Live everything!!!!

[Boner]

Guys, just had a call to go and have a look at a faulty lighting circuit.
Customer suspected that it was the MCB was faulty, but this wasn't the case.
Upon further investigation it turned out that EVERYTHING was Live, neutral, earth and switches.
Have isolated the circuit, as there wasn't any time to look at it today, but has got me scratching my head! I'm guessing that something has gone through a wire somewhere, hence why everything is sparked up.
Anyone got any advice or experience of a similar situation?
Cheers - Boner.

 

[Octopus]

Has the homeowner been doing any DIY or had a water leak in the last 24 hours?

 

[Boner]

No, first thing I asked them - two little old ladies.
Said that it tripped out, then when they reset it, did a bit of flickering and then died.
I'm guessing rodents...

 

[oldtimer]

First of all is it just this lighting circuit and if so you may have a broken neutral and earth. To test this run a earth lead from the met and mesure the neutral voltage against this if it is the same as the line ie 238 volts then there is your problem as for the earth you may get 70 volts. Remember to use a multimeter as this will give you a voltage reading opposed to a live indication.

 

[nickblake]

ill agree with old timer on this one you say every thing is live , if its a TNCS earthing arrangement then the chances are the supply has lost its neutral , and the live is back feeding down the neutral to the connection poit at the earth block then back up the earth , you will also find that any earthed / bonded metal work could be at mains potential to , do a Ze reading at the board and see what the readings are it should be below 0.35 ohms , if its higher then call the DNO

 

[Kamikaze]

Yes, what nickblake said!

 

[Boner]

Thanks Oldtimer, will give that a bash. Yes, just the lighting circuit.
Presumably voltage flowing through the neutral, through the lamp then down the switch wire would explain why it was live even when switched off?

 

[oldtimer]

Thanks Oldtimer, will give that a bash. Yes, just the lighting circuit.
Presumably voltage flowing through the neutral, through the lamp then down the switch wire would explain why it was live even when switched off?

On a lighting circuit you can have the switch off in one room and on in the room next door hence you may get backfeeds. Remember break the circuit down if you have to and use a multimeter to get a voltage display not a voltage indicator ie a pile of leds. I would start from scratch with this disconnect from DB and check out the circuit