# SD QO AFI problems



## te12co2w (Jun 3, 2007)

We wired a 4000 plus sf house in the winter of 2008. One panel on each of 2 levels. Probably more than 15 SD QO Afi breakers. Actually CAFI. Everything checked out at the time. This is summer home and the homeowner is now complaining about nuisance tripping of the afi breakers. Happens when the wife runs the vacuum. I pulled one 20a and one 15a breaker, replaced them, and checked the other circuits on the upstairs panel. The 20a that we replaced holds but the other breakers still trip with their vacuum.
Sears Kenmore vacuum. The SD tech said that Sears vacuums are defintely on the list that creates a problem. They have reprogrammed their breakers to deal with this problem. Any breaker with a date code of 0822 or lower can be troublesome. Of course the ones I put in were in the bad batch. This code is on the case of the breaker next to and above the handle.
SD will replace the breakers, but no one is offering to pay the labor bill.


----------



## Dennis Alwon (May 9, 2009)

The manufacturers are never willing o pay labor. Just replace the breakers and be done with it. My experience has been that Sq. D has had more problems than the rest. I have never replace a Ge AFCI. The one problem we had was a bad hook up by a helper which was quickly rectified.

I have also had problems with Cutler hammer and Siemens in the past but not ge. Ge is the brand I have been installing for years.


----------



## busymnky (Feb 16, 2009)

I use alot of cutler hammer gear and have problems with the br AFI breakers. The breaker trips but the handle stays in the on position. So the homeowner calls and I talk them through it via phone. If it happens again I usually have to show up in person in order to reassure them that the equipment is working properly. No big deal, just one more thing to schedule into a busy day. Thanks for the word on the SDQO, I installed a bunch back in Jan., no callbacks on them so far.


----------



## I_get_shocked (Apr 6, 2009)

I had a friend who bought a newly wired/ renovated condo with all cutler hammer gear/ AFCIs. Just recessed lights on would cause the breakers to trip with about 2 amps drawing on a 15a circuit. Three out of five AFCIs were tripping daily (2-3 times / day)

I called cutler hammer and the tech explained that since the home is within 5 miles of an AM radio station (colleges in Boston surround the home) that can cause the breakers to nuisance trip. He also explained that dirty power can cause surge protectors to dump onto the ground wire and appear to be a ground fault which he claimed was common early in the morning when the power company "changes capacitors". I don't know how much truth there is to that statement though. Also the homeowner didn't have any devices plugged in as this was a new home he was in the process of moving into. No surge protectors anywhere. I did notice however the ones that were tripping were all on the same Line in and I am not sure if that is a coincidence

The point is Cutler hammer did send out free replacement breakers- this time they were a "compact" style BR with green handle. Not one trip since we installed them.


----------



## Toronto Sparky (Apr 12, 2009)

I found that a lot of older style fridges tend to trip them as well.
Hair dryers also. 
Also seen old dimmers trip them.


----------



## captkirk (Nov 21, 2007)

Never mind all the money your loosing. Look at all the lives they are saving...


----------



## user4818 (Jan 15, 2009)

captkirk said:


> Never mind all the money your loosing. Look at all the lives they are saving...


It's "you're losing," not "your loosing." :thumbsup:


----------



## captkirk (Nov 21, 2007)

Peter D said:


> It's "you're losing," not "your loosing." :thumbsup:


 Maybe im a "looser"


----------



## MDShunk (Jan 7, 2007)

Megger the offending appliance and the reason the AFCI is tripping will become abundantly clear. I have yet to get good megger readings on an appliance that occasionally trips AFCI's.


----------



## user4818 (Jan 15, 2009)

MDShunk said:


> Megger the offending appliance and the reason the AFCI is tripping will become abundantly clear. I have yet to get good megger readings on an appliance that occasionally trips AFCI's.


Won't that destroy the appliance? :blink:


----------



## MDShunk (Jan 7, 2007)

Peter D said:


> Won't that destroy the appliance? :blink:


If you do the test improperly, sure. I'd recommend instead that you check, at the attachment cord prongs, from hot to ground and from neutral to ground. If the attachment cord is two-prong, test from hot to something metal on (in) the appliance and from neutral to something metal on (in) the appliance. Common offenders, such as refrigerators, sump pumps, condensate pumps, electrostatic air cleaners, and garage door openers, all feature 3-prong attachment cords, making a megger check pretty easy.


----------



## te12co2w (Jun 3, 2007)

MDShunk said:


> Megger the offending appliance and the reason the AFCI is tripping will become abundantly clear. I have yet to get good megger readings on an appliance that occasionally trips AFCI's.


 I haven't been back on this one yet. Plan to get there soon. I have no doubt that a megger check on the vacuum will convince me where the problem is. Convincing the the ho though, will likely be a lot harder. He was already telling me that it couldn't be his vacuum because it was brand new. I can envision the same thing with all the other motor driven appliances in a home. I had some problems when AFI's first came out and was hoping not to see any more problems related to this. Wishful thinking, I guess. I honestly wonder if residential fires related to arc faults have decreased since we have been mandated to use them. I haven't actually taken the time to research this issue in depth.


----------



## KayJay (Jan 20, 2008)

Circuit breaker manufacturers know that motors, heating appliances and AFCI’s don’t get a long. That’s a big reason why they’re not currently required in areas where motors and heating appliances are used, such as kitchens [countertop and stationary appliances] and bathrooms [hair dryers, heat/light/vents, Jacuzzis]. 
IMO, the fact that manufactures are blaming appliances for the majority of problems by causing 30mA [GFI] ground faults, not the AFCI circuit breaker itself, is a load of smack.
Anytime I investigate these nuisance trips, I can plug these very same appliances into a much more sensitive GFCI protected circuit and they will run without problems. This puts the theory of ground fault [GFI] nuisance trip problems to rest and places the blame squarely where it belongs, on the AFCI circuit breaker designs. As far as a functioning appliance operating perfectly within manufactures design spec causing an arc fault, that is also bunk.


----------



## Safety-Guy (Jan 22, 2007)

te12co2w said:


> Convincing the the ho though, will likely be a lot harder.


Convincing Ho's of anything that does not involve giving them money is always tough:whistling2:


----------



## user4818 (Jan 15, 2009)

MDShunk said:


> If you do the test improperly, sure. I'd recommend instead that you check, at the attachment cord prongs, from hot to ground and from neutral to ground. If the attachment cord is two-prong, test from hot to something metal on (in) the appliance and from neutral to something metal on (in) the appliance. Common offenders, such as refrigerators, sump pumps, condensate pumps, electrostatic air cleaners, and garage door openers, all feature 3-prong attachment cords, making a megger check pretty easy.


Ok, I get that. But seems to me that it would only prove the current leakage part of the AFCI is working, not the mystical mumbo jumbo magic box in the AFCI that detects arcs.


----------



## macmikeman (Jan 23, 2007)

te12co2w said:


> I have no doubt that a megger check on the vacuum will convince me where the problem is. Convincing the the ho though, will likely be a lot harder. He was already telling me that it couldn't be his vacuum because it was brand new.


This is where that Supco500 megger is handy. I have one. It displays "bad" , "caution", and "good" with a few leds in a sliding scale along the printed part. It is not my primary megger, but it is very easy to demonstrate problems to home owners with it. Much easier than trying to convince/ explain to them what the meg ohm readout on my Biddle is pointing out.


----------



## busymnky (Feb 16, 2009)

I got a good laugh out of the am radio & early morning explanations- thanks shocked! Marc you are right about meggering, but by the time I get to that point, I've located the problem and only need to verify/prove it. To avoid problems, I avoid motor loads. Keep the bath fans off AFI circs., don't put dining on a small app. circ., etc. It's not foolproof but seems to help.


----------



## sparky.jp (May 1, 2009)

The reason that ACFIs don't like appliances like vacuum cleaners is that they have what is known as the universal motor (one which has brushes) in them. This term I believe dates back 100 years or so ago when there were still DC electrical systems in use (mainly on the east coast), and the "universal motor" appliances would run on both AC and DC systems. Most blenders, kitchen mixers, and other small motor-based appliances also use these motors.

Getting back on track, the minor arcing (perfectly normal) that happens at the motor brushes is what is causing the ACFI to trip, because it is looking for ARCING in the circuit--Duh!

How the ACFI manufacturers distinguish between "normal" arcing such as what happens inside of a vacuum cleaner motor, and "abnormal" or undesirable arcing such as happens inside of a loose wire nut, is one of the heavily-guarded trade secrets of each manufacturer and can be considered a modern-day "black art". Obviously this technology is in its relative infancy and still has a ways to go (IMHO, I am doubtful that it will ever be possible to pefect this technology in order to completely avoid all instances of nuisance trapping). Homework for somebody out there--try plugging in a 120V MIG welder to an ACFI-protected circuit and report back.

Really, if we all wanted to be perfectly safe, we should eliminate dangerous arcing electricity from inside the home altogether and go back to using open flames for light and heat. Oh wait . . . :laughing:


----------



## drsparky (Nov 13, 2008)

sparky.jp said:


> The reason that ACFIs don't like appliances like vacuum cleaners is that they have what is known as the universal motor (one which has brushes) in them. This term I believe dates back 100 years or so ago when there were still DC electrical systems in use (mainly on the east coast), and the "universal motor" appliances would run on both AC and DC systems. Most blenders, kitchen mixers, and other small motor-based appliances also use these motors.
> 
> Getting back on track, the minor arcing (perfectly normal) that happens at the motor brushes is what is causing the ACFI to trip, because it is looking for ARCING in the circuit--Duh!
> 
> ...


No black art, the arc signature of a motor is steady, the arc signature of a fault is random.


----------



## MDShunk (Jan 7, 2007)

macmikeman said:


> This is where that Supco500 megger is handy.


You're right about that. Laugh if you want to, but I grab the M-500 for most basic troubleshooting. It's not too much money and it's been a workhorse for me for go/no-go testing.


----------



## brian john (Mar 11, 2007)

Not sure what reading Marc is getting BUT if it is lower that NETA specs I'd argue (POLITELY) with the HO for their covering the labor.


----------



## kbsparky (Sep 20, 2007)

Regarding the use of universal motors on AFI protected circuits. Most power tools in use today also utilize motors with brushes. They will usually work fine on AFI circuits, but with a caveat: Many tools utilize an electric braking mechanism, which momentarily throws it into "reverse" when you release the trigger switch. :001_huh:

Of course, this is a safety feature which significantly slows down the rotating speed when you are finished with your task. This feature also tends to trip out AFI breakers, since there has to be some stress or strain applied to those brushes. 

Case in point: On numerous occasions I have witnessed where such a tool can be used only once. A chop saw will start and run just fine, but as soon as the trigger switch is released (actuating the momentary reverse and braking mechanism) the AFI breaker will trip. The carpenter has to reset the breaker after each time he cuts a piece of wood with that saw. 

We ended up having to use an extension cord plugged into another non-AFI circuit for his saw to work without this nuisance tripping. :whistling2:

FWIW, even my battery operated deWalt drill has the same reversing/braking mechanism. 

Try this experiment: Run your drill at full speed, and then pull the battery without releasing the trigger switch. The drill will take much longer to slow down, without that electric reversing/braking feature. :blink:


----------



## te12co2w (Jun 3, 2007)

macmikeman said:


> This is where that Supco500 megger is handy. I have one. It displays "bad" , "caution", and "good" with a few leds in a sliding scale along the printed part. It is not my primary megger, but it is very easy to demonstrate problems to home owners with it. Much easier than trying to convince/ explain to them what the meg ohm readout on my Biddle is pointing out.



I also use one of these things, and I use it a lot more often than any other megger. It is just so handy and compact. One thing that really annoys me about it though is those short leads.


----------



## electricalperson (Jan 11, 2008)

arc fault breakers always trip for a reason. in my experience i never had a bad arc fault. usually the biggest problem that causes them to trip is shared neutral conductors. check multigang boxes that the helper cut in to find if all the neutrals of multiple circuits are tied together. check to see if the EGC is touching the neutral screw too. the ideal suretest circuit tester will check for shared neutrals if you have that tool.

you can lift the conductors from the panel and megger them to find shorts and spliced neutrals

splicing the neutrals all together is a violation of 310.4 your putting them in paralell


----------

