Question

The ampacity of feeder wires for a group of motors is equal to the sum of the full load current rating of all motors plus what percent of the highest rated motor in the group?

Answer 1

The ampacity of feeder wires for a group of motors is equal to the sum of the full load current rating of all motors plus a certain percentage of the highest rated motor in the group. This additional percentage takes into account any power spikes or surges that may occur when the motors start up or operate at full load.

Step-by-step explanation:

The ampacity of feeder wires for a group of motors is equal to the sum of the full load current rating of all motors plus a certain percentage of the highest rated motor in the group. This additional percentage takes into account any power spikes or surges that may occur when the motors start up or operate at full load.

For example, if we have a group of motors with full load current ratings of 10A, 15A, and 20A, and the highest rated motor in the group is 20A, we would calculate the ampacity of the feeder wires as follows:

1. Sum of the full load current ratings: 10A + 15A + 20A = 45A
2. Additional percentage of highest rated motor: 20A x 10% = 2A
3. Ampacity of feeder wires: 45A + 2A = 47A

Therefore, the ampacity of the feeder wires for this group of motors would be 47A.