Cooktop/Wall oven branch ckt & taps

[designer82]

I have one large 11.5 kw standalone cooktop and one 3.5kw standalone wall oven.

Per Table 220.55 notes, this is how you calculate the branch circuit rating, please see below image.

That is nice, but what about the conductor size for the individual taps from the JB?

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Thanks

 

[augie47]

See 210.19 (A)(3)

 

[designer82]

See 210.19 (A)(3)

Thank you for the reference.

That section only says "tap conductors shall have an ampacity not less than 20 A & shall be sufficient for the load to be served."

Well that does't tell me much. At total connected load that cooktop would draw (11.5kW / 240V) 47.9 A.
And per the demand calculation, that entire branch circuit only needs to be 38.3 A.


Appreciate any further guidance.

 

[designer82]

I could just make the branch circuit 50 A, the cooktop tap also 50 A & the oven tap 20 A.

Thoughts?

 

[wwhitney]

That's fine; or you could make the branch circuit 40A, the cooktop leg 40A, and the oven leg 20A.

Edit: although if they ever remove the oven from the circuit, the branch circuit will now need to be 50A!

Cheers, Wayne

 

[CoolWill]

I'd probably just do a 6-6-6-6 SER and attach the appliance whips straight to it in the J-box. 40 amp. I'm pretty cheap. But at the same time, messing around with taps in a box kinda sucks too. If the runs are short enough, I might just run two circuits. Probably be taps in a box either way, really.