LeftieBiker wrote:OP: the circuit has to be rated 25% higher than the continuous power draw. At 16A, that works out to 16*1.25 = 20A, and a power draw of 20A requires at least 20*1.25 = 25A. Outlets and breakers come in 20A and 30A varieties in that range.
The duty cycle is actually 80%, not 75%, so the circuit must be rated 20% higher than the device draw. I think it tends to get rounded up. And you can find 25 amp breakers, it's just harder.
Continuous load on a circuit is limited to 80% of the breaker and wire rating. This means that a circuit must be sized for 125% of the actual continuous load. Example: 24 ampere actual load X 125% = 30 amperes for circuit rating. 30 amperes X 80% = 24 amperes maximum allowable continuous load. Duty cycle is a different issue.