Diesel fire alarm pump overheating 1

[AlarmTec]

Does anyone know of any code or standard that says "a fire alarm diesel pump must be able to run this long before blowing up itself'?
I was on a project where the specs required a 10 hour diesel tank but the pump died after running for 2 1/2 hrs.
According to the tech the heat exchanger became clogged with debris from the pond it was using for a source of water.

 

[cdafd]

1. What is a fire alarm diesel pump?

2. Is this a diesel water pump ???

3. If so what is it feeding? Fire hydrants? Fire sprinkler system? Other???

4. Why is it running so long, or why does it have to run so long

 

[AlarmTec]

1, 2&3. It is a diesel water pump that feeds a sprinkler system and gets its water from a pond.

4. When the pump starts it has to be manually stopped. It ran for four hours because no one knew that it was running.

 

[cdafd]

Thanks for the clarify

1. So what is the sprinkler system protecting??
Storage, hanger , office building?? ????

2. Some reason it is not monitored for pump running??

 

[AlarmTec]

1. It is protecting an assisted living facility.

2. Pump running contact was being monitored but the system was shut down by the electrical while installing a generator. An underground leak started the pump and it ran 2 1/2 hrs until the electrical restored power. By this time the pump had overheated from a clogged heat exchanger by debris sucked from the pond.


So that is why I am curious to if there is something with pump code or design requirements that says it should be able to run for XX time. (ignoring the pond debris)

 

[skdesigner]

If I might make an observation, "ignoring the pond debris" might be why you no longer have a working fire pump engine. NFPA 20 specifies a minimum fuel tank capacity, not a minimum run-time. Fire pump drivers are designed to run to destruction - the thought process being that it is better to sacrifice the equipment than to lose water supply to the suppression system until the last possible second.

The issue is not that the engine didn't run for as long as it should have, it is that the unit was installed improperly in the first place (or quite possibly, the wrong unit was installed). This underscores how incredibly crucial it is to have a knowledgeable engineer to specify the system, a knowledgeable contractor to install the system, and then to have that followed up with a comprehensive inspection, testing and maintenance program (NFPA 25).

It sounds like your fire pump unit did exactly what it was designed to do: start-up after sensing a loss in system pressure and keep spinning for as long as it possibly could. The silver lining is that this did not happen in an emergency situation. Engines can be replaced, lives can't.




R M Arsenault Engineering Inc.

http://www.rmae.ca

 

[cdafd]

Not sure what current nfpa says if it says anything

But set the pump to run till someone shuts it off
Or

Set it to shut off after so long and if it senses no loss of pressure it stays off, but if it senses loss of pressure it kicks back on??

 

[AlarmTec]

Thank you for the reply skdesigner.

I think you are exactly correct. If I may ask everyone another question... On a "properly designed and installed" system, should the pump be able to run for 2 1/2 hrs without damaging itself?

 

[cdafd]

In nfpa 13 saw that one hazard required a hour and a half of water supply

 

[LCREP]

A few things to consider. The controller monitoring was taken out of service. Did they follow an impairment plan as per NFPA 25? See below

15.5* Preplanned Impairment Programs.
15.5.1 All preplanned impairments shall be authorized by the impairment coordinator.
15.5.2 Before authorization is given, the impairment coordinator shall be responsible for verifying that the following procedures have been implemented:
(1) The extent and expected duration of the impairment have been determined.
(2) The areas or buildings involved have been inspected and the increased risks determined.
(3) Recommendations have been submitted to management or the property owner or designated representative.
(4) Where a required fire protection system is out of service for more than 10 hours in a 24-hour period, the impairment coordinator shall arrange for one of the following: (a) Evacuation of the building or portion of the building
affected by the system out of service
(b)*An approved fire watch
(c)*Establishment of a temporary water supply (d)*Establishment and implementation of an approved program to eliminate potential ignition sources and limit the amount of fuel available to the fire
(5) The fire department has been notified.
(6) The insurance carrier, the alarm company, property
owner or designated representative, and other authorities having jurisdiction have been notified.
7. The supervisors in the areas to be affected have been notified.
8. A tag impairment system has been implemented. (See Sec- tion 15.3.)
9. All necessary tools and materials have been assembled on the impairment site.

If they followed NFPA 25 someone should have been checking the pump since the monitoring was impaired. Had the controller been monitored it would have signaled a high water temperature alarm. If someone checked the pump they could have shut the pump down because of the running condition and the pump would not failed. Had this been a fire was the pump manned, did they know how to open the by pass cooling line? See link below for what I am referring to. The bottom line is open at all times and the top is closed. If the pump started to overheat the top line could be opened to prevent overheating.

When was the last time the strainer before the pressure reducing regulator was cleaned? Given the water source was a pond, was this the only strainer on the line, if so poor design.

So yes the pump should have run longer than 2.5 hours BUT if you do not follow impairment procedures or maintain the equipment it will fail.

 

[AlarmTec]

Thank you for the reply LCREP.

You bring up an interesting point. The campus was actually under construction at the time of the incident BUT the power was off from the campus for 6 1/2 hours.

So this brings and interesting thought. I would assume that with an over 6 hour power outage that a Preplanned Impairment Program would be required and that they would have been required to do the following...
15.5*
15.5.1
15.5.2 (1) through (9) but skip (4)as it for over 10 hours

Is my thinking correct? Thank you everyone again for helping me with pump codes.