change pendant light - wire question

levis2891

i'm in the middle of changing a light in a bedroom and stupidly didn't take a pic of the fitted wires before taking it down and now i'm abit stuck

its supposed to be a simple swap of a normal plastic pendant light but i've looked at lots of wiring images and i'm still unsure

theres 2 wires
1 - black
1 - 1 wire black 1 red

i think the light is the last on the rig hence why a single black instead of a double wire. also no earth, although its a plastic light that shouldn't matter


i thought red-live, both black-neutral
but after reading, what i understand is one wire is for the light the other is the light switch so
live black(switch one)-live, black-neutral and red-loop (tho will that work with only 1 red?)....does that sound right?

any advice would be appreciated

zax47

This might shed some light on things for you. (pun definitely intended!)

There are several legitimate ways to wire lighting circuits - I suspect yours has all the main live loop & switch interconnections at the switch (rather than the light) but the neutrals looped from the light - which is half one method and half another!!

As an electrician I would check if either of the black wires becomes live with the power & light switched on, as a DIYer I can understand if you don't want to do that (!) and would not suggest you try something you are not comfortable with or confident about. Take a look behind the switch to see what's there - any more than just a red & black pair suggests "loop at switch" method has been used, for the live at least.

PURELY FROM WHAT YOU HAVE DESCRIBED, if none of the blacks has red tape or sleeving on, then connecting the two blacks to each other and the neutral terminal of the new fitting and the red to the other terminal should see things right, but this is JUST MY SUGGESTION based on what has been described. IF you do that and the RCD or MCB trips when switched on, then one of the blacks is a switched live (but that wouldn't make any sense in the context of what you've described!!).

keith969

Normally I'd expect a black/red pair which would be the neutral/live for the lighting circuit, and another black/red pair which would be the wires to the switch. Then one of the switch wires will connect to the lighting circuit live, and the light will connect to the other switch wire and the lighting circuit neutral. The switch is always in the live side so that the light is not live when switched off.

levis2891

thanks for both your advice. i did buy electrical tester to identify the live and wired everything up properly, it turns out the switch had to be replaced thats why it didn't work :rolleyes:
that and the previous owners did their own style wiring up which i had to sort (unused wires in switches not taped up or even marked just left there)

but finally we have a light that can be switched on and off!

once again thanks for your advice, now at least i have a basic understanding of wiring so even i can change a light switch myself :beer: