I've just rewired my house and was using the old consumer unit with
some aftermarket MCBs. I'm pleased to say everything has been working
fine. I decided I should go for a new consumer unit to give me more
control over my circuits and safety. I've bought an already populated
Volex CU from Screwfix. This has a 63A RCD (VR63) which trips at 30mA.
I installed the unit and wired everything up (no instructions came with
it), with the busbar not cut so (presumably) everything is protected.
With everything connected I can switch on really low current devices
like lamps plugged in to sockets or mobile phone chargers absolutely
fine. The second I try and switch on something more hungry, like a TV,
fridge, freezer DVD player or computer the RCD trips out. This doesn't
happen EVERY time, just most of the time. I've tried this with all the
lighting circuits off and every other ring circuit off and it does it
on all three (kitchen, downstairs and upstairs). I can't understand why
this happens, so I've been reading up on circuit capacitance and TNC /
TNCS supplies, but as I'm not a sparky by trade I've just got confused.
On top of this, with the mains on and some lamps switched on or even
off, when I press the "T" button to test the RCD, nothing happens.
Shouldn't it trip itself? I'm thinking (hopefully) that I haven't done
anything stupid, and that the RCD is in fact faulty out of the box. Can
anybody help me with this? I've gone back to the old consumer unit for
now, and I'm not happy! (though at least I can watch TV and have a cup
of tea).
Thanks,
Skote