Tap for a microwave from a 50-amp branch ckt; 210.19(C)?

[Amplitude Electrical]

My question about a particular situation is based on exception no.1 to 210.19(C)- "Conductors- minimum ampacity and size, Household Ranges and Cooking appliances"

210.19(C)
Exception No. 1: conductors tapped from a branch circuit not exceeding 50 amperes supplying electric ranges, wall-mounted electric ovens and counter-mounted electric cooking units shall have an ampacity of not less than 20 amperes and shall be sufficient for the load served. These tap conductors include and any conductors that are a part of the leads supplied with the appliance that are smaller than the branch circuit conductors.

Citing this exception, would it be code-compliant to tap a short section of 12/2 NM wiring to a 50-amp branch circuit for the purpose of a dedicated receptacle
for a wall-mounted microwave? The microwave is mounted directly above an in-wall electric oven.

 

[winnie]

Certainly not for a _receptacle_, because all the rules for receptacles would still pertain.

I believe you could tap 12/2 NM from a 50A branch circuit if the wall mounted microwave were listed for hard wiring as an oven. But a microwave with such a listing is probably some sort of fancy hybrid unit with microwave generator, resistance heating, and fans.

-Jon

 

[Little Bill]

I believe that exception is referring to whips to the appliance itself. I could be wrong. There would be no OCPD for the MW receptacle otherwise.

 

[Todd0x1]

Besides all the obvious issues others have pointed out, theres this from 210.23:

(2) Utilization Equipment Fastened in Place. The total rating
of utilization equipment fastened in place, other than luminaires,
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 basically if an appliance uses more than 50% of the circuit ampacity it needs to be on a dedicated circuit.

 

[Amplitude Electrical]

Certainly not for a _receptacle_, because all the rules for receptacles would still pertain.

I believe you could tap 12/2 NM from a 50A branch circuit if the wall mounted microwave were listed for hard wiring as an oven. But a microwave with such a listing is probably some sort of fancy hybrid unit with microwave generator, resistance heating, and fans.

-Jon

I believe that exception is referring to whips to the appliance itself. I could be wrong. There would be no OCPD for the MW receptacle otherwise.

Besides all the obvious issues others have pointed out, theres this from 210.23:

(2) Utilization Equipment Fastened in Place. The total rating
of utilization equipment fastened in place, other than luminaires,
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 basically if an appliance uses more than 50% of the circuit ampacity it needs to be on a dedicated circuit.

Thanks all, I knew that it wasn't right; I was just trying to figure out the formula to get there

 

[augie47]

You might be interested in this earlier discussion.....

210.19(A)(3) Exception 1

Old modern style house, concrete slab, vaulted ceiling, that has a 210.19(A)(3) Exception 1 setup. No remodeling going on customer is just replacing the built in microwave oven. They appear to have a 50A circuit that feeds a 50A range receptacle and a 20A 240V receptacle in a upper cabinet for...

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