hi there this problem occurs even if no other lights on in the house and always when you switch them on. Just had bloke in to test light fitting and whatever kind of meter he uses said it was giving a reading when it shouldn't be, he said it should read clear. and this could be damage caused by heat going through it after a length of time. Hope you know what he was meaning better than me. Have just bought new fittings and with 3 spots instead of 4 so will see how they go. Really appreciate your help and if problem hasn't gone I will let you know.
You cannot do this yourself
Remove all bulbs on the circuit
Switch all the lights on ( with no bulbs in )
INSULATION TEST at 500Volt between L and N
L and E and N and E
Ask for the readings
That will cover the WHOLE circuit
If they are low ask him why and if he can locate and sort it
If he cannot get someone that can.
You say it is one room so all he needs to do is test between the switch in that room to the lights within that room , with NO bulbs in.
Hi Bloke took my light fitting down and did a test taking out all the bulbs and did something with wires he had on it and thats when he said he was getting a reading when it shouldn't be so he thought fitting was faulty. He said to try new lights first to see if cured problem if not he would come back. Touch wood new light fittings hasn't tripped breaker so Im keeping my fingers crossed, also chose ones with a spot less just to reduce watts slightly in case I was bordering on overload.
Bulbs blowing will often cause mcb to operate, and this does not indicate a major problem.
Bulbs blowing regularly, is usually caused by 1 of 5 things.
1. Cheap bulbs that have travelled thousands of miles to get here
2. Poor connection in the lampholder
3 Poor connection in Spring contact bulbs, ie screw type
4 Very occasionally, tightness of terminals at switches
5 Your proximity to a sub-station. If you are near one you will get more power, so that those further away can get a reasonable supply (voltage drop over distance). I think the supply companies agree to supply 230v,
+/- 7%, and this can make a huge difference to lamp life.