Fire Pump Feeder

[steve holt]

1. Does a fire pump feeder from an back up generator need to be fed directly from the generator or can it be fed from an emergency switchboard?
2. Does a fire pump feeder which is tapped off the main service after the meter but before the main (making it a service disconnect) need to include the grounded conductor even if it the fire pump or controller does not need and will not use the neutral?

 

[infinity]

1) We always provided a disconnect tapped ahead of the emergency switchboard or directly off of the generator.
2) Yes the neutral is required to bond the service disconnect.

 

[steve holt]

1) We always provided a disconnect tapped ahead of the emergency switchboard or directly off of the generator.
2) Yes the neutral is required to bond the service disconnect.

Thanks for the reply infinity.
Regarding your response to question 1, although that is common practice, is it a code requirement? I have seen it done where the FP is fed from the EM SWBD, and I cannot find anything in 695 that precludes that practice.

 

[augie47]

I have installed them that way as shown on engineered drawings and it's been accepted. Note the requirements of 695.4(B)(3) including the reference to 700.10(B)(5)

 

[TX+ MASTER#4544]

steve holt: fire pump feeder,etc
Hello, steve holt
Akin to The great Mike Holt, the guru of influential teaching and a revered mentor?

Interesting questions from you. Hope you have time to read this:
Section 695.3 Power Source(s) for Electric Motor-Driven Fire Pimps......"shall have a reliable source of power'' as found in the following sections:

695.3 (A) Individual Sources........"reliable, carry indefinitely the sum of the locked-rotor current of the pump motor(s).....and the pressure maintenance pump motors and be one of the following,

695.3 (A) (1) Electric Utility Service Connections or (2) 0n site Power Production Facility or 695.3(A)(3) Dedicated Feeder .".....where it is derived from a service connection as described in 695.3(A) (1)"

695.4 (C) Feeder Source. (C1) Size,... (2) Overcurrent Protection 695.6 (A)(2) Feeders.
659.6(A) (2) ".............to an on site standby generator meeting all of the following in (1)(2)(3)(4)

695.3(A)(1) Electric Utility Service Connection This is where you find out about your emergency switchboard question.
It also pertains to a "dedicated feeder" as found in 695.3(A)(3) Dedicated Feeder

The last part of your question says that the transfer switch that you will install will be inside the fire pump controller and it will be listed as service rated equipment and not included as one of the maximum 6 means of disconnects, see 230.2 Number of Services (A)(1) Fire Pumps

Starting in the 2020 NEC (or it may have started in 2017) a grounded conductor (a neutral conductor) is required to be included with the phase conductors. You can size it as per T.250.102 (C) (1) based on phase conductors. You need a low resistance fault current path for it to return back to the source, so that is it's only reason needed.

A few other non-required items are AFCI,GFCI, over-load relays (heaters) type FMC wiring method.
The motor controller disconnect must be lockable in the (on) closed position.

Do you need calculations for sizing conductors and OCPD?

Check out Article 695 Fire Pumps for a complete overview.

Thanks for reading
Comments accepted
TX+MASTER#4544

 

[don_resqcapt19]

steve holt: fire pump feeder,etc
Hello, steve holt
Akin to The great Mike Holt, the guru of influential teaching and a revered mentor?

Interesting questions from you. Hope you have time to read this:
Section 695.3 Power Source(s) for Electric Motor-Driven Fire Pimps......"shall have a reliable source of power'' as found in the following sections:

695.3 (A) Individual Sources........"reliable, carry indefinitely the sum of the locked-rotor current of the pump motor(s).....and the pressure maintenance pump motors and be one of the following,

695.3 (A) (1) Electric Utility Service Connections or (2) 0n site Power Production Facility or 695.3(A)(3) Dedicated Feeder .".....where it is derived from a service connection as described in 695.3(A) (1)"

695.4 (C) Feeder Source. (C1) Size,... (2) Overcurrent Protection 695.6 (A)(2) Feeders.
659.6(A) (2) ".............to an on site standby generator meeting all of the following in (1)(2)(3)(4)

695.3(A)(1) Electric Utility Service Connection This is where you find out about your emergency switchboard question.
It also pertains to a "dedicated feeder" as found in 695.3(A)(3) Dedicated Feeder

The last part of your question says that the transfer switch that you will install will be inside the fire pump controller and it will be listed as service rated equipment and not included as one of the maximum 6 means of disconnects, see 230.2 Number of Services (A)(1) Fire Pumps

Starting in the 2020 NEC (or it may have started in 2017) a grounded conductor (a neutral conductor) is required to be included with the phase conductors. You can size it as per T.250.102 (C) (1) based on phase conductors. You need a low resistance fault current path for it to return back to the source, so that is it's only reason needed.

A few other non-required items are AFCI,GFCI, over-load relays (heaters) type FMC wiring method.
The motor controller disconnect must be lockable in the (on) closed position.

Do you need calculations for sizing conductors and OCPD?

Check out Article 695 Fire Pumps for a complete overview.

Thanks for reading
Comments accepted
TX+MASTER#4544

It is unlikely that AFCI would be required where there is a fire pump.
Overload relays are only permitted to provide an alarm, and not permitted to stop the fire pump.
FMC is not permitted for the protection of the circuit conductors to the fire pump.

 

[TX+ MASTER#4544]

It is unlikely that AFCI would be required where there is a fire pump.
Overload relays are only permitted to provide an alarm, and not permitted to stop the fire pump.
FMC is not permitted for the protection of the circuit conductors to the fire pump.

All of my remarks are from the 2023 NEC.
The OLRs are in the motor controller, (the magnetic starter) for excess ampacity for field installed conductors.

Thanks for your comments.
TX+MASTER#4544

 

[TX+ MASTER#4544]

I have installed them that way as shown on engineered drawings and it's been accepted. Note the requirements of 695.4(B)(3) including the reference to 700.10(B)(5)

Yes, you're in line with 695.4 and 700.10 (B)(6) about the switchgear.
Note: The (B) (5) is about "a traveling cable to an elevator", in the 2023 NEC.
No, problem.

TX+MASTER#4544Thanks,

 

[don_resqcapt19]

All of my remarks are from the 2023 NEC.
The OLRs are in the motor controller, (the magnetic starter) for excess ampacity for field installed conductors.

Thanks for your comments.
TX+MASTER#4544

As are mine!

The motor conductors are not protected from overload or excess ampacity on a fire pump circuit. The fire pump controller does have overcurrent protection but that is provided by the fire pump controller manufacturer and the installer has nothing to do with the settings of that protection. That protection must carry 600% of the motor full load current for at least two minutes without opening, and 300% for at least 10 minutes without opening.

FMC is not a wiring method that is permitted in 695.6(D)(1).

 

[TX+ MASTER#4544]

2023 NEC
Yes, I understand what you wrote.
And ,I did say in my OP that "a few other non-required items like AFCI, GFCI , overload relays (heaters) type FMC wiring method"

I believe we both agree that the fire pump motor is designed to extinguish the fire disregarding all other features that are typically found in the analysis of a standard motor.

695.4 (B) (2)(1) "Overcurrent protective device(s) shall be rated to carry indefinitely the sum of the locked rotor current of the largest fire pump motor and........"
Furthermore, "The requirement to carry the locked-rotor motor currents indefinitely shall not apply to conductors or devices other than overcurrent devices in the fire pump motor circuit(s)."

So, burn baby, burn, cause the motor won't stop 'till the fire's out!
As if the motor was connected to a never ending uninterrupted nonstop source of power.

Thanks for your comments
TX+MASTER#4544