Fuse for outside light?

[hard-work]

CU with RCD. Does an outside light still need an FSU switch with a fuse?

 

[bernardgreen]

Does a an outside light still need an FSU switch with a fuse?

It is a good idea to have a double pole switch to enable the lamp(s) to be fully isolated ( Live and Neutral, open circuit, Earth remains connected ) for the time when the lamp is damaged or water logged.

If the supply is from a lighting circuit with a 6 amp MCB and the cable can carry 6 amps then the fuse is not needed, If the supply is from a 32 amp MCB and the cable to the lamps is rated less than 32 amps then a fuse is needed,

EDIT in red

 

[hard-work]

This will most prob be off the lighting circuit, so no need for a fuse. Double pole make sense of course, which will most prob be the case, but what do the reg's say? Or what do most do?

 

[bernardgreen]

See my corrected posting /

 

[JohnW2]

This will most prob be off the lighting circuit, so need for a fuse. Double pole make sense of course, which will most prob be the case, but what do the reg's say? Or what do most do?

The regs don't require anything (if it's fed from a 6A lighting circuit) - but if you don't have a DP switch, you might come to regret it if/when your outside light fills with water and trips your house RCD.

Ironically, you will probably find that an FCU (which will have a DP switch) is quite a lot cheaper than a DP switch - so an FCU (with a 3A) fuse might be the way to go.

Kind Regards, John

 

[John D v2.0]

agree FCU is the cheapest way to get a DP switch. When I needed a 20A DP switch for outside sockets, I found the cheapest was to get one engraved with "heater" or something and then stick a label over the label.
But no, the outside light doesn't need any switch other than the main means of isolation and suitable fault protection for the cables. But take the manufacturer's instructions into account.

 

[hard-work]

The aim is to get a double pole switch of some description. But the existing outside light is switched from an ordinary switch on the far side of the room, not the outside wall. It picks up a neutral from somewhere. So difficult to get a double pole switch in as unable to detect the neutral buried in a ceiling somewhere, although that is the aim. If too difficult them the existing setup will reman except RCD protection.

 

[John D v2.0]

if the CU has an RCD in it, it would have tripped already if the neutral was coming from other than the same RCD. So I think you're okay there.

 

[hard-work]

As been mentioned it is the light filling with water is the problem taking the lights out.

 

[John D v2.0]

fair enough, well by the time you sort out the wiring so you can get away without an RCD you would have separated the neutral off anyway, at which point you can just add the switch.