48 volts on neutral

[Aspenpatrick]

I am actually a pretty good electrician, but am baffled by what I found today. During a remodel and adding a few new boxes for future lights I received a shock from a neutral wire and a floating ground. The house is old and there are no grounds on most of the circuits. I was confused for there is no ground except for about 20 ft going from one new box to another but not connected to panel ground. In fact the ground is terminated with a wire nut in each box but are not connected to anything. Yet when I tested the neutral to ground voltage, I found 48 volts. Subsequently I tested a few other outlets in the house and also found neutral to ground voltage of 48 v. I then unplugged all devices. Voltage to ground disappeared. Only when I plugged in a device with a ground did the neutral to ground voltage reappear. I then went to the main panel thinking I had a bad neutral somewhere, and disconnected each circuit one at a time and found no neutral to ground issues at the panel and the neutral voltage only disappeared when I turned off hot to circuit. Different circuits were found to have neutral to ground voltage only when a grounded plug was put into that outlet. I assumed that the ground of the device was allowing me to read neutral voltage. Hot to neutral is correct everywhere. I am baffled. Suggestions?

 

[don_resqcapt19]

What were you using to measure the voltage? Take a look at this article.

 

[K8MHZ]

What were you using to measure the voltage? Take a look at this article.

But he did get a shock, and I haven't found ghost voltage to be able to do that.

 

[K8MHZ]

Here are some of the things I have found in places with voltage present where it shouldn't be.

Switched neutrals for lights and receptacles.

Hot and neutral reversed in two wire circuits.

Hot faulting to 'floating' ground. I am using 'floating' to say that the EGC is present in an outlet, but not bonded to the neutral.

Bootleg EGCs

Hot faulting to ungrounded metal box.

All of the above can be confusing. So, in order to reduce confusion it's best to know what you are measuring from.

The only way you can be sure of which is hot and which is N, is to reference from the panel. Take your readings from the neutral bar. A modified extension cord is great to use, that way you can bring your neutral reference around with you.

Use a solenoid tester to test for hard wired voltage. They won't read 'ghost' voltages. There are other ways, but that is the easiest.

 

[Aspenpatrick]

Here are some of the things I have found in places with voltage present where it shouldn't be.

Switched neutrals for lights and receptacles.

Hot and neutral reversed in two wire circuits.

Hot faulting to 'floating' ground. I am using 'floating' to say that the EGC is present in an outlet, but not bonded to the neutral.

Bootleg EGCs

Hot faulting to ungrounded metal box.

All of the above can be confusing. So, in order to reduce confusion it's best to know what you are measuring from.

The only way you can be sure of which is hot and which is N, is to reference from the panel. Take your readings from the neutral bar. A modified extension cord is great to use, that way you can bring your neutral reference around with you.

Use a solenoid tester to test for hard wired voltage. They won't read 'ghost' voltages. There are other ways, but that is the easiest.

Thank you you for your response. I eliminated ghost voltage reading by the mere fact that I got shocked when I touched a neutral and a floating ground. And subsequently found 48 v through the house. In addition I was able to cut voltage in half when I disconnect additional branches tied to original source. All of the outlets are wired correctly and am working on all the lighting circuits. There are "bootleg" egc's by the fact walls are plaster and the metal boxes are touching the metal lathe.

Patrick

 

[GoldDigger]

This is still an indication that one or more pieces of connected load or the wiring itself has a fault which is putting current onto the EGC network.