Dodgy looking circuit and lights not working

[jamie Smith]

Hi guys

I’m new to this forum and there appear to be some knowledgeable, helpful people here. Great.

I don’t know who wired my house, but I’ve seen something which confused the hell out of me. In the roof space above my bathroom I have a 30 amp former shower cable, which runs into a fused spur (13 amp). The outlet from the spur runs into a junction box. One tail from this powers underfloor an heating thermostat, which works fine.

The other tail goes into a 5 amp fused spur. The outlet from this spur goes into a junction box. One tail goes into a light switch, the other into a daisy chain of spotlights…..which don’t work. I’ve tested the fuses and they’re ok, it’s not tripping at my consumer unit and the junction boxes and spurs appear to be wired properly.

1. Is this a safe setup – I’m not convinced?
2. Any ideas on what could be the matter with the spotlights (I’ve eliminated the lights themselves as being the problem)

Thanks

 

[Steve]

All sounds OK, but I would have the circuit protective device as 20A. And move the 5A FCU to the UNFUSED side of the 13A FCU.

Check the lightswitch for continuity.
Check for continuity in the switch cable, with the switch in both positions (at the junction box)
Check the lamps for continuity (that they actually read a resistance, not 0)
Check for voltage between L and N at the junction box, to see if you actually have power. Do the same at the lights.

All these tests require a cheap autoranging multimeter.

 

[jimbox]

if you don't have a multimeter, you could check if the light switch is the problem by bypassing it at the junction box after the 5A FCU. Use a bit of suitable wire to effectively short that part of the circuit out.

[Naturally, turn off the power whilst working on the junction box!]