I'm replacing a cooktop with a used cooktop. The wiring is shared with a wall oven. The wall and oven have 4 wires - red, white, black and bare. The outgoing cooktop has 3 wires - red, white and black. The incoming cooktop has 3 wires - red, black and bare. Shoul I wire the bare wire from the incoming cooktop to the bare wire from the wall or the white wire from the wall?

Thanks,
Sixto
87 300D