Microwave tripping AFCI during the night

[cowboyjwc]

Lots of great comments. Turns out that the homeowner would wake up about 4am and use the toaster (they forgot to mention that). Sure enough it trips the AFCI every time. Moved the breaker for the counter top to another slot on the other side of the panel (it was 2 away from the AFCI). No more tripping. Strongly suggested a new microwave. The wife like that idea!

Don't you just love the "oh, I didn't tell you that?"

Had one, garage is dead, no GFCI in there, breaker good, nothing wrong in the attic. Two hours of searching and calling finish capenter to see what they had done. Wife says, did you tell him about the receptacle in the powder room not working.:? Problem solved.

 

[kwired]

Lots of great comments. Turns out that the homeowner would wake up about 4am and use the toaster (they forgot to mention that). Sure enough it trips the AFCI every time. Moved the breaker for the counter top to another slot on the other side of the panel (it was 2 away from the AFCI). No more tripping. Strongly suggested a new microwave. The wife like that idea!

You lost me there, I thought the toaster was the offending appliance:?

 

[Dennis Alwon]

You lost me there, I thought the toaster was the offending appliance:?

I think he meant toaster

 

[kwired]

I think he meant toaster

Well he sure spelled it like microwave:lol:

 

[GoldDigger]

Don't you just love the "oh, I didn't tell you that?"

Had one, garage is dead, no GFCI in there, breaker good, nothing wrong in the attic. Two hours of searching and calling finish capenter to see what they had done. Wife says, did you tell him about the receptacle in the powder room not working.:? Problem solved.

Had a similar problem myself. Current dining room was originally a screened porch and had been closed in as part of a remodel. The switched dining room light (in the converted area) stopped working. The problem was an unused/unknown outside GFCI outlet that was upstream of the now inside lighting outlet.

 

[growler]

Lots of great comments. Turns out that the homeowner would wake up about 4am and use the toaster (they forgot to mention that). Sure enough it trips the AFCI every time. Moved the breaker for the counter top to another slot on the other side of the panel (it was 2 away from the AFCI). No more tripping. Strongly suggested a new microwave. The wife like that idea!

You lost me there, I thought the toaster was the offending appliance:?

You know I have never tried a toaster on an AFCI protected circuit.


I think I would put everything back where it was and try a different toaster on this circuit just to see what happens.

I find it just darned strange that a toaster on a different circuit could give a reading of a fault to ground. Those breakers may not be as great as we think.

 

[Doc777]

Lots of great comments. Turns out that the homeowner would wake up about 4am and use the toaster (they forgot to mention that). Sure enough it trips the AFCI every time. Moved the breaker for the counter top to another slot on the other side of the panel (it was 2 away from the AFCI). No more tripping. Strongly suggested a new microwave. The wife like that idea!

The counter top breaker was in the #6 slot on the panel and for some reason was causing the microwave AFCI in the # 2 slot to trip when ever anything plugged into the counter top outlets was turned on. I had heard of this kind of AFCI tripping before so on a hunch I moved the counter top breaker to a slot on the other side of that panel (along with the neutral) and that has fixed the tripping of the AFCI.

 

[ptonsparky]

The counter top breaker was in the #6 slot on the panel and for some reason was causing the microwave AFCI in the # 2 slot to trip when ever anything plugged into the counter top outlets was turned on. I had heard of this kind of AFCI tripping before so on a hunch I moved the counter top breaker to a slot on the other side of that panel (along with the neutral) and that has fixed the tripping of the AFCI.

Would the new location happen to be on one of the following slots? 3,7,11,15,19 or did it go back on the same incoming line as before?

 

[mbrooke]

Skipping ahead, maybe an internal MOV in the circuit board is leaky to ground?

 

[mbrooke]

:ashamed1:

Should have read ahead. Anyways its good that it was the toaster.

BTW, I would really, really think about putting the microwave on a separate circuit. If that is an over the range micro than it really should be on a dedicated to begin with. Of course older houses had one circuit for everything but its a nice thing to recommend a new home run.

 

[kwired]

The counter top breaker was in the #6 slot on the panel and for some reason was causing the microwave AFCI in the # 2 slot to trip when ever anything plugged into the counter top outlets was turned on. I had heard of this kind of AFCI tripping before so on a hunch I moved the counter top breaker to a slot on the other side of that panel (along with the neutral) and that has fixed the tripping of the AFCI.

I also have to ask if you moved it from L1 to L2. Just other side of panel would not make as much difference as switching from one line to the other I would think. I have seen AFCI's trip during transient events that originated outside the protected circuit, maybe the toaster is introducing some kind of transient voltage. Seems a little unlikely as it should be a resistive load, but maybe there is arcing going on when the heat control opens at end of toasting cycle.