You mentioned surge from sunbeds.
Yes, for a fraction of a second as they start the draw more current
But I get the impression that you have a slow trip due to heating up.
Yes, I personally think it's due to heat conduction.
Don't forget, the 6 amp lights does not trip when the sunbeds are not busy... so it isn't heating up due to itself, or it would trip whenever - it only trips when the sunbeds are busy
The heat would not be caused by a switch-on surge.
No, but maybe the heat would compound a problem if the 6amp was picking up on another switch on surge OR the heat or vise versa I don't know - I am here to ask
"D" type MCBs have no additional resistance to heat, only to switch-on surge.
Yes, I thought the same... same for type C but people have suggested both - would make sense if somehow the 6a was picking up some sort of surge from another circuit... like the sunbeds one - this is what I am asking... can this happen
If the MCB was heating up due to overload, an adjacent hot MCB would prevent it losing excess heat, so it would get hotter until it tripped.
No, I am thinking the adjacent MCB being hot and conduction heat to the next one along... being only 6 amp, causeing a thermal trip - again this makes sense but I don't know if this can happen
Have you tried taking out some of the lamps on the circuit that keeps tripping to reduce the load? Or fitting energy-saving lamps to save yourself money on electricity?
No, can you get energy saving halogens? Also, the load per breaker is not that high, in fact previously BOTH rooms were on only a single MCB (the one that trips). Then I split the rooms to have there own breakers and the one that trips was still tripping (as said, I took this breaker out today and put in another 6amp one, if it was a tempramental breaker it could be solved - just investigaing my options now so I know what to do for the best if it trips again, as it's intermittant it could take weeks before I see the prob again)
We had early suggestions (and a 14p wager) that the cause was damaged wiring. Can you rule this out yet? Visual inspection and an insulation test would help.
Not entirley, I did look at them all when I took all the bulbs out but I didn't nip up all connections which I could do next... I also need to have a look at the switch