[miamicuse]

As a really WAG, I'll go with the right hand pole.

OK, I'll do that and report back.

Now, if I am not getting power in one phase due to some intermittent faulty utility connections on one pole, I will also get 0V across the line/load on the breaker regardless if it's open or close because it's 0 in 0 out right?

 

[joe-nwt]

Correct. But you can check the utility in by measuring line to neutral. Thing is, it's pretty hard to correct a utility problem by resetting a breaker.

 

[flyingron]

As a really WAG, I'll go with the right hand pole.

Only on the bottom half of the hour.

 

[Old Thomas]

You must be younger than me. We old people focus on our task and ignore the phone. Younger people drop everything if a call or text comes in. It is a generational thing.

 

[miamicuse]

Go straight to the main breaker in the main panel. Don't touch anything else. Measure where you have indicated. 120V indicates the breaker is open regardless of handle position. 0V indicates the breaker is still closed and the problem might be in the meter base, or more likely the utility connections.

So far I'm guessing the main breaker as the problem goes away on reset.

Well today for most of the day nothing happened. No loss of power. I was starting to think may be the intermittent issue has gone away....then it happened after dusk. Yesterday also happened after dusk. I am not sure what might have triggered it, more lights came on with more demand?

So I went to the main panel with some of the circuits now off.

The main breakers in the following picture, I put my multimeter and checked voltages on points A B C D.

Between A and B - almost 0, 0.14, 0.13, 0.15 but practically zero.

Between C and D - 120V, again flashing between 118 119 121...

Next I went and turned off all the double pole breakers that are 240V. Repeated the test from A to B, then C to D, same results.

Then I flipped the main breakers OFF then back ON, now all the circuits seem to come back. I then repeated the tests when everything is restored.

Between A and B - again the same, practically zero.

Between C and D - now it is very low, instead of the 120V when I lost the circuits, now it's 2.2, 2.1, 2.4, 2.1...but it doesn't go down to 0.1-0.2 like it is with the other pole.

So does this suggest that the right side of this quad breakers has gone bad?

 

[miamicuse]

If the quad main breakers are the issue here, then I will need to call an electrician to have it replaced as I can't do it myself with that thing always energized. He will need to turn power off at the meter correct?

Does this preclude any utility line issues? No need to call POCO now?

I wonder if this is something caused by my short accident. If that is the case, would the breaker in the subpanel (the one that tripped) where the short happened also be a problem? The main breakers didn't trip that time - or may be it did internally? I have never seen the main breaker trip come to think of it.

 

[joe-nwt]

So does this suggest that the right side of this quad breakers has gone bad?

Well, my WAG paid off! That's exactly what that means.

Yes power will have to be cut to replace that breaker.

The 2.something-ish volts you are reading indicates a high resistance across the contacts. Not high as in kilo ohms or anything but high for contacts. In essence, you were pre-heating the thermal element in that breaker. So when you added a load that should normally not cause a trip, boom, game over.

 

[DanS26]

Wait a minute.....there should be no potential between A to B or C to D. Those points are in line....no potential. OP should be reading volts between A to C to get 240v or B to D to get 240v.
He should also test each point to the neutral to get 120v each.

The reading he had of 118esh from C to D might indicate a short downstream on that phase. I think the breaker is doing its job and replacing it will not correct the problem.

 

[joe-nwt]

Wait a minute.....there should be no potential between A to B or C to D. Those points are in line....no potential. OP should be reading volts between A to C to get 240v or B to D to get 240v.
He should also test each point to the neutral to get 120v each.

The reading he had of 118esh from C to D might indicate a short downstream on that phase. I think the breaker is doing its job and replacing it will not correct the problem.

I think just maybe he would have noticed a 200A short circuit along the way. A second load in his pants would be his first indication...

 

[miamicuse]

Strange...today everything seems to be working, power was normal. I had the pool pump (240v) running, then I lowered the thermostat to 72 degrees (outside temp is 75 my thermostat was 78) so force the central AC to turn on to stress the system, turned all lights on inside the house during the day, and nothing tripped. Strange.

Tomorrow I will call an electrician to come replace the main breakers. He can turn off power at the meter right? Or this will require POCO to come pull the meter?

 

[miamicuse]

Wait a minute.....there should be no potential between A to B or C to D. Those points are in line....no potential. OP should be reading volts between A to C to get 240v or B to D to get 240v.
He should also test each point to the neutral to get 120v each.

The reading he had of 118esh from C to D might indicate a short downstream on that phase. I think the breaker is doing its job and replacing it will not correct the problem.

I agree that it should be 0v between points A & B, and points C & D, but with one leg lost power, and C & D has 118v, doesn't it mean the contacts between C & D is open which is a problem as the handle is still in the ON position?

If I have a short downstream, well I did have a short when the bare copper touched the bus.

As to measuring between A to C or B to D, I thought about doing so, but then I wasn't sure what would happen when connect A to C, wouldn't that send power of the same leg down to D so both sides now will have the same leg? I didn't know if that would cause any harm so I didn't try.

If I do have a short downstream still, how can I check for it? May be I can check it once the breakers are replaced.

 

[Grounded-B]

Wait a minute.....there should be no potential between A to B or C to D. Those points are in line....no potential. OP should be reading volts between A to C to get 240v or B to D to get 240v.
He should also test each point to the neutral to get 120v each.

The reading he had of 118esh from C to D might indicate a short downstream on that phase. I think the breaker is doing its job and replacing it will not correct the problem.

The only way to get a voltage of 118V from point C to point D, is to have an open between the 2 points. When the breaker is "ON", it should not be open between C and D

Replacing the MAIN breaker is the solution.

 

[seharper]

OK I am not quite following the "Then see if all those wires go stone dead and stay there." I don't have that many 240V circuits, since I use gas, so range, dryer, water heater etc...are on gas. The only 240v loads are the pool pump, and the two central AC systems. So I turn off the breakers for those in this subpanel as well as the main panel correct? Then what is the next step? Wait for the problem to happen again

It sounds like you're way ahead of this, but just for the record...

If you are testing for "a lost phase", then turning off all 240V loads will result in all the 120V loads on the lost phase going immediately dead. They will no longer be being held up by cross-connection through the 240V loads.

If the loss of phase is intermittent, then the 120V load loss will also be intermittent during this test.

 

[miamicuse]

Some new development. I called an electrician to come replace the main breakers, but let's hold off on this and let me provide more updated information.

First of all, nothing happened yesterday the entire day and night, no loss of power. So the loss of power does not always happen at dusk, and I still don't know what triggers it. As I stated I try to power up as many things as possible to try to replicate the issue including pool pump, both central AC units, shop vac, window AC, all lights. No problem. Then I turned everything off, and a few hours later, it happened again. I lost one leg of my power.

So I took out of multimeter and did more measurements while the main breaker handle was still in the ON position.

As I stated last time I measured voltage differences:

Between A & B: almost zero
Between C & D: about 120v.

This time I took additional measurements:

Between A & neutral: 120v but it fluctuates.
Between B & neutral: 120v
Between C & neutral: 120v
Between D & neutral: around 4.12v

and if I flip off all the 240v breakers the results are the same.

then it gets better, see next post.

 

[miamicuse]

So while I had the dead front opened again, I decided to take a closer look all around inside the panel with a flash light, and paying extra attention to the right side of the main breakers. I noticed something.

Do you see it? Just to the right of the main breakers, is a electrocuted dead lizard.

I wonder if that could be what's been causing my problem? I used a plastic stick and flicked it out of the way, turned the main breakers off and back on, and it was fine for a few more hours until it happened again. So now I know the lizard was not the cause.

At that point I called the electrician.

 

[miamicuse]

The electrician asked me to send photos of the main breakers. Two hours later he arrived but he said they do not have my 200A main breakers in stock, but he got a new set of Siemen's breakers and he will try it.

So he pulled the meter, then removed my existing breakers. The new breakers (it is a wider breaker with one single switch) did not fit, too wide. So we are back to looking for the old breakers. He told me they are no longer manufacturing old style breakers due to COVID, and if I want to find a matching one I will have to search online for one.

When he put the old breakers back on, he said that my lugs are a bit corroded and he dared not put the proper torque on them fearing they may break. He will search for a set of breakers matching what I need then come back next week.

An hour later he said they are selling my breakers on ebay, a used refurbished one is $200, there is a new one for $400+. He said he can actually order a new panel for $450+ and use the same guts in that panel to swap mine out, new breakers new bus new lugs the only thing old will be the enclosure. He could do that in one day that way I can use the new updated breakers and everything is new inside for probably $850-950 labor included.

Does this sound reasonable?

 

[miamicuse]

It sounds like you're way ahead of this, but just for the record...

If you are testing for "a lost phase", then turning off all 240V loads will result in all the 120V loads on the lost phase going immediately dead. They will no longer be being held up by cross-connection through the 240V loads.

If the loss of phase is intermittent, then the 120V load loss will also be intermittent during this test.

It is intermittent in that I cannot tell what triggers it. Once it happens it seems to always be resolved temporarily by reseting the main panel whole house breakers. Then it may stay fine for 2 hours or 2 days.

I am curious, if I have a 240v device running , say a swimming pool pump, if I lose one leg, what will the pool pump do? Will it burnt up or will it just quit?

 

[joe-nwt]

The lizard didn't get electrocuted from touching the hot leg while sitting on that plastic insulator.

$950 is reasonable for that job in my opinion.

If you lose 1 leg there is absolutely no way you can say what will happen with certainty. The 240volt devices are still connected through the other circuits through a new and strange series/parallel configuration. The results cannot be even guessed at unless you map out every load in the house. So far the load distribution in your panel seems to be in your favour though.

 

[jbfan]

I wouldn't use a used refurbished breaker unless there is no other choice. If the price is less than 1K, that is pretty good, and you have piece of mind that you have new breakers.

 

[miamicuse]

I wouldn't use a used refurbished breaker unless there is no other choice. If the price is less than 1K, that is pretty good, and you have piece of mind that you have new breakers.

Yes I am going forward with getting the guts inside that main panel totally replaced.

The lizard didn't get electrocuted from touching the hot leg while sitting on that plastic insulator.

$950 is reasonable for that job in my opinion.

If you lose 1 leg there is absolutely no way you can say what will happen with certainty. The 240volt devices are still connected through the other circuits through a new and strange series/parallel configuration. The results cannot be even guessed at unless you map out every load in the house. So far the load distribution in your panel seems to be in your favour though.

So how did the lizard die? It's head was completely missing I thought it must have gotten BBQed from getting near the bus.

I am going forward with the electrician getting a panel that matches mine and swapping out the guts. However he said it comes with new main breaker with a single switch (instead of the one bar across 4 handles). But now I am wondering if I should just replace the whole panel including the enclosure...but there are multiple conduits connected to it if he needs to pull back all those wires it will add a lot more work. Decisions decisions.