upstairs lighting issue

[stephen Sharp]

Evening all.

Bit of an odd issue I'm having last few days. Late afternoon the upstairs lights are very dim....apart from onsuite. 5 other lights(bedrooms, landing, bathroom) are dim, and you can't have more than one on at a time. Infact if you switch one on then go to the next and turn on, it switches the 1st one off.......then around 5 everything works fine. All lights on, full power.

All very odd. Nothing trips.

Any thoughts? I have checked light switches for loose connections. Lights are on there own circuit. And pretty sure if any thing was loose I'd have the problem in the evenings.

Thanks

 

[Murdochcat]

That sounds like a bad connection somewhere in the circuit

 

[stephen Sharp]

I thought that....not checked any of the light fittings yet. Just seems weird everything seems to work after 5. Saying that I was fiddling with the bathroom cord connection when they came back on in the bathroom.

Onething I have noticed is the bathroom light makes quite a loud buzzing sound(from the transformer). I think this might be the 1st light in the circuit as it is directly above the fuse box in the garage.

Still don't explain why everything works fine in the evenings.

 

[FrodoOne]

One thing I have noticed is the bathroom light makes quite a loud buzzing sound(from the transformer). I think this might be the 1st light in the circuit as it is directly above the fuse box in the garage.

If this is a Ceiling light and NOT a Mirror light (working from a Transformer),
it is likely that that is where you have a loose (Line or Neutral) connection, which is heat sensitive
OR
the connection at any such Transformer is where the fault is located.

 

[ericmark]

My thoughts are likely a line and neutral swapped somewhere. It is common for the switch wires to be brown/blue or red/black where really they should be brown/brown or red/red. One would like to think originally oversleeved, but it means an error in identification can mean lights wired in series rather than parallel.

 

[stephen Sharp]

Thanks....nothing has changed apart from replacing a transformer in the bedroom lights above the bed that had failed. I have disconnected that just to see - problem still there.

I did some testing.

All lights switches are reading 67v, apart from onsuite that is 240v - pretty sure that will be on the same circuit.

 

[stephen Sharp]

All sorted...a switch wire from the start of the circuit had been damaged at some point(probably a mouse). Weekend was messing around in the loft so maybe moved some cables etc......which caused arcing. Cable stripped back and reinstalled...all seems good.

 

[JohnW2]

My thoughts are likely a line and neutral swapped somewhere.

The OP is surely talking about a problem that has arisen in recent days, not one that has been there ever since the wiring was installed?