lighting circuit fault

welsh_dude_6 · Nov 26, 2011

Hi guys, was asked to have a look at a lightng circuit in a local house but it has baffled me. the mcb hasnt tripped and neither has the rcd. no changes to fittings etc. out of the whole house 2 lights still work and the rest dont. teting the voltage at a few of the light fittings. im getting 240 between earth and live but earth and neutral only 24v? didnt have time to do continuity on circuit etc as was only a quick call as going out. just wondered if any1 gotideas of what it can be? any help appriciated, cheers.

welsh_dude_6 · Nov 26, 2011

sorry i meant between live and neutral im getting 24v.

Deleted member 26818 · Nov 26, 2011

Most likely a loose connection, usually at the last light fitting that is working.

welsh_dude_6 · Nov 26, 2011

Will do that, thanks, just upon quick check consumer unit under stairs, kitchen next to it ok. lounge next to that ok then from there on it doesnt work. as stated, i had 240 earth to live but only 24 neutral to live. so it would be a loose neutral?

Deleted member 26818 · Nov 26, 2011

Neutrals, are very prone to becomming loose.
I'm certain that it was explained to me once why, but I'm buggered if I can remember.
Something to do with cyclilic thermal expansion and contraction or similar.

ezzzekiel · Nov 26, 2011

spinlondon said:
Something to do with cyclilic thermal expansion and contraction or similar.

yeah thats what i thought :20:

Specialist · Nov 26, 2011

Reasonably common fault, especially with cheap fittings.

telectrix · Nov 26, 2011

broken or loose neutral in a ceiling rose ( assuming loop in at lights ). could be a break in a conductor, but unlikely. hopefully you've not got JBs under the floor all over the place.

seb77 · Nov 27, 2011

i had the same problem mate, it turned out to be a loose neutral in a connector block behind a switch. There were 4 neut's going into the block but one was wedged in between the copper terminal and the plastic housing. it had been fine for 3 years and slowly came loose. Also seen afew neutral faults at ceiling rose...over tightened and snapped or simular.