Remove Diesel & Keep Only Electric Fire Pump?

2/23/2024

We have a building with an Extra Hazard Group 1 in a fairly rural location. We have an Electric, Diesel and Jockey (electric) pump system.

We had our diesel go out, sent away for repairs. What are the requirements for just having just electric in place?

My concern is is the fire department cuts power if they come on site for industrial fire, or lose power due to weather, then we would have no suppression in service.

The fire department can provide 1,500 gpm at 100 psi from a Type 1 engine through the FDC, (so 750 gallons). We have a pond to draft from.

What would be the considerations? Amount of water available?

In the event of power loss, the size of the FDC versus the size of the riser (a 6-8" dry pipe valve)?

What would realistic attack line demand be for a hydrant/hose line? Can you think of anything else I'm not thinking of?

Thanks in advance for the help!

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11 Comments

2/23/2024 08:19:45 am

My first thought is a back up generator should be on site which is able to supply the fire pump for the NFPA required water demand. The generator sizing should be for the duration of the water supply at the horsepower requirements for the sprinkler system demand. Depending on the types of systems, there might be varying durations and sprinkler demands that would need to be compared to see what the generator sizing should be. There are many factors that go into generator selection such as fuels readily available in the area, but in some cases the cost of a generator is not prohibitive when compared to a diesel fire pump install. However some facilities already require a generator so it is not a big deal to add the extra demand of a fire pump.

Secondly, the FDC is only an NFPA 13 requirement to supplement water supply, not to fully supply a sprinkler system. Depending on the type (pipe diameter, length, number of outlets) of FDC it may not be enough to ever satisfy sprinkler demand. A discussion with the fire department based on response times, and the system performance through the FDC would be a good idea to determine if the FD/AHJ is okay with potential power outages impairing the pump.

Glenn Berger

2/23/2024 08:28:59 am

Just having a single electric fire pump is satisfactory per the codes IF you have reliable power and IF your client doesn't want back-up equipment.

Power for the electric fire pump should be ahead of the building shut-off "switch." as such the fire department should not be cutting the power to the fire pump as part of their response plan.

Jack G

2/23/2024 08:31:40 am

Keep the diesel. Em generator would cost a couple hundred thousand.
Back when this was installed, there is a 25% reduction in insurance premiums for having a secondary or backup water supply, and the premium is probably big for x- haz-1.

Franck

2/23/2024 08:35:17 am

Another concern might come from the Insurance Company.
Depending on the insured values and the expected loss scenarios (PML/MFL), 2 fire pumps might be required, or additional premium applied.
Supply by Fire Department via FDC is not considered as an alternative to a fire pump. And 1500 gpm à 100 psi might not be sufficient for EH Gr 1 (check with the hydraulic calculations results and requirements for hoses/hydrants as it will be the same water supply for both in that case).

Back up generator is an option (but might be more costly than put back the diesel pump if there is none).

Another concern is that most Fire Department will put out the power when arriving on site. One possible solution is then to have 2 different switches : one for the entire plant and one dedicated for the electric pump, so that you can switch off the poser ton the plant without switching off the power to the pump.

Otherwise, many facilities have just one pump.
And electric pumps are more reliable than diesel pumps (except if no power, but how often it happens?).

Anthony

2/23/2024 08:38:49 am

Fire pump back up is one of the more difficult parts of the job for 'sprinkler guys' like me. The easiest options are always diesel back up or a generator with automatic transfer switch. The back up power or source of water only comes into play in section 9.3 where the fire department can't supply the required water to tall buildings.

code says:
9.2.2 The normal source of power required in 9.2.1 and its
routing shall be arranged in accordance with one of the following:
(1) Service connection dedicated to the fire pump installation
(2) On-site power production facility connection dedicated to the fire pump installation
(3) Dedicated feeder connection derived directly from the dedicated service to the fire pump installation
(4) As a feeder connection where all of the following conditions are met:
(a) The protected facility is part of a multibuilding campus-style arrangement.
(b) A backup source of power is provided from a source independent of the normal source of power.
(c) It is impractical to supply the normal source of power through the arrangement in 9.2.2(1), 9.2.2(2), or9.2.2(3).
(d) The arrangement is acceptable to the authority having jurisdiction.
(e) The overcurrent protection device(s) in each disconnecting means is selectively coordinated with any other supply side overcurrent protective device(s).
(5) Dedicated transformer connection directly from the ser-vice meeting the requirements of Article 695 of NFPA70,National Electrical Code

9.3.1 Except for an arrangement described in 9.3.3, at least
one alternate source of power shall be provided where the
height of the structure is beyond the pumping capacity of the
fire department apparatus.

9.3.2*Other Sources. Except for an arrangement described in
9.3.3, at least one alternate source of power shall be provided
where the normal source is not reliable.

9.3.3 An alternate source of power for the primary fire pump
shall not be required where a backup engine-driven fire pump,
backup steam turbine-driven fire pump, or backup electric
motor–driven fire pump with independent power source meeting 9.2.2 is installed in accordance with this standard

So as long as the fire department can supply the building height then you only need to make sure the power to the pump follows the rules of 9.2.2.

IF your power supply flows that and all the rules of NEC then there is no need for the diesel.

Greg

2/23/2024 08:46:21 am

Good question. I've recently evaluated the same choice for diesel fire pump keep, or remove.

In reviewing a few U.S. state adopted codes for fire protection, I've concluded that water supply provisions adequate to supply sprinkler systems and hydrants are required, and that the supply must meet the demands, and be reliable.

A specific statement does not appear for dual 100% capability. I believe I'm correct in saying that redundancy of pumps to provide additional reliability, above that of meeting the demand requirement of hydrants and sprinkler systems, does not appear to be within the model codes.

However, corporate expectations to control property loss, and insurance company recommended practices will tend towards ensuring 'highly reliable' water supplies. The term 'highly reliable' denotes the capability for a water supply system to be available through a plethora of conditions, of which one should consider electrical power loss, underground line break/service, fire pump service and maintenance, fuel delivery (for extended fire events), ground level water tank inspections, suction cleanout (for natural bodies of water), etc., etc., etc.

The best design concepts for creating highly reliable service comes from the recommendations within FM Global Data Sheets and other property insurer publications. The "extra" within the guidelines of the insurer's recommendations is above code minimum but may be in-fact 'good business sense', and be practical to rule out fire risk and consequence.

Ancillary references to reliability that include terms such as "defense in depth" would come from the U.S. DOE fire program's design for water supply, or U.S. DOD UFC documents. In such DOE / DOD programs, further consideration than dual pumps occur, through a design including remote pump houses, extensive sectional control valving, and considerations for elevated tanks (the most reliable of all).

Jesse

2/23/2024 09:01:31 am

The electric pump is sufficient presuming the electric utility is reliable.

Having served as a professional firefighter for nearly 20 years I can attest that, yes indeed fire will turn off the power, But the pump should have a dedicated service. And the FD in their pre-planning should know which power to disable and which to leave on.

Franck brings up a good point re: the insurer. Depending on the insurer, and the values involved, property carriers consider themselves an equal AHJ. When the PML reaches a specified value, the insurer may require multiple pumps and failure to provide may limit coverage. If it does, you need to ensure that their impairment procedures are being followed.

Kimberly Olivas

2/23/2024 09:47:10 am

By Code, electric fire pumps can only be used exclusively if the AHJ has deemed the power supply to be reliable enough. You cannot set your electric fire pump up with any shut off switches before the controller either. It has its own feed. If the fire pumps were the electric and a diesel pump back-up, then it could be possible to get rid of the diesel. But that's up to the AHJ, I would think. I am just talking off the cuff; I was excited to see a question I might be able to help answer. :)

Dan Wilder

2/23/2024 12:02:17 pm

As with everyone else, Reliable power as determined by the AHJ/Insurance. If the pump is on site backup gens and has the appropriate switches/panels to make that transition

There are several rental companies that can provide a temp diesel pump, trailer mounted, with or without a jockey pump, manual or automatic off via pressure solenoid, cell notification....lots of options. We have done multiple pumps in this fashion during maintenance down time or catastrophic failures that have occurred.

Pete

2/23/2024 03:13:06 pm

Someone please sell me a diesel jockey pump. The reason is with all my 2-pump electric/diesel installations, when there's a site-wide power outage, the diesel doesn't function as a back-up pump. The electric jockey pump always fails with the power outage, same as the electric fire pump. The diesel pump comes on due to normal system pressure drops over a couple hours without a jockey pump. Then a tech gets a call from the central station and must respond to shut the diesel pump off. The set-up is hardly a substitution for reliable power.

sean

2/26/2024 01:24:40 pm

I think your biggest issue is right now the original design included both pumps. The code requires to maintain the system and equipment as first designed.

By reducing that you place a larger risk on liability.

Remove Diesel & Keep Only Electric Fire Pump?

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