I am installing a Kenmore cooktop with a red, black(grey), copper wire. I have a 220 line that is black, white and copper. How do I connect these.

The black and white should be the 240 volt feed, which would connect to the red and black input of the cooktop.

The bare copper wires will be the equipment grounds, which should be spliced, and also connect to any metal junction box with a short tail.

Should use a voltage tester to be sure the black and white is actually 240 volts across them.