[jhein]

About 4-5 years ago we started having these weird, intermittent, irregular "brown outs" at our house. I have a Generac backup generator and if I would switch over to the Generator, everything would instantly return to normal. Then after a few minutes, switch back to regular power and it would be fine, until next time. I had the power company out several times and they could never find anything. They even put a recorder on my meter and never detected anything and I know we caught at least one episode when the recorder was on. The last time it happened was about 2 years ago.

Then yesterday it started again. Had 3 episodes in the last 24 hours. Now it's a little different. Instead of brown outs, I'm losing power completely, but not the whole house, but it is on at least 4 different circuits. Then, just like before, if I switch off the grid power, the generator runs and power instantly comes back in the dead circuits. Let it run for a few minutes and then everything is fine back on the grid power. I've never found anything at my panel, no breakers tripping.

We bought the house in 2008, was built in 2007. Since we bought it, we've made many changes, all done by professional electricians. We've had Two different backup generators. A major addition on the house, Outdoor heaters installed. New mini split AC unit for the addition.

I'm having my electrician come out and look at it. Any ideas?

[OG68]

You're experiencing a loss of one of the two 120 lines in the power supply from your utility or at the meter or generator transfer switch.

Similar problem happened to my Aunt's house. Edison came out and looked and couldn't find anything wrong with the power supply and suggested an electrician inspect the house wiring.
This went on for several months. Finally total failure happened when the power pole transformer failed and the neighborhood had only a single phase power supply.

Ask your neighbors if they are experiencing the same problem. Could be a line problem or between the house meter and your transfer switch.

[Trulyvintage]

My previous career was as a
licensed journeyman & master
electrician & electrical contractor.

You can’t troubleshoot over
the internet.

You need the serving local
utility company to come
out - pull your electric meter
and check the line side voltage.

Coordinate this with a visit at
the same time with a licensed
electrical contractor to inspect
the meter socket for loose connections
and/or arcing & burning at the
wire terminations and/or bends
in the wire that could have nicked
the wire insulation.

From the point of service entrance
you need to trace the feeders and
neutral back at every junction box
and termination point.

Jim

[Ben M.]

Kinda agree with Jim. I am an electrical engineer and write all the safety procedures on how to test my equipment and troubleshoot it, plus I know how to work on all of it as well and how to use the test equipment to get the right answers. It's not necessarily for the faint of heart if you aren't trained or understand how to work it and can cause loads of problems.

That said, the easiest way to isolate the problem is to open the electrical panel at your house when it is acting up and measure the 2 phases coming in to ground and to each other. If you have an imbalance or aren't getting the right voltage then any of those measurements tell you what your problem is and potentially where.

It sounds like you have either a problem with a phase drooping or the ground\neutral failing. Whether this is at the electrical utility transformer\lines or at your main power box or in a sub-panel somewhere in the house is not something I can determine over the internet. Any electrician worth their license can make measurements with a multimeter and determine it in pretty short time.

I had a squirrel chew through my earth ground from the transformer several years ago and ended up with a 40V imbalance between phases that would do very similar weirdness you describe. When I called the power company to tell them they were completely uninterested until I told them exactly what the measurements were and then they perked up and had a crew there in less than 2 hours to have it fixed - a missing neutral can kill someone and they were not going to take on that liability by blowing me off.

[Stuart]

I agree it's likely one of the hot legs or possibly the neutral has a poor connection. It could be anywhere between your breaker panel and the utility transformer, although in my experience it seems to happen more often at the transformer. Call your utility, tell them what's happening and ask them to come out and check.

[jhein]

Thanks for the replies. Well, we'll see what the electrician finds.

The transformer has checked out OK. The recorder they put on the house at the meter didn't detect anything. It stops immediately when switching to the generator.

So if the power coming from the transformer to the meter is good, and when I feed the panel from the generator everything is good, to me that seems to suggest it's between the meter and the transfer switch.

[GtoFM]

Did the recorder monitor both the street side and the house side of the meter? My guess is your electrician will start with the main circuit breaker, transfer switch and connecting wiring.

[OG68]

[poncho-mike]

I have seen this happen in two situations.

My first house had fuses that snapped into a plastic carrier that plugged into an electrical box. A fuse got hot and blew, and in the process it scorched the copper. This causes the resistance to increase, and when current draw was high it would get hot and cause the lights to dim.

The second was on my current house. It has breakers that snap in to a panelboard. The panel board has a blade type connection. The breaker has a spring loaded connection that applies pressure to the blade. For some reason, the breaker connectors lost tension, causing the connection to get hot. I replaced the breaker and sanded the panel board connection until I saw clean copper. I believe I used some type of conductive paste on the panel board blade as well to prevent corrosion.

Both issues had the same root cause, the connection between the fuse or breaker and the panel board had become burnt or corroded, increasing the resistance at the connection.

[gtohunter]

Had a similar issue, in that my wife would tell me "the microwave won't work"...I'd go check and it would fire right up. After putting up with these sporadic mystery "outages" I took a trouble light, and connected to one buss in the breaker panel, and sat down to watch TV. After a little while, the light started to flicker, which led me to the main, which I determined to be bad. Couldn't find a replacement main (obsolete), so I had to replace the panel and breakers.

[carbking]

JOB FOR PROFESSIONALS, NOT INTERNET FOLKS TRYING TO BE HELPFUL!

After several years working for a power company in the electrical engineering department (before I starting doing carburetors), I could make a guess, but not going to.

I can tell you from personal experience that a house fire, even if estinguished within 5 minutes of combustion, is absolutely no fun, and expensive.

Get the professionals out today!

Jon

[jhein]

Originally Posted by carbking

JOB FOR PROFESSIONALS, NOT INTERNET FOLKS TRYING TO BE HELPFUL!

After several years working for a power company in the electrical engineering department (before I starting doing carburetors), I could make a guess, but not going to.

I can tell you from personal experience that a house fire, even if estinguished within 5 minutes of combustion, is absolutely no fun, and expensive.

Get the professionals out today!

Jon

Yes, for sure. I called Monday morning and this afternoon was the best I could do. I only posted here to see what people who know thought it may be. My guess is still the transfer switch itself, or bad connection between the meter and the transfer switch. I've been running the house off the generator and everything operates normally in the house.

[jhein]

OK, my electrician just left and after 1 hour and 20 minutes of troubleshooting found nothing wrong. Of course, we could not duplicate the problem while he was here.

However, he believes it's between my meter and the transfer switch, possibly the meter itself. Unfortunately, he's not allowed to remove the meter, only the power company can do that. The transfer switch, generator and panel were OK.

So now I need to get the power company and the electrician out here together. I'm not sure how long it's gonna take to coordinate that so I've called the power company to have them come out again and check the meter or maybe just swap it out if they can't find anything else.

What a PITA. At least he doesn't think my house is going to burn down. I hope he's right.

[jhein]

I had a second electrician out this morning and we found the problem. When the transfer switch was installed they spliced the wires coming from the meter into the house panel to run them out to the transfer switch (different electrician than I have now). The splice connections are the problem. I got lucky because he was done checking everything and found no problems. He was just getting in his van to leave when the power went out. He came back in and since he was already suspicious of the splice, he moved it and the lights came back on. So now they have to coordinate with the power company to come out and remove those spliced wires and run new ones. So I'm back on the generator for now. But at least we found the problem.

[Elarson]

Splices sound like a sketchy approach. My generator installation has fresh cable from the meter to the transfer switch and fresh unspliced cable from transfer switch to the circuit breaker panel.

Off topic, but I did have a totally different weird problem once. Power goes off, generator kicks on and runs the house fine for a few hours. Utility power comes back on, transfer switch kicks back over and now the power is flickering. I go out and open up the transfer switch and there is a distinct smell and a sizzling sound. Turns out that a stink bug got into the utility power contacts when they were open and was now fouling up the connection. Switched back to generator and blew the fried bug out with compressed air. Good ever since.

Eric

[jhein]

Originally Posted by Elarson

Splices sound like a sketchy approach. My generator installation has fresh cable from the meter to the transfer switch and fresh unspliced cable from transfer switch to the circuit breaker panel.

Off topic, but I did have a totally different weird problem once. Power goes off, generator kicks on and runs the house fine for a few hours. Utility power comes back on, transfer switch kicks back over and now the power is flickering. I go out and open up the transfer switch and there is a distinct smell and a sizzling sound. Turns out that a stink bug got into the utility power contacts when they were open and was now fouling up the connection. Switched back to generator and blew the fried bug out with compressed air. Good ever since.

Eric

That's for sure. I was not aware of that 15 years ago when they installed it. If I were, I would have objected. Seems like a failure waiting to happen. Although the electrician today did say there are legit ways to do it, but based on how it looks he can't tell exactly what they did until he can take it apart. But regardless of the technique, it failed. Anyway the good news is that it's an easy fix. The other good news is that I have the backup generator. That's some of the best money I've ever spent.

[Shiny]

Thanks for sharing and good job on being persistent.

Intermittent connections are a total PITA to isolate so glad you had a miraculous event when the electrician was there. That never happens to most of us. You need to buy a lottery ticket!

I understand something like 98% of all failures in electronic products are caused by interconnect failure (not components). I don't know if that's true for home wiring but probably a good guess.

We recently had a similar issue - lights on one circuit would randomly go out in one room, then come back on. The first electrician showed up, wiggled an outlet and the lights came on. He told us the outlet probably shorted and the breaker tripped without mechanically moving because it was old... ???? Really??? He replaced the outlet and breaker and left. The lights were on the rest of the day.

When the lights went out again the next day, we accidently discovered an outlet in an upstairs room was also dead. This outlet was on a different breaker. Neither breaker had tripped.

A 2nd electrician then found both circuits shared a common neutral wire in a 4-conductor romex cable and went hunting for connections. It took him about an hour and opening at least 6 junction boxes before finding the problem. The initial installer had taken the "easy path" and had just stabbed multiple neutral wires into those spring-clamped connections (holes) in the back of an outlet. One of these wimpy connections was carrying the current for two circuits in the shared neutral. He said this was bad practice and the connection had degraded, probably from thermal cycling. He replaced this with a wire nut (as should have been done initially) and all has been good since. We got a good electrician the 2nd time!

[Stuart]

Utilities splice wires all the time without incident. However, it sounds like this one failed for some reason - it may have been improperly done to start with, but that's just speculation.

[jhein]

So just to wrap this up, the second electrician came back out today with the power company. They got everything fixed. Replaced all the cables from the meter to the transfer switch. There was also a cable from the transfer switch back to the panel that had a nick in the insulation that they also replaced.. The picture below shows the coupler used for the splice. There were no screws to tighten down on the cables. So it was a compression fit, or possibly they crimped it somehow. The body does look a little irregular like maybe it was crimped. The two electricians here had never seen anything like it before but I think they were both like 18 years old. LOL. But, they were prompt, polite, worked fast and seems like they did a good job. So I give them two thumbs up.

[necdb3]

I can't believe someone did a splice like that inside a panel box. Way too much room for error. I assume you removed tape or jacketing before this picture was taken?