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Dave Plowman (News) Dave Plowman (News) is offline
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Default Voltage at light fitting when light switch off ?

In article ,
LaserMark wrote:
On Sat, 15 Sep 2007 14:00:39 +0100, "Andrew Mawson"
wrote:



LaserMark wrote in message
.. .

I'm measuring 17 Vac across my bathroom light fitting when the light
switch is off. I'm also measuring 34 Vac across my landing light
fitting when the light switch is off. If I isolate the upstairs
lighting at the consumer unit then it drops to around 1.3 Vac.

What's going on?


What are you using to measure the voltage? If you are using a modern
high impedance meter such as a Fluke, then what you are measuring is
the capacitive coupling between a live wire and an isolated one, and
it is quite normal. If on the other hand you are using an older meter
based on a moving coil movement then it is time to worry!

AWEM


I'm using a Fluke 77. So why am I seeing 17 Vac on one fitting and 34
Vac on another fitting?


I'm amazed you bought such an expensive tool without knowing what it does.

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Dave Plowman London SW
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