Half hot or switched outlet problems

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inspectored

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While doing a final inspection we ran across a dilemma that seems nobody can answer, so here it is. Using my Ideal model number 61-056 AFCI/GFI
tester, I checked a switched outlet with the wall switch off. I noticed the indicator lamps on the tester were dim so I got my digital voltmeter and read a voltage of 31.4 volts on the AC range. I know digital meters are sensitive and that reading induction might be the case here. So I used my analog meter and read the same voltage.
Is the use of 14-3 NM cable the cause of this induction or what? Any answer would be appreciated. Thanks
 
Re: Half hot or switched outlet problems

Was the switch one of the lighted toggle type? (neon light in switch)

Ed
 
Re: Half hot or switched outlet problems

So I used my analog meter and read the same voltage.
Click to expand...
When you say analog do you mean a coil type volt meter? If this is inductance a coil type meter (Wiggy) will load the circuit and should not show any voltage but if there is a lighted switch it will cause it to light.
 
Re: Half hot or switched outlet problems

My fluke will read 27 to 31 volts on 1/2 switched receptacle when switch is off.Haven`t noticed plug tester registering from this voltage.I have always attributed it to leakage at the switch.Digital meters can be so useful in trouble shooting.Same switched receptacle on a 3 way and made up wrong travellers swapped with 3 wire to receptacle it will read 40 to 42 volts.Not sure why but when I see that I know to open the box and remake the joint. ;)
 
Re: Half hot or switched outlet problems

I think Ed might have the right suspicion. Many of Leviton's Decora switches are back-lighted and you may be reading through the neon bulb inside the switch.
 
Re: Half hot or switched outlet problems

I just did a little math and it sounds pretty close.

Those little neon bulbs in switches have a 33k resistor in series. (At least 10 or 20 years ago they did) I don't know what the neon bulb adds for resistance, but:

120/33000 = 3.6 milliamps

A typical LED runs on about 10 milliamps

Thats really close to the half on neighborhood for an LED.
 
Re: Half hot or switched outlet problems

I am using a Simson model 260 multimeter and a Fluke Digital multimeter. All switches are standard without the lighted rocker, and the houses are new construction. Thanks for all who have responded.
 
Re: Half hot or switched outlet problems

The Simpson 260 is also pretty high in input impedance. You shouldn't be using these meters to test like this anyway. Get yourself an electrical tester like the Wiggy that will load the circuit and give a true reading.

-Hal
 
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