Switched receptical neutral?
- Thread starter elecold
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fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
Are you measuring the voltage with a high impedance meter? It is high impedance unless it says "low-Z".
if you use a low-Z meter you will probably see that these are phantom voltages (capacitively coupled) from the hot 120V wire for the other half of the receptacles.
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- Location
- New Jersey
- Occupation
- Journeyman Electrician
Are there lighted switches when in the OFF position?
elecold
Member
I came across an issue where I was getting 99volts on the switched receptical and 120 on the constant part of the receptical.
The rest of the outlets down the branch circuit line were 99volts also....
So I opened up the switched outlet. I discovered that in addition to the brass tab being removed the silver grounded tab was removed. (no pigtails obviously)
I replaced with a new receptical and removed just the brass tab. The issue was fixed.
Could it be that the other outlets that I had 120 volts on the switched and constant part were detabbed incorrectly also. :? Would the missing neutral tab explain the 15 volts on the dead switched portion?
The rest of the outlets down the branch circuit line were 99volts also....
So I opened up the switched outlet. I discovered that in addition to the brass tab being removed the silver grounded tab was removed. (no pigtails obviously)
I replaced with a new receptical and removed just the brass tab. The issue was fixed.
Could it be that the other outlets that I had 120 volts on the switched and constant part were detabbed incorrectly also. :? Would the missing neutral tab explain the 15 volts on the dead switched portion?
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
We need more precise details of exactly what was where to be able to accurately answer that, but if you had the tabs broken off on the neutral side of receptacle - you probably had voltage issues - more like lack of voltage where it is needed in some places.
Otherwise assuming neutral is intact all the way through the circuit you can easily read a voltage on the switched circuit because of capacitive coupling. The fact the constant "hot lead" is in same raceway or cable with the switched lead creates a capacitor - a very weak one, but a typical digital meter with a high input impedance will measure this voltage and display it, a "low input impedance" meter will draw enough current just performing the test that it will "short out" this weak capacitor and you will not read any voltage.
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