Fire pumps and generators

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mshields

Senior Member
Location
Boston, MA
In a medical office building low rise building that needs a fire pump. There is an argument in office as to whether or not the fire pump requires generator backup.

I haven't done a fire pump in a while but it seems to me that I've seen fire pumps without generators. Of course they need to be tapped ahead of the main but I thought the generator was only a requirement if it were a high rise.

Also, in the back of my mind I recall seeing taps ahead of the service transformer and a dedicated service transformer put in for the fire pump. Is that an option.

Thanks,

Mike
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
In a medical office building low rise building that needs a fire pump. There is an argument in office as to whether or not the fire pump requires generator backup.

I haven't done a fire pump in a while but it seems to me that I've seen fire pumps without generators. Of course they need to be tapped ahead of the main but I thought the generator was only a requirement if it were a high rise.

Also, in the back of my mind I recall seeing taps ahead of the service transformer and a dedicated service transformer put in for the fire pump. Is that an option.

Thanks,

Mike

Take a look at NFPA 20 Chapter 9 and NFPA 20 Annex A starting in A9.x... It is often the case that an alternate source will be required even in a low rise application.
 

mgookin

Senior Member
Location
Fort Myers, FL
In a medical office building low rise building that needs a fire pump. There is an argument in office as to whether or not the fire pump requires generator backup.

I haven't done a fire pump in a while but it seems to me that I've seen fire pumps without generators. Of course they need to be tapped ahead of the main but I thought the generator was only a requirement if it were a high rise.

Also, in the back of my mind I recall seeing taps ahead of the service transformer and a dedicated service transformer put in for the fire pump. Is that an option.

Thanks,

Mike

I suggest you call the fire marshal that has jurisdiction.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Take a look at NFPA 20 Chapter 9 and NFPA 20 Annex A starting in A9.x... It is often the case that an alternate source will be required even in a low rise application.

It will hinge on what the AHJ considers "reliable" power. Here in NJ you are usually covered if you tap on the line side of the service entrance conductors, no additional sources are needed for low-rise construction.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
It will hinge on what the AHJ considers "reliable" power. Here in NJ you are usually covered if you tap on the line side of the service entrance conductors, no additional sources are needed for low-rise construction.
But the cited Annex section gives the AHJ guidance as to what may or may not be a reliable source of power. It is fairly restrictive.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
But the cited Annex section gives the AHJ guidance as to what may or may not be a reliable source of power. It is fairly restrictive.

It's not that bad. I'd guess that over 95% of NJ would be "reliable" based on no more than 10 continuous hours of outage in the previous year. Could be tough if you had decided to install a fire pump the year after Sandy came ashore :lol:. And further note that the Appendix A material specifically says your power doesn't have to be perfect. See A.9.3.2 (1) and (2).
 

iwire

Moderator
Staff member
Location
Massachusetts
It's not that bad. I'd guess that over 95% of NJ would be "reliable" based on no more than 10 continuous hours of outage in the previous year. Could be tough if you had decided to install a fire pump the year after Sandy came ashore :lol:. And further note that the Appendix A material specifically says your power doesn't have to be perfect. See A.9.3.2 (1) and (2).

Code aside do you feel one supply is a good design?

Doesn't the buildings insurer have input here?
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Code aside do you feel one supply is a good design?

Doesn't the buildings insurer have input here?

Personally I'm a belt-and-suspenders kind of guy and generally I'd like to see a second source for electric drive pumps. However, I'm not paying the bill so anything above code compliant depends on the largess of the owner. Owners who have had to deal with a major fire loss in the past tend to be quicker to open the vault for this kind of option.

Insurers could raise the bar but I haven't seen much of that with regard to pump motive power. Unless the insurers are colluding with each other, an owner can probably find an underwriter who's fine with the code minimum.
 

iwire

Moderator
Staff member
Location
Massachusetts
Personally I'm a belt-and-suspenders kind of guy and generally I'd like to see a second source for electric drive pumps. However, I'm not paying the bill so anything above code compliant depends on the largess of the owner. Owners who have had to deal with a major fire loss in the past tend to be quicker to open the vault for this kind of option.

Insurers could raise the bar but I haven't seen much of that with regard to pump motive power. Unless the insurers are colluding with each other, an owner can probably find an underwriter who's fine with the code minimum.

Thanks.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
It's not that bad. I'd guess that over 95% of NJ would be "reliable" based on no more than 10 continuous hours of outage in the previous year. Could be tough if you had decided to install a fire pump the year after Sandy came ashore :lol:. And further note that the Appendix A material specifically says your power doesn't have to be perfect. See A.9.3.2 (1) and (2).
List item 3 is not really clear...I think it is talking about the overhead service drop, but if it includes overhead distribution and transmission, almost no utility supply would be reliable.
3 The normal source of power is not supplied by overhead conductors outside the protected facility. ...
 

topgone

Senior Member
In a medical office building low rise building that needs a fire pump. There is an argument in office as to whether or not the fire pump requires generator backup.

I haven't done a fire pump in a while but it seems to me that I've seen fire pumps without generators. Of course they need to be tapped ahead of the main but I thought the generator was only a requirement if it were a high rise.

Also, in the back of my mind I recall seeing taps ahead of the service transformer and a dedicated service transformer put in for the fire pump. Is that an option.

Thanks,

Mike
Think out of the box! If the discussions/arguments in your office revolves around solving the possibility of having no fire pump providing the needed water for fire fighting (during blackouts), why go for a backup generator when you can buy an engine-driven fire pump? Is it hard to find engine-driven pumps in your area?
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
Think out of the box! If the discussions/arguments in your office revolves around solving the possibility of having no fire pump providing the needed water for fire fighting (during blackouts), why go for a backup generator when you can buy an engine-driven fire pump? Is it hard to find engine-driven pumps in your area?

Been involved with many diesel powered fire pumps over the years. They have there place, but bring on a whole host of other issues. Every job is unique so only a full engineering analysis can tell you the best type of pump/prime mover.
 

junkhound

Senior Member
Location
Renton, WA
Occupation
EE, power electronics specialty
Sidelight story on fire pumps with backup gen. -- aka, supports 'full engineering analysis" approach of the previous comments.

Facility I was working in 2001 when Seattle area had a 6.9 earthquake had large water storage tanks plus a river pickup with diesel driven backup fire pumps as many of the buildings contained high value electronic areas and hazardous materials.

Anyway, some of the buildings were totaled, a couple because of the fire pumps. Earthquake knocked out power.

Earthquake broke some of the main 8" fire pump feeders. Pumps and diesels came on full bore trying to maintain pressure in the wet fire mains. Totally flooded buildings 'from the inside' and damaging walls from water pressure.

One person had the 8" main that ran above their office break. 10 ft by 12 ft office. Filled in a matter of seconds, door opened to inside of office. Luckily was able to break a window to get out before drowning!
 

Sahib

Senior Member
Location
India
An overhead tank with sufficient capacity may not require even a fire pump. But what is the code provision in that respect?
 

junkhound

Senior Member
Location
Renton, WA
Occupation
EE, power electronics specialty
overhead tank

That is what used to be the case in major cities (maybe not in India?)

If one takes Amtrak into Midwest or east coast cities (esp Chicago), one sees literally hundreds of small towers on top of late 19th and early 20th century buildings with nothing on them. Used to be wooden water tanks for fire reservoirs !

There are still two businesses in NYC that repair old wooden water tanks. http://www.nydailynews.com/news/mon...-tank-icons-new-york-skyline-article-1.329344
 

ron

Senior Member
overhead tank

That is what used to be the case in major cities (maybe not in India?)

If one takes Amtrak into Midwest or east coast cities (esp Chicago), one sees literally hundreds of small towers on top of late 19th and early 20th century buildings with nothing on them. Used to be wooden water tanks for fire reservoirs !

There are still two businesses in NYC that repair old wooden water tanks. http://www.nydailynews.com/news/mon...-tank-icons-new-york-skyline-article-1.329344

This is a picture from my window this morning at about 20 of them (maybe a few more than 20)
IMG_0887.jpg
 
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