Crazy AFCI

[Dennis Alwon]

If you're getting something back on the neutral, I wouldn't see why an AFCI wouldn't see that. Try disconnecting the neutral from the oven and then turn it on and see what happens.

I can pass this on to the ec but to be clear this is not my job and I have never been there

 

[busman]

So are you saying that a Arc fault signature somewhere else in a electrical system can cause a AFCI to trip in an unrelated circiut?

WOW

Harmonic currents in one circuit cause harmonic voltages at the source due to the source impedance. These harmonic voltages cause harmonic currents in all other circuits on the same source.

This type of EMI is a system wide problem. Don't know if it will trip an AFCI though.

Mark

 

[cowboyjwc]

I can pass this on to the ec but to be clear this is not my job and I have never been there

I understood that.

 

[garisilver]

Okay, my turn.
I was at a house that has a afci problem. This one trips when the whole house water heater turns on, but only when a ceiling fan or window shaker that on that afci circuit are on. I know from experience that motors can be a problem (my own vacuum cleaner sometimes), but obviously the water heater is not on the afci circuit.
I moved the afci circuit to another afci, but that one trips too. So it seems that it's circuit related, not breaker related.
I'm going back to take apart every outlet on the circuit and see if I can discover something, but I can't see, even if I find a problem, why the water heater is causing it to trip.
Any thoughts?
And what if I don't find a problem?

 

[GoldDigger]

SWAG: The water heater has an arc signature component which is traveling to the problem AFCI. But that AFCI will not act on that conducted signature unless its own current sensor is seeing more than 8 amps.
Result: The AC is fine and is just enabling the AFCI to react to the spurious signature.

 

[FREEBALL]

Dennis what circuits are tripping are they kitchen circuits, is there a range hood over/involved with the range that may be connected somehow. That may be creating a circuit from ground to neutral. just spitballing.

 

[garisilver]

Goldigger, so that would mean the afci observes what's happening through all the circuits in the panel, not just the one connected to it? And why only that afci circuit? There are 4 others. I wonder about that.
And what does that leave me to tell the homeowner? " Your wiring is fine, you need to install a new water heater with a different electrical signature."
And I'm not trying to be funny.

 

[K8MHZ]

Okay, my turn.
I was at a house that has a afci problem. This one trips when the whole house water heater turns on, but only when a ceiling fan or window shaker that on that afci circuit are on. I know from experience that motors can be a problem (my own vacuum cleaner sometimes), but obviously the water heater is not on the afci circuit.
I moved the afci circuit to another afci, but that one trips too. So it seems that it's circuit related, not breaker related.
I'm going back to take apart every outlet on the circuit and see if I can discover something, but I can't see, even if I find a problem, why the water heater is causing it to trip.
Any thoughts?
And what if I don't find a problem?

Is it possible that the circuit wiring for the afci and the heater are run close to, or next to each other for some distance?

What is the location of the heater breaker in comparison to the location that the afci breaker would trip?

Other than that, what else do the two circuits have in common?

Also, what brand and model afci is being problematic?

 

[K8MHZ]

He went there last week an witnessed first hand that 3 afci's would trip when the home owner turned on the oven. Apparently she has never used this oven in the months that she has been there. The electrician reset the breakers and turned on the oven and pop all three afci's would trip. Poltergeist again I guess. I told him to get the power company to put a recording meter on the line side and see what is going on.

This sounds quite similar to the above. Afci's on separate circuits being tripped by a heating element not on those (that) circuits.

It would be interesting to find out the answers for the above on this problem, too.

 

[GoldDigger]

I am saying that the breaker should reject an arc signature coming from somewhere else in the system, but it does not do that perfectly.
The other AFCI breakers might not be tripping because they do not have the required 8A load.
It is possible that a different maker's AFCI will not trip, or it might be necessary to put a filter on the panel end if the water heater circuit. Or the heater may have a defective thermostat or heating element, both of which should be replaceable.
But IMHO the first step would be to confirm whether the breaker tripped from AF or GF.

 

[Dennis Alwon]

But IMHO the first step would be to confirm whether the breaker tripped from AF or GF.

How would you do this?

BTW, this thread being brought back made me call the guy who is dealing with it. He has not resolved the issue but he has changed the breakers even used BR series
breakers that fits a Siemens panel. BTW, Siemens took the GF out of their afci breakers. I am assuming that the when he used the new ones they were the generation without the gfp but I am not certain.

Interesting is the fact that it is very intermittent and happens more frequently during the hot summer months (panel is in an unconditioned garage).

 

[GoldDigger]

How would you do this?

I would hope that at least one of the breaker types that were used has the ability to indicate the cause of the last trip, either via indicator LEDs or the timing of the trip when turned on with the test button held down. The instructions for the breaker should describe this feature if present.

The intermittent nature combined with tripping on several types of breaker makes me suspect a brief strong arc when one of the heater thermostats opens or closes. It will be a high current arc that might feed over via VD to the other breaker.
Replacing the stats or adding filters might not cost much more than repeatedly replacing the breaker, and might end the string of call back visits.

PS: just to be clear, I am referring to garisilver's problem, not the original one for the thread.

 

[garisilver]

Thanks for the replies.
I'm heading to the customers house now to rip the place apart. I'll post my findings.

 

[Dennis Alwon]

Thanks for the replies.
I'm heading to the customers house now to rip the place apart. I'll post my findings.

Understand that afci need to see a minimum of 4 or 5 amps before they will trip, I know Ge is at that range not sure about other. My guys ran into this and kept turning on the two fans and everything was fine except on high speed the breaker would trip or if the lights were turned on with the fans on medium speed. They assumed lights and I told them it was the fan. Since the afci didn't see 4 or 5 amps the fans that caused the problem would not trip. I used an older generation afci and all was well.

 

[mopowr steve]

Gotta love em.
Talked to a Siemens rep last week, she said that they installed an additional filter in arc fault breakers after June of this year to help with transients. You should be able to download instructions on how to read date code on breakers if you would like to try latest revisions.

 

[K8MHZ]

Gotta love em.
Talked to a Siemens rep last week, she said that they installed an additional filter in arc fault breakers after June of this year to help with transients. You should be able to download instructions on how to read date code on breakers if you would like to try latest revisions.

Who gets to pay for that?

 

[mopowr steve]

Who gets to pay for that?

Well, if you ask nicely you may get replacement breakers from them in conjunction with your supplier (if your supplier has good communication with them) Labor is on you.
There not going to advertise this.

 

[K8MHZ]

Well, if you ask nicely you may get replacement breakers from them in conjunction with your supplier (if your supplier has good communication with them) Labor is on you.
There not going to advertise this.

Wow, what a deal. After we get them shoved down our throats we get to take it in the rear. And that's if we ask nicely. A friend of mine is an EC and just recently had to have a colonoscopy and an upper GI at the same time last week. That's what AFCI problems remind me of.

It's too bad a senator's son wasn't an electrical contractor.

 

[garisilver]

Back from the house with the afci problem. I checked connections in the panel again, checked for grounded neutral, and went through every box on the circuit. NO MWBC and no doubled up neutrals. I'm not a fan of back stabbed devices, so I remade them all as I went. I had one neutral slip out of the back of a receptacle as I pulled it out of the box (exactly why they're such junk) and got excited that this was the problem, but nope, the problem was still there. I took the heater apart and checked the connections there, even flipped the phases for the hell of it. Nothing helped.
In regards to the 8 amps I keep seeing here, I found the circuit was tripping when I turned the water on and the circuit had 3.2 amps on it.
Filtering was mentioned in an earlier post, but I don't think that we should have to tolerate afci's that need to have accessories added on to them to make them work. If the technology is this problematic, then it shouldn't have been imposed on us as a requirement until ALL of the problems were solved.
OK. I'll get off my pulpit now.
I think my next step is to call the heater manufacturer and GE, the breaker manufacturer and see where that goes.
I also have to admit that I put in a regular breaker to accommodate the home owner for the holidays, but I want to fix the problem, not work around it. Stay tuned.
And if anyone else has some input, I'm still listening. Thanks again

 

[GoldDigger]

Were you able to extract a fault type from the breaker?