66Volts to ground.

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Benton

Senior Member
Location
Louisiana
I have some brick lights that I am working on. When I measure the voltage from hot to neutral I get about 70V, from hot to ground I get 120V, and when I measure from neutral to ground I get about 66V to ground. The light will not work from hot to neutral, but will from hot to ground. I think that the voltage is being induced because the panel wiring is good. It is hard for me to tell 100% because it is all concrete inclosed. What are your thoughts?
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Use a low impedance voltmeter.

Mark

That won't change this:

The light will not work from hot to neutral, but will from hot to ground.

It sounds like he has an open neutral.

The light is acting like a low impedance tester.

Your advice is good overall, though. I use both types. One cool thing about the Vol Con I use is that it tests AC, DC, DC polarity and continuity without having so much as to touch a switch. Super cool tool for troubleshooting.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Which low impedience tester do you use?

Who makes the Vol Con tester? I'm not familiar with it.

Ideal makes them. I use the XL. I got it at Home Depot.

61-086.jpg


http://www.idealindustries.com/prodDetail.do?prodId=61-086

I don't like the tips of the leads and did some modification to mine.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I use a Fluke T+Pro, don't go anywhere without it :D.

That looks like a great device. Too bad I am losing my faith in Fluke due to their decision to have their meters made in China. If I am going to buy a Chinese product I sure don't want to pay for it like it was made in the US.

The Vol-Con goes for about 40 bucks. It works great but I do like the digital readout on the Fluke. For 90 bucks, not bad if it's a US product. A bit pricey for a Chinese made one, though.
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
That looks like a great device. Too bad I am losing my faith in Fluke due to their decision to have their meters made in China. If I am going to buy a Chinese product I sure don't want to pay for it like it was made in the US.

The Vol-Con goes for about 40 bucks. It works great but I do like the digital readout on the Fluke. For 90 bucks, not bad if it's a US product. A bit pricey for a Chinese made one, though.


Ah crap, and that is just what they will be in a few years. The advantage will be that we will be able to get something that is very similar and a heck of a lot cheaper in just a matter of a year or two. Name brand may even be the same, you & I won't be able to tell the difference, until it blows up in our hands.
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
I don't think the 66v on neutral is induced but what is left after the resistance of a bad connection. Or completely open and getting enough throug ground or concrete to give you 66v. I may be wrong.

Your not.

We've had two of those this week already and one last week. One of which showed itself via the loose bonding screw in the panel. It glowed.
 

Benton

Senior Member
Location
Louisiana
I think y'all are right but....

I think y'all are right but....

I think you guys are right about the loose neutral, but unfortunately I can't do anything about it. The only access I have is in the panel. I would be able to re-pull it but the fixtures are concrete enclosed and only 8" x 2". I can get them to work by using the ground. I am thinking about moving the ground from the grouding bus and putting it on the neutral bus so as to not have current on the panel.
 

quinn77

Senior Member
I think you guys are right about the loose neutral, but unfortunately I can't do anything about it. The only access I have is in the panel. I would be able to re-pull it but the fixtures are concrete enclosed and only 8" x 2". I can get them to work by using the ground. I am thinking about moving the ground from the grouding bus and putting it on the neutral bus so as to not have current on the panel.

first off...that would be a violation of 200.6(a), second, if conductors are enclosed in nonmetallic raceway, you would lose your E.G.C.
even with REALLY good insurance I absolutely would not go that route. if you have jboxes without access, etc. and are unable to locate the open neutral ( which is the problem ) then I would disconnect and walk away with a smile.
 

kwired

Electron manager
Location
NE Nebraska
I don't think the 66v on neutral is induced but what is left after the resistance of a bad connection. Or completely open and getting enough throug ground or concrete to give you 66v. I may be wrong.

I have some brick lights that I am working on. When I measure the voltage from hot to neutral I get about 70V, from hot to ground I get 120V, and when I measure from neutral to ground I get about 66V to ground. The light will not work from hot to neutral, but will from hot to ground. I think that the voltage is being induced because the panel wiring is good. It is hard for me to tell 100% because it is all concrete inclosed. What are your thoughts?


The neutral is not open, there is an impedance someplace in the neutral, there would be no drop across the load if it were open and full voltage would be seen between neutral and ground. There has to be current flow before there can be a drop in voltage.

It is possible the neutral conductor is open but the current has found an alternate path from this point through a poor conductor such as an incomplete or ungrounded metal raceway in contact with earth.

Isolate each section of conductor (between lights, junctions, etc) and meg each neutral to ground to find which section of conductor is defective. If all lights on the circuit are experiencing this the problem is between the first light and the source.
 
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