Really struggling to find a 30A electric cooktop, most of them are 40A and we have the Jenn Air JEC9530 that is running on two #10 wires to a double 30A breaker.
I finally found a cooktop that says it only requires 30A, but the manual says it must be run on #8 wire.
I do not know what I should do, the electric line for my cooktop runs from my kitchen through the foundation all the way to (who knows where) before finally ending up in the breaker box on the far side of the garage wall.
Edit: I just looked at the serial plate for the JEC9530 and it says 7.5kW which should be a 40amp breaker right? Yet it's running on a dual 30A breaker with #10 wire…
Edit 2: We are looking at two cooktops, G9CE3065XB or LCE3010SB. I found a manual that states the G9CE3065XB will run on a 30A breaker fused at both ends but the manual still says #8 wire. Here's a link to that manual, search for G9CE3065 https://www.homedepot.com/catalog/pdfImages/81/816870c8-4d4b-431b-916f-6ad03d647630.pdf
Best Answer
Cooking appliances are a bit weird
The NEC treats household electric cooking appliances (ranges, cooktops, ovens) somewhat differently due to their rather uneven loads. This starts in section and table 220.55 of the NEC, which applies an 80% demand factor to the load of a single household cooking appliance rated not more than 8.75kW. As a result, your JEC9530's nameplate rating gets this factor applied to it, causing it to be considered a 6kW cooktop for the purposes of load calculations, as 220.14(B) invokes 220.55, and 220.10 invokes 220.14 in turn.
From here, we divide by 240V to get 25A for the maximum demand load of the cooktop, then apply 210.19(A)(3) to allow us to use 10AWG wire and a 30A breaker, as the conductors only need to be large enough to serve the load, with no 125% continuous load adjustment in sight.