What size feeder is needed for a 100Amp service?

For a 100 Amp service, a feeder size of at least 3 AWG copper or 1 AWG aluminum is typically required, according to the National Electrical Code (NEC). However, the exact size may vary based on factors such as the length of the run and the type of insulation used. It's important to consult local codes and possibly a licensed electrician to ensure compliance and safety.