Power Surges & 5-volt Difference Between Legs or Loose Neutral

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mxlplx00

mxlplx00

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Location
Watsonville, California
Occupation
Electrician
It's been stormy here and power outage have been common. I had a lady call me Friday and say that her mobile home power went out a couple of times, came back on, tripped a breaker and burned out some bulbs. I went out, reset the breaker, turned on everything and read 1-amp. I thought that it was going to be a loose neutral but when I read the voltage on the legs I had 119v and 124v.

Thinking about it now maybe I should have turned on a large appliance then read the voltage. I've seen lost or weak service neutrals before and this didn't look like one to me. Is a 5-volt difference between legs something to be concerned about when there are no heavy loads on? I also read resistance from ground to neutral and got 0Ω in a segregated panel with my t5-600.

The meter is a few doors down. I assume the bonding jumper and grounding rod are there. I couldn't get access.

Yesterday she told me that an Amazon brand power strip plugged into the kitchen counter made a noise and smoked a bit with nothing plugged into it. She threw it out.
She texted me today and said:
"This morning the lights flickered a few times, power went out and came back on but not 100%, flickered again, bulb in bathroom popped. So I called PG&E and the guy came out and checked where the meter is two doors down and said everything looked okay there."

I've been thinking power surge from the storm but this has to be a loose neutral right?

I checked the lugs in her panel and they are tight. PG&E checked the meter but said the portion between the meter and her coach are the responsibility of the park.
The park has a box outside her coach but it's locked. She called the park and they told her that they'll have someone look at it but if it isn't their fault she will be billed for it.

Thanks
 
mxlplx00 said:
It's been stormy here and power outage have been common. I had a lady call me Friday and say that her mobile home power went out a couple of times, came back on, tripped a breaker and burned out some bulbs. I went out, reset the breaker, turned on everything and read 1-amp. I thought that it was going to be a loose neutral but when I read the voltage on the legs I had 119v and 124v.

Thinking about it now maybe I should have turned on a large appliance then read the voltage. I've seen lost or weak service neutrals before and this didn't look like one to me. Is a 5-volt difference between legs something to be concerned about when there are no heavy loads on? I also read resistance from ground to neutral and got 0Ω in a segregated panel with my t5-600.

The meter is a few doors down. I assume the bonding jumper and grounding rod are there. I couldn't get access.

Yesterday she told me that an Amazon brand power strip plugged into the kitchen counter made a noise and smoked a bit with nothing plugged into it. She threw it out.
She texted me today and said:
"This morning the lights flickered a few times, power went out and came back on but not 100%, flickered again, bulb in bathroom popped. So I called PG&E and the guy came out and checked where the meter is two doors down and said everything looked okay there."

I've been thinking power surge from the storm but this has to be a loose neutral right?

I checked the lugs in her panel and they are tight. PG&E checked the meter but said the portion between the meter and her coach are the responsibility of the park.
The park has a box outside her coach but it's locked. She called the park and they told her that they'll have someone look at it but if it isn't their fault she will be billed for it.

Thanks
Click to expand...
I've told MH Parks to unlock the Box and if the issue is there, I will send them the Bill. They would usually agree.

I had the phone company pull the same shtuff. I asked them for a billing address so I could send them the bill for my diagnostics. PMO.
 
ptonsparky said:
The difference of 5 volts to neutral must be made up on the other L-N to point to a compromised neutral.
L1-L2 = 240 Then L1-N=115 & L2-N=125
YMMV.
Click to expand...
Could also be a compromised ungrounded conductor and many items are on that side making her think power is out when it fails.

OP never mentioned line to line voltage so not knowing that 124 isn't necessarily too high. If you have readings much over 125 though it is much more likely due to a bad neutral.

Best test for OP is to connect a 1000-1500 watt load line to neutral and let it run for a bit while monitoring voltage. Loose connection whether on grounded or ungrounded should start showing itself in the voltage readings in relatively short time if not immediately. If nothing happens do same thing on other ungrounded line, and monitor not only line to neutral but also line to line volts while doing so.

Do not put the test load on both ungrounded conductors at same time, you want to force unbalanced current to flow on the neutral so it will heat up if it is bad.
 
ptonsparky said:
I've told MH Parks to unlock the Box and if the issue is there, I will send them the Bill. They would usually agree.

I had the phone company pull the same shtuff. I asked them for a billing address so I could send them the bill for my diagnostics. PMO.
Click to expand...
If you have proven the problem is upstream from tenant you can inform them liability is potentially on them if it causes damages to tenants appliances and such and see if that motivates them to want to do something about it.
 
Hi again and thanks. You guys are amazing.

To Kwired I believe that I was getting 244v line to line.

I got worried last night and went back @ 8:00 to test under 120v loads. Before I went out I asked her how it was behaving and she said the lights have been flickering a bit but nothing bad. I noted that the storm has passed but PG&E could still be working on the lines.

I tested with the microwave mostly and added different appliances here and there and I think the biggest difference that I saw was 125v to 117v. It seemed to fluctuate a lot. While I was there it seemed the lights flicker a bit much. She also noted that one of her electric blankets quit working. I test it for power and it was hot to the controller with my non-contact tester. I told her not to use them tonight.

I strongly suggested that they get a hotel or something but they declined.

Her and her husband really got into it and started turning on all the heavy stuff they could think of but I told them if it balances the load out the difference would lessen.

They asked me what I thought and I told them that a loose neutral is usually easier for me to see, that I'll see voltages like 185v to 65v with the microwave throwing sparks and the refrigerator totally failing. But if here the neutral is slowly failing or has a loose connection that it's probably arcing and slowly degrading the connection further.

I told them that maybe they could get a second opinion.

She said that she moved in two years ago. I wonder if it could be a poorly designed or degrading distribution system and maybe she's at the end of the line with the park trying to cover this up. Earlier we had went next door and asked the guy if he's seen any flickering and though he seemed a little out of it he mentioned last week.

So I finally packed it up to leave and I was about 2-miles away when they called me back. They told me that when the refrigerator cycled on that the kitchen lights dimmed to almost going out completely to the point that it reset the clock on the oven to 0:00.

So I went back and did more load testing. I tested the frig with an amp-probe by having them unplug it then plug it in. I got 2.1A before unplugging then after disconnecting and restarting I got 10.5A for 5 to 10 seconds then it would drop down to 1.2A.

This went on for a while and I finally left but I told them that my kids have moved out and have an extra room with clean sheets that they could use. They declined.

I told them that I'm not really sure of what's happening but it looks to me like a failing neutral. To maybe get a second opinion and that the list of things going wrong here seems to be quickly piling up. To bring this list to the park and get them on it.

What do we have, first the power outages in the storm, phantom breaker tripping with bulbs burning out. She said she heard a noise when the bulbs went out on two occasions. The Amazon power strip made a noise, went out and smelled like smoke, the frig causing the light to go out and resetting the oven clock and the fluctuating voltage difference.

Thanks again
 
You should monitor both legs to neutral while varying the load on each. If it’s a neutral problem, one will rise as the other drops.
 
Hi again,
She texted me this morning and said that she was in the other room and smelled smoke, came out and her VHS played was actually smoking and she turned off the main breaker. She said that she informed the park manager and they were sending their electrician Monday. So I dropped everything and went right out.

I have alligator clips for my good Fluke and was going to use that and mt T5-600 to check both legs when switching loads. Like Retirede suggested.

When I got there I looked around a bit, unplugged the VCR then went to the panel turned it on (probably not my brightest idea) and started taking a few reading when the light bulb above my head popped. I shut it down and read for continuity between ground and neutral and it was wide open.

So I told her that the feeders have completely failed and to tell the manager to get someone today. That the the place is uninhabitable and it's their fault.

After some phone tag she has the manager and is politely trying to tell her and is getting a good deal of resistance. I ask to speak with her and I'm trying to tell her that the park feeders have failed and she doesn't want to believe me. I say look, I've tested to your "locked" box on the side of the coach (I guess it's called a pedestal) and the coach is good, PG&E has check to the meter from their side and they're good the rest is your responsibility. That this place is popping light bulbs smoked a power strip two days ago and a VCR this morning. The power cannot be turned back on until you have the feeder fixed today. It's uninhabitable and your responsible. I look over and my customer it looking at me cringing.

So we get word back that they're showing up today sometime. So I leave.

The lady texted me this evening and says that they sent a guy and guess what "we lost the neutral" that he called his boss and they're going to try to rig something up to get her going. She then texted me a few hours later and they had strung a big SO cord along the fence two coached down to the meter bank.

She thanked me profusely and said that if I wasn't so insistent that they wouldn't have come until Monday. She said that they're going to run her on the power cord until they get some bids to redo the underground. Her main is only 50-amps for a double wide. IDK how they can run a mobile home off of just 50-amps.

Thanks so much for your help everyone. I should have been more insistent way earlier but it still looked iffy to me. I did tell them at every turn that they should turn it off and get a hotel. I don't get this kind of stuff often, I spend a lot of time crawling wire here and there. You guys are an amazing recourse and have never steered me wrong.

Have a great Friday!

Marc
 
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