Fault on lighting circuit HELP!!!!

lost-sole · Jul 2, 2011

I have just installed an additional light for someone in a kitchen (spot light), I put a new switch drop in and and swapped 1g switch to 2g switch as he wanted it independent from other, when i wired the loop into light i broke into a permanent feed to another light and fitted a JB as there wasn't and additional light near for feed. Connected 3 plate method tested before i connected light I got 236v between L-N L-CPC and as soon as i connect light voltage drops to 84v, so i tried another light just in case there was a fault on fitting and still 84v disconnect light and back to 236v. Iam average at fault finding usually when there is no voltage etc but this one has thrown me. Can anyone help?

beaver74 · Jul 2, 2011

havent read fully as im just logging off but sound like you are in series

lost-sole · Jul 2, 2011

in parallel?

bozobro0 · Jul 2, 2011

make sure you did joint into a permanent feed,then i would check my neutrals.

beaver74 · Jul 2, 2011

lost-sole said:
in parallel?

no if it was parralel you would be getting line voltage

Octopus · Jul 2, 2011

Loose connection, incorrect connection?

Sparky Ninja · Jul 2, 2011

If the voltage is only changing when the load is introduced then it does sound suspiciously like it's been connected in series.

SirKit Breaker · Jul 2, 2011

Work your way back. Re-instate the circuit to how it was before you did you addition. Then think logically what you did and how you did it when you installed the new light. You will probably answer your own question as to what the fault is.

This is how i would have done the job based on the info you give.

Install new switch drop to go with existing, and use only one core as the switched live back to the fitting, link common from existing switch across to common on new switch this gets your 2 gang switch working OK and gives you a switched live at the fitting. Then run a neutral from the most accessible neutral on that circuit to new fitting, hey presto job done. Before anyone jumps in, the CPC has been omitted for clarity.

Cheers.............Howard