240V Cooktop installation

[maurice]

Hi. I've done plenty of wiring around the house, but this presents a new challenge. I'm wiring in a new cooktop, and it's wired differently from the last one (which seemed to have a breaker for every element, four 20 Amp breakers for the cooktop). This time, the cooktop runs on 240V with a 30A breaker.

The wiring instructions seem to indicate that the two hot wires (red and black) from the breaker box each get wired to corresponding red and black wires from the cooktop, the bare copper ground from the cooktop gets wired with the bare copper from the breaker box, and to the junction box, but the neutral from the breaker box isn't used? Does this sound right? Would I just wire-nut the neutral and leave it in the box?

The whole thing is to be on its own 30A breaker, is it okay if this is the breaker in the main panel, or should I have a subpanel under the cooktop?

TIA for your help.

Cheers.

maurice

[RBM]

If the new unit requires a thirty amp breaker, it also requires thirty amp wire, which is #10. The existing circuit may have only had #12 which is what's required for 20 amp. If you have two sets of # 12 for the old cook top, you CANNOT parallel them. If the unit doesn't require a neutral, and you have a four wire feeder, just cap it in the junction box

[EXT]

That seems to be the way they do it now. I just changed a built in oven. The old one had its own sub-panel with a half dozen breakers, the new one just wired directly to the circuit fed by a breaker in my main panel. The oven used a white neutral. If you don't have a white wire for the cooktop, it means it runs only on 240 volts, so I would just cap the white wire in the junction box. You don't need a separate sub-panel in this case.

[dpb]

Good!! That was the first thing came to mind was that OP didn't even mention the problem of being (apparently) under-sized capacity w/ the feeder...

[RBM]

If it requires 40 amp, be sure the feeder is at least #8 copper. No, you don't need to disconnect the neutral at the panel end