Indeed, although even then, to be totally safe, you should really do a test to make sure that main switch has really done its job.OK - so common sense prevailed - If the main switch is off then no power flows past there in to the CU.
True, I take this point on board for the future, thanks
Thermal 'triggering', almost certainly, but I frankly wouldn't expect an MCB to behave like that - unless, perhaps, the one next to it was red hot or on fire - I therefore suspect that you have a 'shot' MCB.I have run the suggested test and disconnected the lighting circuit completely and left the MCB on. At first it wouldnt reset from the previous test a min or before - then after a couple of minutes i tried again and it reset OK. I then started up the oven and grill and it tripped after about 30seconds.
So i am presuming this would suggest that it is thermal triggering then?
Kind Regards, John
I can now feel a little warmth coming from the MCB but it definitely isnt really hot.
Ok great i will get a new MCB for th lighting circuit then and let you know how it goes.
Thanks