[Shop-talk] Electrical Question

[Pat Horne]

Bob,

Sounds like you have leakage current flowing past the breaker. An easy 
way to be sure is to turn the breaker off and check the voltage. Then 
plug a lamp into one of the sockets on that circuit and turn the lamp 
on. It should not come on. Now check the voltage across the switch again 
and I suspect it will be zero.

Go ahead and replace the switch, then turn the breaker back on and 
everything should be fine.

The reason you are seeing voltage on the switch is that the circuit is 
open with the switch off. Any leakage current will produce a voltage 
into an high resistance (open circuit). I wouldn't worry about it unless 
there is still voltage (more than a volt or two)across the switch with 
the lamp plugged in. If you have voltage, replace the breaker.

Peace,
Pat

Thusly spake Bob Spidell:
> Got a question for the electrician-types out there:
>
> I needed to replace a wall switch, and when I finally determined which 
> breaker
> was on the circuit when I opened the breaker I still saw 40V AC on the 
> two poles.
>
> Does this mean I have a ground loop, or is there something about house 
> wiring
> I don't understand.  The house is old--built in the late '50s--if that 
> matters, and I think
> it's mostly two-wire circuits.
>
>
> bs
>
>   


-- 
Pat Horne, Owner, Horne Systems 
(512) 797-7501 Voice		5026 FM 2001
Pat at HorneSystemsTx.com	Lockhart, TX 78644-4443
www.hornesystemstx.com
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