Short when light turned on sometimes

[aaelectric]

We have been doing work in a flat where we had taken down light and put a temp ceiling rose. All was fine for a month then we fitted new expensive chandeliers. Worked fine for a few weeks then on some mornings the circuit would trip with a bang. Went back did a ir test all was clear 10m ohms between n-e l-e. Tested light that it was blowing from all was clear. Left off for a few days no problem. Refitted it and after a week it starts happening again. Light supplier says it carnt be the light as it would not cause a short. Any thoughts it run in singles in conduit.

 

[telectrix]

a guess would be that you have a faulty lampholder and it intermittently shorts, only when the lamp is screwed in.

 

[snowhead]

a guess would be that you have a faulty lampholder and it intermittently shorts, only when the lamp is screwed in.

And warmed up.

Unless the light manufacturer has been and tested the light, they cannot say that it can't be the light, well actually they can say what they like, but it doesn't mean it's correct.

 

[Darkwood]

If you have now isolated the fault to one of two fitting then remove the fitting fit drops up temp' and see if all issues stop for a few weeks, inspect the chandeliers for flash marks in the connection cups etc .... has your fixing screws for the chandelier pierced into a cable and maybe creating an intermittent issue?


It could be a number of things but it just comes down to elimination ....we can second guess all week but you're the one on site with the testers so do a common sense approach even if it means removing a suspect fitting for a few weeks...

Ask the correct questions too

Does the fault occur after a period when no one is doing anything or does it occur when the lights are switched etc .... questions help to narrow things down, have other trades been in?... nailed a cable, screwed a carpet grip down etc ....

 

[aaelectric]

It only seems to happen when they come in the morning norhing else on. Once it happens and they reset rcbo all work ok for the rest of the day check cable for any damage by screw no problem there. As said when it was being refurbed we had a temp ceiling rose installed with no problems for two months. Problem is now the jb is not accessible as light existing was wired in conduitNd we had to move the light centre which meant adding a little cable and covering over jb. We tested from that cable itself with no problems showing.

 

[Darkwood]

It only seems to happen when they come in the morning norhing else on. Once it happens and they reset rcbo all work ok for the rest of the day check cable for any damage by screw no problem there. As said when it was being refurbed we had a temp ceiling rose installed with no problems for two months. Problem is now the jb is not accessible as light existing was wired in conduitNd we had to move the light centre which meant adding a little cable and covering over jb. We tested from that cable itself with no problems showing.

Is there a lamp blown when they trip the power... is it full of bargain bucket lamps and in fact no issue exist its just normal nuisance tripping of the lamps popping.

I hope the JB is maintenance free ..

 

[aaelectric]

Lampsnot blowing all the time there is 9 in each jb is maintanance free we used twisters for connections would a l-n fault happen when the light is on for the rest ofday after it trips. Would of thought i would keep happening throughout the day ifit was

 

[Knobhead]

Lampsnot blowing all the time there is 9 in each jb is maintanance free we used twisters for connections would a l-n fault happen when the light is on for the rest ofday after it trips. Would of thought i would keep happening throughout the day ifit was

Pardon? Maintenance free?

You may as well have used sellotape for what use they are.

 

[aaelectric]

Are they not i was told by whilsaler they are

 

[telectrix]

wholesaler once told me that the earth was flat.

 

[Knobhead]

Are they not i was told by whilsaler they are

You’ll not find many electricians that would use them.
They’ve been around in one form or another for 70+ years, they haven’t got any better.

The wholesaler probably told you they were maintenance free so he could get rid of what he’s been conned in to buying.

 

[Knobhead]

Have a look on the IDEAL website, no mention of MF.

 

[stevethesparks]

Its about time them things were banned / taken off the market

 

[Knobhead]

Couldn't agree more Steve.

Beats me why the Americans like them so much. As screwits they were a disaster in the making.

 

[aaelectric]

I thought they were quite good if used properly they twist the cables together and you can check if all isgood as they screw off

 

[shanky887614]

I thought they were quite good if used properly they twist the cables together and you can check if all isgood as they screw off

the only maintinence free connection i would trust is soldered.

if you want to be really picky use leadfree solder then it wont fail till the insulation has melted off lol