Microwave "tapped" off of range circuit conductors

J

JoeNorm

Senior Member
Location
WA
Kitchen remodel of an original 1956 house. They want to keep the microwave in the same location but are adding a toaster right next to it. I noticed the receptacle for the microwave is pulled off of the range circuit. It's not long, in a metal box, and it's worked for 70 years without issue. But I wonder when it's just time for an upgrade, especially since the toaster will now be sharing the receptacle.

The range wire is all old cloth jacketing. It wouldn't be impossible to replace, but definably will add to the job. Is it even an option to leave that setup in place if I have access?
 
JoeNorm said:
Is it even an option to leave that setup in place..?
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Existing construction was built to code:
210.19(A)(3) Exception 1

Remodels are subject to 210.12(D), and the Dennis Alwon Exception

Be careful not to modify the tap > 6ft, or add outlets, since no AFCI exists > 20A.

Replacing oven tap with #12 home run for microwave would ruin a beautiful thing with the existing design.
 
ramsy said:
Existing construction was built to code:
210.19(A)(3) Exception 1

Remodels are subject to 210.12(D), and the Dennis Alwon Exception

Be careful not to modify the tap > 6ft, or add outlets, since no AFCI exists > 20A.

Replacing oven tap with #12 home run for microwave would ruin a beautiful thing with the existing design.
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I doubt the microwave is 70 years old. Possible but highly unlikely. When they changed the appliance to a microwave is when the code violation occurred and hasn't been fixed.
 
We haven't been told if the range is 240V or 120V. If 240V, I don't see how that is legal or a tap since there would not be OCP to match wiring and appliance.
 
ramsy said:
210.19(A)(3) Exception 1
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In order to make that work, there are several hoops to jump through. Because the OP mentions a receptacle, I'm assuming that this microwave is 120V and <= 15A and cord-and-plug connected.

First, the range circuit has to be 50A, not 40A.

Second, the microwave would have to qualify as a "wall-mounted electric oven." That rules out a portable microwave sitting on a counter, but is plausible if it installed as a built-in.

Third, that section requires that the tap conductors, including "the leads supplied with the appliance" to have an ampacity of at least 20A. So the microwave cord would need to have at least #12 copper conductors.

Lastly, 210.21(B)(3) still applies, as the 50A branch circuit supplies at least two outlets, the "wall-mounted electric oven" and the range. So the receptacle would need to be a 50A receptacle, meaning either a 5-50 (do they exist?) or a 14-50. The microwave cord would need to have the corresponding plug.

As far as I can see, if you satisfy all of the above, the install could be compliant. But I may be overlooking some other provision that would throw a wrench into the works.

Cheers, Wayne
 
ramsy said:
If you wont cite code, please explain why code provided in post #2 wont work?
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Two things come to mind
1: We don't know the rating of the circuit for the range
2: IMO, the tap rule is meant to be for another cooking appliance, like a countertop unit, microwave, wall mounted oven. It was not meant for a general receptacle for a microwave, toaster, and whatever you want to plug into it.
 
~ 2023 ~

210.8(D) would also apply. It covers not just receptacles but also the branch circuit / outlet for that equipment.
 
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