Microwave Oven

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Carlos G

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-Service Calculations-Residential-Standard Method:
How must be treated a microwave oven...like a 'cooking unit' (T-220-55) or a fixed appliance (220-53)?
Carlos G
 

charlie b

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Location
Lockport, IL
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Retired Electrical Engineer
I treat is as though it did not exist. The receptacle outlet into which it will be plugged will have already been counted in the VA/sq ft figure. I think that is all that is needed.

Some may say that, knowing a specific appliance will be installed, you have to add that separately. I can't argue against this viewpoint. It's just not my viewpoint. But if you are going to count it, then use its nameplate information to assign a load value.

Since you put this in the exam preparation area, I infer that this is, or was, a test question. The "right answer," unfortunately, is going to be whatever the author of the question wants it to be. Do you have a more nearly exact wording of the question?

Welcome to the forum.
 

augie47

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Tennessee
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State Electrical Inspector (Retired)
CharlieB, You sure keep my mind active. First off, for the OP, I agree with your last statement, it probably depends on the test writer.
I had not given thought to what you stated and on doing so only confuse myself.
I don't disagree with you, but two things cause me to wonder. First, and I realize it's not NEC, Mike Holt has a "microwave" listing in his free download on load calculations (although it could refer to permanent wired).
Secondly in using the optional calculation we see the following wording:
"a. All appliances that are fastened in place, permanently connected, or located to be on a specific circuit ".
Would this not mean a dedicated circuit for a microwave would need to be counted when using the optional method ?
Art 220 is a weak area for me, so I post this so you might enlighten me.
 
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