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Weird problem installing new lights

504 Views 6 Replies 2 Participants Last post by  Delphi51
I replaced 3 fluorescent fixtures with LED fixtures, 25 watts each, in 3 bedrooms.
These are all on one breaker with wires running to lights in the middle of each bedroom and in each, down to wall outlets. The problem is that somehow the white neutrals have about 40 volts on them, leaving only 80 from hot to neutral on the outlets. These voltages are seen in the light box wires but the light itself gets the full 120 volts.

I disconnected the wire nuts for the several white and black wires in the boxes for each light, joined on their way to the outlets and cleaned the bare ends with sandpaper. This did not help at all.

Anyone have an idea what could cause this fiasco?
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Can you take pics of the wires in the wire nuts, and are you daisy chaining off of an outlet/plug?
Thanks for your interest, Contra! I have some pictures and the 1967 electrician definitely daisy chained the three bedrooms.
oops, very new on this forum. I was a little confused yesterday as we had company and I was very tired from working on my electrical problem. Better today. This morning I checked bedroom 1 and all was well - no problem with the plugins.
I hope works on this forum.
I went back to bedroom 2 and finished installing the LED fixture.

You might check the twisting of wires together - I have no formal training in that.

Ready to go.

working. Plugins in bedroom 2 also working.
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Yesterday I found that space is limited in a post here - I was in the middle of typing my post when the site crashed with a "cannot open a new page" error. So today, I know to keep short posts.

This is where trouble begins. The white neutral wires to the outlet have a 65 volt potential with respect to safety ground, which leaves the hot to neutral too low voltage to handle anything I plug in to it.

Here are some of my electrical tools.

I got brave enough to break the code this morning to see if I could learn something about the problem. I used a very light cliplead to connect the neutral to safety ground and used the clampmeter to read the current gowing through it. It was 60 mA with no load on any of the 3 outlets connected to this first one. All of them worked and had 120 volts. With a pole light (LED) using one of the affected plugins, the neutral to ground current dropped to 30 mA.

This low current suggests that I shouldn't get into too much trouble by permanently connecting neutral to ground in one or more plugins.

I also wonder if there could be a poor connection where the neutral to this long string of lights and plugins connects in the breaker box?

Any other ideas?
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Worse trouble! I tightened all the screws holding the neutral wires to ground in the breaker box. One was really quite loose so I thought I might have solved the problem. However the 60 volts on the neutral wires in the plugins jumped to the full 120 volts. Loosening that one that was so loose makes no difference. I'm stumped. I called my electrician friend up the street and he is going to send his partner over to work on it tomorrow. His apprentice was the last to work on that breaker box, installing a spa service. He billed $250/hour for that.
All's well that ends well! I went to the electricians office at lunch time and my friend confessed that he forgot to tell his partner to look at my problem. We talked about it and I mentioned I found three white wires in the light box in bedroom 3 which had different voltages so I didn't connect them together. My friend said that was normal and all the whites should be connected together. The partner, a former physics student, asked if I wanted him to fix it or fix it myself. I really wanted to finish it myself after that tip!

I wish this forum would give a warning before time expires while typing a post!

The explanation is that there was a small load on one of the plugins causing current with nearly 120 volts to flow through the white wire to the light box in the ceiling. It must be connected to a white going back to the breaker box ground. I connected all three whites with different voltages together and everything works!

Lesson 1 - Remember that electricity flows in circuits, there and back.
Lesson 2 - take pictures of a light fixture wiring being replaced before taking it apart.
Lesson 3 - If you are a teacher, be nice to students who may become electricians, mechanics, nurses or doctors.

Moderator, you may mark this problem as solved, but I hope you will leave it here for others to possibly make use of.
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