DIY Doctor UK DIY Forums

Posted: **Sat Nov 24, 2007 9:29 pm**

trying to replace an old external light
coming out of the wall there are 2 red wires 2 black wires and 2 bare wires ( presumably earth????)

i fastened the 2 red wires up to the live connector
the 2 black wires up to the neutral

and fastened the 2 bare wires into a connector

light came on but as soon as i tried to turn it off at the switch it blew the fuse??????

help please!!!!!!

Posted: **Mon Nov 26, 2007 8:52 am**

carlos edwards.
this is part p work and notifiable , and not diy.
get in a part p reg sparky .

BLAKEY1963

Posted: **Sun Dec 16, 2007 2:21 pm**

I have a related question to this...

The house we bought (5 years old) has a fitting for an external light, we've bought a ligh and i was going to fit it but once uncovering the wiring I was faced with 1 red, 1 black and what appears to be copper wire.

With the fitting needing earth, live and neutral, is this fitting safe to fit as it is or does something need to be done first?

Posted: **Sun Dec 16, 2007 8:11 pm**

Blakey, this is not notifiable works to part P.

Sounds like you have a pemanent live and switched live mixed. What were the original connections on the old fitting. You might need a multimeter to find out what connections you have.

Mark, is this twin and earth cable, if so then the bare copper wire is an earth and needs earth sleeving. It should be ok to use.

Check the how to section for more advice

Posted: **Sun Dec 16, 2007 9:47 pm**

I've checked the 'how to' section and found it didn't really help with this question.

Dumb question (well possibly) what do you mean by putting the sleeve on? Do you mean covering the bare copper wire with the earth green and yellow sleeve?

I wouldn't know if its twin.

Posted: **Sun Dec 16, 2007 10:26 pm**

carlos,
the 2 reds go together in a spare term block not connected to the fitting, the 2 blacks go to the lights brn. & blue wires, one to each, the bare ones should be sleeved/taped grn/yel and connected to the earth term. on light.
the 2 blacks are one Neutral & one switched live, which should have red sleeving/tape but often missing. with a B.C. lampholder or a modern ES type it makes no difference which way round you connect it, regards SPARX

Posted: **Sun Dec 16, 2007 11:02 pm**

[quote]fastened the 2 red wires up to the live connector
the 2 black wires up to the neutral [/quote]

If the two black wires are live and neutral then the fuse would have blown at switch on.... not switch off.

Posted: **Sun Dec 16, 2007 11:34 pm**

I would add its good practice to always have the centre contact of the es holder as live.

Will then ensure to conform to reg 553-03-04.

sparx is right to a point it's not always compulsory,but you cannot be certain the lampholder on some cheap foreign fittings, is to bs standard and would be safer if the bulb ever shatters exposing the metal casing or you touch the thread screwing the lamp into a non bs edison screw holder.

Posted: **Mon Dec 17, 2007 7:30 pm**

Yes mark, earth sleeving. Connect to light fitting and let us know what happens.