Hello all,

We have a strange problem with our electrics. Our main living room
light does not work or the wall lights in the same room. Same thing in
the master bedroom and one of the lights in the hall. All other lights
in the house are fine.

I invited a friend over who knows something of electrics and he
checked the fuses and took voltage readings at the light fixture and
the at switches.

He found that there was no voltage at the switch ( about 3V ) but
managed to get a reading of 246V at the light fixture in the lving
room. He got about 150V in the hall !!!

We both thought you should either get 0V or 240V !!

Does anybody know what could cause these strange readings or have had
similar problems in their house ?


Cheers

On 23 Jun 2004 07:09:12 -0700, (Richard Snell) wrote:


Does anybody know what could cause these strange readings

Probably a digital multimeter...
Try an AVO 8

Geo

Richard Snell wrote:
Hello all,
snip
He found that there was no voltage at the switch ( about 3V ) but
managed to get a reading of 246V at the light fixture in the lving
room. He got about 150V in the hall !!!

We both thought you should either get 0V or 240V !!

Digital meters can often measure the small capacitive currents induced
by wires lying next to each other.
This is not a 'real' voltage, if there is any load, it will fall to zero.

In article ,
(Richard Snell) writes:
Hello all,

We have a strange problem with our electrics. Our main living room
light does not work or the wall lights in the same room. Same thing in
the master bedroom and one of the lights in the hall. All other lights
in the house are fine.

I invited a friend over who knows something of electrics and he
checked the fuses and took voltage readings at the light fixture and
the at switches.

He found that there was no voltage at the switch ( about 3V ) but
managed to get a reading of 246V at the light fixture in the lving
room. He got about 150V in the hall !!!

We both thought you should either get 0V or 240V !!

Does anybody know what could cause these strange readings or have had
similar problems in their house ?

The strange readings are caused by a high input impedance meter,
and capacitive coupling of disconnected conductors to nearby live
conductors.

--
Andrew Gabriel

In article , Ian
Stirling writes
Richard Snell wrote:
Hello all,
snip
He found that there was no voltage at the switch ( about 3V ) but
managed to get a reading of 246V at the light fixture in the lving
room. He got about 150V in the hall !!!

We both thought you should either get 0V or 240V !!

Digital meters can often measure the small capacitive currents induced
by wires lying next to each other.
This is not a 'real' voltage, if there is any load, it will fall to zero.

Also the mains voltage is "nominally" 240V but I've seen it as low as
200V and as high as 265V.

If he found no voltage at the switch, sounds like he was measuring
across the switch? To get anything meaningful, one meter probe has to go
to earth or neutral, the other probe to the voltage being measured.
--
Tim Mitchell

On 23 Jun 2004 07:09:12 -0700, (Richard
Snell) wrote:

Hello all,

We have a strange problem with our electrics. Our main living room
light does not work or the wall lights in the same room. Same thing in
the master bedroom and one of the lights in the hall. All other lights
in the house are fine.

I invited a friend over who knows something of electrics and he
checked the fuses and took voltage readings at the light fixture and
the at switches.

He found that there was no voltage at the switch ( about 3V ) but
managed to get a reading of 246V at the light fixture in the lving
room. He got about 150V in the hall !!!

We both thought you should either get 0V or 240V !!

Does anybody know what could cause these strange readings or have had
similar problems in their house ?

Hi,

A test lamp should tell you if the wire is genuinely live or not,
needs connecting to a working neutral though.

cheers,
Pete.