In standard construction this would require a 15 amp breaker and 14 gauge copper wire.
3000 / 240 = Amps. You de-rate a breaker by 20 % for continuous load like an oven. You could get by with a 20 Amp breaker and 12 AWG wire. However, I would recommend 30 Amps and 10 AWG for an oven for the long run.
A #10 wire has the capacity for 30 amps. No breaker larger than 30 amps should be used to protect the circuit.
For typical residential house wiring 12 AWG wire is required for a 20 Amp breaker. If you change out the breaker for a 25 A breaker you would have to rewire the circuit with 10 AWG. In that case you could up the breaker to 30 Amps. All outlets and switches should be rated at the same voltage and current as the breaker.
For a 100 Amp breaker panel it would be 2 AWG. For 150 Amps it would require 2/0 (2 ought) aluminum wire.
Depending upon what type of "unit", you would want at least an 85-amp breaker, and the next standard size would be 90 amps. You might use an 80, depending upon the duty cycle of the unit, but the 90 will be required for constant use.
Canada and US - Standard size breaker in home panel is 40 amps for stove. If not standard range open Discuss Question page.
I = W/E. 1500/240 = 6 amps for each heater. In parallel the total connected load will be 12 amps. A #14 conductor is rated at 15 amps and de rated to 80% can carry 12 amps continuous. The breaker needed for this would be a two pole 15 amp breaker. If this is a new installation I would use a #12 conductor for the two heaters on a two pole 20 amp breaker. The conductors will run much cooler using a larger size.
Look on the heater and see what amps it is pulling. That will determine the wire size and breaker size. It must be on a dedicated circuit. 15 amps = AWG # 14 wire with 15 amp breaker 20 amps = AWG # 12 wire with 20 amp breaker 30 amps = AWG # 10 wire with 30 amp breaker 40 amps = AWG # 8 wire with 40 amp breaker
Add 25% so it comes to 42 amps
Add up your amps to calculate your breaker size. Add up your loads (amps), divide by 0.8, and choose that size breaker. If that number does not correspond to a standard size breaker you go to the next higher standard size breaker.
Minimum size is 10 gauge with a 30 amp breaker. To be safe I would install an 8 gauge with a 40 amp breaker.
Its been a while since ive brushed up on my electricity knowledge, but im fairly certain that breaker capacities are based on amps. I think you would have to know the amperage of the motor before you were able to conclude what size you need.
What size breakers are needed for a 30kva transformer 208 volt feed 600 volt out put
The 225 amps is the secondary output amperage. Look on the machines nameplate to find the input amperage. It is that amperage that is needed to size the feed wire and there the breaker size. When you find that amperage you may want to re question the breaker size.
20 amp In North America code states a two pole 15 amp breaker will do the job.
15 amps
The smallest size in breaker panels is 30 amps and the smallest breakers that can be installed into a 30 amp panel are15 amps. If more info is needed go to the discussion page tab and explain what you are trying to do.