Hot Neutral Wire

[MacInAction]

A friend's fan has two sets of wires in the ceiling box: One is 14-3 from the switch box, the other is 14-2 that runs from the ceiling box to a nearby outlet.

When the neutral wires were briefly separated to swap a fan, the one that led to the live outlet would indicate 120 volts when tested. When the neutrals were reconnected, voltage was no longer detected. Also, a GFCI outlet tester indicated reversed hot/ground when the neutrals were initially separated to swap the fan. When everything was reconnected, the tester indicated no problems and the new fan operated normally.

We were too pressed for time to open the outlet to check for any previous mistakes.

Is the hot neutral a normal occurrence in this situation, or should the outlet or something else now be inspected?

 

[Snoonyb]

What form of instrument was used to perform the voltage test?
Does the recepticle have something plugged into it?

 

[MacInAction]

It was the type with dual lights, one for 120 and another for 240. Yes, there were items plugged into the receptacle.

 

[jeffmattero76]

I am not an electrician, but have seen this action multiple times in my rental properties when doing electrical work. It has been explained to me that what you are seeing when the neutrals are separated is current (from something upstream) that is "trying" to go back on the neutral. By disconnecting the neutral wires, that current lost its path back.

In most, if not all of the cases I have seen, it was due to a shared neutral (two different circuits using the same neutral). Thus if the breaker is turned off on the one circuit you are working on, and there is a load on the other circuit, you will see this.

Hope that helps, but you may want to wait for some of the real electricians to weigh in.

 

[JoeD]

Everything you describe is perfectly normal. You should not be working on the circuit with the power on. The switch is not a proper safety disconnect.

 

[MacInAction]

You should not be working on the circuit with the power on.

Yes, I would normally turn off everything at the panel. There were too many ongoing activities in the house that day to flip the breaker, which has a lot of frequently used outlets on the circuit. I love insulated pliers....

If the items in the live outlet had been unplugged, would that mean the 120v tester would no longer act as a pathway back to the neutral and illuminate?

 

[Snoonyb]

Yes, because the return path is broken.