I have an older house in SE PA and am observing something with an
electrical circuit that it not intuitively clear to me. First let me
describe my panel configuration;

The feed into the house comes into a main circuit breaker box. There
is a sub panel hanging off the main breaker panel. Out of this sub
panel is fed (among other things) a 20-amp circuit feeding some
recessed lighting fixtures and ceiling fan in my den.

The circuit comes straight from the sub panel to a junction box in the
ceiling. From there it feeds a switch box on the wall containing two
single-pole switches (one for the lights and one for the fan). The
neutral is not carried down to the switch box. Everything works great
with the exception of the problem described below.

When the switch is in the closed position, I get a voltage reading of
120-volts (reading both to neutral and ground from the "hot") - which
is what I expect. However, when the switch is in the open position I
get a reading of about 30 volts (reading both to neutral and ground
from the "hot") - which I do NOT expect. Can anyone lend some wisdom
here as I am a bit stumped.

As I type this it occurs to me that the switch might be bad and that I
should check this before proceeding much further. It is a brand new
switch but Occam's Razor tells me to start there.

Thanks in advance for your time . . .

L

John, I appreciate the speedy response. When I measured, the only
load on the circuit were 6 recessed lighting fixtures. I was
measuring from the "hot" of the circuit to the neutral of the same
circuit and I was reading 30 volts at that point. However, I did not
try to measure with no load whatsoever on the circuit - I will try
that tonight (as well as looking at the switch). I have just never
seen voltage that high between the neutral and the voltage side of an
"open" circuit.

Thanks again for your time . . .

L

"Larry Fox" wrote in message
om...
John, I appreciate the speedy response. When I measured, the only
load on the circuit were 6 recessed lighting fixtures. I was
measuring from the "hot" of the circuit to the neutral of the same

"hot" with the switch controlling it off? Otherwise you should have gotten
120v. If you are actually measuring across the load with the switch off then I
don't understand it either. The load should short the inputs to the meter with
some resistive load. However if you were measuring from the open switch side to
some convienient neutral then I would suspect that you are getting voltages due
to noise and or line load induced voltages caused by long runs and powered
equipment on line.

circuit and I was reading 30 volts at that point. However, I did not
try to measure with no load whatsoever on the circuit - I will try
that tonight (as well as looking at the switch). I have just never
seen voltage that high between the neutral and the voltage side of an
"open" circuit.

Neither have I. Try putting a resistive load across the 30 v. My guess is it
is going to drop to virturally nothing.

Regards,

John

Maybe the sub panal ain't grounded right
"JTM" wrote in message
...

"Larry Fox" wrote in message
om...
John, I appreciate the speedy response. When I measured, the only
load on the circuit were 6 recessed lighting fixtures. I was
measuring from the "hot" of the circuit to the neutral of the same

"hot" with the switch controlling it off? Otherwise you should have
gotten
120v. If you are actually measuring across the load with the switch off
then I
don't understand it either. The load should short the inputs to the meter
with
some resistive load. However if you were measuring from the open switch
side to
some convienient neutral then I would suspect that you are getting
voltages due
to noise and or line load induced voltages caused by long runs and powered
equipment on line.

circuit and I was reading 30 volts at that point. However, I did not
try to measure with no load whatsoever on the circuit - I will try
that tonight (as well as looking at the switch). I have just never
seen voltage that high between the neutral and the voltage side of an
"open" circuit.

Neither have I. Try putting a resistive load across the 30 v. My guess
is it
is going to drop to virturally nothing.

Regards,

John