I'm installing a KitchenAid KECC607BBL electric cooktop. The instructions state the following:

"a 3-wire or 4-wire, single phase, 120/240 volt, 60Hz, AC only electrical supply is required on a separate 40-amp circuit....."

"The cooktop is rated 120/240 volt. Some models have a neutral (white) wire."

So it seems to me that it will work with either a 120V or 240V circuit. But the instructions are remarkably vague. It makes no mention of how to set the cooktop to use 120V vs 240V, or how the wiring will differ depending on which is used. The wiring from the cooktop includes black, white, red, and green wires. Of course, black is hot, white is neutral, green is ground, and red is the "other" hot on a 240V circuit, and red is not present in a 120V circuit. So, if I wanted to use 240V I understand how to wire it - just match up the colors. But if I want to use 120V, what do I do? Do I just leave the red wire unconnected?

The other issue is current rating. Normally, a 240V circuit (range/dryer/etc) is 40 amps, which is achieved by protecting each "half" of the 240V circuit with a 20 amp breaker tied together so that if one trips the other trips. But in a 120V implementation, will a single 20 amp circuit suffice? I cannot use a 40 amp breaker without replacing the wiring. The wiring is standard kitchen-type 20 amp 12 gauge.

Installation manual attached. Any advice much appreciated!
Tim

Thanks, although I'm mystified why they'd use the phrase "The cooktop is rated 120/240 volt" in the instructions. Bummer. Now I'll have to run a new 240V circuit all the way from the main panel.

Follow-up question.... Since it states that the appliance requires 40 amps, that's effectively two 20 amp 120 volt circuits so does that mean I can use 12/3 romex (with ground) to wire this?

And finally, would a 20 amp tandem breaker such as this be appropriate:
Shop Square D Homeline 20-Amp Tandem Circuit Breaker at Lowes.com

EDIT: I just realized I was confusing Tandem and Double-pole breakers. I need a double-pole breaker not a tandem breaker. However, it's not clear to me whether a rating of "40 amps" means 20 each for a total of 40, or whether that's 40 each which would be 80 in total which is too much.