Square D Dual Function Breakers are randomly tripping on unrelated branch circuits

[Rideronthestorm]

I am troubleshooting a new, permitted, complete rewire job that includes a new 200 amp Square D Home panel as of 2016 and has been in service with no problems until recently. Really clean install.
Nearly all breakers are dual function AFCI and the others are dumb. Each leg has 123.5 VAC.

Breaker 9 is a DF-AFCI breaker supplies a home office and is frequently tripping but only when a high load appliance on another branch is starting, furnace, microwave, chop saw etc. The lights dim down, brownout of sorts, and then breaker 9 trips. Sometimes other breakers, on the opposite bus, will trip too, like the smoke detector circuit. Although now fixed, the furnace blew its 24vac transformer. At one point we had no appliances plugged in, including power strips, except the LED ceiling light was on and breaker 9 still tripped when the cop saw was started. The ceiling light passed my inspection.

I am stuck! I like to figure stuff out on my own and its hard for me to ask for help but can only beat my head against the wall for so long. I have been through nearly every outlet looking for a loose wire. All neutrals are in twisted pigtails and secured on the outlets.

Is this an internal or external problem and additional insights could you provide? (note: Square D has a quick test procedure that I followed and some tip immediately and others do not. The test tripping appears to pick its circuits randomly.)
Thanks

 

[ramsy]

..Square D has a quick test procedure that I followed and some tip immediately and others do not. The test tripping appears to pick its circuits randomly

OEM tech support will advise replacement if self-test procedures don't function normally.

Years of exposure to high-frequency motor/drive noise has caused GFCI circuity to permanently fail/trip.
2 years of exposure to high frequency LED-driver noise may be a good run for AFCI's.

High-voltage transients have been reported to cause similar symptoms as your AFCI's, until replaced.

 

[ptonsparky]

I am troubleshooting a new, permitted, complete rewire job that includes a new 200 amp Square D Home panel as of 2016 and has been in service with no problems until recently. Really clean install.
Nearly all breakers are dual function AFCI and the others are dumb. Each leg has 123.5 VAC.

Breaker 9 is a DF-AFCI breaker supplies a home office and is frequently tripping but only when a high load appliance on another branch is starting, furnace, microwave, chop saw etc. The lights dim down, brownout of sorts, and then breaker 9 trips. Sometimes other breakers, on the opposite bus, will trip too, like the smoke detector circuit. Although now fixed, the furnace blew its 24vac transformer. At one point we had no appliances plugged in, including power strips, except the LED ceiling light was on and breaker 9 still tripped when the cop saw was started. The ceiling light passed my inspection.

I am stuck! I like to figure stuff out on my own and its hard for me to ask for help but can only beat my head against the wall for so long. I have been through nearly every outlet looking for a loose wire. All neutrals are in twisted pigtails and secured on the outlets.

Is this an internal or external problem and additional insights could you provide? (note: Square D has a quick test procedure that I followed and some tip immediately and others do not. The test tripping appears to pick its circuits randomly.)
Thanks

Call their tech support. You may need to replace the breakers with newer models. I recently looked at a panel of QOs that are being replaced. IDK if the Homeline series suffers from the same problems. Do not be surprised if the replacements will be at the homeowners expense.

Loads like the chop saw are notorious for tripping AFCIs. Do not use them as a test load.
Make sure you have no crossed neutral or shared neutrals.

 

[Stebs]

If you're doing the onboard test to see why it trips and it trips immediately, it's a ground fault. If it trips after 5 seconds, it's a thermal fault. I have one on my office and it trips randomly on ground fault, only thing I can think of is I have a ups plugged in and it may be self testing periodically, although I've never disconnected it to try as it's been too random.

 

[MAC702]

In what limited experience I have T-shooting older AFCI breakers, just replacing with the newest breaker has solved it.

If wanting to do more T-shooting, swap breakers around and see if the problem stays on the same circuit or chases the breaker around the panel.

 

[Rideronthestorm]

Been thinking about purchasing a Siemens Intelli-Arc Fault Diagnostic Tool not for just this job but others too. They are a lot of money but are they worth it? I have never seen one in use and I don’t know anyone who has experience using one.

 

[ActionDave]

Been thinking about purchasing a Siemens Intelli-Arc Fault Diagnostic Tool not for just this job but others too. They are a lot of money but are they worth it? I have never seen one in use and I don’t know anyone who has experience using one.

Each manufacturer has their own secret sauce that they put in arc faults so I can't see where any tool that says it can diagnose afci could be telling the truth.

The first thing I do is swap out the afci with a standard gfci breaker to see if there is a real problem.

Every afci problem I've ever had was either a wiring error or an electronic load that caused a nuisance tripp. The manufacturer's have already admitted that they are beta testing them on the American public at the same time that they are forcing the sale of them so they will send you a new breaker, but they won't pay you for your time.

 

[mopowr steve]

I have one, and all I can tell you is that it doesn't necessarily show you where the problem is it no more than shows you what the breakers are "seeing" in relation to amperage draw and severity of arcing uh-hm interference which looks like arcing.

I've posted this a number of times, you almost have to camp out at your customers house like I did for a day after 5 trips trying to nail down what it is.

This situation had various Siemens afci's trip randomly throughout the panel. I took apart can lights, looked over everything even admittedly explained that wall paddle fan speed controls are a culprit (and they are) esp the fixed speed types while changing speeds. Long story short, I camped out one day and as we watched tv I also was watching my Intelliarc diagnostic tool and it indicated a high probability of arc fault when a particular commercial came on that had a bright white screen at the end, and happened to trip one of the breakers but not of the circuit associated.
So once the necessary amount of current is flowing through arcfault breakers to start sensing they also see this interference through-out all of them that are connected to that phase. Leaving it a guessing game.

Anyhow had them change their flat screen tv and hadn't had a problem since. Chalking it up as an interference problem with the switching/PWM power supply of that tv that has to ramp up current to drive a bright white screen.