Lighting cct voltage has dropped from nominal 240v to 138v | on ElectriciansForums

Discuss Lighting cct voltage has dropped from nominal 240v to 138v in the Lighting Forum area at ElectriciansForums.net

Doomchild

DIY
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West Penno NSW
Hi all,

last week I decided to start painting the inside of the house and began in the kitchen. So to paint the ceiling, I lowered all LED downlights and left them prised using the spring loaded mechanism allowing to paint under the gimbals, so no weight was placed on the wiring whatsoever.
After paining and re-fitting the lights as previously done, the downlights no longer come on and on checking the voltage at both switches and receptacles the voltage is now 138V instead of the expected 240V.

All other lighting is working fine so we are having to cook by candle light - LOL.

Have checked:

  • All wiring in the roof and all seems to be ok - physically that is.
  • Junction boxes with NFF.
  • Switches ok with some been replaced as a precaution
  • Cct breaker supply is at 240v,but for some reason it is lost to what appears to be high resistance but if it is the case I have been unable to find it. It would also appear that this may be a case of a floating neutral, but again I am not sure where to begin as I cannot determine mid-way so I can troubleshoot one half and then break it down further.

NB. LED lights are 240v so no tranformers are being used.

Any help is much appreciated.

Cheers.
 
Hi all,

last week I decided to start painting the inside of the house and began in the kitchen. So to paint the ceiling, I lowered all LED downlights and left them prised using the spring loaded mechanism allowing to paint under the gimbals, so no weight was placed on the wiring whatsoever.
After paining and re-fitting the lights as previously done, the downlights no longer come on and on checking the voltage at both switches and receptacles the voltage is now 138V instead of the expected 240V.

All other lighting is working fine so we are having to cook by candle light - LOL.

Have checked:

  • All wiring in the roof and all seems to be ok - physically that is.
  • Junction boxes with NFF.
  • Switches ok with some been replaced as a precaution
  • Cct breaker supply is at 240v,but for some reason it is lost to what appears to be high resistance but if it is the case I have been unable to find it. It would also appear that this may be a case of a floating neutral, but again I am not sure where to begin as I cannot determine mid-way so I can troubleshoot one half and then break it down further.

NB. LED lights are 240v so no tranformers are being used.

Any help is much appreciated.

Cheers.
Sounds like you may have disturbed some connections when you lowered the Lighting fixture, try tightening the connections up BUT ONLY AFTER SWITCHING THE POWER OFF it that doesn't work you will probably need the help of an Electrician, hope this helps
 
have done that also but no luck.
Thanks nonetheless.
If more that one fitting look to meassure voltage at each fitting.

Are they all consistantly low Volts?

If not the issue likely lies between the fitting with low Volts and the one with normal.

If it is the case that all are low volts then look between the first fitting and switch.

There could be a other reasons for this but the above is the simplest and most likely to look at.
 
It's consistently low volts on all fittings/ switches.

As the painting must go on, I decided to leave the troubleshooting for another day - yet to come. In any case, yesterday a set of ligts came on so tested all lights and found them all to be working correctly. I switched them all on/off a few times and could not get them to remain off so assumed the 'problem' had rectified itself somehow. So switched all lights off and then later as I turned one of the switches back on, I found that the lights would not come back on again...... I think they are possessed somehow.

Is there a way to finding out if a phase is missing? I cannot work out how the voltage could drop to 138v for no reason.... any one come accross this before?

Cheers.
 
Domestic premises are normally always single phase and even if your property had 3 phase then the lighting would be on 1 phase (230v)
2 phases = 400v, the loss of 1 phase in this situation = 230v

As others have said, it is likely to be a poor connection probably due to you pulling the switches/fittings
To rectify I would start by examining every fitting and switch you have touched an recheck the connections are tight and copper making contact. Also check any junction boxes in the attic etc. if you cannot see the problem then you will have to do some continuity test in a logical order WITH THE POWER OFF
If you don't have test equipment or are unsure on what to do next then I suggest getting an electrician in who can go through it logically with the correct test equipment
 
Roger that!! I will recheck of connections again although I didn't find anything untowards the first time.

Shall report back once done.

Thanks again.
Check that youve not tightenrd the cables down onto the insulation.

They mey be tight in the terminal but not making a true connection.
 
Well I am at a loss as to what the issue was as I haven't had the chance to get up and re-check the wiring. As it happens, we had a big lightning storm here in Sydney last night which has somehow rectified whatever was amiss.
Basically as the storm was passing by, the hall light turned on and upon checking the other lights that were out in the kitchen I was surprised to see them all functional once again.
They haven't faltered all day so will let it be for the time being.

Any ideas?

Cheers.
 

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