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Voltage drop on a/c line

Sometimes it could be you may need to tighten screw on breaker. Maybe change receptacle and make sure all connections are tight. Make sure you are actually using a receptacle rated at 20 amps. Not the 15 amp that is common. The 20 amp should have a bit more surface area. These are the easiest and the cheapest places to check first. Make sure you turn power off before servicing breaker or receptacle. I work with a lot of refrigeration and equipment and this seems to be a problem a lot. May even change breaker. Depending on model, could have an internal problem like bad contact or what not. Would hate for you to have to change meter and not be the problem.
 
Have you determined if the voltage sag is before or after the main panel yet? If not, the power company can come out and load test your drop, it's free here, call them.
 
Another thing to try before you blame service which it may very well be. Check other circuits in the panel and see if they have a large drop as well or if it is just that particular circuit. As I said it is easier and cheaper to check this little stuff first before ruling it as meter. But I have seen a bad feeder line to service panel and this caused a voltage drop on 1 leg but not the other on the mains. Just stuff to think about.
 
Actually, my voltage varies anywhere from 120-125 and averages 123 depending on the time of the day. I was using 120 to demonstrate the voltage drop at the time it was 120. The 113 number was the measure after the amp was drawing current.

I must've misread.

Sometimes it could be you may need to tighten screw on breaker.

I had an electrical disaster due to something similar.

The meter box was old and had a bakelite insulator on the ground.

I woke up one morning to a very bright light in the bedroom and smoke from the VCR.

The connection to ground was lost along with an Astron PS and other stuff. For some reason 220V came in.
 
On the circuit which supports the washer and gas dryer, the voltage drops as well. I have a call into my ulitity company to discuss this. I suspect that it is the same all along the street. I never noticed this before. The amp draws so much current that it was apparent that something was wrong. I have a feeling they are going to tell me to 'go fish'. At least they can check the meter. I'll post a closure to this. I'm sure others will benefit if they are experiencing the same issue.

Thanks again, for you input ...
 
Almost every circuit breaker used in the United States up to about 2 years ago is under a non-recall replacement now.

Your problem is going to be the little area in the circuit breaker that PINCHES the mains busbar. Those have been found at fault in SO many home fires that the NFPA recommends replacing them... It's going to be an insurance issue soon, watch.

Problem is, the only way to replace them is to replace your panels.

Federal Pacific Electric FPE Stab-Lok Panel Circuit Breaker Hazard, Repairs, Electrical Panel Replacement Electricians Directory for Stab-Lok Repairs

Its for FPE Stablock style breakers, which you'll find a 90 percent chance of having in existing construction in the US.


Now you know, and knowing is half the battle. The other half is the 2-300 dollars you'll need to replace your panel and every breaker yourself... Double to triple that if you have stucco and can't do the job yourself.

--Toll_Free
 
I called the utility company. They are going to measure the circuit from their side, monitor the voltage for a week and check the meter for calibration. They are also going to look at the panel per your post and advise, based on the measurements, if I need to repace it. He indicated that at the last amperage upgrade/permit, the panel was not at risk but will check nonetheless.

I am going to move the circuit for the shack to the other side of the 220 leg which has an average of 5 more volts. This will put me within spec for the amp under full modulation, which is 1350 PEP. I did make a note to self to turn off the circuit feeding the subpanel so I don't fry. Heh...

Thanks for all your tips and help.
 
Last post

The circuit in the shack now has 124 - 125 volts at idle. The good news is under full modulation, the voltage is over 115. I'm seeing 117-119. I had to move the garbage disposal off the good leg and swap in the shack circuit. Tough decision that. I'm going to pull in 220 and be done with it. I'll then have the two 20amp circuits with 125 volts to compliment the 220 which idles at 247 volts. I think I'm good to go now.
 
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As an update, the utility company came and checked the service to the main panel. They re-cinched the connections on their side of the service to me, ran a 200 amp stress test and the voltage is now stable on both legs. The two 120 circuits were hunting and dropping trying to stabilize between the two legs due to a faulty neutral connection. The voltage is extremely stable now. (I post this in case others have a similar issue).
 
Thank you much!

Just goes to show.... Sometimes you do all you can do, and it IS the utility company.

I'm also glad to see that ute co's are starting to actually listen and help.... Depending on the load, it could have been costing you money, or them... Or a fire!

Last time I had to upgrade my utility service, it was NOT easy... Until I found out one of the pole climbers was an actual superbowl operator in the area I lived :) Made it easy after that!


--Toll_Free
 
They were very responsive and thorough. I told them I had voltage sensitive equipment. They looked up, saw the beam and got to work - at no cost to me. I am a happy camper now.
 
LOL, I have a restaurant that still has a panel full of the old Federal pacific breakers. They haven't been made in years and the company closed. Have had a few shorts were the breaker never tripped and had one when I turned it off it was still supplying voltage. Had to replace a 3pole 60A breaker. Cost $600 for just one. NOS. Trying to get work to replace the entire panel. Scary stuff working with that stuff. I always use a face sheild and heavy gloves with class 1 electrical gloves underneath. You learn to to great care when dealing with those. Anyways, glad you got it all figured out and it didn't cost anything. Just time. Working with the equipment I mentioned kinda prepares ya for working on HV stuff. 1 mistake is all it takes.
 

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