I had an interesting situation recently when I had a call back on an inspection where I had found an exterior receptacle that tested just fine, a GFCI receptacle. The reason for the call back was that the homeowner Had found out by using the receptacle, that it worked fine under a small load, such as a hand drill, but the breaker tripped when they plugged in an upright vacuum cleaner. And, along with the receptacle tripping, all the lights in the kitchen (on the other side of the wall) would go out also. In the garage, there were AFCI breakers, One of which was tripped. When the AFC I breaker was reset, power was restored to the kitchen lights and exterior GFCI receptacle. I informed them that I was sorry to hear about this strange problem, but they needed to contact a licensed electrical contractor to further investigate this issue. I had never seen such a screwy problem before, and I told him them the same. The home is approximately 15 months old. Any thoughts?
Answered your own question…
My WAG is the AFCI was seeing the motor in vacuum cleaner as an arc fault and tripping. IMO somethings not right, because an exterior receptacle should not be on the same circuit as the kitchen lights, being that the house is only 15 months old.
Also as a side note, many of the first generation/s of AFCI devices were known for nuisance trips.
I agree, a job for a licensed electrician is the right call.
Wasn’t that helpful! Jonass posts just to hear himself. I’m with Kevin, the AFCI is the likely culprit, let us know what the sparky says.
Concur. Even the latest AFCI breakers trip easily with large electric motors (large vacuums, table saws, chop saws, etc.). Depends upon the particular appliance sometimes, e.g. one vacuum will trip the AFCI and the next one will not. For that reason, as homeowner, it helps to have a strategically-placed receptacle or two within the interior of the house that is not AFCI-protected.
BTW. As homeowner (flipper, handyman), I sometimes go into the panel and swap conductors on breakers (AFCI to regular) if I am doing a construction project in a particular room, then swap it back when the project is done.
I’m glad you posted about this. I need to remind myself on homes where AFCIs are installed that I need to mention the likelihood of nuisance tripping, so that they don’t get the perception that I missed something after they move in and the TV goes out when somebody fires up the vac.
I thought it screwed just fine? 
I had the same type of situation happen to me years ago for a regular client then once again after I inspected a home for my brother in law. After all receptacles were tested as correctly functioning. Thank God standards don’t require home inspectors to check for draw loads for electrical receptacles. You did nothing wrong and it’s either the faulty AFCI or possibly there is a loose neutral wire somewhere. Good luck, hopefully after you explain this to them it goes away.
That’s common. The first thing I would do is put an ammeter on the circuit with the appliance running. There’s a chance that they are simply overloading the circuit.
I’d also look at the vacuum cleaner. Specifically, I’d look to see if the motor uses brushes. Bad brushes can trip an AFCI. In that case, the AFCI breaker is doing its job. What some people might think is merely nuisance tripping, might be an indication of a motor problem.
In my experience, when people buy an appliance that has a motor with brushes, they never check the brushes. I’d suggest to the customer that they look at the brushes if the vacuum cleaner has them.
When the carbon wears to where the lead is exposed and can contact the commutator, a motor, especially a fractional HP motor, can usually run for a long time before the commutator is damaged enough that it will no longer run. I’ve seen vacuum cleaners that have had the brushes readily accessible and in plain sight. It only takes seconds to check them, but the user of the appliance needs to know that they should be checked occasionally. They usually have what looks like a screw-in cap, or a straight-slot screw head that is either flush with the motor housing or slightly recessed. Some are in a spring-loaded cartridge instead of having the more traditional design like the one in the picture. The picture is a new brush for a Rainbow brand vacuum cleaner.
There are other motor problems that can also cause an AFCI to trip, but I’d look at the brushes before anything else. A commutator brush is a normal wear part.
Someone once gave me a nice hammer drill off a job where the brushes had worn completely down and melted the handle. I ordered two brushes and a new handle for about 10 bucks and had a like new bosch hammer drill.
Those old time metal case drills (Black & Decker still have it) were fun when the brushes wore down!
Sounds like there’s too much on one circuit, and why would an exterior receptacle be on the same circuit as kitchen lighting? Was there a double tap in the panel box with the exterior receptacle + kitchen on the same breaker? Needs evaluated by an electrician to correct. Looks like the builder took the cheaper bid for wiring the home. I’d be looking for other wiring issues as well.
Some further testing is required to determine why the CB tripped in the first place. Newer AFCI devices should not trip when using a vacuum (this was a probelm with first few generations of AFCI protection). Could be as Scott suggested that the circuit was overloaded and it has nothing to do with the AFCI protection. I would start with plugging the vacuum into another AFCI protected circuit and see what happens.
They should, but they do not. Recent personal experience trying to run an older high-power Rigid Shop-Vac inside a house with brand new (2023) AFCI breakers was frustrating. Normal (smaller, newer) vacuum cleaner (Dysan) ran just fine. All living area circuits in the house were 20-amp. George’s comments about worn brushes fits with my experience as well. I am now thinking that the older and bigger the motor, the better chance it is going to trip an AFCI (even if it is brand new).
You’re probably right about older equipment although AFCI manufacturers insist that they should work. Personally I dislike AFCI’s. Having been given the choice when upgrading the service in my home I don’t have any installed.
I personally don’t like the nuisance factor, of course. However, we recently had PoE Network Switch go bad and it completely fried inside (e.g. sparks and flames). We were extremely lucky that our personal house (that does not have AFCI’s) did not catch on fire. The normal breaker did not trip, btw. If we had AFCI’s installed, we would not have a worry about anything like that in the future. I always recommend AFCI’s or additional AFCI’s in my home inspection reports because they greatly enhance fire safety.
Thank you all for the informative answers to my question. I have not heard anything from the homeowner yet and I don’t expect to as I am pretty sure they wanted me to pay for an/the electrician to come out and fix the problem! Sour grapes!
Many electricians around here are reluctant to install them and allowed not to. We are on the 2020 Indiana Residential Code which is based on the 2018 IRC and the 2017 NEC, which requires AFCI protection. But here in Allen County, contractors are given the option to use 2009 Indiana Residential Code, which exempted AFCI’s.
Residential-Electrical-Affidavit-PDF.pdf (101.9 KB)
Im not against the technology it’s just that IMO it is not there yet. We hear all of the time about nuisance tripping not related to any hazardous condition and for that reason I disike them. I can remember back to when GFCI protection became required and the first decde or two they were awful. AFCI’s will get there eventually.