Design Of Motor Branch Circuits: Several Motors

Under some conditions, the NEC permits two or more motors to be supplied by a single branch circuit and protected by one overcurrent device (Section 430-53). Some of these conditions are given in the following paragraphs:

1. Two or more motors, each not exceeding one horsepower in rating and each having a full-load current not exceeding 6 Amperes, may be used on a single branch circuit protected at not more than 20 Amperes for 125-Volt motors or at not more than 15 Amperes for motors up to 600-Volts. Individual running overcurrent protection is unnecessary unless required by Section 430-32.
2. If the branch circuit protective device satisfies the requirements of Section 430-52 for the motor with the smallest rating, two or more motors may be supplied by the same branch circuit. Each motor must have individual running overcurrent protection, and the branch circuit protective devices must be capable of supplying current to the combination of motors without opening under the most severe normal conditions that might be encountered.