Breaker in house tripped by outbuilding with separate service

[retirede]

Typically with a neutral issue you will see lights brighten or dim throughout the house. A voltage meter would help you.

Water heater would be 240V only. I think it’s unlikely that it would trigger a neutral issue symptom.

 

[hillbilly1]

I never thought about the WH heater having triacs. hmmm.

Yeah, they use it for temperature control do low flow situations. When they first came out, temperature control was very bad, I had a gas one that had a variable flame control. It would not adjust quick enough with pressure fluctuations, so I was always getting cold and hot water because of my well pump. I even put a pressure regulator on it, but still not very good temp control. This was back in the 90’s I believe. I took it out and put in a tank type.

 

[ptonsparky]

Water heater would be 240V only. I think it’s unlikely that it would trigger a neutral issue symptom.

True. I was thinking small 120volt unit. He did mention 50 amp breaker.

 

[hillbilly1]

True. I was thinking small 120volt unit. He did mention 50 amp breaker.

That’s why I was thinking it was a pulse problem, not a neutral problem. After finding out my Square D QO arcfaults were reacting to line side arcs, I thought that might be the issue. My service to the main house is about 150’, then it goes to the second house which is another 80’. The main house is pre-arc fault.

 

[Little Bill]

Currently there is “no load” on the circuit at the house. Everything unplugged or switched off at wall. No smart devices plugged in. Since I have tied it to the water heater scenario I have seen it trip both with things plugged in and with no load. We have done a very extensive search and trace of house wires and are certain of the circuit path and connections.

It’s a very strange thing to think that noise from the heater would travel through the wires to the utility box (275 feet) and then to the house (another 250+ feet).

When the breakers (original and new) trip neither of the LEDs on the breaker are lit. So I can’t say for sure if it’s an arc, ground, or load fault. I assume arc since that seems the most fussy part of the breaker. Would it be worth swapping in a GFCI or AFCI breaker for temporary troubleshooting? Not sure what would be gained by that if it makes a difference.

I asked what the load was on the tripping circuit because it may not require AFCI, or GFCI. If it doesn't require either, I would just put in a regular breaker and be done with it.

 

[Dennis Alwon]

First I would try an afci breaker without the gfci. I assume the gfci is not needed so an afci would suffice. They may be hard to find now that everyone seems to have gone to the dual unit gfci/afci.

Second, I believe a Ge afci/gfci or straight Gfci will fit the Siemens panel. I would try that and see if the issue disappears. If it does then there is something happening that I cannot explain.

 

[hillbilly1]

I never thought about the WH heater having triacs. hmmm.

SCR’s are also used, and probably more common.

 

[ptonsparky]

SCR’s are also used, and probably more common.

Could the POCO transformer be so small that the wave form distortion is causing grief? Why only one breaker?

 

[synchro]

SCR’s are also used, and probably more common.

Triacs are really two anti-parallel connected SCRs integrated in one device

 

[Joethemechanic]

POCO transformer be so small

A bad connection at the point of common coupling? Might not be causing a bad voltage drop

 

[hillbilly1]

Could the POCO transformer be so small that the wave form distortion is causing grief? Why only one breaker?

That’s a good question, though when the poco had the bad connection at my house, sometimes it would only trip one breaker, sometimes four or five. I was sitting in the living room one day, and heard click..click click..click, several of the arc faults tripped.

 

[hillbilly1]

Maybe because the pulses vary frequently due to water flow, the breaker see’s it as an arc? Unlike a motor which would have a consistent arc or pulse? I wonder if a capacitor would dampen the pulses?

 

[hillbilly1]

I wonder if the poco has a bad connection on one hot leg, and that’s the same leg the breaker is on, so the water heater is causing that connection to arc more because of the high amperage pulses? FOP test or maybe infrared scan to locate?

 

[Joethemechanic]

I wonder if the poco has a bad connection on one hot leg, and that’s the same leg the breaker is on, so the water heater is causing that connection to arc more because of the high amperage pulses? FOP test or maybe infrared scan to locate?

Swap spaces so the breaker is on the other leg

 

[TwoBlocked]

The loose connection might be in the Water Heater itself. Triacs/Scrs operate very fast and might be causing enough spark on a loose connection in the heater to "ring" on the entire secondary circuit of the pole transformer, causing that breaker in the house to trip. Fairly easy to check the connections in the heater. Check the connections on the 50A breaker, too.

 

[TwoBlocked]

Had loose load connections catch MOV's on fire in an SCR controller once.

 

[synchro]

... In 2022 we had some renovation work done at the house. The electrician patched in to existing wiring to add some outlets and lights upstairs and as part of that changed a breaker to AFCI/GFCI. Everything worked fine for awhile until I retired and then we noticed the house upstairs breaker would occasionally trip. We went through extensive troubleshooting for about 6 months. Removed all devices and loads, replaced breaker, inspected all wiring and boxes in circuit, traced things, etc.

Are there any dimmers on the circuit with the AFCI/GFCI breaker that's tripping? If so, they might have a MOV protecton device across the line input and equipment ground terminals. Then if there's a voltage surge caused by the fast turn-on of SCRs/Triac in the water heater, it could cause some current to flow to ground through the MOV. And that might cause the AFCI/GFCI breaker to trip.

So if there are dimmers on the circuit, they could be removed or replaced with plain mechanical switches to see if it makes a difference.

 

[ptonsparky]

The common denominator is the OP retired. He needs to go back to work.

 

[Dennis Alwon]

The loose connection might be in the Water Heater itself. Triacs/Scrs operate very fast and might be causing enough spark on a loose connection in the heater to "ring" on the entire secondary circuit of the pole transformer, causing that breaker in the house to trip. Fairly easy to check the connections in the heater. Check the connections on the 50A breaker, too.

Can you imagine your neighbor, who lives on the next lot, has a water heater that is wrecking havoc on your panel. That just doesn't happen , till now, unless the op is crazy...hahaha

 

[Joethemechanic]

Can you imagine your neighbor, who lives on the next lot, has a water heater that is wrecking havoc on your panel. That just doesn't happen , till now, unless the op is crazy...hahaha

On an industrial scale it seems to be happening more and more. Mostly plants with lots of 6 pulse VFDs creating 5th and 7th harmonics. The harmonics travel past the PCC and wreak havoc on nearby customers. For mitigation the customer causing the harmonics usually has to do some kind of phase shifting for some portions of their loads using delta/wye or zigzag transformers