# Save me from idiots (Fire Sprinkler system)



## flyingron (Dec 15, 2020)

Over Memorial Day weekend one of the pipes feeding a fire sprinkler head in our guest bath developed a small leak. The sprinkler company, after initially claiming they didn't install our system, came out and said they needed to order parts for it. They shutoff and drained the system.

Several days ago frick and frack, the plumbers, show up to fix the system. They come up to me and say the electrical is not working, the motor starter closes but the pump don't run, just hums. Of course, these guys don't have a clue. I get my meter out and open the control panel. While there appears to be a 2-pole disconnect and the unit appears to be a 240V unit, I'm reading 120V to ground on L1 and 0V (hard) L2 to ground, and 120V L1 to L2. I can't even find the breaker, so I send frick and frack home (no point in having these guys watch me diagnose things).

After hunting down the breaker around a bit I find that L2 is indeed connected to the neutral bus in the panel. That's odd. I look at the motor. Well, it can be strapped for either 120 or 240. I take the cover off. Nope it's set up for 240V. Well this thing USED to work and nobody has touched it. Anyhow, for jollies I move the L2 wire over to 240V. Now it hums louder for about eight seconds before the thermal kicks it off.

Hmm. The manual is not in good shape but I don't see any clues there. I call up the manufacturer but the guy who knows about this system is in a meeting. He finally does call me back when I'm away from the house and don't get to talk to him.

In the meantime, I download a copy of the manual. The section on "Filling the system" has a big NOTICE box that says: Fill system using domestic water supply. Do not use pump and tank for initial fill of the sprinkler system, and then gives step by step instructions to do that and purge the air out of the system.

First, step. Hunt around looking for a female-to-female (aka washing machine) hose that is necessary to connect the drain on the system to the hose bib. Of course, it's not quite long enough so find a hose not in use elsewhere. Throw all the valves and watch the system come up to the tap pressure. So far so good.

Now it says to loosen a bolt on the pump to allow any trapped air out. I loosen it. Not much happens. Loosen it some more. A little air and some water comes out. Loosen it more. The bloody plug comes out and flies across the basement followed by a geyser of water. I stuff my finger in the hole like the little Dutch boy. However, I can't reach the hose bib to turn off the water. Great. Take my hand away and dive for the valve and get it shutoff, but I'm soaked.

Put the plug back in. Turn all the valves to the operating position. Turn the system on to automatic. The thing cycles about six times and then sits there showing good pressure. Dry off, clean up. Put the covers back on everything.

So we have:

1. Plumbers who can't read manuals (and no clue what they're doing).
2. The electrician who wired it up not only to the wrong voltage, but committed a code violation or two in the process.

I'm not sure why it ever work, but the pump must have turned enough on 120V when wired for 240 to bring the system up to pressure. I had stood there when it was installed with the fire marshall (I was the first in our county to get one of these things) while we tested it (right down to hearing them dispatch the fire call over his radio).

No question, just venting. I hate plumbing (don't get me started on irrigation systems. The only thing worse than plumbing is plumbing I have to dig for).


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## Thom Paine (Nov 24, 2021)

[/QUOTE]


Great story of intrepid perseverance !! congrats !

What you experienced happens to Pros also.

That strange guy "yellin' at the sky" or "barking at the moon" might just be a General Contractor.[/QUOTE]


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## Thom Paine (Nov 24, 2021)

Dupe delete


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## Old Thomas (Nov 28, 2019)

You have a fire pump? Is it on a well, storage tank or a booster pump?


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## rogerwh (Mar 1, 2021)

Old Thomas said:


> You have a fire pump? Is it on a well, storage tank or a booster pump?


That’s what I was thinking. Like to see a model number and manufacturer name.


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## Old Thomas (Nov 28, 2019)

I have inspected a lot of buildings and I have never seen a fire pump in a single family residence. I am curious about the structure and it’s fire protection system.


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## flyingron (Dec 15, 2020)

I have the first (and probably only) residence in our county with a dedicated fire sprinkler system. Most residential systems are fed from the regular domestic water supply. I'm kind of out in the boonies, and spent years as a firefighter and my grandfather was the chief deputy in a major NE fire department.

My system is designed for residential but it's on the higher end. It has a big polytank that feeds the fire pump and dedicated piping out to the various sprinkler heads. There's even an FDC connection on the outside of my house. The system is from here: Custom RFP Systems - General Air Products. Mine looks pretty much just like the one in the picture there.

Essentially, the thing fills with water and pressurizes the system. If there's a fire, the fusible link in the head goes and water flows. The pressure drops causing the controller to kick the pump on. I'm on a well, so I have the poly tank. If I had put the pool in when I built the house, they would have just drawn water from the pool instead. The poly tank is refilled from the domestic water supply. Hopefully, by then the fire is out or the engines have arrived and they've hooked an inch and a half up to the FDC and are pumping into the system.

I can tell you after years in the fire service, fires in (properly) sprinklered buildings are non-events. We just go in, turn off the water temporarily, replace the head that's off, and turn it back on.

Here's a picture of the house here: House_Fernando


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## hornetd (Oct 30, 2014)

Old Thomas said:


> I have inspected a lot of buildings and I have never seen a fire pump in a single family residence. I am curious about the structure and it’s fire protection system.


National Fire Protection Association Standard 13D Standard for the Installation of (Fire) Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes is the standard that is used for the inspection and acceptance of fire sprinkler systems in 1 & 2 family detached homes. One version of such a system is called a limited water supply system. Just as* flyingron *described it, they are installed in homes which are not supplied by a domestic water system which will provide a sufficient volume of water at the pressure required to discharge an effective pattern of water spray to extinguish or control an incipient fire. To make up for the inadequacy of such a home's domestic water supply's inadequacy these systems are fitted with a fire pump and water reservoir that is capable of supplying the needed supply to the sprinkler system to either extinguish the fire or hold it from spreading until manual fire suppression personnel and equipment can be brought into action to supplement the systems water supply and complete extinguishment. 

Tom Horne


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## GrayHair (Apr 9, 2015)

I serviced fire alarms and inspected sprinkler systems for many years, and like @Old Thomas, never encountered a residential fire pump. One is never too old to learn and if you're not learning, you are stagnating. Thanks!


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## Old Thomas (Nov 28, 2019)

Now I understand, thanks for explaining. Curious, does the pump have a backup power supply? You are correct, GrayHair, live and learn.


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## GrayHair (Apr 9, 2015)

Old Thomas said:


> Curious, does the pump have a backup power supply?


I would think not, unless the residence has a suitably sized automatic back-up generator. 

Off the top of my head, I don't remember a commercial fire pump with back-up power. But the controllers are often service rated and connected ahead of the main disconnect. It would take quite a genny to start a 3-phase pump motor.


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## hornetd (Oct 30, 2014)

GrayHair said:


> I would think not, unless the residence has a suitably sized automatic back-up generator.
> 
> Off the top of my head, I don't remember a commercial fire pump with back-up power. But the controllers are often service rated and connected ahead of the main disconnect. It would take quite a genny to start a 3-phase pump motor.


Yes it does take "quite a genny" to start a Standard 13 sprinkler system fire pump but that is not how they are sized. Unlike all of the other power electrical systems supplying fire pumps the "Engine Alternator Set" (Generator), which is the back up supply for a a fire pump, must be capable of delivering 125% of the motors load continuously. The only bit of slack that we got around the Metropolitan Washington, District of Columbia area was that the generator could be fueled with natural gas because of the Washington Gas Light Company's record of service reliability. NFPA # 20 Standard for the installation of fire pumps has several requirements for the alternate source of power required for fire pumps. 

The pumps used in NFPA 13D; for Domestic; systems are not required to have a back up power source. They're not even required to be supervised for power availability. All of that is left to the occurrence of periodic testing the interval between which I do not now recall.

Tom Horne


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## flyingron (Dec 15, 2020)

The house in question does have a backup generator, 80 KW worth with automatic start and transfer switch.


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## jbfan (Jul 1, 2004)

The building I maintain had 2 pumps. One, the original, was a diesel installed in 1973. The other one, and electric, installed in 1988. 
Both decided to go tang uniform within 1 month of each other last year.
We opted to increase the size of the electric pump, and abandon the diesel.
Both have their advantages. The main one for the diesel, was it came on with a power loss.
The electric pump is feed before the building with it's own transformer.
We were asked if we wanted it added to the generator, but we said no.


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## hornetd (Oct 30, 2014)

jbfan said:


> The building I maintain had 2 pumps. One, the original, was a diesel installed in 1973. The other one, and electric, installed in 1988.
> Both decided to go tang uniform within 1 month of each other last year.
> We opted to increase the size of the electric pump, and abandon the diesel.
> Both have their advantages. The main one for the diesel, was it came on with a power loss.
> ...


Out of nothing more than idle curiosity may I ask why you decided against adding generator back up to it. 

Tom Horne


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## jbfan (Jul 1, 2004)

hornetd said:


> Out of nothing more than idle curiosity may I ask why you decided against adding generator back up to it.
> 
> Tom Horne


My back up generator would not support the extra load of the fire pump.


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## hornetd (Oct 30, 2014)

jbfan said:


> My back up generator would not support the extra load of the fire pump.


I thought that might be it but I just wanted to actually know. Thank you for taking the time to answer. 

On a couple of hotel builds we built load shedding into the fire pump and generator installs so that if the fire pump was needed a control circuit would shunt trip some of the feeder breakers open freeing up enough capacity from the generator to run the fire pump at the NFPA 20 required ampacity. 

-- 
Tom Horne


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