Safe method for testing breaker in a transformer

[Birds]

Another newbie question here...

What is a safe method for testing the circuit breaker in a vintage postwar transformer?

I would like to make sure it does trip, and use a VOM to see many amps it will trip at, but I don't want to damage anything.

Thanks,
Birds

[ADCX Rob]

I use a variable resistive load - it must be sized for the higher end of the unit you are testing & then some more for overhead.

Most VOMs(typical max might be 10 amps, BUT DC) will not handle the current you are looking to test for in an AC circuit, a basic 20-25 amp AC panel meter will be a much better choice. An AC voltmeter included in/with your load testing circuit will give a lot of insight as to the actual power delivery capability of your transformer.

Rob