# microwave circut



## cabinet runner (Nov 11, 2008)

Hey sparkys I have a quick question .

I'm doing the cabinet removal and install portion on a condo remodel .

Electrician is going to tie a new undercabinet microwave outlet off the 20 amp circut the fridge is on . He says that is all that will be on that circut and will be fine .

His other option is to tie off the garbage disposal circut but it is only 15 amps . I think this is the better way to go as not using these appliances at the same time seems doable . Not so with the fridge /micro combo . 


I'll admit it wold be almost immpossible for him to run a new circut to the breaker panel since the unit has concrete floors and ceilings . 

I've expressed my concern about this not being right and the money I will have to charge if I must remove some cabinets because he is wrong and the breaker trips every time they use the micro .

I know enough about electric work to stay away from it and he is the proffesional BUT is he right ? 

Thanks


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## 220/221 (Sep 29, 2007)

Code says that the *built in* micro must have it's own 20A circuit.

The refer is* likely* on with the counter top receps circuit. Refer + micro = coffee maker = tripped breaker.

If the refer is for some reason on a *dedicated* 20 amp circuit, you will be OK amps wise but still not to code.



If the refer is for some reason on a *dedicated* 20 amp circuit, use it for the micro and tap off the kit recep circuit to refeed the refer.





> I'll admit it wold be almost immpossible for him to run a new circut to the breaker panel since the unit has concrete floors and ceilings .


Conduit or cable ?


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## mrmike (Dec 9, 2008)

220 is right on. Also,If you read the installation instructions of that microwave it will state that in big letters that it should be wired to its own dedicated circuit. But I see more of them on with other appliances all the time, just like room A/C's . 
If it were me I would insist on a dedicated Circuit on its own than to have it on with either fridge or disposer. Take the time now to get it done right to avoid future problems. There is always a way to get a wire there even if it means conduit on the backside of the wall...............


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## naptown CR (Feb 20, 2009)

220/221 said:


> Code says that the *built in* micro must have it's own 20A circuit.
> 
> The refer is* likely* on with the counter top receps circuit. Refer + micro = coffee maker = tripped breaker.
> 
> ...


ding ding ding the correct answer is in red

Whoever said run a conduit on the back side of the wall remember this is a condo probably a highrise and the back side of the wall is probably the neighbors kitchen.


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## Magnettica (Dec 19, 2006)

210.23 (A)(2)

(2) Utilization Equipment Fastened in Place. The total 
rating of utilization equipment fastened in place, other than 
luminaires (lighting ﬁxtures), shall not exceed 50 percent of 
the branch-circuit ampere rating where lighting units, cord- 
and-plug-connected utilization equipment not fastened in 
place, or both, are also supplied.

So what that's saying is that if the microwave is say 1100 watts, that calculates to 9.1 amps at 120 volts. That could definitely be on with the refrigerator circuit. 

But is it a good design that'll never get a callback? 

Most likely NOT.


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## crazyboy (Nov 8, 2008)

Magnettica said:


> 210.23 (A)(2)
> 
> (2) Utilization Equipment Fastened in Place. The total
> rating of utilization equipment fastened in place, other than
> ...


So its legal as long as it only draws 50 percent of the amp rating of the circuit?


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## Magnettica (Dec 19, 2006)

crazyboy said:


> So its legal as long as it only draws 50 percent of the amp rating of the circuit?


The microwave is legal, correct.


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## Magnettica (Dec 19, 2006)

Btw, welcome to CT. What part of NJ are u from?


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## crazyboy (Nov 8, 2008)

Magnettica said:


> The microwave is legal, correct.


I thought that was the case, was just clarifying. Thanks


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## TxElectrician (May 21, 2008)

Mag has the requirements dead on.

New construction I prefer to run a dedicated circuit to microwave and refrigerator, in addition to the required minimum 2 small appliance circuits.


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## cabinet runner (Nov 11, 2008)

Thanks guys ... good info there . It is an old hi rise buiding built in the mid 70's . The electrical feeds I saw when some of the drywall was removed were conduit coming out of the concrete ceiling . However the microwave wall is against the adjoining unit and in that space the wires are the old metal clad stuff . 
I am going insist that he tells the owner that what he is doing is not up to code . Thanks again for the info . I didn't think what he was doing was correct BUT he is the expert so I didn't want to run my mouth without being sure .


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## naptown CR (Feb 20, 2009)

and don't use romex either


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## ampman (Apr 1, 2009)

TxElectrician said:


> Mag has the requirements dead on.
> 
> New construction I prefer to run a dedicated circuit to microwave and refrigerator, in addition to the required minimum 2 small appliance circuits.


 true


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## ampman (Apr 1, 2009)

we did a job early 90's where they poured a floor a day three stories and we ran smurf with some kind of connectors for concrete but we taped all boxes and connections because concrete will get where you dont want it any way you could add or subtract circuits at will with this wish i could remeber that system name


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## mrmike (Dec 9, 2008)

naptown CR said:


> ding ding ding the correct answer is in red
> 
> Whoever said run a conduit on the back side of the wall remember this is a condo probably a highrise and the back side of the wall is probably the neighbors kitchen.


I said this just to use it as an example, that it can be done somehow & should be done!!
There is some mis-information here in these replies. 
You *cannot* just take the appliance tag ratings & say one circuit will handle it & you should be fine????. Those are just the running currents stated. You *Must* figure in the Starting currents especially the Fridge !!! There are also defrost heaters in them. 
Why take the chance?? What would you do if it were your own kitchen?


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## ampman (Apr 1, 2009)

mrmike said:


> I said this just to use it as an example, that it can be done somehow & should be done!!
> There is some mis-information here in these replies.
> You *cannot* just take the appliance tag ratings & say one cicuit will handle it & you should be fine????. Those are just the running currents stated. You *Must* figure in the Starting currents especially the Fridge !!! There are also defrost heaters in them.
> Why take the chance?? What would you do if it were your own kitchen?


 what?? so what do you do take the fridge nameplate and multiply x 125%:no:


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## Jim M (Jun 7, 2007)

The instructions for the microwave will call for a dedicated circuit as others have pointed out. 

To play games trying to get it to work is not worth it, and would still be a code violation. Is this the type of work you want to be known for doing?


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## Magnettica (Dec 19, 2006)

Speaking of dedicated circuits... how many of you are running 20 amp homeruns for kitchen hood exhausts? 

Some of those require their own dedicated circuit too.


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## TxElectrician (May 21, 2008)

You must be talking about the commercial type hoods that many HOs are putting in. I have done a few of those. When you have done them, which trade does the install?


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## 220/221 (Sep 29, 2007)

We are required to.....if it's plugged in I think.

I believe the reasoning is that someone will likely change it to a micro/vent in the future.


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## Magnettica (Dec 19, 2006)

TxElectrician said:


> You must be talking about the commercial type hoods that many HOs are putting in. I have done a few of those. When you have done them, which trade does the install?


I leave a metal romex connector on the end and if they use they use it. No I don't normally install the range hoods.


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