Replacing a cooktop - old is electric and new is electric induction - Can i use the same wire and just change the breaker?
You need to see what the instructions say about breaker protection and circuit size. I'd say no you can't use same wire and just change the breaker and there a good chance the wiring wasn't appropriate for your old cooktop. You probably need a forty amp breaker and #8 AWG CU wire. Again, check the installation directions to determine the electrical needs. Also verify what size wire you have installed. Your existing 30 amp breaker more than likely has #10 AWG wire attached which is good for 30 amps.