# Microwave keeps tripping



## WronGun (Oct 18, 2013)

I installed a 20A dedicated circuit for a microwave .. single Receptacle handy box about 30' of 12/2 straight to a new combo breaker... trips every single time I turn the microwave on , about 10-15 seconds of running.... I don't get it 


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## HackWork (Oct 2, 2009)

Did you try it on a normal breaker? Or a different AFCI?


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## macmikeman (Jan 23, 2007)

Sounds like a short circuit. Put an afci in that tells you why it is tripping like either Seimens or Eaton and maybe some others. Those two will let you know if it is arc, short circuit, or overload.


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## A Little Short (Nov 11, 2010)

macmikeman said:


> Sounds like a short circuit. Put an afci in that tells you why it is tripping like either Seimens or Eaton and maybe some others. Those two will let you know if it is arc, short circuit, or overload.


Doesn't sound like a short to me as the OP said it runs for 15 secs before tripping. Sounds like another "crappy" AFCI to me!


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## macmikeman (Jan 23, 2007)

A Little Short said:


> Doesn't sound like a short to me as the OP said it runs for 15 secs before tripping. Sounds like another "crappy" AFCI to me!


Could be. Some processes change during the course of the event- Washing machines for instance that hold fine until the spin cycle and then short out. Maybe this micro gets hot enough something shorts after the temp rises inside the cooking chamber.


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## HackWork (Oct 2, 2009)

A Little Short said:


> Doesn't sound like a short to me as the OP said it runs for 15 secs before tripping. Sounds like another "crappy" AFCI to me!


Yup. And to verify I always try a normal breaker to see if it trips. If it trips a normal breaker than it's a short or overload, if not then it's the AFCI.


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## WronGun (Oct 18, 2013)

Afci/gfci combo was what kept tripping... it was getting late, customer needed micro for weekend so I put a regular breaker in and all is fine.... however this job is getting inspected 


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## drspec (Sep 29, 2012)

why would you install a microwave on an AFCI?


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## backstay (Feb 3, 2011)

I see no mention of a load check? Did you put an amp meter on it ?


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## 99cents (Aug 20, 2012)

Sometimes a miswired AFCI breaker will only trip under load. I had it happen once. I had neutrals mixed up in the panel.


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## drspec (Sep 29, 2012)

Im still confused why a microwave is installed on an AFCI to begin with

handy box to me implies its an above the range type and AFCI protection isnt required

am I missing something?


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## 99cents (Aug 20, 2012)

drspec said:


> Im still confused why a microwave is installed on an AFCI to begin with
> 
> handy box to me implies its an above the range type and AFCI protection isnt required
> 
> am I missing something?


I dunno about American code but, up here in the frozen north, it isn't a receptacle circuit that is included in the exceptions.


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## Barjack (Mar 28, 2010)

drspec said:


> Im still confused why a microwave is installed on an AFCI to begin with
> 
> handy box to me implies its an above the range type and AFCI protection isnt required
> 
> am I missing something?


It depends on which code cycle he's on.

2014 NEC:



> *210.12 Arc-Fault Circuit-Interrupter Protection.* Arcfault
> circuit-interrupter protection shall be provided as required
> in 210.12(A) (B), and (e). The arc-fault circuit interrupter
> shall be installed in a readily accessible location.
> ...


The 2011 NEC (which is what the Florida Building Code has adopted), doesn't list kitchens.


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## drspec (Sep 29, 2012)

Barjack said:


> It depends on which code cycle he's on.
> 
> 2014 NEC:
> 
> ...


I forget about the new requirements for kitchens

NC amended that section and kitchens are excluded


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## WronGun (Oct 18, 2013)

backstay said:


> I see no mention of a load check? Did you put an amp meter on it ?




11 amps 


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## WronGun (Oct 18, 2013)

drspec said:


> why would you install a microwave on an AFCI?




My error I thought it had to be on one... I've seen dozens of new construction setups with combo breaker on the micro circuit 


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## drspec (Sep 29, 2012)

I guess it would depend on your area and what code cycle you're on

Check with your AHJ


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