Fused Light switch help

[alovella]

b]Hi all, I need help as I seem to be stuck for answers. I have a kitchen larder where I wish to add a light switch. There used to be a single 15amp socket for an old blow heating system which has now been removed apart from the socket itself of which Id like to spur from to a fused switch 3amp to install a light. Although for the life of me I cannot get the damn light to work. I've checked all the way through the wiring using a test screwdriver on all live terminals & all light up ok as showing live, but I noticed that a blue wire from the Fused Switch lights up to. I feel this is not the norm & suggests a break in the cable. Be gratefull for any help. tony[/b]

 

[JohnD]

Neon screwdrivers are not reliable.

Throw it away and invest £10 in a Multimeter. Let us know if you still have a prob.

 

[breezer]

i bet the socket is disconected some where.

have to agree with the above about neon screwdrivers too

 

[Taylortwocities]

I concur with the above. the neon screwdriver will light up if you f*rt near it so its possible that your old socket has been dosconnected and the neon is lighting due to induced voltages.

Maplin have a nice deal on multimeters. £5.99 and its buy one get one free!

 

[alovella]

It's actually a fused tester as I don't use the neon testers purely because of what you alreay have said. they come on at their own accord. Should not be on the market really. Suprised british standards allowed it. Did they? anyway I do have a multi meter but without being to technical can someone please for the time being tell me how I use this to test the wiring. I have ordered a very good book as suggested by somebody on this site from Amazon about how to correctly use a multimeter but right now I need to use it to find his faultI have a rapitest DM25 IF IT'S ANY HELP.

 

[Steve]

set the multimeter to 300 volts AC ~

Put the red probe to the live terminal. Put the black probe to the neutral terminal.

This will give you the voltage between live and neutral.

 

[bernardgreen]

set the multimeter to 300 volts AC ~

Put the red probe to the live terminal. Put the black probe to the neutral terminal.

This will give you the voltage between live and neutral.

Put neutral on first otherwise you have a meter and probes all at live potential.

 

[alovella]

OK Ive used my multi meter and tested the wires. I've 2 Volt settings so I have done a test with both settings. Setting 1 shows V-... which show 200m 2 20 200 & 1000. I used 1000 setting and probing the neuteral first with black lead then Live red with red probe it only flashes 0 & 1 So, I have now used the V setting with the twirly line at the side of it. This time the settings are 700 200 20 2 200m Ive used 700 as I've not got 300. Same test but this time it shows 63volts? Don't seem right to me. What does this suggest? I'm assumming it should be showing as 240volts? It this is correct then I must have a fault in the cable between the Spured socket and the Fused Switch. Your comments much appreciated.[/b

 

[bernardgreen]

V with - is for DC measurements,

V with ~ is the one for AC.


63 volts between Live and Neutral suggests one of them is open circuit.

( Open circuit means the wire is broken somehow )

It would seem that with one wire open circuit the read would be zero but capacitive inter wire coupling creates false readings.

To find which wire is open circuit measure with black lead on earth and red lead on live, If you get 230 volts here then the live would apear intact and the neutral open circuit.

Now measure with black lead on earth and red lead on neutral. If the reading is more than 10 volts then the neutral is almost certainly the wire that is open circuit.


,

 

[Steve]

Test you meter on something you know to be working, on 700V AC ~

It should be between 210 and 250 volts.

 

[alovella]

b]Many thanks all for your help. Problem now solved. The socket I spured from has tested as showing 237 volts but at the fused switch it was showing as 63. The fault turns out the cable, new as it was supposed to be had a a break. This was the only fault I could assume, so I replaced the cable with another new bit & that now also shows as 237volts. Hey presto, my assumtion was right. alls now working. Thanks again all[/b]

 

[securespark]

My guess is if you have a "live" neutral, it is open circuit.

Trace it back from whence it came & check the connections.