Does the NEC's requirement for sizing overcurrent protection for fire pumps to accommodate the locked rotor ampacity of the motor apply to up-stream primary overcurrent protection (utility company's equipment), or does the NEC only cover overcurrent devices within or ahead of the fire pump controller (building equipment)?
What I've got is a 200 HP 480V 3PH Electric Fire Pump with a dedicated utility pad mount transformer. The utility company wants to provide a 300 kVA transformer at 19.9 KV 3PH primary and 8 Amp primary fuses.
The 200 HP fire pump LRA per NEC 430.251(B) is 1450 Amps at 480V 3PH. This locked rotor information for the motor would equate to about 1205 kVA and 35 Amps at 19.9 kV 3PH.
Now, the NEC does not require conductors to be sized by the LRA nor does it require transformers to be sized for the LRA. But in order to meet NFPA 20 and be a "reliable service", wouldn't the utility company's transformer and primary fuses need to accommodate the LRA? The utility is saying they want to size the transformer for the 200 HP load and then protect their transformer, hence the 8 Amp fuses. This would not carry the LRA indefinitely as is required by the NEC. But does the NEC get to determine what the utility company does?