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The installation specs for my cooktop read as below:

-Connected Load (kW Rating) @ 240 / 208 Volts = 7.2 / 6.2 kW

-Amps @ 240 / 208 Volts = 35.0 / 35.1 Amps

-Recommended Circuit Breaker – 30 Amps

The circuit I have available is on a 240v 40 amp breaker running 8 AWG wire.

First, it's a little strange that the manufacturer lists a 35 amp draw and recommends a 30 amp breaker. I'm guessing that has something to do with the NEC 220.55 Demand Factors table. But according to the table 1 appliance at 8,000 watts divided by 240v = 33.3 amps. I'm stumped there.

Second, it would seem to me that since the cooktop leads will be hardwired in a junction box, there wouldn't be a plug compatibility issue. Then the only problem might be the gauge of the wiring coming out of the cooktop provided by the manufacturer?

Finally, in a separate manufacturer specs doc lists the "Minimum circuit required" as 30 amp... which makes me think that a 40 amp circuit would be fine even though the other doc "recommends" a 30 amp circuit.

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The term they are supposed to use is Minimum Circuit Amapcity (MCA) and/or Maximum Over Current Protection (MOCP). In your case the MCA is 30A, but they apparently didn't provide an MOCP, just a "suggested" one. I think you are fine with a 40A breaker, so long as your conductors in the wall to the receptacle are rated for that and at #8, they are.

The rating on any circuit in the NEC is based on "continuous" current, defined as 3 hours or more. On a stovetop, it's highly unlikely that you would have ALL burners set at FULL output for 3 hours or more.

  • And even set on FULL, they would cycle ON and OFF. – JACK Aug 28 at 20:29
  • I bet some of the manufacturers recommendations come down to no one ever using all burners at one time even tho some ratings and data plates probably have to list the "worst case". – JPhi1618 Aug 28 at 20:29
  • There is also the Table 220.55 utilization factoring procedure to take into account – ThreePhaseEel Aug 28 at 23:20

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