FabSwingers.com forum: Electrical problem

By *riskygaz OP Man
48 weeks ago

birmingham

DIY gone wrong, i went to replace two batten light fittings with new LED fittings, i disconnected all the wires as normal, wrired two up then turned the power on, and nothing

then it struck me that both fittings are connected to small emergency lights, i had thought there was a lot of wires,

while looking at the wires to find the permanent live, i discovered that the live wires only have around 12 volts in them, and the earth wires have 240 volts,

I have checked that i hadn't damaged any of the wires as best i could, Got no idea whats going on i have spent the day trying to fix it.

The boss will not be happy on Monday.

Any guesses as to what has happened ?

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By *riskygaz OP Man
48 weeks ago

birmingham

well i am off to bed, i will have another go at it in the morning, but not feeling to hopeful that i am going to figure out what has gone wrong, typical i had to pic those lights, out of all the other ones i could have done, lots of suspended ceiling lights to do, they are sooper easy done lots off them.

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By *radleywigginsMan
48 weeks ago

northwest

240v at earth? Sounds suspicious.

Was the system working properly beforehand?

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By (user no longer on site)
48 weeks ago

Oh Em Gee

Can't help, but when you discover what it is, do share!

Glad you're not hurt.

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By (user no longer on site)
48 weeks ago

"Oh Em Gee

Can't help, but when you discover what it is, do share!

Glad you're not hurt."

The 12V isn't the problem imo, that's low voltage lighting and some transformer running up there with lots of wires.

But Earth at 240V - no tripping and shorts either? This sounds like a DIY bodge job where the guy wanted 2x switched lines running through the ceiling and decided to reuse the Earth as a separate switched circuit.

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By (user no longer on site)
48 weeks ago

Sounds like you either have some miswiring or you’ve lost the Neutral somewhere. 12v is telling, sounds like a transformer output. Is it dc or ac? Potentially it’s induced but gut says miswired Lv transformer.

If you’ve any 12v lighting on the same circuit there’s a good chance it is miswired. This fault also may have been pre existing as a batten doesn’t really care where the electricity comes from but a led does. I’m supposing you have no rcd/rcbo as it’s not tripped so you cannot tell.

There really isn’t enough info to say any more

Tbh this is dangerous and nothing like changing something like for like. Definately have a look at your work with the circuit off. If nothing comes to light get a spark out before you get bitten.

Nb when you have 230v through earth weird stuff can happen. Shocks from radiators, sinks, hot tubs. Don’t leave this.

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By *xstevenxxMan
48 weeks ago

Ashbourne

240 at earth

Someone but earth in live somewhere in the lighting circuit.

If that’s the case you be bigger problem- why it’s not tripping out at the fuse board

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By *ris GrayMan
48 weeks ago

Dorchester

Sounds like somebody has been playing with this circuit you need somebody with a tester who can test that circuit but its not looking good for you to sort it out before your boss gets involved.

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By (user no longer on site)
48 weeks ago

240 at earth but 12 ? I’d be interested to know how your measuring this

Are you using approved voltage indicator?

What are you testing between to get your reading?

Testing L to E should give you 240

L to N should give you 240 too

N to E should give 0

With that in mind, are you sure what your testing is correct?

Swapping lights is an extremely easy job and I’d have to ask myself, what’s more likely, you have a magic circuit that didn’t trip with 240 to earth

Or you are not experienced with electric and you’ve made a mistake and the wiring is fine

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By *orny-DJMan
48 weeks ago

Leigh-on-Sea

240V on Earth?

Sounds like it's time to call an electrician

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By (user no longer on site)
48 weeks ago

"240V on Earth?

Sounds like it's time to call an electrician"

A good one!

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By *riskygaz OP Man
48 weeks ago

birmingham

"240v at earth? Sounds suspicious.

Was the system working properly beforehand?"
yes it was i have definitely got something wrong

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By *riskygaz OP Man
48 weeks ago

birmingham

"240 at earth but 12 ? I’d be interested to know how your measuring this

Are you using approved voltage indicator?

What are you testing between to get your reading? i have a electricians MFT at work, someone has suggested that because its a two way switch setup, that the wires i am treating as earth might infact just be yellow wires, used to link the two switches together,

i have replaced plenty of lights in the past, its the two way switching settup that i think has caught me out this time,

Testing L to E should give you 240

L to N should give you 240 too

N to E should give 0

With that in mind, are you sure what your testing is correct?

Swapping lights is an extremely easy job and I’d have to ask myself, what’s more likely, you have a magic circuit that didn’t trip with 240 to earth

Or you are not experienced with electric and you’ve made a mistake and the wiring is fine "

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By (user no longer on site)
48 weeks ago

Try switching the switches one at a time to see it the 240 on the earth clears. If so it's used as a switch wire and is probably the love you need for the new batton lights. The 12v does feel like it's a selv output for an led light so there will be a transformer in the ceiling somewhere

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By (user no longer on site)
48 weeks ago

"Try switching the switches one at a time to see it the 240 on the earth clears. If so it's used as a switch wire and is probably the love you need for the new batton lights. The 12v does feel like it's a selv output for an led light so there will be a transformer in the ceiling somewhere "

Live not love

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By (user no longer on site)
48 weeks ago

"240 at earth but 12 ? I’d be interested to know how your measuring this

Are you using approved voltage indicator?

i have replaced plenty of lights in the past, its the two way switching settup that i think has caught me out this time,

Testing L to E should give you 240

L to N should give you 240 too

N to E should give 0

With that in mind, are you sure what your testing is correct?

Swapping lights is an extremely easy job and I’d have to ask myself, what’s more likely, you have a magic circuit that didn’t trip with 240 to earth

Or you are not experienced with electric and you’ve made a mistake and the wiring is fine "

If it’s old colours then you could have a yellow wire which is actually your strapped, not your earth

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By *r X46Man
48 weeks ago

Liverpool

You can do on of two things.

Stand bare foot in a metal bucket of salt water while you work on this.

Or call a qualified electrician

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By *ldgeezermeMan
48 weeks ago

Newcastle

You mentioned emergency lights

The 12V could be from a battery that supplies them

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By *riskygaz OP Man
48 weeks ago

birmingham

"You mentioned emergency lights

The 12V could be from a battery that supplies them "
Mmm yes that's true i hadn't thought about that. Had another go at it today, but i had to admit defeat in the end, we will be calling an electrician tomorrow, be interesting to find out what i have mixed up.

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By *riskygaz OP Man
48 weeks ago

birmingham

Update, We had an electrician out this morning to look at the problem, and i can hold my head up hi on my DIY electrical skills, it turns out that i had done nothing wrong.

There is a problem with the neutral wire from the consumer unit. They are going to have to come back during the Christmas holiday period and take down all the light fittings on that corridor and test all the wires individually to locate the faulty wire, might have to run a new neutral wire from the consumer unit. Nice to know i didnt screw up, and the boss is ok about it

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By *olly_chromaticTV/TS
48 weeks ago

Stockport

"Update, We had an electrician out this morning to look at the problem, and i can hold my head up hi on my DIY electrical skills, it turns out that i had done nothing wrong.

I once found a light circuit in my house where the neutral return from just one of the lights went back to a different circuit on the fuse box (before modern consumer units). Fuses kept blowing, and if the fuse for the return circuit was blown or removed but the offending light was still switched on, mains live would go the wrong direction around half the wiring in the house.

Only found it when I changed out the fuses in the box for plug-in current overload breakers and put in a RCD for the shower circuit, then every single time the wonky light was turned on the RCD would trip out. Fixed by installing a new return wire for the light, back to the correct circuit in the box. As far as I could tell the circuit had been that way from the time the house was built, all I can think is that the sparks installing the original house wiring had run out of cable that day, his bodge managed to reduce one cable length by about 2 metres...

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