My house wiring is four wire (red, black, white and ground (copper)). My present cooktop is also four wire. This is connected through a terminal block. I want to install a new cooktop which is only three wire (red, black and ground(copper)). The new cooktop instructions say red to red, black to black and ground to ground. What do I do to the white wire that is a part of the house wiring. For the new cooktop, do I leave the house white wire untouched and connected at the terminal block and connect the rest (red to red, etc.)?