CU Mystery

[SLMitchell]

Downstairs lights not working - changed fuse, still nothing. Swapped the whole cartridge with the upstairs lights one and now downstairs working, upstairs out. Assumed then the cartridge is the problem, got new one and exactly the same thing is still happening - both cartridges and fuses definitely ok, but when both are in only one will work. When they are swapped around the lights that were previously not working will work again. Have also tested the original one that was removed and it works fine in the consumer unit in the garage, so it appears none of the fuses or holders are actually faulty. Any ideas ?

 

[breezer]

broken nuetral?

 

[IJWS15]

Is it a rewireable fuse or cartridge fuse unit?

As I read your post one of the lighting circuits does not work but not allways the same one.

When initially you swopped the fuse carriers over the fault moved with the carrier but now both carriers work in another fuse box.

 

[Lectrician]

Busbar stab on the correct side of the 'vice' type terminal on the carrier?

 

[sparkyspike]

If one circuit is working, then leave it alone and just work on the circuit that doesn't work. Make sure you have the correct fuse (test it if you can) and that the cartridge is properly connected to the busbar. All obvious stuff, but I can't think of much else right now. Are we talking about cartridge fuses?