Sizing the MCCB for motors and non-motor feeders

 To size a Molded Case Circuit Breaker (MCCB) for motors and non-motor feeders, follow these steps:

1. For motors, determine the full-load current (FLC) from the motor nameplate or use the appropriate table from the National Electrical Code (NEC) 1. Size the branch-circuit conductors at no less than 125% of the motor's FLC21.
2. For non-motor feeders, calculate the total load current based on the connected equipment.
3. Determine the appropriate MCCB rating based on the calculated current and any additional factors, such as short-circuit protection, overload protection, and coordination with other protective devices13.
4. For motor circuits, consider additional factors such as motor starting current, torque requirements, and motor control methods3.
5. Consult the MCCB manufacturer's guidelines and product specifications to select the appropriate MCCB model.

Remember to follow the NEC and local electrical codes for proper sizing and installation of MCCBs and conductors41.