230v neutral to earth ? row of lights gone out mcb not tripped

[marlon89]

Hello all,

I have recently attended a job where a row of lights have gone out and was advised and seen for myself when i got there that no breakers have tripped.

First i took the cover off of the panel with the mcb's that feed all lighting circuits in open office area , and checked i have 230v on load side on mcb , which i did have on all mcbs to rule out a faulty breaker. I next went to the nearest light fitting to the riser where dbs where and found 230v at fittings with lights not working (all on sensors ) and ballast units also had 230v.

I then was advised (by site engineer) that sometime in the past these lights had lost power and had been rewired by someone ?? not sure if they were qualified or not ... i then went to a room at the end of the office area where he advised me they repowered this lighting circuit which has now gone out but power still there couldn't see any polarity faults but didn't get a chance to check all fittings as was in working hours of a office.

At the end fitting i was getting 230v between N-E and i haven't come across this before would appreciate any help

 

[Darkwood]

Welcome to the forum marlon89

 

[Deleted member 72666]

What voltage did you measure between L & N at the fittings?

 

[marlon89]

230v N-E and L-E at fitting with lamps not working

 

[Simonslimline]

Line+Neutral voltage?

 

[Barry White]

230v between neutral and earth usually means a lost neutral or polarity reversed did you test between L and N on the same fitting? and L and earth

 

[HandySparks]

Post removed

 

[marlon89]

Yes on the same fitting one of the furthest away from dB's , what I don't get is why are none of the lights working if ballasts and main connections in fitting have 230v ?

 

[Octopus]

Time to do some basic tests

 

[marlon89]

Time to do some basic tests

Haha yes I'm going back on Monday out of hours as couldn't conduct further tests due to being a very busy office floor .

Thanks for your input murdoc. ..

 

[conrad]

What tester are you using? Did you check which breaker was isolating the supply to prove where the circuit is fed from?

 

[Lucien Nunes]

i was getting 230v between N-E

230v N-E and L-E at fitting with lamps not working

what I don't get is why are none of the lights working if ballasts and main connections in fitting have 230v

Crikey. It's a circuit with a supply, a switch and a lamp, and it's broken somewhere. Ask yourself where. It doesn't seem to be the line...

 

[snowhead]

Crikey. It's a circuit with a supply, a switch and a lamp, and it's broken somewhere. Ask yourself where. It doesn't seem to be the line...

I can't think of a more common fault that gets people stumped.

 

[HandySparks]

Crikey. It's a circuit with a supply, a switch and a lamp, and it's broken somewhere. Ask yourself where. It doesn't seem to be the line...

I wrote something similar at post 7, but then thought "why bother"!

 

[Besoeker]

230v between neutral and earth usually means a lost neutral or polarity reversed did you test between L and N on the same fitting? and L and earth

Yes, that would be the most obvious thing to check I would have thought.

 

[marlon89]

But these lights were working fine up until Friday no one has touched wiring recently , but thanks guys . So it may have come out one of the fittings or sensor's ? Can't think of any other options that could have happened ? as no one has touched circuit recently to my knowledge.

 

[marlon89]

Crikey. It's a circuit with a supply, a switch and a lamp, and it's broken somewhere. Ask yourself where. It doesn't seem to be the line...

I was getting 230v N- L at fitting as well .. so how can it be broken ?

230v L - N 230v N-L and 230v N-E row of lights out mcb not tripped .

 

[Lucien Nunes]

230v L - N 230v N-L and 230v N-E

Re-read what you typed and confirm whether it is what you meant to type!

 

[Marvo]

Lol, I guess it might be possible with the right (read 'wrong') digital tester and no 'low-z' range

 

[marlon89]

Re-read what you typed and confirm whether it is what you meant to type!

Yes this was what I was getting !! 230v N-L 230v N - E and 230v E to N .

If I was getting not 230v between L and N then obvious it's a broken neutral but this is what iv been writing and people are saying it's a broken neutral when it can't be !!