What is the maximum load on a480/277, 3 phase, 4 wire panel with a 20 amp, 2 pole circuit breaker, is there a chart that I can use, using different voltage systems? What is
The rule of thumb if you need to go to the next higher CB rating?

A 20A breaker can handle a load of 20 amps. The voltage is incidental.
You go to the next higher breaker when the load is too much for the circuit. Many commercial circuits are considered a continuous load so that you can only load a circuit to 80%.

What is the basis of your question? What is the application?

3 phase, 2 pole?

Are you trying to calculate load on the entire panel, or just the 20 amp circuit?

Single Phase VA (Volt-Amperes) = Volts times Amps for the two pole circuit.
Three Phase VA (Volt-Amperes) = Volts times Amps times 1.73 for the panel.

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Originally Posted by Tonylac

What is the maximum load on a480/277, 3 phase, 4 wire panel with a 20 amp, 2 pole circuit breaker, is there a chart that I can use, using different voltage systems? What is
the rule of thumb if you need to go to the next higher CB rating?

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There are no charts, we use Ohm's Law calculations.

There are no "rules of thumb", we use the National Electric Code.

Answer Stan's questions to get better answers.

Sure,:

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Originally Posted by KeepItSimpleStupid

3 phase, 2 pole?

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Why not? A 480 volt single phase load can be supplied by a 3 phase panel.

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Originally Posted by stanfortyman

A 20A breaker can handle a load of 20 amps. The voltage is incidental.
You go to the next higher breaker when the load is too much for the circuit. Many commercial circuits are considered a continuous load so that you can only load a circuit to 80%.

What is the basis of your question? What is the application?

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I am trying to learn how to fill out a 480/277v, 3p, 4w panel. I have a load of 5425/phase.
Is 20a-2p cb good?

Also, how do you convert kw to kva using 80% P.F.
Thanks a lot guys. :)

Do you have a 3 phase load or a single phase load?

5425/phase generally indicates a 3 phase load.

And your talking about 2 pole breakers or say a 480 single phase load.

277 I'd have to do some research.Not sure if they are 2 pole or single pole breakers.

80% pf means multiplying by 1/(0.80) or 1.25