Conductors to Fire Pump

[Fitzdrew516]

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

 

[iwire]

Why not run the tap from the pad mount on the ground?

 

[Fitzdrew516]

Why not run the tap from the pad mount on the ground?

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

 

[ron]

I think the reference takes you to 230.6 for conductors outside the building, but does not necessarily allow them to be run across the roof and down the wall out to the pumphouse, and be considered "outside" even though intuitively they seem to be.

 

[mgookin]

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

It's certainly a common way to power a 2nd building, which is what you're doing I believe. Customer will probably have a 2nd electric bill to deal with assuming the meters are load side of the tranny, but that's ok.

 

[petersonra]

I think the reference takes you to 230.6 for conductors outside the building, but does not necessarily allow them to be run across the roof and down the wall out to the pumphouse, and be considered "outside" even though intuitively they seem to be.

It appears to me that 230.6 is not defining all cases of what constitutes an "outside" conductor, but rather is adding some cases where one can consider conductors as being "outside" when they might well be considered not outside otherwise.

The word outside does not appear to have any special definition in the code so we have to use the dictionary definition. I think it is unlikely that any definition of outside would not include being located on the roof or other exterior location of a building exposed to the weather (except on one side).

 

[ron]

It appears to me that 230.6 is not defining all cases of what constitutes an "outside" conductor, but rather is adding some cases where one can consider conductors as being "outside" when they might well be considered not outside otherwise.

That is not what AHJ's have enforced in my experience.

The language in 230.6 appears to define what it means for conductors to be outside in the case of services and when other sections refer the reader to 230.6, like this one.

I would hate for a fire on an upper floor to damage un-rated conductors on a roof, and stop a fire pump from protecting the rest of the building.

 

[petersonra]

That is not what AHJ's have enforced in my experience.

The language in 230.6 appears to define what it means for conductors to be outside in the case of services and when other sections refer the reader to 230.6, like this one.

I would hate for a fire on an upper floor to damage un-rated conductors on a roof, and stop a fire pump from protecting the rest of the building.

so are you claiming that service conductors run on messenger wires from poles are not outside?

I don't have an issue with suggesting that fire pump conductors should not be run in a conduit across the roof if that adds some extra danger, but I am not convinced 230.6 is the reason not to do so.

 

[ron]

so are you claiming that service conductors run on messenger wires from poles are not outside?

I'm not, but I suspect somewhere in 230, it allows service conductors to be on messenger wires and does not require the conductors to be "outside the building"

 

[david luchini]

I'm not, but I suspect somewhere in 230, it allows service conductors to be on messenger wires and does not require the conductors to be "outside the building"

I don't think there is any such allowance for service conductors on messenger wires in Art. 230.

I agree with Bob, 230.6 lists conditions where conductors which are physically within or beneath a building or structure are "considered" to be outside of the structure.
I don't see any conditions in 230 where conductors which are physically outside of a building or structure shall be considered to be inside the structure.

 

[Fitzdrew516]

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

 

[iwire]

NEC aside in this area we are often prohibited from placing emergency generators on roofs. I doubt we would be allowed to run fire pump conductors across a roof as described either.

 

[GoldDigger]

NEC aside in this area we are often prohibited from placing emergency generators on roofs. I doubt we would be allowed to run fire pump conductors across a roof as described either.

I see two potential reasons to prohibit fire pump conductors "inside" the building.
One is to reduce their exposure to fire damage, which argues against running either on the roof or on a non-fire-resistant outside wall.
The other is the same as for general service conductors, namely keeping conductors without effective OCPD from starting fires inside the building. By this criterion on the roof might be OK.

 

[mgookin]

Oh, man I've sparked some conversational debate! I love it! In any case,...
-Drew

We're pretty sure we're all related somehow.
We just haven't figured out how yet.

 

[GoldDigger]

We're pretty sure we're all related somehow.
We just haven't figured out how yet.

In the words of an SF short story:
"If all men were brothers, would you want your sister to marry one?"

 

[gadfly56]

On the Roof??

On the Roof??

Why is the fire pump on the roof? Usually it's easier to push water than it is to pull it. Is the building built into the side of a hill where the water service comes in from the top?

 

[mgookin]

.... The issue is that the main electrical service is going to be in a "penthouse" at roof level. ...

... Is running the conductors across the roof and down the wall out to the pumphouse located by the fire pond OK? ...
Thanks,
Drew

Why is the fire pump on the roof? Usually it's easier to push water than it is to pull it. Is the building built into the side of a hill where the water service comes in from the top?

Service is at roof level.
Pump is in an outbuilding.

 

[iwire]

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.

Many of the large box stores we do have the service in the rear and the fire pump at the front as far as I know we leave the pad mount twice, once to the service and once to the fire pump. I don't know how the fire pump power company metering is handled.

 

[Fitzdrew516]

Thanks for the help, guys. One more thing - I just got off a conference call with the fire protection engineer and what he designed was a system that would need 2 separate services (One for the fire pump controller and one for the jockey pump controller). So essentially what he is proposing is off the secondary of the utility xfmr I would have (3) services: (1) To the building's service and (2) to the pump-house for each of the pumps.

Now... this seemed odd and pretty asinine to me. So I asked him - Why wouldn't we have one feed straight to the fire pump controller which then fed the fire pump and the jockey pump? His answer - "Uh, I'm pretty sure that's code". A couple things with that -

A) I've never seen any code that would say you need two separate services for each pump; kinda dumb if you ask me.

B) From a logical standpoint I can't tell you why 2 services would benefit from a life safety point of view; I mean, if one service goes down the whole system isn't going to run regardless. It's not like that's some sort of contingency to ensure it works.

C) If anything wouldn't this be against code? Assuming both pumps are the same voltage you can't have two services to a building unless approved by an AHJ.

Anyway - this is a curve ball thrown at me. This guy didn't sound too confident and I'm not quite sure he knows what he is talking about. So I guess my question is: Is there some sort of code that would require this, or is the guy off his rocker?

Thanks again,
-Drew

 

[ron]

a system that would need 2 separate services (One for the fire pump controller and one for the jockey pump controller). So essentially what he is proposing is off the secondary of the utility xfmr I would have (3) services: (1) To the building's service and (2) to the pump-house for each of the pumps.

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.