Fire pump riser

[mcelweec@gmail.com]

Im on a project where they want to run the fire pump riser up a shaft to the roof of an 11 story
building to a generator,since they are encasing the fuel lines in concrete they have given me the option of running GRC.The conductors are 600mcm cu,which require a support every 40 ft,can a regular box be used at each interval,or do I need to put the box behind a 2 hr rated access panel?

 

[gadfly56]

Is there a disconnecting means at the generator?

 

[iwire]

I cannot answer your question but I will say I was in a project before where an emergency generator was planed for, purchased and instaled on a roof and it still sits there unused as during the inspection process the fire deptment said no way. They did not allow emergency generators on the roof of the building they are serving.

Take it for what it is worth.

 

[mcelweec@gmail.com]

A generator on the roof is a common install in NYC ,with the conductors from the generator to the fire pump having to be either M.I. Cable or in GRC and concrete encased.

 

[DARUSA]

A generator on the roof is a common install in NYC ,with the conductors from the generator to the fire pump having to be either M.I. Cable or in GRC and concrete encased.

Also RHH 2 hrs fire rate cable is allowed too.EMT conduit,steel couplings also pipe need to be supported every 6feet , proper support for the wire is required too!!!

 

[iceworm]

... they want to run the fire pump riser up a shaft to the roof ...

Q: What exactly is a "riser"?

It appears to be a slang term - which is okay, it can still have a definitation.

From context here are a few definitions I've found:
1. A vertical conduit.
2. In "Riser Diagram":

2a. A drawing showing vertical and horizontal conduits routing
2b. Occasionally seems to refer to a "one-line diagram". Which has nothing to do with couduit routing​

Maybe it is a commercial building slang term. I've been hanging around industrial dirt dawgs (field hands) for over forty years and "riser" is rarely to never used.

Maybe it is a slang term that is defined by context - similar to many other fine American slang terms.

Whoops - I got to go the work. Maybe back tomorrow.

ice

 

[iwire]

Q: What exactly is a "riser"?

It appears to be a slang term -

I would not call it slang, it appears in the NEC many times and typically means a cable, conduit, bus duct bringing a circuit to a a floor or more above from where it starts.

 

[iceworm]

I would not call it slang, it appears in the NEC many times and typically means a cable, conduit, bus duct bringing a circuit to a a floor or more above from where it starts.

You're right it does. I did a search - 213 times in the 2011.

I'll leave the question on "riser diagram" for another day.

ice

 

[iwire]

You're right it does. I did a search - 213 times in the 2011.

Well now I learned something, I would have guessed a dozen.


The riser diagram is just the print that shows all the risers. I might be able to post one if you would like

 

[brian john]

I cannot answer your question but I will say I was in a project before where an emergency generator was planed for, purchased and instaled on a roof and it still sits there unused as during the inspection process the fire deptment said no way. They did not allow emergency generators on the roof of the building they are serving.

Take it for what it is worth.

In Washington DC it is done all the time and typically MI for distribution. Saw a job with 500 kcmil MI cable..STRONG ELECTRICIANS

 

[iwire]

In Washington DC it is done all the time.

There are many around here as well, it just happens no 'emergency generators' on roofs in that jurisdiction. We could load the same roof with as many 'optional standby generators' as we want.

Truthfully I see some logic in it.

 

[iceworm]

Well now I learned something, I would have guessed a dozen. ...

I only looked at 20 or so. All but one were about vertical raceways.

... The riser diagram is just the print that shows all the risers. ...

So, it only shows the routing of the vertical conduits? Does not show the routing for the horizontal conduits? That seems strange.

... I might be able to post one if you would like

Don't spend any extra time. I deal with a lot of drawings showing cabletray, conduit, and MC cable routings. These same drawings also show equipment locations. The drawings will be titled "Equipment Layout".

ice

 

[jusme123]

...was on project where they put generator on roof and ran cable tray up the side of the building from the basement.

 

[infinity]

Also RHH 2 hrs fire rate cable is allowed too.EMT conduit,steel couplings also pipe need to be supported every 6feet , proper support for the wire is required too!!!

Is the 6' support rule a separate NYC requirement? Also where in the NYC electrical code would the 2 hour rated conductors in EMT fall under? Would that apply to only limited service fire pumps?
Here's the 2011 NYC requirement:

SECTION 695.6
Section 695.6 ? Revise to read as follows:
695.6 Power Wiring. Power circuits and wiring methods shall comply with the requirements in
695.6(A) through (E), and as permitted in 230.90(A), Exception 4; 230.94, Exception 4; 230.208;
240.4(A); 240.13 and 430.31.
(A) Supply Conductors. Fire pump and limited service fire pump supply conductors shall be physically
routed outside a building(s) and shall be installed as service entrance conductors. Where supply
conductors cannot be physically routed outside buildings, routing through buildings is permitted where
installed in accordance with Section 230.6(1), (2), (4) or (5).
Exception: The supply conductors located in the electrical service room and generator room where they
originate and in the fire pump room shall not be required to have the minimum 2-hour fire separation or
fire resistive rating.
(B) Circuit Conductors.
(1) Fire Pumps. Fire pump supply conductors, including emergency supply conductors where
emergency power is provided, on the load side of the final disconnecting means and overcurrent device
shall be kept entirely independent of all other wiring. They shall supply only loads that are directly
associated with the fire pump system, and shall be protected to resist potential damage by fire, structural
failure, or operational damage. They shall be permitted to be routed through a building(s) using one of
the following methods:
(1) Encased in a minimum of 50mm (2 in.) concrete using rigid metal conduit (steel RMC),
intermediate metal conduit, electrical metallic tubing or schedule 80 non-metallic conduit.
(2) Rigid metal conduit (steel RMC) within an enclosed construction dedicated to the fire pump
circuit(s) having a minimum of a 2-hour fire resistance rating.
(3) A listed electrical circuit protective system with a minimum 2-hour fire resistance rating. The
installation shall comply with any restrictions provided in the listing of the electrical circuit
protective system.
Exception: The supply conductors located in the electrical service room and generator room where they
originate and in the fire pump room shall not be required to have the minimum 2-hour fire separation or
fire resistive rating.
(2) Limited Service Fire Pumps. Limited service fire pump supply conductors shall be installed in rigid
metal conduit (steel RMC) or intermediate metal conduit (steel IMC).
Exception: Where there are multiple sources of supply with means of automatic transfer from one
source to the other, electrical metallic tubing (EMT) shall also be permitted.

 

[don_resqcapt19]

...So, it only shows the routing of the vertical conduits? Does not show the routing for the horizontal conduits? That seems strange. ...

It is not really a conduit layout, but more of a one line type drawing. The equipment on an elevation will be shown on that elevation, but you have no idea of where on that elevation that the equipment will be located. You will find the actual locations on other drawings. This drawing will generally show the origination and ending points for the conduits, the conduit size and the size and number of conductors. It will also show the breaker and or panel sizes. It gives you a good general overview of the electrical systems. You will also find riser diagrams for other systems such as sound and fire alarm. You many even see a "riser" diagram for larger single story facilities.

 

[iceworm]

...This drawing will generally show the origination and ending points for the conduits, the conduit size and the size and number of conductors. It will also show the breaker and or panel sizes. It gives you a good general overview of the electrical systems. You will also find riser diagrams for other systems such as sound and fire alarm. You many even see a "riser" diagram for larger single story facilities.

Okay.
A "Riser Diagram" does not have anything to do with physical routing of "risers".

It is not really a conduit layout, but more of a one line type drawing. ...

From your description, a 'Riser Diagram" is exactly a "One-Line" drawing. What more would you say it takes to be a one-line?

What will be the title on these drawings? "Riser Diagram"? or "One-line diagram"? I've never seen a drawing titled "Riser Diagram".

Is "Riser Diagram" a slang term that means "One-Line Diagram"? If the term appears as a drawing title, I would not consider it to be slang.

ice

 

[don_resqcapt19]

Okay.
A "Riser Diagram" does not have anything to do with physical routing of "risers".


From your description, a 'Riser Diagram" is exactly a "One-Line" drawing. What more would you say it takes to be a one-line?

What will be the title on these drawings? "Riser Diagram"? or "One-line diagram"? I've never seen a drawing titled "Riser Diagram".

Is "Riser Diagram" a slang term that means "One-Line Diagram"? If the term appears as a drawing title, I would not consider it to be slang.

ice

Most sets of electrical drawings that have riser diagrams also have one-lines. The level of electrical detail is greater on the one-line than on the riser. The drawing titles would be "one-line" and "riser" as the case may be. While the riser does not have physical routing of the conduits, it does show the floors that the equipment is on. That is not normally found on the one-line.

 

[iwire]

Don described the differences I see.

I find the riser print to be one of the more helpful prints when trying to get an overall feel for the job.

In short it shows me what equipment is on what level, and the conduit information but not routing in between.

It is nice when they also include notes under the equipment with the room information (Electric room 1B etc)

Some of our jobs forgo the 'one line' and provide the info on the riser plan.

 

[iceworm]

Most sets of electrical drawings that have riser diagrams also have one-lines. The level of electrical detail is greater on the one-line than on the riser. The drawing titles would be "one-line" and "riser" as the case may be. While the riser does not have physical routing of the conduits, it does show the floors that the equipment is on. That is not normally found on the one-line.

Don described the differences I see.

I find the riser print to be one of the more helpful prints when trying to get an overall feel for the job.

In short it shows me what equipment is on what level, and the conduit information but not routing in between.

It is nice when they also include notes under the equipment with the room information (Electric room 1B etc)

Some of our jobs forgo the 'one line' and provide the info on the riser plan.

Now, I'm thinking the use is primaily multi-story commercial. I can see where the information and layout on a "Riser Diagram" are extremely helpful.

I've worked Navy (surface ships and subs), refinery, paper and pulp, pipeline, and small utility. "One-line drawings", "Equipment Layout drawings", panel schedules, and a cable schedule spreadsheet are the predominent building directions. After building is complete, the one-line becomes the predominent maintenance tool. That's the one needed for arc-flash calculation or energy isolation.

Learned something new today. And who knows, I may see a riser diagram some day.

Thanks,

ice

 

[DARUSA]

Is the 6' support rule a separate NYC requirement? Also where in the NYC electrical code would the 2 hour rated conductors in EMT fall under? Would that apply to only limited service fire pumps?
Here's the 2011 NYC requirement:

It falls under:
(3) A listed electrical circuit protective system with a minimum 2-hour fire resistance rating. The
installation shall comply with any restrictions provided in the listing of the electrical circuit
protective system. Also the 6 feet falls under 110.3b manufacturer requirement.
Take a look here:http://www.datatechtx.com/pdf/lifeline/FPU-05.pdf
Thx