How to find a dead short

[dazlav]

Hi all ,

I have had a problem with my downstairs lights , fuse keeps blowing , have had an electrician around this morning , tested the fuse box and said it was a dead short , he said the hardest part is finding the short , we would have to pull all carpets up and floorboards up , check all wiring for signs of possible rodent nibbling .

i was just wondering if there were an easier way to narrow down the area of damage , don't fancy having to move all furniture and pull all carpets up and floorboards.

Many Thanks

Darren

 

[pjcomp]

First place to check is where the wiring surfaces, ie the light fittings and switches - these are easiest to get at without damage/disruption. If this doesn't find the problem, next step is to disconnect each fitting and test between them, which should pin down the approximate area of the problem and limit the area of disruption.

While rodent damage can't be ruled out, it's statistically more likely to be a problem at a light fitting. Have you got any downlighters? Sometimes the problem will be a cable draped over a fitting which has cooked out with the heat from the lamp.

Did the problem start following any other work in the property - floorboards up, carpets down, pictures hung?

PJ

 

[Spark123]

Second what pjcomp says, do you have an enclosed bathroom light or an outside light on this circuit (thinking water ingress in an outside light)?

 

[dazlav]

Thanks pj will do as you suggested , i have not been doing any diy to cause the problem , i thought my electrician would of done these checks , he did check my bathroom lights , its an extension with flat roof , we had a leak a few weeks ago and the pull cord stopped working but had it mended , was thinking same as spark 123 about water , all dry when checked , on Saturday afternoon we had quite a bit of heavy rain , that's when the lights went , sparky checked it all said it was ok .

Thanks Darren

 

[RMS]

Your electrician needs to split the circuit and test in sections. This way they can eliminate healthy wiring and narrow the dead short down.

Have you nailed any pictures up recently or had any DIY work carried out? A decent electrician should be able to identify the location of the fault within a couple of hours.

 

[flyingsparks]

Your electrician sounds useless. Why hire a electrician if they are not going to find and solve the problem? Leaving it to you, whom you have no knowledge of fault finding or testing gear, I think you need to get them back..

But I would check the bathroom area again if you had damp coming in there before...

 

[RF Lighting]

I think you need to get them back..

I think you need to get someone who actually knows what they're doing to have a look.

 

[flyingsparks]

I think you need to get them back..

I think you need to get someone who actually knows what they're doing to have a look.

Yes good point, thats what I ment!

 

[dazlav]

Thanks all , don't think i will get the same electrician back , don't think he was really that interested in taking the job , 30 years experienced electrician who i picked from an approved list of local tradesmen , just gives the good ones a bad name.

my father inlaw is coming down tomorrow to check all the light fittings and switches , hopefully will be able to narrow the fault area down , if not will try another electrician , will need one anyway to mend the fault if we find it.

 

[bernardgreen]

If your father in law has the knowledge, ability, test equipment and competance to find the fault it is possible he also has the knowledge, ability and competance to be able to repair the fault.