Have you added any new electrical devices in the space covered by the breaker?

If not, have the breaker replaced. After time, a breaker can go bad. Ask me how I know.

@Virgil Carter Fine Art in the two bedrooms, one new outlet was added and on the same circuit breaker, two new outlets were added in the renovated living space. Because they added a new outlet in this particular bedroom, the contractor had to switch out the existing breaker with a new ACFI circuit breaker.

On a modern AFCI breaker, a VC shouldn't trip it. When they first came out, it was an issue. Now, it doesn't seem to be. Just replace it.

@DavidR thanks for the advice. I actually have two vacuums that I could test out. In my downtime, I was going to go through entire house testing out each outlet. So from the feedback that I'm receiving, you believe the root cause is likely the actual breaker and not one of the outlets. That makes sense if it happens with EVERY outlet .

I agree with DavidR. I had some early GE AFCI's that were problematic. When I upgraded them to the later versions the nuisance tripping went away.

@Ron Natalie the AFCI's are brand newly installed. I would imagine these are the newest versions but what do I know??

In the old wiring two circuits may share a neutral outside of the panel.

RES, doubtful it is "old wiring" if there's AFCI's in play. Any sharing of current carrying conductors (hot or neutral) past the AFCI itself WOULD NEVER WORK. It will trip with just about any load.

The arcing that can occur between the brushes and rotor in a motor can cause an AFCI to detect an Arc Fault, as it's designed to do. I have some older corded tools that frequently trip an AFCI when under a moderate to heavy load (drill, belt sander, shop vac).

@Ron Natalie and @DavidR - It's definitely a Scooby Dooby Doo Mystery to Solve...I tested out all of the outlets in the upper level. It appears as though there is one circuit breaker tripping. The photo with the blue sticky is the culprit. Now here is the interesting data point to add and perhaps it's a total voltage versus availability?? My Dyson DC39 is consistently tripping all outlets for this circuit breaker. I even unplugged everything and it immediately trips (TV, Two Computers, Printer, Router).

However, I took my little Shark Rocket stick and it did not trip. I looked at the Shark site (wattage is 500 with amps of 4.2). The Dyson DC39 I could not find exact wattage.

Even if the root cause is the vacuum, shouldn't it trip in the other bedroom & associated areas that have an ACFI breaker? Because it DOES NOT trip there.

Blue Marked One is The Tripper. It looks like it is 15 Amps for two bedrooms, bathroom, and TV wall with router.

Second Panel Recently Installed with ACFI Breakers and No Tripping Issue

Any and all participants may solve the mystery.

Thanks,

Karla

Those are two different manufacturer panel. The upper is an Eaton (formerly Cutler-Hammer) type CH panel. The bottom is a Schneider/Square D Homeline (HOM) panel. Both are reasonably high quality.

As mentioned things with small universal motors are notorious for arcing as they wear. Despite Dyson's hype, the D39 has a pretty common motor with brushes that can wear out (as well as the commutator they ride on) and cause arcs that the AFCI will properly trip on. You might try replacing the AFCI breaker that's causing a problem with a more recent one. You might have someone take a look at the vacuum.

@Ron Natalie my only thought though is the AFCI is not tripping on the other bedroom. If the root cause was the vacuum, would it not have tripped there too? I've thought about just going out and getting a new vacuum just to test out the theory.

Replace the breaker for $49. Cheaper than a new vacuum.

It could be a more susceptible breaker in that location, but if your Dyson's a few years old, you might have worn brushes. Fortunately, that thing is designed to come apart and be serviced unlike other stuff on the market these days. New brushes are $10 and some time with a screw driver.

@ Ron Natalie and @res architect and @virgil carter fine art. An update - the electrician came out and found an issue with one of the outlets. I believe it was a ground fault issue. I had told him that the breaker was blinking both a 4 and 5 blink alert signal. When they fixed the outlet, they tested by turning on vacuum. My husband said it did not trip the breaker but the lights flickered. Fast forward to today and I turn on my space heater which trips the breaker. I then reset breaker but heater is still on and works. Then I test out the vacuum and it trips it. The electrician is now saying no heater and vacuum at the same time. I think its an indication that blink 4 was not addressed. Opinions / Thoughts?

Space heaters will often chew up most of the capacity of a circuit.

Sounds who ever wired this was <...>. Let's say you have a avg circuit with 15A capacity. Most vacuums take between 8A - 12A. Heaters like 10A - 15A by themselves. And if this was not bad, the starting current of 12A vacuum [when you just turned it on] could be up just under 15A [designed that way].

No you can not have space heater and vacuum on the same circuit, you are exceeding the ampacity of the circuit, your wires [exceeding its temperature rating] will be heating up carrying too much load.

NEC: Circuits for continuous loads and items such as water heaters or space heaters that are treated as continuous loads, must be sized to 125% of the load.

Tripper. It looks like it is 15 Amps for two bedrooms, bathroom, and TV wall with router.

LOL, bathrooms are another big issue. The first number is IRC, second number is NEC.

Separate 20A circuit for bath receptacles only OR___ [3703.4] {210.11C3}

• Dedicated 20A circuit to each bathroom_ ________ [3703.4X] {210.11C3X}

Max rating of fixed space heater on general lighting circuit

15A circuit: 900W; 20A circuit: 1,200W___________ [3702.5] {210.23A2}

Hi @BT - I think your first assessment of <...> would be my differential. The heater though has not tripped the ACFI in the past. We could not get it to replicate a second time either. The vacuum is tripping it now without heater plugged in. The vacuum does not trip in any of the other bedrooms that had major electrical work.

This electrician has spent 7+ hours and could have fixed this by listening to the customer. The initial breaker gave a 4 blink and 5 blink code. When I looked this up, it says over-voltage and ground fault issue. First visit they replace with new ACFI breaker and three hours later say we need a half day to fix this. This was after first suggesting to replace with a regular breaker once inspected. Everyone posted to not do this and so I was adamant that it be fixed properly.

Second visit they found the neutral issue and thought they were done. Apparently not.

Now they're going to have to come back a 3rd time. It is the opinion of my husband and I that they need to put the rooms on separate breakers. We have two people teleworking in both rooms and a router pulling power on the tv wall.

I think I know what they did. They probably pulled single wire 14-3 [instead of two], split it into the multi-wire circuit... That is when red goes to one bedroom and black goes to another bedroom or tv or your router - saves the cable, right!? Wrong. Someone had an idea that each red and black can carry 15A at full load [true], but not the neutral 30A, (but again they are relying on phase shift between red and black).

The problem is that arc fault sees more like 12A [let's say on red] from a vacuum and more from like your TV or router [like from the black conductor]. Trips. (I would unplug TV, router, every device etc just for a test and plug only the vacuum... See if the breaker will trip)

Other option that may be that that old Easton panel has bad ground or bonding screw between the neutral and ground was left in, or may be they only ran 3 wires between the main panel and subpanel (suppose to be four).

> This electrician has spent 7+ hours

OMG

Before letting them it:

1. Test for multi-wire circuit setup. (Unplug everything on that circuit and only plug a vacuum see if it trips.)

2. Remove four screws from the subpanel, without touching anything take a picture and post.

It should not take 7 hours.

If they wired up the circuit as a MWBC (which is what BT is trying to explain), there's no way the AFCI's depicted could EVER work. It indeed is a ground fault situation. You can't share conductors on the load side of separate GFCI or AFCIs. The only way you can do that is to have all the current carrying wires go through the same (that is, 2-pole) device.

@BTThere's actually two sub-panels. The original sub-panel was an Eaton type CH panel (see above screen shots at beginning of post). The second panel is a Schneider/Square D Homeline (HOM) panel. My gut tells me they put too much on one circuit breaker. The circuit breaker indicated this with the blinks. The issue is how do you fix it without tearing into a wall? Most of the main level of the house was taken down to the studs. They ran all new wire except for the two extra bedrooms and bathroom. This is a 15 a circuit breaker. When I asked about upping it to a 20a, the electrician said it was not possible due to the existing wiring in the two bedrooms.

I believe they have on the 15 amp circuit - 2 bedrooms, 1 bathroom, living room outlet where router and tv is, hallway with smoke detector, kitchen cabinet lighting, and second smoke detector. I found out about kitchen cabinet lights when the breaker was first tripped by the contractor while adding a dimmer to a kitchen cabinet. Perhaps this is where your theory comes into play that when they added new wire, they split it into the existing wire??

During their second attempt to fix, they did find an issue in the under kitchen cabinet light. I think it was the ground fault issue. Unfortunately when they tested the fix (per hubbie), they had unplugged everything and then ran vacuum. The vacuum did not trip it but lights flickered.

Today we had router going, two computer, and room lights. I flipped the switch on the floor space heater (which I've used before without issues) and it tripped the breaker. Then after resetting the breaker I turned heater on and no issues. The vacuum though tripped it every time I turned it on.

The contractor and electrician are coming tomorrow at 7:30 and I'm dreading it because I know I'm going to have to fight with them to do it right. I know that I'm all done with this sloppy work.