Microwave tripping AFCI during the night

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Don't know if this is the case with the MW in the OP.
But we had a microwave one time that did something crazy. We came home one night and smelled something that smelled like electronics smell when hot or burning.
I just happened to look at the MW and the glass was all frosty/smoked looking.

When I went to open the door, it was hot to the touch. After the door was opened, I saw that the glass turntable had "exploded".
Apparently the MW had turned itself on during the day and ran long enough that it heated the glass up so much that it shattered. We had noticed a few odd things happening to the oven on occasion, but didn't give it much thought.
That was kind of scary thinking that it could have caught the house on fire!

I'm not saying the OP's MW is turning on, but some of the electronics could be cycling during the night causing the AFCI to trip.

7 years old, I vote to replace the MW!:happyyes:
 
Little Bill said:
7 years old, I vote to replace the MW!:happyyes:
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I don't know how old my microwave is. I'm sure it was made in the early '80's. It has two dials; one for time one for power level. No buttons, no clock, no LCD, no settings for popcorn steak TV dinners pie al la mode........

Just try and replace it and you will get a black eye, a bruised shin, a hind end full of buck shot, a good cussin', another bruised shin and as many kicks as I can give you before you get off my property.

And don't you dare come back!
 
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ActionDave said:
I don't know how old my microwave is. I'm sure it was made in the early '80's. It has two dials; one for time one for power level. No buttons, no clock, no LCD, no settings for popcorn steak TV dinners pie al la mode........

Just try and replace it and you will get a black eye, a bruised shin, a hind end full of buck shot, a good cussin', another bruised shin and as many kicks as I can give you before you get off my property.

And don't you dare come back!
Click to expand...

So the best thing to do with a 7 year old microwave is to replace it with an older one. ;)
 
ActionDave said:
I don't know how old my microwave is. I'm sure it was made in the early '80's. It has two dials; one for time one for power level. No buttons, no clock, no LCD, no settings for popcorn steak TV dinners pie al la mode........

Just try and replace it and you will get a black eye, a bruised shin, a hind end full of buck shot, a good cussin', another bruised shin and as many kicks as I can give you before you get off my property.

And don't you dare come back!
Click to expand...

Ah come on, tell me how you really feel!:p

I would never bother you old micro, pager, transistor radio, or black/white TV!:roll:
 
ActionDave said:
I don't know how old my microwave is. I'm sure it was made in the early '80's. It has two dials; one for time one for power level. No buttons, no clock, no LCD, no settings for popcorn steak TV dinners pie al la mode........

Just try and replace it and you will get a black eye, a bruised shin, a hind end full of buck shot, a good cussin', another bruised shin and as many kicks as I can give you before you get off my property.

And don't you dare come back!
Click to expand...
Mine was mid-80's, 2 dials, handle broke but I put it back together with hose clamp, still worked a couple of years ago when we got a combo range hood/microwave. This one has all kinds of digital stuff that I don't need, in fact took a few days to figure out how to use (used--no owners manual). I like the old one better.
 
readydave8 said:
Mine was mid-80's, 2 dials, handle broke but I put it back together with hose clamp, still worked a couple of years ago when we got a combo range hood/microwave. This one has all kinds of digital stuff that I don't need, in fact took a few days to figure out how to use (used--no owners manual). I like the old one better.
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No owners manual - probably can find one on line if it isn't any older than about 10 years, may be hit and miss if older than that.
 
GoldDigger said:
So the best thing to do with a 7 year old microwave is to replace it with an older one. ;)
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You darn right it is.

Little Bill said:
Ah come on, tell me how you really feel!:p

I would never bother you old micro, pager, transistor radio, or black/white TV!:roll:
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Hey now, I had no problem giving up my rotary dial phone.

readydave8 said:
Mine was mid-80's, 2 dials, handle broke but I put it back together with hose clamp, still worked a couple of years ago when we got a combo range hood/microwave. This one has all kinds of digital stuff that I don't need, in fact took a few days to figure out how to use (used--no owners manual). I like the old one better.
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Exactly what I'm talking about. I open the door, put in my tamale or yesterdays pizza, turn the dial, shut the door and I'm good to go. One more thing that is great is it has a real bell that makes a real "Ding" instead of that awful electronic "beep, beep".
 
ActionDave said:
You darn right it is.

One more thing that is great is it has a real bell that makes a real "Ding" instead of that awful electronic "beep, beep".
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Man you got that right, one ding & I open it whenever I want, the new one keeps beeping until the door is opened or I push "cancel" button, well sometimes I'm trying to finish something else, quit beeping at me!
 
readydave8 said:
Man you got that right, one ding & I open it whenever I want, the new one keeps beeping until the door is opened or I push "cancel" button, well sometimes I'm trying to finish something else, quit beeping at me!
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Mine courteously beeps at me every minute if I fail to acknowledge it. I think that even this can be disabled by the right magic sequence of keypresses.
 
Back to OP - microwave tripping AFCI during the night - maybe a late night burglar is heating up something to eat:D
 
kwired said:
Back to OP - microwave tripping AFCI during the night - maybe a late night burglar is heating up something to eat:D
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I just read on a ham radio forum that some radio operators are inadvertently tripping their neighbor's AFCI breakers by transmitting on certain HF frequencies.

Maybe there is an operator in the area that only works HF at night. That would mean 75, 80 or 160. If the case, the antennas for those bands are going to be quite large and should be high off the ground.

The ARRL is looking into this and preparing to address the manufacturers. One poster said he had an electrician put a SqD breaker in an Eaton panel and that fixed the tripping problem.
 
K8MHZ said:
I just read on a ham radio forum that some radio operators are inadvertently tripping their neighbor's AFCI breakers by transmitting on certain HF frequencies.

Maybe there is an operator in the area that only works HF at night. That would mean 75, 80 or 160. If the case, the antennas for those bands are going to be quite large and should be high off the ground.

The ARRL is looking into this and preparing to address the manufacturers. One poster said he had an electrician put a SqD breaker in an Eaton panel and that fixed the tripping problem.
Click to expand...

Any idea of what kind of distance one should be looking for such an antenna if this may be the problem? 100 ft, 1000 ft, 10,000 ft?
 
kwired said:
Any idea of what kind of distance one should be looking for such an antenna if this may be the problem? 100 ft, 1000 ft, 10,000 ft?
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With a high power output into a directional antenna, it could easily be 1000 feet, IMO.

It could also be an unlicensed high power CB transmitter used at night too, I guess. That would more likely have a vertical antenna and be closer.

In other circumstances, there have been reports of AFCIs being tripped by PF correction capacitor banks switching in and out on the POCO side.
 
dedicated circuit?

dedicated circuit?

if the circuit is dedicated for an appliance does it have to be an afci? I have not kept up w the code since I am now just a yes man employee however in our company dedicated circuits are never afci protected.... however a little trick I have found useful is to replace the afci w/ a gfci breaker to eliminate other faults and if it holds I do know that code states something to the affect of all device points which are not gfci are to be afci or something to that affect... wish I had my book so I could be more helpful however I hope to point you in right direction
 
OnPoint522 said:
if the circuit is dedicated for an appliance does it have to be an afci? I have not kept up w the code since I am now just a yes man employee however in our company dedicated circuits are never afci protected.... however a little trick I have found useful is to replace the afci w/ a gfci breaker to eliminate other faults and if it holds I do know that code states something to the affect of all device points which are not gfci are to be afci or something to that affect... wish I had my book so I could be more helpful however I hope to point you in right direction
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If outlets (see art 100 definition of outlet) are in an area mentioned in 210.12 the entire circuit must have AFCI protection - some exceptions with existing installations now that there supposedly are in wall type AFCI devices.

No matter what your opinion of AFCI and its credibility is, GFCI and AFCI are not the same thing and are not interchangeable. Replacing an AFCI with a GFCI is only good for eliminating a ground fault condition as a troubleshooting method and not an acceptable installation practice.

210.12 makes no exceptions to exempt protection, it does allow non protection in limited sections at the beginning of the circuit in some cases, and does exempt a fire alarm system from needing protection, but otherwise no exceptions, if the circuit supplies outlets in the areas mentioned AFCI is required.

There are outlets that do not need AFCI or GFCI protection, but there is becoming less of them every code cycle, and sounds like some examples I can give you out of 2011 will require one or the other in 2014. Some examples in 2011 are a dishwasher, disposer, a microwave in a kitchen - receptacle is not a receptacle serving countertops (like an over the range or in the cabinet unit), or any kitchen receptacle not serving countertop spaces, laundry outlet can be debatable depending on conditions of where the laundry outlet is located.

Lighting outlets not in rooms mentioned in 210.12 do not need AFCI and would very seldom need GFCI protection, as long as they are not on a circuit with other outlets requiring AFCI. So, add to the list above - kitchen lighting, exterior lighting, garage lighting, unfinished basement lighting, other crawlspace lighting, bathroom lighting.
 
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GoldDigger said:
With a high power output into a directional antenna, it could easily be 1000 feet, IMO.

It could also be an unlicensed high power CB transmitter used at night too, I guess. That would more likely have a vertical antenna and be closer.

In other circumstances, there have been reports of AFCIs being tripped by PF correction capacitor banks switching in and out on the POCO side.
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The actual incidents were with neighbors next door or across the street. So, 100 feet is what I would expect based upon what I have heard so far.

A signal strong enough to trip an AFCI should also be able to overload the front end of an AM broadcast receiver. To check that, tune to a frequency with no station and leave it set with the volume up enough to hear the background static. If a garbled, scratchy form of interference appears and coincides with the breaker tripping, a powerful signal from a radio (could be ham or illegal CB) just may be the cause. If that is the case, it would be time to start keeping a log of the time and date of the events.
 
Thank you!

Thank you!

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!
 
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