120 volts on romex ground wire
- Thread starter wouter
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ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: 120 volts on romex ground wire
Grounded conductor or equipment grounding conductor?
Grounded conductor or equipment grounding conductor?
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: 120 volts on romex ground wire
Ryan beat me to ?
Ryan beat me to ?
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: 120 volts on romex ground wire
ok are you measuring this between neutral and bare ground? if so chances are you have a open neutral.Or less likely an open ground wire
ok are you measuring this between neutral and bare ground? if so chances are you have a open neutral.Or less likely an open ground wire
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: 120 volts on romex ground wire
I agree with the open neutral if there is no voltage between the hot and neutral but if there is then some how the hot has energized the ground wire and the only time I ran into this was on a post lite where the UF was nicked underground and burned off, and the grounding conductor was lost back to the service but the hot had bonded to the ground toward the post lite. It burn't the post right off at the ground level. The snow was melted all around the post and where the break in the UF was.
[ February 06, 2004, 02:07 AM: Message edited by: hurk27 ]
I agree with the open neutral if there is no voltage between the hot and neutral but if there is then some how the hot has energized the ground wire and the only time I ran into this was on a post lite where the UF was nicked underground and burned off, and the grounding conductor was lost back to the service but the hot had bonded to the ground toward the post lite. It burn't the post right off at the ground level. The snow was melted all around the post and where the break in the UF was.
[ February 06, 2004, 02:07 AM: Message edited by: hurk27 ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: 120 volts on romex ground wire
Oh one other time I ran into this was when a previous electrican cheeted on grounded type receptacles and bootleg a ground from what he thought was the neutral. but the polarity was reverised at a J-box in the attic and this heated up any thing that was connected to this ground. In this case a freezer in a garage that the home owner was getting shocked from. The plug the freezer was plugged into even had a ground wire but it was hot. so I used a extention cord from a known good receptacle and went searching.
Oh one other time I ran into this was when a previous electrican cheeted on grounded type receptacles and bootleg a ground from what he thought was the neutral. but the polarity was reverised at a J-box in the attic and this heated up any thing that was connected to this ground. In this case a freezer in a garage that the home owner was getting shocked from. The plug the freezer was plugged into even had a ground wire but it was hot. so I used a extention cord from a known good receptacle and went searching.
tonyi
Senior Member
Re: 120 volts on romex ground wire
I've found the Greenlee Circuit Seeker to be good for tracing things through walls. Unlike some others, the Greenlee can work on dead branches since its sender is using a battery rather than the branch power. I got the Greenlee primarily so I could power down the real "weird ones" and work'em dead.
You can work this problem from both ends too. Starting back at the panel find that branch and work forward rather than back. Might get lucky and find the problem in a j-box or cable in the basement.
Rule out the easy accessable stuff first
I've found the Greenlee Circuit Seeker to be good for tracing things through walls. Unlike some others, the Greenlee can work on dead branches since its sender is using a battery rather than the branch power. I got the Greenlee primarily so I could power down the real "weird ones" and work'em dead.
You can work this problem from both ends too. Starting back at the panel find that branch and work forward rather than back. Might get lucky and find the problem in a j-box or cable in the basement.
Rule out the easy accessable stuff first
Re: 120 volts on romex ground wire
hey guys thanks for all the responses
this circuit is in a bathroom feeding a vanity light and then feeding some receptacles in an ajoining living room - house is about 50 yrs old.
strange thing when i turn the vanity light off the powwer on the bare ground wire goes off as well
hey guys thanks for all the responses
this circuit is in a bathroom feeding a vanity light and then feeding some receptacles in an ajoining living room - house is about 50 yrs old.
strange thing when i turn the vanity light off the powwer on the bare ground wire goes off as well
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: 120 volts on romex ground wire
BINGO you just confirmed open neutral.The hot is feeding thru the bulb and your reading it on the white wire.Now just go look for that open neutral.
Its the neutral that is hot,not the ground.
[ February 06, 2004, 09:11 PM: Message edited by: jimwalker ]
BINGO you just confirmed open neutral.The hot is feeding thru the bulb and your reading it on the white wire.Now just go look for that open neutral.
Its the neutral that is hot,not the ground.
[ February 06, 2004, 09:11 PM: Message edited by: jimwalker ]
Re: 120 volts on romex ground wire
ran into this exact problem before, turned out to be the polarity was reversed on the GFI and the ground had been landed on the load side of the nuetral termination, this work was done by a home owner and he had no idea. turns out a plug tester will not show anything is wrong on this situation, hope this helps if,, you would keep everyone posted with what you find out! justin
ran into this exact problem before, turned out to be the polarity was reversed on the GFI and the ground had been landed on the load side of the nuetral termination, this work was done by a home owner and he had no idea. turns out a plug tester will not show anything is wrong on this situation, hope this helps if,, you would keep everyone posted with what you find out! justin
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: 120 volts on romex ground wire
Love them home owners.Wish big orange would give them books out free,makes lots of service call work
Love them home owners.Wish big orange would give them books out free,makes lots of service call work
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: 120 volts on romex ground wire
Wouter you have an open ground wire between the bathroom and the panel and somwhere the ground is touching or connected to the switch leg to the light maybe in the switch box. or in a buryed box as the bathroom most likly been remodeled over the years. many times I have found where somone has extended a old KT circuit and tried to bootleg a ground off what they thought was a neutral but the wire covering was so faded that they got it mixed up with the hot and everything that was connected to the ground wire was giving a nasty shock. and with out a way to trace wires in the walls it will be hard to find unless it is behind the med cabnet or in an old light box in the ceiling with an attic above it. Good luck.
Wouter you have an open ground wire between the bathroom and the panel and somwhere the ground is touching or connected to the switch leg to the light maybe in the switch box. or in a buryed box as the bathroom most likly been remodeled over the years. many times I have found where somone has extended a old KT circuit and tried to bootleg a ground off what they thought was a neutral but the wire covering was so faded that they got it mixed up with the hot and everything that was connected to the ground wire was giving a nasty shock. and with out a way to trace wires in the walls it will be hard to find unless it is behind the med cabnet or in an old light box in the ceiling with an attic above it. Good luck.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: 120 volts on romex ground wire
First thing to prove is if the ground wire is indeed hot or if its the neutral that is hot.A fast way to check is run a piece of thhn wire from neutral on panel to where the receptacle is located.Now with volt meter see if you have 120 between this wire and the ground or the neutral.At least then we have confirmed what is hot.
If this is old romex it might have undersized ground wire,and they easily melt open.
First thing to prove is if the ground wire is indeed hot or if its the neutral that is hot.A fast way to check is run a piece of thhn wire from neutral on panel to where the receptacle is located.Now with volt meter see if you have 120 between this wire and the ground or the neutral.At least then we have confirmed what is hot.
If this is old romex it might have undersized ground wire,and they easily melt open.
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