fire pump service

[mcelweec@gmail.com]

is a fire pump service sized based on the FLA or the 6 times rule?

 

[chevyx92]

is a fire pump service sized based on the FLA or the 6 times rule?

I believe its the LRA.

 

[Volta]

I agree, the minimum OCP for a supervised connection is based on the LRA 695.4(B), though the conductors need only be sized for 125% as long as they limit the voltage drop 695.7.

 

[Pierre C Belarge]

The overcurrent device and the conductors are not sized the same. The overcurrent device will be larger than what one is typically used to in regards to protecting conductors.
695.4(B)(1)

 

[DARUSA]

Fire pump

Fire pump

Service fire pump disconnect switch 6 times of the FLC showing in the table 430.250 for 3 phase motors( need to carry the LRC of the motor )
Wire Size 125% of the FLA showing on the motor name plate + 100 % of the sociated load ( jokey pump)
Voltage droop up to 15% is allowed .

 

[don_resqcapt19]

While 6 times FLA is a rule of thumb for locked rotor current, you should use either the marking on the fire pump or table 430.251(B).

 

[DARUSA]

While 6 times FLA is a rule of thumb for locked rotor current, you should use either the marking on the fire pump or table 430.251(B).

Here in NYC is a clear rule ( 6 times ) but you right 2008 code 430.251 B table ,if you make the matts you will see it is probable 6 time too.
Remember table shows FLC and this Matts you should be make it based on FLC not FLA.

 

[DARUSA]

Fire pumps

Fire pumps

695.4 B 1 a. NYC amendments Maximin SCP. 600%

 

[mcelweec@gmail.com]

i have a generator capable of handling 125% of fla but not 600% do i have to replace the generator?

 

[gadfly56]

Service fire pump disconnect switch 6 times of the FLC showing in the table 430.250 for 3 phase motors( need to carry the LRC of the motor )
Wire Size 125% of the FLA showing on the motor name plate + 100 % of the sociated load ( jokey pump)
Voltage droop up to 15% is allowed .

The pressure maintenance (jockey) pump is NOT an accessory load, but is separately considered at 125% per NFPA 70-2005 695.6 (C) (1). You also can't tap the jockey pump controller conductors from the fire pump controller per NFPA 20-2007 10.3.4.8. The OCPD must carry the LRC for both the fire pump(s) and jockey pump(s) and the FLA for the "associated fire pump accessory equipment".

 

[mcelweec@gmail.com]

695.3 b(1)

 

[DARUSA]

i have a generator capable of handling 125% of fla but not 600% do i have to replace the generator?

if you transformer can carry the 125% of the sum of the fire pump and pressure maintenance pump motor loads , and the 100% of the ampere rating of the fire pump's accessory equipment then you are fine per 695.5 A

 

[DARUSA]

The pressure maintenance (jockey) pump is NOT an accessory load, but is separately considered at 125% per NFPA 70-2005 695.6 (C) (1). You also can't tap the jockey pump controller conductors from the fire pump controller per NFPA 20-2007 10.3.4.8. The OCPD must carry the LRC for both the fire pump(s) and jockey pump(s) and the FLA for the "associated fire pump accessory equipment".

You are 100% correct for the wire size Sir!!! But yes you can tap the fire pump feeder for the Jokey pump as long you don't make the tap inside of the Motor control.

 

[mcelweec@gmail.com]

transformer?

 

[DARUSA]

transformer?

I guess it was to late yesterday