Induced Voltage?

Franck · Aug 23, 2009

My mother told me her landing energy efficient bulb kept flashing when off.
Checked it out and then got a second opinion.The 50v LED on tester lit when across bulb when off.
Disconnecting the 3 core + earth and testing it looked like this to be problem.
Pulled in a new cable between the two switches from adifferent direction and still the same.
Any ideas?
The top switch has been replaced as well and bottom one had switch wire disconnected and 50v + still there.

Darkwood · Aug 23, 2009

What is the 50+ volts between, have you checked all combinations of testing at this light point what are the readings?

Franck · Aug 23, 2009

There was 50v between live and nuetral in ceiling rose and when switch was in off position there was 50v between switch wire and earth.
This is obviously somewhere between 50 and 100 volts as the 100v LED had not lit.
The only other observation is that switching off at one switch had 24v lit and the other switch in off position gave me the 50v.

Darkwood · Aug 23, 2009

First of all just check all equip' bonding is done as well as main earthing, all connections in board are tight then re-check, do you get 240v when switch on and between what?
Just because you have a earth wire dont assume its a good earth, do a earth loop impedance test to comfirm reliable earth, if still stray voltages do insulation test on lighting you could have water in joint or outside light ive had this before with the result been a rat fried to cable and adjacent pipe.

Franck · Aug 23, 2009

Many thanks, i will go over tomorrow and do some more checks, will leave a message as soon as i get more information.

Des 56 · Aug 23, 2009

2-way switching and energy efficient lamps dont get on very well with each other

This problem when I have encountered it,usually is tied in with inductiive and/or capacitive effects onto the switch live leg of a 2-way system when there is a feed picked up at one switch and a pair of strappers to the second switch
However you state the 3 core and earth,so I assume its a standard conversion circuit,so am a little surprised by that
I can omly think it may be of help to reconnect the cable using a different core for the common or get shot of the energy lamp

benji · Aug 23, 2009

borrowed neutral/loose connection at adj.ltg.?

yours benji

Spudnik · Aug 23, 2009

Cheap CFL's can also cause probs..

RME ELECTRICAL · Oct 28, 2009

i had this same problem today, living room light on 2 way switching in a high rise block wired in old piro , getting 48 v at light in living room , 8w at other lights, living room light flashing when switched off, removed all lamps and done insulation resistance tests , cable s seem ok, disconnected main earth, still same problem, can anyone help

also tenent going through lots of lamps!!!

Sintra · Oct 28, 2009

RME ELECTRICAL said:
i had this same problem today, living room light on 2 way switching in a high rise block wired in old piro , getting 48 v at light in living room , 8w at other lights, living room light flashing when switched off, removed all lamps and done insulation resistance tests , cable s seem ok, disconnected main earth, still same problem, can anyone help

also tenent going through lots of lamps!!!

What type of system is it on TT, TNS etc.