Conductors to Fire Pump

[gadfly56]

Although you could power the jockey (pressure maintenance) pump from your regular building distribution since it is not a fire pump, you can also power it from the fire pump service per 695.

One service with a separate tap for each. IIRC, you can't run the service into the fire pump controller and then tap from there to the jockey pump controller (NFPA 20-2013 section 10.3.4.5.1).

 

[Fitzdrew516]

One service with a separate tap for each. IIRC, you can't run the service into the fire pump controller and then tap from there to the jockey pump controller (NFPA 20-2013 section 10.3.4.5.1).

That's how I have it designed as of now. 1 service with a wire-way with three taps, (2) to the controllers and (1) to a small panel for the pumphouse lighting, heat, etc.

 

[gadfly56]

That's how I have it designed as of now. 1 service with a wire-way with three taps, (2) to the controllers and (1) to a small panel for the pumphouse lighting, heat, etc.

Although you can power auxiliary loads from this tap, I'm not sure the POCO or AHJ will agree that building utilities qualify. The POCO may get cranky about not getting paid for the power thus consumed. If your tap is after the meter, the AHJ may have an issue. The separate service tap is supposed to ensure that if the building's meter is pulled, you still maintain fire protection so it usually goes before the meter.

 

[John120/240]

Although you can power auxiliary loads from this tap, I'm not sure the POCO or AHJ will agree that building utilities qualify. The POCO may get cranky about not getting paid for the power thus consumed. If your tap is after the meter, the AHJ may have an issue. The separate service tap is supposed to ensure that if the building's meter is pulled, you still maintain fire protection so it usually goes before the meter.

If the building requires a Fire Pump, it usually means the size of the service is significant. In such cases pulling the meter doesn't disconnect power because the meter is connected via CT's.

 

[gadfly56]

If the building requires a Fire Pump, it usually means the size of the service is significant. In such cases pulling the meter doesn't disconnect power because the meter is connected via CT's.

OK, I guess my lack of familiarity with commercial services tripped me up here. I haven't dealt much with service entrance gear. My work has usually been at some sub panel in the facility for the fire alarm system.

 

[JoeStillman]

I guess I never really thought of just running two separate feeds off the utility transformer. Excuse my ignorance - Is this a common way to handle a fire pump application? I've always assumed the standard was to run it to the gear and then run a line side tap to ensure the feed is always live.

Thanks,
-Drew

That's how I do it. Then you don't have any issues with the fire pump conductors sharing a cubicle in the gear with regular service conductors. See 696.3(A)(1).

 

[hornetd]

Oh, man I've sparked some conversational debate! I love it! In any case, it seems that it would be easiest to go ahead and run a second feed off the utility secondary. Does anyone have any reasonable qualms as to why this wouldn't be the best route? Any other considerations I would have to take into account for this design?

-Drew

One mistake I have seen made with a second set of service conductors for a fire pump is the failure to pull a neutral from a wye connected secondary to a three phase pump's combined service disconnecting means and controller. When you supply a three phase load with no line to neutral loads from a wye connected transformer's secondary you are allowed to reduce the size of the neutral but you are not allowed to leave it out.

 

[hornetd]

Although you can power auxiliary loads from this tap, I'm not sure the POCO or AHJ will agree that building utilities qualify. The POCO may get cranky about not getting paid for the power thus consumed. If your tap is after the meter, the AHJ may have an issue. The separate service tap is supposed to ensure that if the building's meter is pulled, you still maintain fire protection so it usually goes before the meter.

In my NOT unlimited experience pulling the meter does not de-energize services larger than about 400 Amps. I doubt that the size of building that we are discussing here would have a service that small if it is large enough to need a separate pump house for fire protection. Whether or not any given set of service conductors is metered is a Public Utility regulatory issue rather than a National Electric Code one. NFPA 20: Standard for the Installation of Stationary Pumps for Fire Protection may well forbid some arrangements of the service supplying a fire pump but NFPA 70: National Electric Code Section 695 does eliminate a lot of requirements that would be imposed on any other motor circuit of the same size. The ones that leap to mind are the wavers for overload and ground fault protection. The underlying principal is that the fire pump should keep running until it destroys itself rather than disrupt the flow of water to the served fire protection equipment.

 

[rlqdot]

So I've gotten into a situation where I need to supply power to a fire pump. The issue is that the main electrical service is going to be in a "penthouse" at roof level. So I need to do a line side tap pull section and then have a separate disconnect for the fire pump, i know that, but the question is about the conductor run.

I know that the conductors need to either be protected in a number of ways, or be "outside the building". So I guess the question is: Is running the conductors across the roof and down the wall out to the pumphouse located by the fire pond OK? Would these conductors be considered "outside the building". I think by code standards they are technically considered "outside the building", but in all practicality is the inspector going to look at conductors on the roof and have an issue, because let's be honest... we're supposed to be protecting the feeders to the fire pump to ensure the fire pump functions properly- What if the fire burns through the conductors on the roof?

Any thoughts/suggestions/discussion would be helpful.

Thanks,
Drew

If the service entrance equipment is on the roof, I would guess that the POCO meter is somewhere at or near ground level ... that would imply that there is a CT cabinet adjacent to the meter from which the fire pump feeder could be tapped and routed to the remote pump building.

The fire pump controller is a service disconnect and is not included in the maximum 6 disconnect count and not subject to the grouping of disconnects rule, so unprotected service conductors from the downstream side of the meter to the fire pump controller / pump are permitted.

There will also need to be branch circuits (or a separate feeder to a general purpose panel in the pump building) from the building power distribution equipment to power any lights, receptacles, heating equipment and jockey pump that may be located in the fire pump building - that equipment cannot be served from the fire pump feeder as I read the code.

Technically, routing the fire pump feeders across the roof and down the exterior surface of the wall is "physically routed outside a building" (NEC 695.6(A)(1)), although it does seem like running those feeders across the roof exposes them to damage or failure due to a fire inside the building that the pump is trying to protect.

On at least one past project that I have been involved with, a fire pump showed up after the service was installed and after the floor slab was poured. This pump was inside the building and tearing up the floor was a very costly option. In the end, a conduit was laid directly on top of the floor slab at the bottom of the wall and encased in concrete that was 2 inches above the top of the conduit and that extended 2 inches past each side of the conduit - in compliance with 695.6(A)(2)(d)(1). Sort of like your situation of running it across the roof of the "on fire" building, but still code compliant.

 

[gadfly56]

So I've gotten into a situation where I need to supply power to a fire pump. The issue is that the main electrical service is going to be in a "penthouse" at roof level. So I need to do a line side tap pull section and then have a separate disconnect for the fire pump, i know that, but the question is about the conductor run.

I know that the conductors need to either be protected in a number of ways, or be "outside the building". So I guess the question is: Is running the conductors across the roof and down the wall out to the pumphouse located by the fire pond OK? Would these conductors be considered "outside the building". I think by code standards they are technically considered "outside the building", but in all practicality is the inspector going to look at conductors on the roof and have an issue, because let's be honest... we're supposed to be protecting the feeders to the fire pump to ensure the fire pump functions properly- What if the fire burns through the conductors on the roof?

Any thoughts/suggestions/discussion would be helpful.

Thanks,
Drew.

If the service entrance equipment is on the roof, I would guess that the POCO meter is somewhere at or near ground level ... that would imply that there is a CT cabinet adjacent to the meter from which the fire pump feeder could be tapped and routed to the remote pump building.

The fire pump controller is a service disconnect and is not included in the maximum 6 disconnect count and not subject to the grouping of disconnects rule, so unprotected service conductors from the downstream side of the meter to the fire pump controller / pump are permitted.

There will also need to be branch circuits (or a separate feeder to a general purpose panel in the pump building) from the building power distribution equipment to power any lights, receptacles, heating equipment and jockey pump that may be located in the fire pump building - that equipment cannot be served from the fire pump feeder as I read the code.

Technically, routing the fire pump feeders across the roof and down the exterior surface of the wall is "physically routed outside a building" (NEC 695.6(A)(1)), although it does seem like running those feeders across the roof exposes them to damage or failure due to a fire inside the building that the pump is trying to protect.

On at least one past project that I have been involved with, a fire pump showed up after the service was installed and after the floor slab was poured. This pump was inside the building and tearing up the floor was a very costly option. In the end, a conduit was laid directly on top of the floor slab at the bottom of the wall and encased in concrete that was 2 inches above the top of the conduit and that extended 2 inches past each side of the conduit - in compliance with 695.6(A)(2)(d)(1). Sort of like your situation of running it across the roof of the "on fire" building, but still code compliant.

If the fire develops to the point that it burns through the roof and damages the conductors, the fire pump wasn't of much use anyway, was it?

If you can convince the AHJ that the lights, etc for the pump house are "associated equipment" you might be able to supply them from the same feeder. Not a good idea IMO, but that's a possible solution.

Was your concrete encasement solution through the entire building or only in the fire pump room? If the latter, it didn't need to be because the feeder can be in MC or equal within the service entrance room and the fire pump room.

 

[rlqdot]

Too long ago to remember, but it seems like the feeder passed through at least one other room before entering the fire pump room. also, local AHJ would not allow any more than 10 feet of unprotected service entrance conductor inside the building, so the concrete encasement allowed us to declare that the conductor was "outside".

 

[gadfly56]

Too long ago to remember, but it seems like the feeder passed through at least one other room before entering the fire pump room. also, local AHJ would not allow any more than 10 feet of unprotected service entrance conductor inside the building, so the concrete encasement allowed us to declare that the conductor was "outside".

If it was long ago enough, FHJR listed cable should have been sufficient.

 

[jeremysterling]

I had a service call last week to run a new circuit for the jockey pump in a forty year old building. The fire pump controller had been replaced and the fire inspector wanted the jockey pump on its own circuit.

The original jockey pump circuit was tapped at the line side of the fire pump controller's OCPD. I moved the jockey pump circuit to a new 3p20a breaker in a panel. Then the fire inspector did not like the original fire pump disconnect that was next to the MDP.

The original fire pump disconnect was tapped from the bus in the MDP with #2's in rigid pipe and had OCPD that was set at 125A. The fire inspector said this circuit should be run directly from the padmount. This would involve significant work.

I'm not sure how this design came about. The AHJ approved a new 600A fused (at 600A) disconnect with #1's using the same rigid pipe and tapped at the same location on the bus in the MDP. The outage was night before last and we got a green tag.

All the conductors are inside.

 

[gadfly56]

I had a service call last week to run a new circuit for the jockey pump in a forty year old building. The fire pump controller had been replaced and the fire inspector wanted the jockey pump on its own circuit.

The original jockey pump circuit was tapped at the line side of the fire pump controller's OCPD. I moved the jockey pump circuit to a new 3p20a breaker in a panel. Then the fire inspector did not like the original fire pump disconnect that was next to the MDP.

The original fire pump disconnect was tapped from the bus in the MDP with #2's in rigid pipe and had OCPD that was set at 125A. The fire inspector said this circuit should be run directly from the padmount. This would involve significant work.

I'm not sure how this design came about. The AHJ approved a new 600A fused (at 600A) disconnect with #1's using the same rigid pipe and tapped at the same location on the bus in the MDP. The outage was night before last and we got a green tag.

All the conductors are inside.

AHJ's can do what they want, I suppose, but as the installer I'd be a little nervous. FHJR listed cable was acceptable as an alternative to burying all the interior wiring in a concrete floor or covering it with 2" of brick or concrete (like a termite run on the surface of CMU). The whole "hoo-hah" with CI and CIC cable at UL had them pull the listing for all the existing cable (RHH and RHW types) and no one's gotten a new listing that I'm aware of for flexible cable (MI being "flexible" for very limited values of "flexible").