Power issues

[blueheels2]

I wired a residential remodel last summer, and in the process I upgraded the service to 400 amps. I installed meter outsid with 200 amp disconnects beside it and then on the interior there are 2-200 amp panels.

Customer reached out about a month ago and said he had a couple of tv’s go bad, also his car charger started malfunctioning. The WiFI portion went out at Christmas and in the past month the charger gets a red light and says it’s overheating. In the process of troubleshooting I realized I messed up and pulled 6NM-B to the charger, it’s a 48A charger. So I’m going to repull in MC next week.

When he called back in early February I went out and verified all of my connections were tight in the service and panel. No’s issues I could tell and no signs of overheating on the charger wire. And while I understand the NM-B is wrong I don’t think that’s what the issue is. Also while there I went through and turned on every load I could think of hear dryer lights oven etc to put the biggest load on the service I could. But no flickering or problems while I was there.

Customer reached out yesterday and said he was cooking with his Sous vide Monday and it quit working mid cycle and is a brick now.

I called the power company and they are going out for a line check today but neighbors aren’t having issues and the transformer feeds. 3-4 houses I believe (engineer told me this on site visit to discuss upgrade). So at this point I think it’s the line to the house or something in the service.

If they don’t find anything today the only thing I know to do is put a power quality meter on the service for a month. I assume I would just hook up to one panel and it will sense if their are surges or neutral loss coming from the source? I was going to rent one. If a meter is hooked up for 2 weeks and a problem occurs on a random day will the meter capture the issue and store it? Is it in sleep mode until an issue arises. If something happens really fast 2 weeks in will it capture it?

Any other suggestions.

 

[LarryFine]

First thing to check is neutral integrity with L-N voltage readings.

 

[gar]

230301-0923 EST

blueheels2:

First question is: Was there failure of loads on both of your 200 A panels. If so, then almost certainly the problem is before the panels, and as Larry said likely a neutral problem. If before the two panels, then most likely a power company problem

Second question is: If problem is on circuits on only one panel, then you have a neutral problem somewhere in or on load side of that panel.

.

 

[ptonsparky]

I always like simultaneous L1-L2 plus L1-N and L2-N.
Check at the line side in of the 400 and verify with checks at the 200 amp panels.

 

[blueheels2]

First thing to check is neutral integrity with L-N voltage readings.

Yeah pretty sure I checked voltage last time but will definitely recheck when I return.

 

[ptonsparky]

Yeah pretty sure I checked voltage last time but will definitely recheck when I return.

Hand held hair dryers or heat guns are all the load you need for voltage checks. (Load up one leg)

 

[Hv&Lv]

I wired a residential remodel last summer, and in the process I upgraded the service to 400 amps. I installed meter outsid with 200 amp disconnects beside it and then on the interior there are 2-200 amp panels.

Customer reached out about a month ago and said he had a couple of tv’s go bad, also his car charger started malfunctioning. The WiFI portion went out at Christmas and in the past month the charger gets a red light and says it’s overheating. In the process of troubleshooting I realized I messed up and pulled 6NM-B to the charger, it’s a 48A charger. So I’m going to repull in MC next week.

When he called back in early February I went out and verified all of my connections were tight in the service and panel. No’s issues I could tell and no signs of overheating on the charger wire. And while I understand the NM-B is wrong I don’t think that’s what the issue is. Also while there I went through and turned on every load I could think of hear dryer lights oven etc to put the biggest load on the service I could. But no flickering or problems while I was there.

Customer reached out yesterday and said he was cooking with his Sous vide Monday and it quit working mid cycle and is a brick now.

I called the power company and they are going out for a line check today but neighbors aren’t having issues and the transformer feeds. 3-4 houses I believe (engineer told me this on site visit to discuss upgrade). So at this point I think it’s the line to the house or something in the service.

If they don’t find anything today the only thing I know to do is put a power quality meter on the service for a month. I assume I would just hook up to one panel and it will sense if their are surges or neutral loss coming from the source? I was going to rent one. If a meter is hooked up for 2 weeks and a problem occurs on a random day will the meter capture the issue and store it? Is it in sleep mode until an issue arises. If something happens really fast 2 weeks in will it capture it?

Any other suggestions.

Ours record every interval you set it to, and record every anomaly.
Customer had an issue with blinking lights, pulsing lights, etc. customer went back and forth with us and the electrician that installed the service.
Finally at 2:00AM the customer called us. I happened to be on call.
I went there and found the problem in the breaker panel.
The factory #4 wire installed from one bar on the side to the next was loose. Whatever was running and had neutrals tied to the right side bar had issues.

Who tightens up factory connections? That electrician does now..

I mention this because it could be something like that

 

[SceneryDriver]

Ours record every interval you set it to, and record every anomaly.
Customer had an issue with blinking lights, pulsing lights, etc. customer went back and forth with us and the electrician that installed the service.
Finally at 2:00AM the customer called us. I happened to be on call.
I went there and found the problem in the breaker panel.
The factory #4 wire installed from one bar on the side to the next was loose. Whatever was running and had neutrals tied to the right side bar had issues.

Who tightens up factory connections? That electrician does now..

I mention this because it could be something like that

Who tightens factory connections? Everyone who bought a QO breaker panel in the last three years. The bus connection to the plug-on neutral rail was loose. It was subject to a huge recall and repair last summer.

Good point to check factory connections.


SceneryDriver

 

[blueheels2]

So I went back out Friday and checked voltages and connections again and found no issues. For a minute there we thought all of the problems were out of 1 panel but then we realized the sous vide machine was coming out of the other. Owners took fhe sous vide machine apart and there were obvious signs of overheating on the hot and neutral. I’ll post a picture later.

Owner also bought himself A PowerTronics Probe 100+ datalagging power analyzer. He’s plugged into a couple of different circuits over the weekend and this analyzer says that there are pulses occurring on the hot and neutral. Neutral pulses have been about 10v. And I believe he had a line pulse of somewhere between 20-50.

 

[blueheels2]

What do you guys think? I have no idea if these pulses could be the problem or if they are caused by normal use of the system.

I reached out to intellirentco on Thursday to rent a logger for a month but no response. Anyone else know a company I can rent from?

 

[hillbilly1]

I wonder if a neighbor on the same transformer has a large air compressor? My cousin did automotive body work on the side, and his neighbors would complain about voltage fluctuations at their houses. The local poco was real bad at loading up four to five houses on a 10kva transformer, which was ok 60 years ago when they were originally connected.

 

[blueheels2]

I wonder if a neighbor on the same transformer has a large air compressor? My cousin did automotive body work on the side, and his neighbors would complain about voltage fluctuations at their houses. The local poco was real bad at loading up four to five houses on a 10kva transformer, which was ok 60 years ago when they were originally connected.

I’m definitely leaning to something is wron on the supply side. Transformer feeds some large houses. And they didn’t upsize the feeder to the house. 200 amp wire for 400 amp service but this is done all the time.

Owner is actually going to ask his neighbor if he can plug the logger in at their house and see if the same issues exist .

 

[synchro]

Owner also bought himself A PowerTronics Probe 100+ datalagging power analyzer. He’s plugged into a couple of different circuits over the weekend and this analyzer says that there are pulses occurring on the hot and neutral. Neutral pulses have been about 10v. And I believe he had a line pulse of somewhere between 20-50.

I assume this power analyzer must be measuring any neutral pulses relative to the equipment ground of the receptacle. Because the neutral conductor of a branch circuit and its equipment grounding conductor are tied together by the bonding jumper or screw in the panel, you wouldn't think there'd be much voltage developed between them. However, if there was a large current surge drawn by a branch circuit load, it might cause a significant voltage drop on the neutral, for example from a motor being started. Or if there is a surge protector on that branch circuit that is conducting current between hot and neutral during voltage surges, therefore causing a surge in current. It might be good to put the power analyzer on a very lightly loaded circuit, and without any surge protectors on it if that hasn't been done already. Also it would preferably be put on a relatively short run of branch circuit conductors.

It sounds like you've done a lot of checking, but the neutral/ ground bond would merit attention based on the neutral pulses that were indicated.

Of course, all of this discussion depends on how well that analyzer can distinguish where the current is actually flowing during a surge.

 

[cadpoint]

Just MO!

There was no mention of Amp readings? You have split service on old existing service laterals (as you posted).
I'm sure that some formulas can be used from the Ohm's law wheel.

Since time has passed since the install could there have been some construction or disturbance around the transformer?

We experienced our coldest week in February, My guess is that it's on the line side.
Compounded with the garage mechanic that has some serious tools!

 

[gar]

230305-1241 EST

From post #9, with high probability, it can at this time be assumed that the problem exists prior to the two main panels, and not likely in either of those panels. However, you need to check the tightness of the input connections to those two panels.

Power companies do not always actually do a good job of monitoring for transient problems. This is from actual experience.

.

 

[blueheels2]

I assume this power analyzer must be measuring any neutral pulses relative to the equipment ground of the receptacle. Because the neutral conductor of a branch circuit and its equipment grounding conductor are tied together by the bonding jumper or screw in the panel, you wouldn't think there'd be much voltage developed between them. However, if there was a large current surge drawn by a branch circuit load, it might cause a significant voltage drop on the neutral, for example from a motor being started. Or if there is a surge protector on that branch circuit that is conducting current between hot and neutral during voltage surges, therefore causing a surge in current. It might be good to put the power analyzer on a very lightly loaded circuit, and without any surge protectors on it if that hasn't been done already. Also it would preferably be put on a relatively short run of branch circuit conductors.

It sounds like you've done a lot of checking, but the neutral/ ground bond would merit attention based on the neutral pulses that were indicated.

Of course, all of this discussion depends on how well that analyzer can distinguish where the current is actually flowing during a surge.

So customer just did this without my prompting. Circuit is dedicated and 5’ away from the panel. 2 duplex receptacles (quad configuration) and nothing plugged in. This circuit was added when I built the service last year. He texted me awhile ago that this circuit noted a 5v pulse on neutral and he felt it was related to him turning on his washing machine. Also said the lights are flickering in the laundry room and the lights aren’t on with the washer. Washer is dedicated.

 

[blueheels2]

230305-1241 EST

From post #9, with high probability, it can at this time be assumed that the problem exists prior to the two main panels, and not likely in either of those panels. However, you need to check the tightness of the input connections to those two panels.

Power companies do not always actually do a good job of monitoring for transient problems. This is from actual experience.

.

Yeah I’ve seen this in the past. Catastrophic failure they can find easily. Getting to the bottom of transformer or line issues is much more difficult.

 

[hillbilly1]

I had a Church that had metal halide lights that would go out in the middle of services. Ga. Power said it wasn’t on their end, so I put a recorder on the main. That week, the maintenance man said there was a slew of poco trucks running up and down the road working on the lines. After the first day, the recorder shown no anomalies. After that, they no longer had power drops! Ga Power wasn’t going to admit it WAS on their end. LOL!