Electrical – using two oven in one outlet

circuit breakerelectrical

I have two ovens. One is 20 amp at 240 V and Second is 30 amp at 240V. And I have one 240 V 50 amp outlet hook up to one circuit. Would this be sufficient enough to run two ovens without overheating the wire and overload the circuit breaker?

I been told the 1 circuit could handle two appliances. I been told electricity 20+30 amp is not equal to 50 amp. They use the average amperage withdrawal calculation to calculate the circuit could handle it.

My question would 50 amp 240 V circuit could handle these two ovens without heating the wire or blowing the circuit?

These ovens will be turn on at the same time.

Best Answer

NEC 220.55

The load for household electric ranges <...> individually rated in excess of 1.75 kW shall be permitted to be calculated in accordance with Table 220.55.

NEC Table 220.55

Based on note #3; since one range is rated 7.2 kW (30A x 240V) and the other is 4.8 kW (20A x 240V), we are able to simply add the total rated kW of both and multiply it by the demand factor as found in Column B -- you have 2 appliances that are both between 3.5 and 8.75 kW, so the demand factor here is 65%.

7.2 kW + 4.8 kW = 12 kW

12 kW x 65% = 7.8 kW or 7800 W

7800 W / 240 = 32.5A

Finally, since the oven circuits are under 600V and noncontinuous loads, the following code applies:

NEC 210.19(A)(1)(b)

The minimum branch-circuit conductor size shall have an allowable ampacity not less than the maximum load to be served after the application of any adjustment or correction factors.

..., i.e. your conductors (wires) should be sized to at least 32.5A (they should be already) and your breaker should then be sized to your wires (which it is.)

Your current 50A breaker will suffice for this application.