AFCI Nuisance tripping

[jfincherok]

Hello all. This is my first post. I've gleaned a lot of good information off this forum to help me solve a problem but I can't seem to fix it. I'm a home builder and between my electrician and I, we've pretty much run out of ideas. I'm in search of ideas.

I have a homeowner who, to my knowledge, had no significant AFCI tripping problems until about 5 months after moving in. Since then (about 8 months), they have had numerous nuisance tripping problems with 3 circuits in particular. The tripping seems to occur intermittently. If it were immediate, it would likely be easier to find the problem. The information from the homeowner to help us trouble shoot has been spotty to say the least. The load center and breakers are from CH.

We have tested and tried many things including insulation resistance testing on line, neutral and ground, remaking all the connections, voltage and current testing (the highest measured current with everything on was 12 amps), replacing the breakers, running extention cords from a non-AFCI circuit to everything plugged into the circuits (which resulted in no tripping for 2-3 weeks). The power utility has been out there and said no problems on their end. We recently put in a pricey whole house surge protector in the panel. I'm pretty sure all the home runs are on 12/2 so there shouldn't be any shared neutral problems. My contractor is pretty good but I've even hired a different one to check things out just to have a new set of eyes. The problem still persists and I'm sure a lawsuit is around the corner.

The theater circuit had the theater lights and plugs, 5 pendant lights in the kitchen, exterior outlet for heat tape (on the irrigation system), and mechanical closet with tankless (gas) water heater and doorbell transformer. We ran a separate dedicated circuit for the theater equipment and a separate dedicated circuit for the mechanical closet. We replaced the heat tape but since it's warmer now, it's not even plugged in. The breaker still trips.

The study circuit has all the outlets in the study, lights in the study and entry and about 5 exterior lights. We've replaced all the CFLs with incandescents for now.

The other circuit has the remainder of the kitchen lights, utility room light, garage lights and I think that's all. Again, we've replaced the CFLs with incandescents.

It seems that when one breaker trips, the others trip also; sometimes with a slight delay. Since the information from the homeowner is spotty I don't know if it is this way all the time. It seems like the fault code at the breaker is frequently a "1" which means a low current "series" arc.

My thoughts on what else the cause could be are as follows:

1. Problems from the utility provider. I don't even know if this will cause a breaker to trip. If so, is there a monitor that will record voltage, current, etc. in real time that we can go back and look at when a breaker trips?
2. All circuits seem to have at least one exterior light or outlet. Perhaps moisture gets in intermittently?
3. Faulty load center? Seems like not much could go wrong there, but is it possible?
4. Something the homeowner is plugging in. I know this is highly possible, but on 3 or more separate circuits? And why would that cause all of them to trip around the same timeframe.
5. Some kind of series arc caused by a loose connection in a fixture. Perhaps a loose wire in a fixture only arcs when there's a vibration from a door closing or high winds? If so, it would seem strange to have that on so many circuits and again, why would it cause multiple circuits to go at the same time?

I know this is long and god bless anyone who gets through this novel and comes up with some good ideas. At this point, I'm happy to turn this over to an expert who knows more than I've learned about this to help me out. Any ideas where I could find such a person in Oklahoma? Thanks for any input!

 

[kwired]

Since you are not an electrical professional according to forum rules we are somewhat limited on what we can help with here.

I will say from some experiences I have had with AFCI's and unexplained tripping - I think they are sensitive to inductive kick back, the source wouldn't need to be in a protected circuit either, it is just a phenomenon on the line and the device doesn't like it. Some GFCI's are more sensitive to this then others as well, but almost all will trip at some level.

I was once working in a new home that wasn't completed yet, we had many of the permanent circuits energized at the time and the power blinked (as in a circuit recloser likely cycled - no big deal in rural areas that happens sometimes) but I noticed several AFCI breakers tripped (but not all of them did) as I was in the same room as the panel when this happened and heard them. After some looking it appeared as though the ones that had load on them at the time were the ones that tripped. I still think there was some inductive kickback involved in that instance being the reason for the trip.

 

[LEO2854]

Welcome to the forum:thumbsup:

Has anyone checked to see if the grounding is correct in the main panel ?


Each circiut must have it's neutral connected to the circuit breaker that feeds that circuit, they cannot be mixed up in any way.

 

[Sierrasparky]

A loose wirenut will cause a problem also.

 

[growler]

running extention cords from a non-AFCI circuit to everything plugged into the circuits (which resulted in no tripping for 2-3 weeks).

If useing extension cords from non-AFCI protected circuits resulted in no tripping for 2 weeks then maybe you should try running extension cords from different AFCI protected circuits to see if they trip. It is possible that whatever is plugged in is bad and not the house wiring.

Be sure to keep track of all this time because if it turns out that they have faulty appliances then I would bill them for time spent trouble-shooting.

 

[kwired]

Originally Posted by jfincherok
running extention cords from a non-AFCI circuit to everything plugged into the circuits (which resulted in no tripping for 2-3 weeks).


You still need to determine if you eliminated a wiring problem or a utilization equipment problem in that situation.

 

[mopowr steve]

We'll here are a couple things that I have found.
I would suggest getting a afci diagnostic tool, Siemens sells one which is supposed to work with multiple brands. It does have a learning curve to it though much like a megger as to what results your seeing.
On a couple occasions now I too have had some hair pulling dilemmas. One instance after a number of trips I found the problem to be with a flat screen TV in a living room that when a program had a bright white screen it would peg my diagnostic tool. And just like you it would trip multiple breakers randomly but found this to be more true on breakers which shared the same phase. So plan on camping out with your customer for awhile and turn everything on and see if your getting readings from unrelated areas.
On another job I found that when 9- t8 4lamp TCP fixtures were on in the garage it to would peg my meter and trip a afci breaker that controlled a totally different circuit which ran some 2nd story lighting. I was able to resolve this by installing a receptacle type surge suppressor on the upstairs lighting circuit (which by the way nocked the reading completely out) and as added precaution moved the garage circuit to the opposite phase. I think when there are devices that create a lot of "noise" on the line they can inductively transfer to other circuits which either run along each other or are tied to the same phase.

 

[kwired]

We'll here are a couple things that I have found.
I would suggest getting a afci diagnostic tool, Siemens sells one which is supposed to work with multiple brands. It does have a learning curve to it though much like a megger as to what results your seeing.
On a couple occasions now I too have had some hair pulling dilemmas. One instance after a number of trips I found the problem to be with a flat screen TV in a living room that when a program had a bright white screen it would peg my diagnostic tool. And just like you it would trip multiple breakers randomly but found this to be more true on breakers which shared the same phase. So plan on camping out with your customer for awhile and turn everything on and see if your getting readings from unrelated areas.
On another job I found that when 9- t8 4lamp TCP fixtures were on in the garage it to would peg my meter and trip a afci breaker that controlled a totally different circuit which ran some 2nd story lighting. I was able to resolve this by installing a receptacle type surge suppressor on the upstairs lighting circuit (which by the way nocked the reading completely out) and as added precaution moved the garage circuit to the opposite phase. I think when there are devices that create a lot of "noise" on the line they can inductively transfer to other circuits which either run along each other or are tied to the same phase.

I think it is a good idea to learn what causes these problems and have a better understanding of AFCI's in general, but still don't think it is right to force consumers to spend the money on all that testing and essentially find there is nothing wrong with any of their premises wiring or connected equipment but rather a flaw in the design of the AFCI that doesn't discriminate the condition from a true fault. The whole AFCI thing was a good idea to pursue, but they forced it on consumers before it was even close to perfected and are making the consumer become part of the testing lab.

 

[cowboyjwc]

See the post "Sunday afternoon call".

 

[Sierrasparky]

See the post "Sunday afternoon call".

Yeah, but I bet that would have been caught by a GFCI too.
Who's to prove that an AFCI would have caught that smoldering mess before it scorched the area.

 

[cowboyjwc]

Yeah, but I bet that would have been caught by a GFCI too.
Who's to prove that an AFCI would have caught that smoldering mess before it scorched the area.

Well, to be honest, we don't know, but we don't know if it wouldn't have either.

 

[J.P.]

I know it's not compliant, but I wont install either GFCI's or AFCI's on deep freezers or refrigerators.

I will run them on their own circuit and use a 20 amp recep and regular breaker.

I agree that AFCI's were forced onto us before they were able to work reliably. There are a lot of variables that come into play. sometimes they catch a bad make up. Sometimes they catch the vacuum cleaner everytime the homeowner uses it.............

GFCI's are usually fine, but sometimes people don't notice they are tripped and lose many dollars worth of food.

Neither device is perfect by any means.



BTW could the OP's problem be the vacuum cleaner? Oftentimes people will move from recep to recep when cleaning.

 

[kwired]

I know it's not compliant, but I wont install either GFCI's or AFCI's on deep freezers or refrigerators.

I will run them on their own circuit and use a 20 amp recep and regular breaker.

I agree that AFCI's were forced onto us before they were able to work reliably. There are a lot of variables that come into play. sometimes they catch a bad make up. Sometimes they catch the vacuum cleaner everytime the homeowner uses it.............

GFCI's are usually fine, but sometimes people don't notice they are tripped and lose many dollars worth of food.

Neither device is perfect by any means.



BTW could the OP's problem be the vacuum cleaner? Oftentimes people will move from recep to recep when cleaning.

I can side with you on the AFCI but not the GFCI protecting a refrigerator or freezer in a garage or unfinished basement. I have been asked more than once to repair/eliminate a tripping GFCI that will not hold in these situations, even had one tell me a refrigerator repair guy told them to have the GFCI removed. I have yet to run into one of these situations where I did not find a fault in the appliance and the GFCI was just doing it's job.

A freezer full of thawed food is still much less of a loss then someone's life. If you don't want to find a thawed freezer put a temperature alarm on it, or P&S does make GFCI receptacles with an audible alarm that sounds when the device is tripped.

I would have no issue with not having GFCI if we had some way of assuring the EGC to the freezer was intact, but other than an indicator light that would likely be ignored anyway, we really don't have much to protect from this condition.

 

[cowboyjwc]

Had someone tell me yesterday that their friend had just built a new house and was having electrical problems. Said that several of the AFCI breakers kept tripping, so the electrician pulled them out and put in regular breakers. Still tripping. Ok so now you have a real problem that you should have been trying to find, but instead of doing that, let's just eliminate the cause that we think it is, which was just doing what it's supposed to.

It's not always the AFCI, sometimes it really is your mistake. Or the carpenters.

 

[tom baker]

CH, Sq D and Seimens all have AFCI CBs with diagnostics that tell why the AFCI tripped, try subbing in one of those if the panel is the correct type.

 

[electric_cal]

We were involved last year with a similar problem with AFCIs tripping for no apparent reason on new construction at a college. This involved some of the dorm rooms. The manufacturer of the panels and breakers was CH.

First thing I would tell you to do is go to the manufacturers website and download the technical information on the breakers. They also have a very good troubleshooting document regarding the AFCI breakers. Then you need to contact their AFCI Application Engineers. They will help you in troubleshooting the problems.

We purchased an Amprobe INSP-3 tester to help in the troubleshooting of our AFCI problems. We followed the CH troubleshooting guide and documented everything. After working with the CH application engineer, and sending them all of our test data, it was determined that they would send us at no charge, all of the newest generation AFCI breakers that we needed.

We replaced all of the AFCI breakers and sent the other breakers to CH for evaluation. We have not had a call back at all. All breakers functioning correctly!

All of the data that the various manufacturers obtain from us in regards to AFCI breakers, not only helps them in improving their product, but helps all of us in the long run. Good luck!:thumbsup:

 

[growler]

The load center and breakers are from CH.
It seems like the fault code at the breaker is frequently a "1" which means a low current "series" arc.

CH, Sq D and Seimens all have AFCI CBs with diagnostics that tell why the AFCI tripped, try subbing in one of those if the panel is the correct type.

They allready have a fault code so they must be useing the breakers with diagnostics.


Series arc would be a loose connection but where. Building wiring or a bad appliance ( maybe just the plug )?

 

[Sierrasparky]

We were involved last year with a similar problem with AFCIs tripping for no apparent reason on new construction at a college. This involved some of the dorm rooms. The manufacturer of the panels and breakers was CH.

First thing I would tell you to do is go to the manufacturers website and download the technical information on the breakers. They also have a very good troubleshooting document regarding the AFCI breakers. Then you need to contact their AFCI Application Engineers. They will help you in troubleshooting the problems.

We purchased an Amprobe INSP-3 tester to help in the troubleshooting of our AFCI problems. We followed the CH troubleshooting guide and documented everything. After working with the CH application engineer, and sending them all of our test data, it was determined that they would send us at no charge, all of the newest generation AFCI breakers that we needed.

We replaced all of the AFCI breakers and sent the other breakers to CH for evaluation. We have not had a call back at all. All breakers functioning correctly!


All of the data that the various manufacturers obtain from us in regards to AFCI breakers, not only helps them in improving their product, but helps all of us in the long run. Good luck!:thumbsup:

That tells us they are still working on perfecting the device and it is not necessarily ready for prime time.

 

[mbrooke]

Hello all. This is my first post. I've gleaned a lot of good information off this forum to help me solve a problem but I can't seem to fix it. I'm a home builder and between my electrician and I, we've pretty much run out of ideas. I'm in search of ideas.

I have a homeowner who, to my knowledge, had no significant AFCI tripping problems until about 5 months after moving in. Since then (about 8 months), they have had numerous nuisance tripping problems with 3 circuits in particular. The tripping seems to occur intermittently. If it were immediate, it would likely be easier to find the problem. The information from the homeowner to help us trouble shoot has been spotty to say the least. The load center and breakers are from CH.

We have tested and tried many things including insulation resistance testing on line, neutral and ground, remaking all the connections, voltage and current testing (the highest measured current with everything on was 12 amps), replacing the breakers, running extention cords from a non-AFCI circuit to everything plugged into the circuits (which resulted in no tripping for 2-3 weeks). The power utility has been out there and said no problems on their end. We recently put in a pricey whole house surge protector in the panel. I'm pretty sure all the home runs are on 12/2 so there shouldn't be any shared neutral problems. My contractor is pretty good but I've even hired a different one to check things out just to have a new set of eyes. The problem still persists and I'm sure a lawsuit is around the corner.

The theater circuit had the theater lights and plugs, 5 pendant lights in the kitchen, exterior outlet for heat tape (on the irrigation system), and mechanical closet with tankless (gas) water heater and doorbell transformer. We ran a separate dedicated circuit for the theater equipment and a separate dedicated circuit for the mechanical closet. We replaced the heat tape but since it's warmer now, it's not even plugged in. The breaker still trips.

The study circuit has all the outlets in the study, lights in the study and entry and about 5 exterior lights. We've replaced all the CFLs with incandescents for now.

The other circuit has the remainder of the kitchen lights, utility room light, garage lights and I think that's all. Again, we've replaced the CFLs with incandescents.

It seems that when one breaker trips, the others trip also; sometimes with a slight delay. Since the information from the homeowner is spotty I don't know if it is this way all the time. It seems like the fault code at the breaker is frequently a "1" which means a low current "series" arc.

My thoughts on what else the cause could be are as follows:

1. Problems from the utility provider. I don't even know if this will cause a breaker to trip. If so, is there a monitor that will record voltage, current, etc. in real time that we can go back and look at when a breaker trips?
2. All circuits seem to have at least one exterior light or outlet. Perhaps moisture gets in intermittently?
3. Faulty load center? Seems like not much could go wrong there, but is it possible?
4. Something the homeowner is plugging in. I know this is highly possible, but on 3 or more separate circuits? And why would that cause all of them to trip around the same timeframe.
5. Some kind of series arc caused by a loose connection in a fixture. Perhaps a loose wire in a fixture only arcs when there's a vibration from a door closing or high winds? If so, it would seem strange to have that on so many circuits and again, why would it cause multiple circuits to go at the same time?

I know this is long and god bless anyone who gets through this novel and comes up with some good ideas. At this point, I'm happy to turn this over to an expert who knows more than I've learned about this to help me out. Any ideas where I could find such a person in Oklahoma? Thanks for any input!

The problem that no one will tell you is that your trying to accurately determine arc faults with $2 bucks worth of electronics. Its not going to happen. If the wiring tests ok and all utilization equipment is ok you have your culprit.

My advise is try another AFCI breaker such as a latter make. If that doesn't work if situation permits it just take them out. You wont gain anything by keeping them neither will the HO. Some equipment just isn't compatible with AFCIs and lots exist. Certain computer power supplies, some dimmers, some CFLs, some televisions, treadmills, VFDs...

 

[mbrooke]

Had someone tell me yesterday that their friend had just built a new house and was having electrical problems. Said that several of the AFCI breakers kept tripping, so the electrician pulled them out and put in regular breakers. Still tripping. Ok so now you have a real problem that you should have been trying to find, but instead of doing that, let's just eliminate the cause that we think it is, which was just doing what it's supposed to.

It's not always the AFCI, sometimes it really is your mistake. Or the carpenters.

Depends on what it is. Before any electrician takes one out they should megger and check connections. Look at equipment too. But, defects aside tripping could also be from overloads. Houses that once had 1 circuit for every room now have 4 for everything outside of the required appliance circuits in an effort to off set AFCI costs. I see new 2000 sqft houses with only 4 15 amp or 3 20amp 120 volt circuits for everything general use + lights. CMP should have increased the va per foot requirements for AFCIs but didn't. AFCIs have back fired enormously.