diffferent voltage question (112 vs 130)

[dragginbalz]

I wired up my plug for my welder (wired on a sub-panel) and tested each hot lead to ground. One side was 112V one was 130V. I tested it a few days later and got the same reading.

I just tested random outlets in the house and some are reading 111-112V the others are 130V. I did not pop the cover on the main panel and check the leads coming into the main panel in the house yet, but it appears that one will be reading 112V and one will be around 130V.

Is this normal? Any ideas what could cause this?

I was thinking I should test them randomly for a few days and see if anything changes (not sure why it would) and if the problem is consistent call the electric company.

Any information, suggestions or solutions are greatly appreciated.

Thank you in advance.

 

[pattenp]

I once had one leg of my under ground power line get nicked by some work being done on a sewer line. Over time the one leg started to bleed power to the earth and I got voltage drop to the point it was like a brown out and my electric range would not heat up nor would my water heater and lights on that leg became dim. You may be having the start of the same kind of problem. That's if you have underground service

 

[mrb]

this is not normal. You have a bad neutral somewhere. Check it at the main, and call the power company. This is the sort of thing that frys televisions and computers.

 

[Aceman]

I can't say I've ever seen that large of a difference between legs in a normal house panel. Unless your panel is very unbalanced and it's causing a voltage sag on one leg, but it's unlikely. Stick your probes right into the wire where it comes right into your house panel from the meter base. If you get the same reading, I'd call the power co. and see what they say. 130 volts seems to be pushing it...

Something else, loose neutrals usually cause the voltage to be quite a bit more unbalanced, like 155 volts and 85 volts. This'll fry equipment in a hurry.

 

[rjohnson]

Call your power company ASAP and don't use electronics unless neccessary, of course, if you're reading this...

 

[dragginbalz]

Well I popped off the main panel cover and tested the wires coming into the main breaker and sure enough, one was reading about 112V and one was right at 130V

I would assume that must be a problem on their end since it is outside the house.(?)

I am going to call them tomorrow. I'll let everyone know what I find out.

Thanks for the advice so far.

 

[ddawg16]

It's going to be an issue at the transformer.....

We had the same problem a couple of years ago....it really showed up when I turned on the table saw...one leg would drop down to about 100V....

Follow the above advice...turn off unecessary electronics....the low side is not a big issue but the high side will start blowing things.

 

[bward76]

I just came across the same problem at a friends house. It ended up that the neutral from the pole was coming apart. I have noticed a pattern with the utility around here that they will deny that there is any problems if any electronics have been smoked. Be sure to have them fix it before it happens.

 

[mrb]

the way this works, is the voltage shifts as the load becomes more unbalanced. For example turn on something that draws 2kw @110 and you will see the voltages become more unbalanced. 240v loads dont affect this. Another thing to check, is if you have a clamp on ammeter, and you have cable tv, throw it on the cable line coming into your house. Since the cable tv drop is bonded at the house and street, you will have current flowing on it if you have a bad neutral.

 

[nate379]

Sounds like a problem at the pole. My folks had something happen like that about 10 years ago. 1 leg and the neutral disconnected off the pole on their house one day. Burned the motor on the sump pump in the basement

 

[dragginbalz]

Update:

I had the electrical company check everything outside the house. He called me (I was at work) and mentioned that everything looks good on the outside of the house and that it must be inside.
He said he did a load test at both were reading 119V @ 23 Amps.

When I got home I tested the wires coming in and they were reading 119V and 128V. I tested them again today and they are the same.


Does this sound like a reasonable variance? I am going to talk to my electrician friend and have him come over and check it out. I have a cheesier voltmeter, but It appears to be functioning ok (I took it to work and tried random outlets and they were all at 119-120V. Scientific I know!)

Thanks everyone for the input!

 

[porschedude996TT]

I think the problem is still in the power companies court. 130v is too high...

 

[travisd]

Perhaps try turning off the breakers one-by-one until something changes?

 

[Stuart in MN]

Try measuring the voltages right at the main lugs of your panel first with the main breaker on and then with the main breaker off. This will isolate everything inside the house; if there's no difference then the problem is outside, and if there is a difference the problem is inside.

Strictly speaking, both voltages are probably within the power company's tolerances but I've never seen them that far apart unless there was something wrong.

 

[mrb]

Try measuring the voltages right at the main lugs of your panel first with the main breaker on and then with the main breaker off. This will isolate everything inside the house; if there's no difference then the problem is outside, and if there is a difference the problem is inside.

Strictly speaking, both voltages are probably within the power company's tolerances but I've never seen them that far apart unless there was something wrong.

thats not entirely correct. It usually take some load for a bad neutral connection to show, so you could have a bad neutral connection on the utility side and the voltage would be fine with the main breaker off

 

[Charles (in GA)]

Disconnect or unplug everything electronic in the house, switch off any automatic flood lights, and other similar items that have electronics in them. In your panelboard, trip every double pole breaker. Now, trip the top row, Left and right, breakers, and the third row, and the fifth row, and so forth down the panelboard. This will leave the house only drawing current off one of the incoming hots and neutral. Measure your hot to neutral voltages. Now, turn on all the single pole breakers you turned off, and now trip rows 2, 4, 6, 8, etc down the panelboard, both the LH and RH sides. This will leave the other hot powering a buss. Again measure your voltages, are they the same as before, did they change due to being loaded/unloaded?

Charles

 

[HoosierBuddy]

I just came across the same problem at a friends house. It ended up that the neutral from the pole was coming apart. I have noticed a pattern with the utility around here that they will deny that there is any problems if any electronics have been smoked. Be sure to have them fix it before it happens.

We had 3 xbox360's blow up at our house in about a 5 week period. I checked my voltage and it read about 127V. I called Duke and they came out and told me everything was fine.

But...It's been a year and we haven't had any more electronic problems.

Kind of makes me wonder if they did fix something and didn't tell me.

Phil

 

[Chris Adams]

We had 3 xbox360's blow up at our house in about a 5 week period. I checked my voltage and it read about 127V. I called Duke and they came out and told me everything was fine.

But...It's been a year and we haven't had any more electronic problems.

Kind of makes me wonder if they did fix something and didn't tell me.

Phil

You may be right. I had a bad water meter, WAY over billing. They told me it wasn't bad, and changed it. Then said there had been no problem, but my water bills dropped 80%...
Gee, they wouldn't lie, would they...

So having the electric company pull the same thing would surprise no one who deals with public utilities.

If it isn't the line voltage I would sure be suspicious of the common. Two common rails in that box perhaps? Or the main common on one line being corroded/loose or something at the rail?

 

[Identaltech]

wondering if you had aluminum wire.
if so aluminum is notorious for oxidation problems and oxidation = resistance
resistance = voltage drop.
If you have one leg with a bad oxidation problem the voltage will be lower on all circuts on that side.
remember you have conections at your breaker box (3) meter box (6) and at your transformer.(3)
if you have overhead power add 3 more at the power head.
15 possible points for a bad conection.

 

[HoosierBuddy]

You may be right. I had a bad water meter, WAY over billing. They told me it wasn't bad, and changed it. Then said there had been no problem, but my water bills dropped 80%...
Gee, they wouldn't lie, would they...

So having the electric company pull the same thing would surprise no one who deals with public utilities.

Hmmm. Actually I work for a public utility.

Our company always tries to do right by our customers. But...when I've had to deal with utilities of my own....I know exactly how you feel.

Phil

 

[Chris Adams]

Hmmm. Actually I work for a public utility.

Our company always tries to do right by our customers. But...when I've had to deal with utilities of my own....I know exactly how you feel.

Phil

Most of us have worked with good people, most of us have worked with honest people.

But even honest and good people will cover their *** and the asses of their coworkers in most situations.


When I was in multi-unit management I sometimes found myself forced to 'spin' something in such a way as to protect my people.

I hated being less than 100% honest with the costumers, but they were MY people...
Same situation exists everywhere.

 

[dragginbalz]

Update :

I had my friend come over and test some things. He pulled the cover off of the meter and it was reading fine (122V & 120V) from the hots to the neutral on the power from the line and the power to the panel. When he tested the hot to the ground rod, that is when it showed the different voltages. It was dark and he wiggled the conduit for the ground wire and we noticed it arcing on the bushing from the meter to the panel. I am not 100% sure but he said the way they originally wired it and the combination of having a huge knockout and reducers, the bushing is not grounding properly. He is coming out Sunday to replace the earth ground wire, add a grounding bushing and reroute the ground wire directly to the panel. He also noticed that the grounding rod was really loose and is pretty sure it is not 8' in the ground since there is an overhang that is less than 8' over the location of the rod. We are going to relocate and drive a new rod also.

Hopefully this makes sense and I am explaining this correctly. I will post what I find out on Sunday (maybe take some pics)

I really appreciate the help. I am just trying to keep this thread alive to hopefully be able to help someone else in the future. I hate when there is a thread with a problem, but the original posted never follows up with the final solution.

Thanks again.

 

[Charles (in GA)]

It was dark and he wiggled the conduit for the ground wire and we noticed it arcing on the bushing from the meter to the panel.

Sounds like that certainly will all need to be fixed, but you should not have arcing in the ground at all. There should not be leakage to ground. After it is all fixed, I'd start checking each and everything in the house for ground fault before it kills someone.

Charles

 

[mrb]

i still say bad neutral somewhere. The arcing on the ground is from current traveling out the ground, and across water pipes or catv line to get back to the transformer.

 

[dragginbalz]

Sounds like that certainly will all need to be fixed, but you should not have arcing in the ground at all. There should not be leakage to ground. After it is all fixed, I'd start checking each and everything in the house for ground fault before it kills someone.

Charles

I forgot to mention that when the arcing at the bushing (between the panel and the meter) occurred he had the wire to the earth ground disconnected. Would this still possibly be a ground fault in the house? I will ask him about it tomorrow.

All of this is beyond my knowledge, so I apologize for my ignorance.

Thanks.

 

[dragginbalz]

Problem solved! He came out today and drove a full 8' rod. He put grounding bushings on the ****** between the meter and panel. Ran a 4 gage wire from the rod to both bushings to the main panel buss and tightened the lock nuts on the ****** as well (they were super loose!)

Took readings both with the main panel off and on and both legs are now reading exactly the same as what is coming into the meter (122V and 124V).

He noticed some overheating of the neutral at the panel and the plastic bushing from the meter to the panel was melted to the ******.

Either way, it looks like the voltage is now normal (I will continue to periodically test it) and a potential fire hazard has been adverted.

Thank you everyone for the input and advice.