No voltage

[meddyliol]

I am connecting a cable from the consumer unit to a double light switch. Having connected it to the consumer unit and before connecting to the switch I tested the mains voltage. There was 250 volts at the consumer end but my meter (Fluke) was only reading about 7V at the other end of the cable which is only about four feet long. Testing with an ohmeter gave zero ohms so the cable seems OK. Any help would be appreciated.

Thanks

Brian

 

[telectrix]

stop before you kill yourself. testing an open end cable connected to supply?????????

 

[meddyliol]

Thanks for your concern but I do not intend killing myself just yet. The wires were not just dangling, I connected them to a terminal block first. I still have an apparent voltage drop of about 143V though.

 

[AP Electrical]

Thanks for your concern but I do not intend killing myself just yet. The wires were not just dangling, I connected them to a terminal block first. I still have an apparent voltage drop of about 143V though.

Nobody intends killing themself doing diy, Does'nt hurt to know your own limitations though.

 

[Dunc]

Sounds like you've connected it up wrong or you're not testing correctly. Either way it sounds like you may be carrying out work that is outside of your skill set as fault finding on a circuit that is only four feet long would be childs play for someone with the correct knowledge to be carrying out this sort of work.

 

[meddyliol]

I have not connected it incorrectly and I do have an HND in Electronic Engineering so am not totally stupid. Its just that I am really confused why there is a voltage at one end but not the other. As it is not an open circuit then there should not be a voltage drop.

 

[pjcomp]

Which side of the MCB did you test at, and is the MCB on or off?

PJ

 

[AP Electrical]

If your cable is intact and only four feet long and at one end l/n has a pd of 230v then unless your at paul daniels house it'll have a l/n pd of 230v at other end

 

[TaffyDuck]

Could be a broken neutral which would give a voltage indication of about 12V or so on the live without the neutral being present. Have you checked continuity Rn?

 

[Mark_Burgess]

Full dead testing should be carried out BEFORE any live Zs testing should be carried out, IF you are competent to carry out the works, you WOULD have found the problem before energising the circuit.

 

[needasparks]

I would check the cable is fully inserted in the mcb and not behind the clamp or held by the insulation instead of the copper.
I guess if nothings coming out then nothings going in but then an HND would have told you that
Might check your maths on the volt drop

As others have said this should be done by a sparks really as if your missing a basic fault like this whatever the problem turns out to be you really should not be playing with it.

 

[Knobhead]

Funny how many we get with a HND in electronic engineering that can’t wire a light ! ! ! !

This smacks of a wind up.

 

[DurhamSparky]

i have a degree in social studies and english language. but i cant chat to women at the bar... what have i done wrong!! am i a looser or do i need to grope them first to get there attention...

 

[telectrix]

or do i need to grope them first to get there attention...

beats the chat up line " get your coat, you've pulled "

 

[HandySparks]

Testing with an ohmeter gave zero ohms so the cable seems OK.

Between which two points (exactly) were you getting this "zero ohms"?
I assume that you tested all three cores?

 

[Octopus]

Thanks for your concern but I do not intend killing myself just yet. The wires were not just dangling, I connected them to a terminal block first. I still have an apparent voltage drop of about 143V though.

How do you calculate you have a volt drop of 143v?

 

[chronyx]

Give it a taste test.

 

[needasparks]

Give it a taste test.

worth a go, 250 -143 =7v never killed anyone

 

[Octopus]

worth a go, 250 -143 =7v never killed anyone

Sounds like the maths the Royal Bank of Scotland used!

 

[telectrix]

worth a go, 250 -143 =7v never killed anyone''

???????????? 1 and 1 is 3?