Problem in a junction box ?

[Jimmy928]

Hi There,

First of all I am not a electrician, I am a carpenter. But my client has had a recent problem with a series of lights... and I am just seeing if its something that I could possibly fix or it is something more serious and need to get a registered electrician in.

There is 7 different light switches in the room. the first 5 work fine. then the last 2 are not working right...
first of all I put my electricity wand up to the light fitting and it is indicated its live so we tried new bulbs/new light batten... still not working so I brought a voltage tester and its reading 2 volts ???

could this mean that maybe the neutral wire has come loose in the junction box when we have re-insulated & plaster boarded the ceiling ?

Any help would be much appreciated.

James

 

[telectrix]

carefully measure the voltage L - E at the light when it's supposed to be on. if you get 240V (ish) then it's a sure sign that the neutral has been lost. i am assuming that the cpc (earth ) has been connected and not just cut off as a builder would do.

 

[Jimmy928]

carefully measure the voltage L - E at the light when it's supposed to be on. if you get 240V (ish) then it's a sure sign that the neutral has been lost. i am assuming that the cpc (earth ) has been connected and not just cut off as a builder would do.

Thanks for the reply.

I tested the five lights that I'm guesting are previous in the circuit and I was getting 220v (ish) but then on the some voltage setting I was get 1-2 volts on the next light. I'm going to have to look more into it tomorrow when I get back to work. just hope I'm not going to have to start cutting holes in the ceiling trying to find the junction box.

 

[Jimmy928]

Has a plastic switch so earth is going to the metal box at the back and also the metal terminal at the light.

 

[telectrix]

so if you get 230V L - E then it's a lost N. may be easier to lift boards upstairs than cut the ceiling. current regs. stipulate that inaccessible junction boxes installed nowadays must now be maintenance free, e.g. wagos in an enclosure instead of screw terminals.

 

[Jimmy928]

so if you get 230V L - E then it's a lost N. may be easier to lift boards upstairs than cut the ceiling. regs. stipulate that inaccessible junction boxes must now be maintenance free, e.g. wagos in an enclosure instead of screw terminals.

Ok great thanks for the help. I will test it again tomorrow and also check to make sure the switch is working correctly.

 

[Deleted member 26818]

It's also quite likely that the problem will be at the last working light, rather than at the first non-working light.

 

[Jimmy928]

I have just tested the light and it seems like the current is working against each other??? It's giving me. Reading of 5 then drops to -5 then goes back to 5... And so on. Sounds like positive and neutral and around the wrong way?

 

[telectrix]

those low readings that you are getting are probably spurious and irrelevant. told you earlier. read the voltage L-E.

 

[Taylortwocities]

The readings you are getting with your "magic wand" are typical of voltages just being picked up in the wiring. You will get this with wands, and many digital multimeters as they have a high impedance.

You really need a proper two probe voltage tester to do any sensible testing.

 

[telectrix]

The readings you are getting with your "magic wand" are typical of voltages just being picked up in the wiring. You will get this with wands, and many digital multimeters as they have a high impedance.

You really need a proper two probe voltage tester to do any sensible testing.

or a properly certified wet finger. :mamazed:

 

[westward10]

Get an electrician in.

 

[Silly Sausage]

Get an electrician in.

Ahhh, it's sounding like the old days again!