Electrical fault

[iain m]

My elderly neighbours have experienced several bulbs blow in ancient table lamps plugged into the ring main which also blows the 5amp fuse in the 13amp plug. 18 months ago they had a Hotpoint dryer catch fire in the garage melting the consumer unit and the gas meter causing considerable house damage all of which has been rectified. When the bulb blows it trips the 6amp lighting MCB in the new consumer unit not the ring main!!!! Is this because its a low value fuse and all the fuses are connected on the live side or something requiring professional attention??    

[CraigHew]

I think newer MCBs are just super sensitive to errors and will trip if a firefly farts three fields away.

We switched the whole house to LED / Low energy bulbs that last far far longer and don't seem to get the consumer unit tripping out now the way it did with the older filament bulbs.

As ever, if in doubt, get a sparky to check it out...

[Rory's Dad]

I agree about getting a sparky in. Had an MCB blow out in my shiny new distribution board which eminated from the garden shed (my fault).  So I went into the garage and power was out but so were the lights. Went into the house and some power and some lights were out too. Turns out that rather than put everything onto one MCB the circuits are split in two so poor ole gits like me don't plunge themselves into complete darkness. Well really!!!

[SootySport]

As above,  MCB's  trip easily with lower currents than the old fuses.    Also sometimes the pylons in the bulbs can fall together and draw more current than usual, again tripping out an MCB.    If they changeover to LED bulbs they won't have this problem and bulbs last for years, so they tell us.

[Ian Kinder (Bagpuss) - Joint Peak District AO]

A common failure mode in traditional filament lamps (bulbs grow in the garden ) is that if the metal base is at the bottom during use, when the filament dies and breaks, it can touch the metal base resulting in an earth fault if the lamp is earthed which will trip the RCD in your consumer unit.

[iain m]

I will pick up a pack of LED bulbs from Screwfix and it will save me further trips in the dark. Regarding split circuits my lighting is split upstairs and downstairs and the ring main left and right which I find very confusing.    Thanks for the info.