Electrical – safely chain lower rated receptacles from higher ones

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.

The answer is it depends on the appliance. As long as the appliance does not expressly forbid using it on a 30A circuit you should be fine. You'll be able to change the plug and put on a 14-30P plug, just ignore the silver terminal (neutral).