the way. It's pretty much the only check they have to do. Make sure a complaint goes in.

 

[SJD]

So what about safe isolation for a distribution board change, how many people would test all the outgoing cables as well as the incoming supply?

I changed a board on Tuesday where one of the outgoing lighting cables was still live after isolating the board. Powered from another board, we think cross connected during some recent building work.

 

[SparkyChick]

So what about safe isolation for a distribution board change, how many people would test all the outgoing cables as well as the incoming supply?

I do

 

[Zdb]

I know people hate volt sticks but I always use mine on cables that I have already proved to be dead. I just see it as an extra line of defence and in fairness it would have detected the voltage in the cross polarity in the OP's scenario and also the live outgoing circuit in the second scenario.

Volt sticks are very useful when used correctly.

 

[Wilko]

So what about safe isolation for a distribution board change, how many people would test all the outgoing cables as well as the incoming supply?

I changed a board on Tuesday where one of the outgoing lighting cables was still live after isolating the board. Powered from another board, we think cross connected during some recent building work.

Ha ha ha - must be Plumbers revenge !

 

[DPG]

Makes you wonder how many of these there are out there waiting to catch people out.

 

[Dillb]

Makes you wonder how many of these there are out there waiting to catch people out.

It wont catch you out if you carry out the correct procedure for isolation though will it.

 

[Squid]

Safe isolation pull main fuse.....

 

[DPG]

It wont catch you out if you carry out the correct procedure for isolation though will it.

No but you get my point.

 

[davesparks]

in fairness it would have detected the voltage in the cross polarity in the OP's scenario

Correct testing during isolation would have the same effect.