Originally Posted by georgeshall
Motor Short-Circuit / Ground-Fault protection is sized as per a percentage of Full-Load Amps, not Power rating (HP). There are four types of SC/GF protection for motors. An MCP should be an Instantaneous Breaker. These might be around 800% to 1100% of Motor Full Load Amps (Not nameplate, NEC tabular value). Look at Table 430.52 to get the percentage of full load amps. Look at 430.248 or 430.250 (or ...) to get the full load amps of the motor.
Eric Stromberg, P.E. Texas