Electrical – upgrade from a 240V 30A circuit to a 240V 50A circuit


I have a new range with a NEMA 14-50P plug. I find my 240V receptacle is for a dryer, with the top blade a 90° one. So I need to change the receptacle out. However, I think my range needs 50 Amps, and the 240V circuit breakers are ganged 30 amp. The reason I think this is the cord on the range is rated for 50 amps. The installed circuit breakers are type QP. Are these all plug in circuit breakers?. Is it sufficient to just upgrade the existing circuit breakers with 50 amp QP circuit breakers. Is that all I would need to do change out the circuit breakers, and change the receptacle? Do I need to change the circuit breakers or would the 30 Amp breakers suffice?

Best Answer

To increase the amp rating of your circuit breaker, you almost certainly need to increase the gauge of all the wiring on that circuit. Circuit breakers are there to protect the wiring for overloading, overheating, melting the insulation, and eventually starting a fire.

Typically, you have the following wire gauges (this may vary with long circuits and your local codes):

  • 15 amps: 14 gauge
  • 20 amps: 12 gauge
  • 30 amps: 10 gauge
  • 55 amps: 8 gauge
  • 75 amps: 6 gauge

So going from 30 amps to 55 amps requires you to rewire that circuit from 10 gauge to 8 gauge wiring.

For your oven, check the specs on the oven itself. It may simply have a plug that's designed for multiple ovens and will work on a 30 amp circuit.