luckyshadow
Senior Member
- Location
- Maryland
Ok Please bear with me. Been a while when it comes to Fire Pumps.
Does the following sound correct ?
25 HP Pump, 208 Volt, 3 Phase:
Disconnecting Means :
According to section 695 in the NEC I use the lock rotor current to size the disconnecting means. I locate the LRC in Table 430.251 ( B)
25 HP 208 volt 3 phase = 404 amps. Section 240..6 for the standard size fuses. Need to go to next largest which is 450 amperes.
Feeder to Controller:
I use table 430.250 to determine the Full Load Current for the 25 hp 208 volt 3 phase pump
25hp + 74.8 amperes so that's 74.8 X 125 % = 93.5 amperes
310.15(B)16 = #3 copper ( 100 amperes)
Does the following sound correct ?
25 HP Pump, 208 Volt, 3 Phase:
Disconnecting Means :
According to section 695 in the NEC I use the lock rotor current to size the disconnecting means. I locate the LRC in Table 430.251 ( B)
25 HP 208 volt 3 phase = 404 amps. Section 240..6 for the standard size fuses. Need to go to next largest which is 450 amperes.
Feeder to Controller:
I use table 430.250 to determine the Full Load Current for the 25 hp 208 volt 3 phase pump
25hp + 74.8 amperes so that's 74.8 X 125 % = 93.5 amperes
310.15(B)16 = #3 copper ( 100 amperes)
