A story about dual function breakers, flickering lights, and galvanic corrosion

markhpc

Member
Location
Minnesota
Occupation
Software Engineer
Hi Folks,

Long time lurker, first time poster. I wanted to share my story for posterity here since this forum has helped me so much in the past. If this violates the rules in any way please feel free to delete, but I hope someone might find it useful so I'll give it a go.

I'm the owner of a SquareD QO panel with a mix of dual function, AFCI, and traditional breakers from ~2015/2016. We have a total of 9 dual function breakers protecting circuits in the kitchen, outdoor receptacles, the garage, bathrooms, etc. We've had several random trips across different breakers over the years but seldom enough that I could never really diagnose what was going on. That all changed 2 days ago after a heavy rain storm. After the storm, every single dual function breaker in the box would eventually trip, sometimes after only a couple of minutes. At other times we could go hours without issue. Sometimes a single breaker would trip, while at other times clusters of breakers would trip one after another. Every single AFCI and traditional breaker was fine. They never tripped once. I did however notice faint buzzing from certain lights and from the breakers themselves. Our LED lights are on dimmers and have always had issues with flickering and they were flickering a bit more than normal. I had always assumed this was primarily due to an incompatibility with our dimmer switches. These clues all turned out to be key, but I didn't know it at the time. I spent hours trying to narrow down what was going on ranging from unplugging every questionable device in the house to turning breakers off one by one to see if I could isolate a specific circuit. I inspected every breaker for lose wires or screws with no obvious culprits. A dual function breaker with a straight run to a single receptacle with nothing plugged into it was tripping multiple times an hour. Nothing made sense. At one point I was convinced that humidity in the basement and temperature differential caused by the warm breakers and cool block walls was causing condensation in the breakers themselves. That was reinforced by a false period of bliss after turning on the AC and pointing a fan at the breaker box, but it didn't last.

After sitting down and thinking for a while, I came to the conclusion that I was chasing ghosts. This didn't seem to be an arc fault issue. It didn't seem like a neutral/ground issue inside my house either. Nothing in the box was lose or wired improperly as far as I could tell. Before heading to bed for the night and calling my electrician in the morning, I decided to inspect the line coming into the house. Everything looked nicely sealed and tidy. No signs of moisture. As I turned around to walk back, I heard a buzzing in the distance that sounded exactly like what I was faintly hearing from the breakers. I walked in the dark to the pole on my neighbors property, and sure enough, it was periodically buzzing loudly (almost more a sizzling sound) and sparking up near the insulators. I called the power company that night, but ultimately they weren't able to make out until late the next afternoon.

The next day as I waited for the power company to come out I called Schneider Electric and spoke to one of their advanced service techs. I relayed my story and asked him if he thought the situation at the pole could explain my tripping dual function breakers. He had me check the date codes on the breakers and explained that the ones I have are first generation and far more sensitive to dirty power issues than the newer ones and that it was quite possible the issues were related. He was very nice and helpful. Later in the afternoon our power company was able to come out and checked out the lines. He couldn't detect any issues when inspecting the power coming into the house, but after I brought him over to the pole he agreed something was wrong and went up to take a look. When he came back down he showed me what was going on. The distribution line is aluminum with a copper wire attached using an aluminum connector. He showed me the connector, and it was quite lose and burned out due to galvanic corrosion caused by the dissimilar metals. He also indicated it was installed improperly, but I wasn't quite sure regarding the details (apparently it was upside down?). He replaced everything on the pole with new connectors and everything has been fantastic since. My LED lights no longer flicker on the dimmers. The overly sensitive dual function breakers are (so far!) no longer tripping. I no longer hear buzzing from my lights nor from the pole.

I wanted to relay this story because I spent so much time running around convinced there was something wrong with the wiring or breakers that I didn't think to check what was happening outside the house. The lesson I learned is to stop and really try to get a bigger picture of what's going on before spending hours trying to endlessly diagnose issues that don't make any sense. I hope this story might help folks in the future avoid the same fate!
 

WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
As a residential electrical contractor, I've battled AFCI circuit breakers. Thanks for sharing your experience. Adds an arrow to my quiver.

I struggle with the amount of labor time needed to troubleshoot AFCI issues. Usually this time/cost falls on the electrical contractor.
 

markhpc

Member
Location
Minnesota
Occupation
Software Engineer
romex: bum noodle indeed!

WSG: yeah, I was surprised that the AFCI breakers were all fine, it was the dual function ones that were constantly tripping. Sounds like that wasn't super unexpected though given the first gen ones I have. Schneider Electric was super helpful.
 

kwired

Electron manager
Location
NE Nebraska
Did they offer to replace the first generation devices for free?

I bet not, or if a contractor is involved his time troubleshooting and replacement is worth nothing to them.
 

romex jockey

Senior Member
Location
Vermont
Did they offer to replace the first generation devices for free?

I bet not, or if a contractor is involved his time troubleshooting and replacement is worth nothing to them.
A point i've repetitively brought up since the '08 debut of 'combination' Kwired ~RJ~
 

kwired

Electron manager
Location
NE Nebraska
but some of us sold out to Pton

~RJ~
Sold out and did something unwillingly because we basically had no choice or at least it made the most economic sense in the particular situation are not the same thing.

Square D has sent me letters on recalls on other products in the past. Last one I had was for some I line breakers, I got the letter because they knew they potentially sold me items that were recalled (basically needed to look at date code to confirm if they were recalled or not). Two of them were in the recall date range. I had to purchase replacements from my distributor (and they are not priced so well when buying single off the shelf items compared to part of a job quote like the originals were) then return the recalled ones to the distributor and presumably get credited. This time it took forever to process the credit, distributor blamed it on Schneider for taking so long.

I didn't get any reimbursement for labor, but though was good idea to do for client's sake since it was a recalled product and client was a frequent repeat client. But if that is how they are going to handle it maybe I won't volunteer to replace these recall items anymore in the future.
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
As a general rule, what the power company guy was trying to explain is that when making splices of dissimilar metals they should be oriented so that the copper conductor is below the aluminum conductor. I’m not a chemist but from experience rain water (H2O) washes down the splice and carries with it the copper element (CU) which will corrode aluminum much faster when it is below the copper conductor. Probably what he was referring to as upside down.
 

romex jockey

Senior Member
Location
Vermont
I didn't get any reimbursement for labor, but though was good idea to do for client's sake since it was a recalled product and client was a frequent repeat client. But if that is how they are going to handle it maybe I won't volunteer to replace these recall items anymore in the future.
and that's the bottom line kwired

we EC's have to eat a world of crappy products

the NRTL's ,CSPC, and whatever other bureaucratic oversight loose nothing, zero, zip nada

the trade rags are all profiteers cloaked in the guise of industry cheerleaders

If we want product review, it has to be grass rooted , from the trenches

and often will confront any electrical theory being foisted on us by these sorts

~RJ~
 

kwired

Electron manager
Location
NE Nebraska
and that's the bottom line kwired

we EC's have to eat a world of crappy products

the NRTL's ,CSPC, and whatever other bureaucratic oversight loose nothing, zero, zip nada

the trade rags are all profiteers cloaked in the guise of industry cheerleaders

If we want product review, it has to be grass rooted , from the trenches

and often will confront any electrical theory being foisted on us by these sorts

~RJ~
I don't think they used to be so much that way, but it mostly got going in the 1980's and later when all the little guys started getting gobbled up by larger corporations and eventually there were only a few larger guys left. And when it comes to kind of products we are talking about here there is basically only about four major players left, not just in North America but worldwide.
 
Location
60077
Occupation
Controls technician
Hi Folks,

Long time lurker, first time poster. I wanted to share my story for posterity here since this forum has helped me so much in the past. If this violates the rules in any way please feel free to delete, but I hope someone might find it useful so I'll give it a go.

I'm the owner of a SquareD QO panel with a mix of dual function, AFCI, and traditional breakers from ~2015/2016. We have a total of 9 dual function breakers protecting circuits in the kitchen, outdoor receptacles, the garage, bathrooms, etc. We've had several random trips across different breakers over the years but seldom enough that I could never really diagnose what was going on. That all changed 2 days ago after a heavy rain storm. After the storm, every single dual function breaker in the box would eventually trip, sometimes after only a couple of minutes. At other times we could go hours without issue. Sometimes a single breaker would trip, while at other times clusters of breakers would trip one after another. Every single AFCI and traditional breaker was fine. They never tripped once. I did however notice faint buzzing from certain lights and from the breakers themselves. Our LED lights are on dimmers and have always had issues with flickering and they were flickering a bit more than normal. I had always assumed this was primarily due to an incompatibility with our dimmer switches. These clues all turned out to be key, but I didn't know it at the time. I spent hours trying to narrow down what was going on ranging from unplugging every questionable device in the house to turning breakers off one by one to see if I could isolate a specific circuit. I inspected every breaker for lose wires or screws with no obvious culprits. A dual function breaker with a straight run to a single receptacle with nothing plugged into it was tripping multiple times an hour. Nothing made sense. At one point I was convinced that humidity in the basement and temperature differential caused by the warm breakers and cool block walls was causing condensation in the breakers themselves. That was reinforced by a false period of bliss after turning on the AC and pointing a fan at the breaker box, but it didn't last.

After sitting down and thinking for a while, I came to the conclusion that I was chasing ghosts. This didn't seem to be an arc fault issue. It didn't seem like a neutral/ground issue inside my house either. Nothing in the box was lose or wired improperly as far as I could tell. Before heading to bed for the night and calling my electrician in the morning, I decided to inspect the line coming into the house. Everything looked nicely sealed and tidy. No signs of moisture. As I turned around to walk back, I heard a buzzing in the distance that sounded exactly like what I was faintly hearing from the breakers. I walked in the dark to the pole on my neighbors property, and sure enough, it was periodically buzzing loudly (almost more a sizzling sound) and sparking up near the insulators. I called the power company that night, but ultimately they weren't able to make out until late the next afternoon.

The next day as I waited for the power company to come out I called Schneider Electric and spoke to one of their advanced service techs. I relayed my story and asked him if he thought the situation at the pole could explain my tripping dual function breakers. He had me check the date codes on the breakers and explained that the ones I have are first generation and far more sensitive to dirty power issues than the newer ones and that it was quite possible the issues were related. He was very nice and helpful. Later in the afternoon our power company was able to come out and checked out the lines. He couldn't detect any issues when inspecting the power coming into the house, but after I brought him over to the pole he agreed something was wrong and went up to take a look. When he came back down he showed me what was going on. The distribution line is aluminum with a copper wire attached using an aluminum connector. He showed me the connector, and it was quite lose and burned out due to galvanic corrosion caused by the dissimilar metals. He also indicated it was installed improperly, but I wasn't quite sure regarding the details (apparently it was upside down?). He replaced everything on the pole with new connectors and everything has been fantastic since. My LED lights no longer flicker on the dimmers. The overly sensitive dual function breakers are (so far!) no longer tripping. I no longer hear buzzing from my lights nor from the pole.

I wanted to relay this story because I spent so much time running around convinced there was something wrong with the wiring or breakers that I didn't think to check what was happening outside the house. The lesson I learned is to stop and really try to get a bigger picture of what's going on before spending hours trying to endlessly diagnose issues that don't make any sense. I hope this story might help folks in the future avoid the same fate!
 
Location
60077
Occupation
Controls technician
This is the kind of thing you really learn from. I have seen a lot of panels with ground bonds removed AFCI breakers that don't function and are red hot. Good on you for taking the time
 
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