Fire Pumps

[lmmillican]

I am looking for some input concerning Fire Pump connections. My head starts swimming every time I look at article 695. If there is a separate utility service feeding the fire pump, and the fire pump controller handles the locked rotor protection required, and the feeder conductors are sized at 125% of the FLC of all the motors, can't the service disconnect just be a non fused disconnect sized for the FLC without having to provide overcurrent protection sized at the locked rotor amps?

 

[jack horner]

I am looking for some input concerning Fire Pump connections. My head starts swimming every time I look at article 695. If there is a separate utility service feeding the fire pump, and the fire pump controller handles the locked rotor protection required, and the feeder conductors are sized at 125% of the FLC of all the motors, can't the service disconnect just be a non fused disconnect sized for the FLC without having to provide overcurrent protection sized at the locked rotor amps?

Yes you are correct

 

[kalanjeya]

cable is being sized for locked rotor ampacity to withstand the schort circuit current where as in incomer it is there already " short circuit current ampacity"

If you come to contorl part " may be of electronic parts" just to contol locked rotor current , no need to carry locked rotor current.

 

[HKYPLR]

In NYC the Fire Pump is fused at 600%

 

[ryan_618]

In NYC the Fire Pump is fused at 600%

600% is locked rotor.