A:Answer You can use either a 3 wire or 4 wire circuit connection. This wall oven must be electrically grounded in accordance with local codes or, in their absence, with the National Electrical Code ANSI/NFPA No.70- latest edition in United States, or with CSA Standard C22.1-1982 and C22.2 No.01982 (or latest edition), Canadian Electrical Code, Part1, and all local codes and ordinances. This wall oven must be supplied with the proper voltage and frequency, and connected to an individual, properly grounded branch circuit, protected by a circuit breaker or fuse. For the circuit breaker or fuse required by this model, see the rating plate to find the wattage consumption and refer to the table below to get the circuit breaker or fuse amperage. A Microwave Combination Wall Oven can consume up to 7,800 W at 240 VAC. A 50 Amp circuit breaker with wire gauge #8 AWG must be used. ^CP