Voltage decrease on 1 leg increase on other

3824 Views 30 Replies 9 Participants Last post by emtnut, Mar 2, 2016

Gsallor

Discussion Starter · Mar 1, 2016

OK so up until 2 days ago everything was working fine, and now all of a sudden I have a problem. I have a 120/240 feeder out the Garage (which was here when I bought the house) there is a 60 amp 2 pole breaker with 2 power wires going out to the garage, and a ground attached box to box, no neutral. As I stated up until 2 days ago everything was working perfect. Than lights started going out one by one, than the fridge. I checked the box in the garage for Power I get 250 across both legs of the main an 125 each leg to neutral with no load, as soon as I plug my fridge in that leg drops to like 40 volts an the other leg increases to like 207. I have been reading a loss of neutral causes this, but I have never had a problem til now. The neutral an grounds are separated an the neutral bar is bonded to the box. I also checked at the breaker in the house no affect to the breaker going to the garage

1 - 20 of 31 Posts

joed

· #2 · Mar 1, 2016

You have an open neutral. There is no doubt about it.
Until you find and resolve the issue don't pug anything 120 volts in or it could burn up.
Straight 240 volt devices, like heaters, should work fine as long as they don''t use the neutral.

Gsallor

Discussion Starter · #3 · Mar 1, 2016

That's what I don't understand there is no neutral out to the garage, and if that is the problem how has it been working all this time?

danpik

· #4 · Mar 1, 2016

Well there has to some kind of connection for the neutral. Probably using the ground wire. Is the feed to the garage in a conduit or is it direct burial? Either way, the neutral signal is using the ground and that has been compromised. Time to pull a proper 4 wire circuit out there and do it right. Two hots, floating neutral and separate bonded ground.

Gsallor

Discussion Starter · #5 · Mar 1, 2016

OK so I ran a neutral from the box in the house to the neutral in the Garage box, still the same problem

joed

· #6 · Mar 1, 2016

Can't be.
Are the voltages in the house correct?
If you ran a good neutral then the problem would be fixed unless it was a POCO issue and then the whole house would be affected.

Gsallor

Discussion Starter · #7 · Mar 1, 2016

Yes no problem in the house, I've done contunity checks from the house to the garage on the neutral wire 0 ohms, checked for shorts. Uhooked everything in the panel besides 1 circuit that has 1 plug on it, I'm at a loss here, I'm tempted to go buy a pull a new 2-2-2-4 aluminum cable, but is that going to fix it? Don't really wanna waste the time an money if that's not the problem

joed

· #8 · Mar 1, 2016

Did you check the connection of the neutral in both panels and any junction boxes along the way.
The problem as described is 100% for sure an open neutral.

this should be in the electrical forum. maybe a mod can move it.

Oso954

· #9 · Mar 1, 2016

The neutral an grounds are separated an the neutral bar is bonded to the box.

In a subpanel, the neutral bar should not be bonded to the box. It is supposed to be isolated from the grounds.

Gsallor

Discussion Starter · #10 · Mar 1, 2016

I've taken the bonding screw out no change

ez2wire

· #11 · Mar 1, 2016

What you are calling a ground is actually a neutral. It may be bare or green but it is effectively still a neutral.

Without a neutral you could not have 120V.

ez2wire

· #12 · Mar 1, 2016

Turn off all loads in garage and go read voltage at the breaker in the house.

ez2wire

· #13 · Mar 1, 2016

Oso954 said:
In a subpanel, the neutral bar should not be bonded to the box. It is supposed to be isolated from the grounds.

Not if is a 3 wire feed. Was allowed till the 2008 NEC.

ez2wire

· #14 · Mar 1, 2016

joed said:
The problem as described is 100% for sure an open neutral.

Oh yeah.

Gsallor

Discussion Starter · #15 · Mar 1, 2016

ez2wire said:
What you are calling a ground is actually a neutral. It may be bare or green but it is effectively still a neutral.

Without a neutral you could not have 120V.

Not quite sure what your referring too here. Also as I stated power at the breaker in the house is fine

AllanJ

· #16 · Mar 1, 2016 (Edited)

Did you say that all the circuits in the main house are okay with no abnormal dimming and brightening of lights? Including when you ran a hair dryer in one of the bathrooms?

Did you say you took a long wire, connected it to the house panel neutral bus bar (terminal strip), strung it up the stairs and across the floor and into the garage, and connected it to the garage subpanel neutral bus bar? And this did not cure the problem in the garage?

While you are at it, tighten up all the little screws and set screws in both panels. Flip off each breaker before touching the screw on it.

Gsallor

Discussion Starter · #17 · Mar 1, 2016

Yes all circuits in the house are fine, no light dimming when running things, no I did not run a long wire across the floor lol. I took the wire that was supposed be hooked to the neutral, that the previous owner used for a ground an hooked it from neutral bar in the house, to the neutral bar in the garage

joed

· #18 · Mar 2, 2016

Is it buried or overhead wire?

Gsallor

Discussion Starter · #19 · Mar 2, 2016

Underground, idk if it's all conduit or just going through the wall

jbfan

· #20 · Mar 2, 2016

That wire is comprised, so you didn't really change anything.

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