I was called upon to size an emergency generator as an alternate power source for a fire pump. There are other loads as well. However, I want to focus on the fire pump load for now. I plan to use the horsepower rating of the motor to calculate load. I reviewed the 2002 NEC Handbook 695.3(B)(1)and learned the generator does not need to be sized for lock rotor of fire pump.
Where the alternative source of power is an on-site generator, the alternative source disconnecting means and the alternative source overcurrent protective device(s) for the electric-drive fire pump are not required to be sized for locked-rotor current of the fire pump motor(s). Rather, the circuit components of the alternative source are permitted to be sized according to Article 430, provided they are â€śselected or set to allow instantaneous pickup and running of the fire pump load.â€ť See 445.12(A).
Did I interpret it properly?