Public Comment No. 5-NFPA 20-2017 [ Section No. 2.3.6 ] · .4, Rotodynamic Centrifugal Pumps for...

Public Comment No. 5-NFPA 20-2017 [ Section No. 2.3.6 ]

2.3.6 HI Publications.

Hydraulic Institute, 6 Campus Drive, First Floor North, Parsippany, NJ 07054-4406.

ANSI/HI 3. 1

.4, Rotodynamic Centrifugal Pumps for Manuals-3.5 Rotary Pumps for Nomenclature, Definitions, Design & Application, Installation, Operation andMaintenance

ANSI/HI 3.6 Rotary Pump Tests

ANSI/HI 1.1-1.2 Rotodynamic (Centrifugal) Pumps for Nomenclature and Definitions

ANSI/HI 2.1-2.2 Rotodynamic (Vertical) Pumps for Nomenclature and Definitions

ANSI/HI 1.3 Rotodynamic (Centrifugal) Pumps for Design and Application

ANSI/HI 1.4 Rotodynamic Centrifugal Pumps for Manuals, Describing Installation, Operation

and Maintenance, 2014.& Maintenance

ANSI/HI 2.3 Rotodynamic (Vertical) Pumps for Design and Application

ANSI/HI

314 .6

, Rotary Pump Tests , 2016.Rotodynamic Pumps for Hydraulic Performance Acceptance Tests

ANSI/HI 9.6.4 Rotodynamic Pumps for Vibration Measurements and Allowable Values

Statement of Problem and Substantiation for Public Comment

Currently the listing of standards is incomplete. I have provided the latest address for HI and the relevant standards for reference.

Related Item

PI

Submitter Information Verification

Submitter Full Name: Gregg Romanyshyn

Organization: Hydraulic Institute

Street Address:

City:

State:

Zip:

Submittal Date: Thu Mar 30 09:35:36 EDT 2017

Committee Statement

CommitteeAction:

Rejected

National Fire Protection Association Report http://submittals.nfpa.org/TerraViewWeb/ContentFetcher?commentPara...

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Resolution: These documents are not referenced in the body of the standard and therefore cannot bereferenced in Chapter 2.


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Public Comment No. 2-NFPA 20-2017 [ New Section after 3.3.32 ]

Lead-acid Battery

Valve Regulated Lead Acid (VRLA) Cell. A lead-acid cell that is sealed with the exception of a valve thatopens to the atmosphere when the internal pressure in the cell exceeds atmospheric pressure by a pre-selected amount, and that provides a means for recombination of internally generated oxygen and thesuppression of hydrogen gas evolution to limit water consumption.

Vented (Flooded) Cell. A type of cell that has electrodes immersed in liquid electrolyte and which theproducts of electrolysis and evaporation are allowed to escape freely into the atmosphere as they aregenerated.


Original text in 11.2.7.2.1 only allows for flooded lead acid batteries. Adding statement for VRLA batteries creates option for users to use lower maintenance batteries in their application. Lower maintenance is achieved by not needing to periodically check electrolyte levels that is needed in flooded batteries. This reduction in maintenance potentially reduces the overall cost of ownership of the stationary pump.Adding definition of different lead acid battery types to support proposed changes to 11.2.7.2.1.Other NFPA standards specifically mention VRLA and flooded lead acid batteries as options, i.e. NFPA 70E-2015 320.2 and NFPA 110-2016 3.3.7.

Related Item

Battery Type


Submitter Full Name: Sean Sullivan

Organization: EnerSys

Street Address:

City:

State:

Zip:

Submittal Date: Tue Mar 21 09:25:40 EDT 2017

Committee Statement

CommitteeAction:

Accepted

Resolution: SR-16-NFPA 20-2017

Statement: This standard has to date specifically specified dry charge batteries with separate electrolytebecause of the typical extended time before the batteries are put into service when the pump set iscommissioned. This was not intended to preclude low maintenance batteries, but to take advantageof the dry charge feature. Should low maintenance batteries have the necessary capacity to meetthe performance requirements of the standard and the engine manufacturer’s requirements withoutsetting dormant on site for an extended period of time, this standard is open to their use. The annexmaterial has been added to explain the differences between flooded and VRLA lead-acid batteriesand their use.


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3.3.67 * Torsional Coupling.

A driveline component capable of transmitting torque having a very low spring constant along the axis ofrotation to "detune" the driveline and move any damaging resonances safely below operating speed .


I believe this information is more appropriate in definition than in the Annex. Delete A.3.3.67 if this Comment is accepted.

Related Item

FR-47


Submitter Full Name: John Whitney

Organization: Clarke Fire Protection Product

Street Address:

City:

State:

Zip:

Submittal Date: Tue May 09 17:53:22 EDT 2017

Committee Statement

CommitteeAction:

Accepted


Statement: The Technical Committee agrees that this language is more appropriate in the definition ofTorsional Coupling than in the annex.


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TITLE OF NEW CONTENT

Type your content here ...

4.3.2 Where remote monitoring that meets NFPA 72 and all of the following requirements, qualifiedpersonnel shall be permitted to monitor the no-flow test remotely.

1. Visual observation adequate to verify the approrioate water discharge through the pacing and circulationrelief valve.

2. Visual observation of both sides of the pump adequate to identify smode emitted from the pump, pumpdriver, or controller.

3. Smoke detection installed in fire pump room with reporting to the remote monitoring site.

4. Suction pressure reporting to the remote monitoring site.

5. Discharge pressure reporting to the remote monitoring site.

6. Audio adequate to identify unusual noise reporting to the remote monitoring site.

7. For diesel engine driver, diesel engine temperature and oil pressure reporting to the remote monitoringsite.

8. Room temperature reporting to the remote monitoring site.

9. Pump speed reporting to the remote monitoring site.

10. Pump and motor vibration reporting to the remote monitoring site.

11. Flow through the circulation relief valve reporting to the remote monitoring site (visual, continuouspressure switch, or continuous flow switch)

12. Flow through the main pressure relief valve (when provided) reporting to the remote monitoring site(visual, continuous pressure switch or continuous flow switch).

13. Temperature of pump impeller casing reporting to the remote monitoring site.

14. Temperature of pump packing reporting to the remote monitoring site.

15. Visual and audible alarm for abnormal operation reporting to the remote monitoring site.

a) Suction pressure

b) Discharge pressure

c) Diesel engine temperature

d) Room Temperature

e) Pump speed in excess of plus or minus 5% or rated speed

f) Pump or motor vibration

g) Inadequate flow through the circluation relief valve

h) Discharge through the main pressure relief valve (when provided)

i) Temperature of pump impeller casing

j) Temperature of pump packing

16) Personnel trained to shut off and reset the fire pump shall be available to respond within 5 minutes of benotified of an abnormal condition whenever the fire pump is scheduled for testing, and within 20 minuteswhenever the fire pump starts..

17) The value of each point monitored shall be recorded at a minimum frequency of every 2 minutes.


See Public Comment No. 6 about the improved reliability that could be achieved with provisions for remote monitoring.


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Related Public Comments for This Document

Related Comment Relationship

Public Comment No. 6-NFPA 20-2017 [Section No. 4.3.1] This is a continuation of Public Comment 6

Related Item

Public Imput 50


Submitter Full Name: Gayle Pennel

Organization: JENSEN HUGHES/AON Fire Protect

Street Address:

City:

State:

Zip:

Submittal Date: Wed Apr 05 12:23:55 EDT 2017

Committee Statement

CommitteeAction:

Accepted


Statement: This revision recognizes that video, measurement, and sensing technology currently exists thatallows for pump operation to be monitored remotely by qualified personnel.


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4.3.1

In the event of fire pump operation Except as permitted in 4.3.2 , qualified personnel shall respond to thefire pump location to determine that the fire pump is operating in a satisfactory manner.


It is possible to improve overall fire pump reliability by providing appropriate provisions for remote monitoring. Currently some required testing is not being performed, some testing is not being supervised, and some testing is monitored by unqualified or marginally qualified personnel. Allowing appropriate remote monitoring for non-flow testing allows the use of specially trained personnel to supervise the test and call for a qualified to respond when necessary. Identifying what needs to be monitored allows the appropriate equipment to be installed at the time the fire pump is installed.



Public Comment No. 7-NFPA 20-2017 [New Section after 4.3.1]

Related Item

Public Input 50


Submitter Full Name: Gayle Pennel

Organization: JENSEN HUGHES/AON Fire Protect

Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: This revision recognizes that video, measurement, and sensing technology currently exists thatallows for pump operation to be monitored remotely by qualified personnel.


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4.4.3

The fire pump manufacturer shall be designated as having unit responsibility for the pump driver,controller, transfer switch equipment, and other accessories required by the listing agency.

4.4.3.1

The fire pump manufacturer shall be able to supply the necessary pump accessories to provide a completepump installation.

4.4.3.2

The fire pump manufacturer shall be held accountable for the complete fire pump unit and satisfactoryperformance of the field acceptance test.

4.4.3.3 *

The fire pump manufacturer shall not be held accountable for items supplied by others that affect the pumpperformance.


As stated in the negative ballot comments, this is impractical, will cause construction delays, and is cost prohibitive. Many of the components and accessories described in the associated annex text are readily available.

Related Item

FR 16


Submitter Full Name: Louis Guerrazzi

Organization: National Fire Sprinkler Association

Affilliation: NFSA Engineering and Standards Committee

Street Address:

City:

State:

Zip:

Submittal Date: Wed May 10 14:08:58 EDT 2017

Committee Statement

CommitteeAction:

Rejected

Resolution: The Technical Committee agrees that unit responsibility is necessary to ensure properinstallations, especially in overseas markets.


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Public Comment No. 28-NFPA 20-2017 [ Section No. 4.4.3 [Excluding any Sub-Sections]

]

The For initial installations and complete pump unit replacements, the fire pump manufacturer shall bedesignated as having unit responsibility for the pump driver, controller, transfer switch equipment, and otheraccessories required by the listing agency. For individual component replacements, responsibility may differand be assigned by contractual purchase documents.


If a driver (electric motor or diesel engine) or controller is replaced due to failure after years of service, the original pump manufacturer should not be held responsible for the new driver or controller.

Related Item

FR-16


Submitter Full Name: Byron Ellis

Organization: Entergy Corporation

Affilliation: Edison Electric Institute FP Task Force

Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Rejected but see related SR


Statement: This revisions removes the assignment of unit responsibility to the pump manufacturer, butmaintains the requirement that a single entity be responsible for acceptable unit performance.


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Public Comment No. 11-NFPA 20-2017 [ Section No. 4.6.2.3.1 ]

4.6.2.3.1 *

Where the maximum flow available from a public or private service the water supply main cannot provide aflow of 150 percent of the rated flow of the pumpat pump at the lowest permissible suction pressure, butthe water supply can provide the greater of 100 percent of rated flow or the maximum flow demand of thefire protection system(s) at the lowest permissible suction pressure, the water supply shall be deemed to beadequate.


As stated in our First Draft Ballot, the change of this term "the water supply" to "a public or private service main" is confusing as the term "water supply" is used two additional times in this section, as well as throughout Section 4.6.2. If the panel wants to change the term, they should be consistent throughout the section.

Related Item

FR-17


Submitter Full Name: Richard Holub

Organization: The DuPont Company, Inc.

Street Address:

City:

State:

Zip:

Submittal Date: Mon Apr 10 08:31:03 EDT 2017

Committee Statement

CommitteeAction:

Accepted


Statement: The change of the phrase "the water supply" to "a public or private service main" that occurred inthe First Draft is confusing, as the term "water supply" is used two additional times in this section,as well as throughout Section 4.6.2. This revision ensures that the terminology is consistentthroughout the section.


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4.10.3

The nameplate shall indicate the maximum pump horsepower demand required to power the pump at anyflow, including all flows less than or greater than 150 percent of the rated flow .


The last sentence is meaningless. In fact, as written, you only have to include all flows less than or greater than 150%, but apparently not equal to 150%. If further explanation is necessary, something should be generated for the Annex to make this clear. This was affirmed in our ballot comment on the First Revision.

Related Item

FR-19




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: This revision makes it clear that the HP requirement must include flows beyond 150 percentbecause the maximum HP could be above 150 percent.


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Public Comment No. 13-NFPA 20-2017 [ Section No. 4.13.1.2 ]

4.13.1.2 Detached Outdoor Fire Pump Units.

4.13.1.2.1

Fire pump units that are in detached buildings or enclosures shall be in accordance with4.13.1.1.2 . outdoor shall be located at least 50 ft (15.3m) away from any buildings and other fireexposures exposing the building.

4.13.1.2.2

Detached installations Outdoor installations shall be required to be provided with protection againstpossible interruption, in accordance with 4.13.1.

4.13.1.2.3

Detached fire pump units shall be installed in a building or enclosure that meets or exceeds therequirements of 4.13.1 as well as the requirements of the locally adopted building code.


As stated in our ballot comment on the First Draft, there was no technical substantiation to delete this capability if the fire pump is properly rated for such installation and approved by the Authority Having Jurisdiction. If this first draft revision is allowed to continue, then the committee should add an exception for pumps installed prior to the date of adoption of this code so that repair or replacement of said pumps is not hindered by this code language. The exception could state:

Exception: Fire Pumps installed prior to the adoption of this code shall be allowed to be repaired or replaced in kind with the approval of the Authority Having Jurisdiction.



Public Comment No. 16-NFPA 20-2017 [Section No. A.4.13.1]

Related Item

FR-21




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted



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Statement: During the First Draft stage, there was insufficient technical substantiation provided to justify theelimination of outdoor fire pumps if properly rated for such installation and approved by theauthority having jurisdiction. This revision reverses the change that was made at the First Draft.


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4.13.1.2.3

Detached fire pump units shall be installed in a building or enclosure as approved by the AHJ that meets orexceeds the requirements of 4.13.1 as well as the requirements of the locally adopted building code.


In Southern climates, mild year round temperatures do not subject pumps to freezing conditions. In mild climates, adequate protection can be provided without the need for 4 solid walls. Many of our power plants and industrial facilities are outdoors on structural platforms with no walls including critical equipment such as Steam Turbines, Feed Pumps, and miscellaneous cooling pumps. Fire Pumps may not need a fully enclosed building to be adequately protected. Further, a fully enclosed building creates adverse affects on ambient conditions, making it hard to maintain interior temperatures below equipment maximums without supplemental building cooling. Outdoor pumps would not be the norm, but at least they would not be prohibited and used only under AHJ Approval. NFPA 37 allows Stationary Engines to be installed outdoors with appropriate protective enclosures. NFPA 37 adequately defines such enclosures as: "A cover intended to protect an engine andrelated equipment." and states Enclosures are neither a structure nor a room.



Public Comment No. 30-NFPA 20-2017 [Section No. A.4.13.1]

Related Item

FR-21





Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: During the First Draft stage, there was insufficient technical substantiation provided to justify theelimination of outdoor fire pumps if properly rated for such installation and approved by theauthority having jurisdiction. This revision reverses the change that was made at the First Draft.


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6.5.3 Mass Elastic System

6.5.3.1* For a separately coupled-type pumps driven by a diesel engine, a torsional coupling shallbe used and mounted on the engine side of the flexible coupling or flexible connecting shaft.

A.6.5.3.1

Torsional couplings are very useful at moving harmful stresses out of the operating speed ranges of thesepump systems. However, if the stiffness or damping characteristic of the coupling is not selected correctly itcan actually make the system torsional activity worse at operating speed.

6.5.3.1.1* For drive systems that include a diesel engine, a torsional coupling, and a horizontal shaftpump, the pump manufacturer shall provide at minimum a 2–mass torsional frequency calculation indicatingthat the speed at which engine firing frequency excites the system resonance is at minimum 30% belowrated pump operating speed.

6.5.3.1.1.1* The torsional frequency calculation specified in 6.5.3.1.1 shall include the mass elasticcharacteristics for a wetted pump with the specific impeller(s) trim, the torsional coupling, flexible coupling orflexible connecting shaft, and the engine.

A.6.5.3.1.1 .1

TWO MASS MODEL HORIZONTAL SHAFT PUMP WITH FLYWHEEL MOUNTED TORSIONALCOUPLING

When using a torsional coupling which has a torsional spring rate much less than the torsional spring rate ofthe flexible connecting shaft and pump shaft, the system should be considered as two lumped inertias (M1,M2) connected by a spring (K) as per Figure 1.

Figure A.6.5.3.1.1 lumped inertia definition (HSC or ES with torsional coupling)

where:

E1 - total inertia of engine and flywheel (kgm 2 )


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M1 = E1 + E2 M2 = P1 + P2 + P3 + P4

E2 - torsional coupling primary inertia (kgm 2 )

P1 - torsional coupling secondary inertia (kgm 2 )

P2 - flexible connecting shaft total inertia (kgm 2 ) – ifpresent

P3 - inertia of companion flange (kgm 2 ) – if present

P4 - wetted inertia of pump impeller (kgm 2 )

K - dynamic torsional stiffness of torsional coupling element (Nm/rad)

6.5.3.1.2* When the calculations required in 6.5.3.1.1 indicate that critical speeds are found to fallwithin 30% above or within 30% below of pump rated speed, then a further detailed set of forced responsecalculations are required of the components indicating there are no damaging vibratory stresses or torqueswithin the pump shaft, coupling or flexible connecting shaft, engine crankshaft stress or excessivecrankshaft damper heat dissipation.

A.6.5.3.1.2

The calculated forced response results should be compared against manufacturers’ recommended limitsfor each component. For torsional couplings this comparison would include vibratory torque and heatdissipation if the spring element is a viscoelastic material.

6.5.3.1.2.1* The torsional analysis specified in 6.5.3.1.2 shall include the mass elastic characteristicsrequired in 6.5.3.1.1.1 plus;

(a) the excitation characteristics of the specific engine and rating

(b) a fully flexible lumped parameter model having multiple elements along the length of the enginecrankshaft, the horizontal shafting, and pump impeller

(c) include the effect of engine misfire

A.6.5.3.1.2.1

As a result of the influence of emission laws engine combustion processes have changed considerablyover the years. The cylinder and injection pressures of modern diesel engines are very different than olderengines. Therefore when doing the calculations of 6.5.3.1.2 it is desirable to have specific enginemanufacturer and rating excitation data. Older hand books that provide diesel engine excitation data aretypically inadequate for these calculations.

This is often referred to as a multi-mass analysis.

6.5.3.1.3 For a system defined in 6.5.3.1 that use a variable speed diesel driver the operatingspeed for the analytical speeds shall be define as a minimum of 30% above pump rated speed and 30%below the lowest possible speed of the variable speed driver.

6.5.3.1.4 The torsional coupling required in par. 6.5.3.1 shall be permitted to be omitted when thesystem or an identical sample system, with same specific impeller trim, has been tested from 0 to 150%flow at the pressures on the flow curve for the pump shaft peak to peak vibratory torque stress has beenmeasured and the following conditions are met;

a) peak to peak stresses shall be measured at all speeds from 25% above pump rated speed to 25%below pump rated speed or 25% below the lowest possible speed of a variable speed system and thereare no stresses greater than 75% of the calculated stress capability of each of the components in thesystem,

b) all vibratory torque measurements shall have remained positive .

Additional Proposed Changes

File Name Description Approved

Whitney_NFPA_20_PC_27_Attachment_with_Figure.pdfAttachment has figure included as did not upload on Terra.



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Torsional failures of horizontal pump systems typically resulting in broken pump shafts have been happening too often the last few years. There is no obvious smoking gun at this time, therefore I am proposing a solution equal to the requirements in chapter 7 for Vertical Turbine pumps that been developed over a number of NFPA 20 revision cycles.

Related Item

PI-195




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Rejected but held

Resolution: This is a complicated topic that needs further study to determine if torsional couplings arerequired for all diesel drive engines.


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1

Baio, Debbie

From: Whitney, John <>Sent: Wednesday, May 10, 2017 4:33 PMTo: Baio, DebbieSubject: NFPA 20 Comments

Deb, Please see below Substantiations for my Comments that are in TerraView; PC 22 Problem and Substantiation This is editorial as a result of changes made during Proposals so text will read correctly. PC 23 Problem and Substantiation This is editorial as a result of changes made during Proposals so text will read correctly. PC 24 Problem and Substantiation

Somehow during the Proposal change “three” was changed to “six” inadvertently. This is to correct it back to three.

PC 25 Problem and Substantiation This language was a part of the original Proposals but did make it into TerraView text. PC 26 Problem and Substantiation

I believe this information is more appropriate in definition than in the Annex. Delete A.3.3.67 if this Comment is accepted.

PC 22 Problem and Substantiation This is editorial as a result of changes made during Proposals. PC 27 Deb, I had submitted PI 195 which was Resolved. Since that was a new par. I do not know how to I would like to submit the following Comment to PI 195 that I can paste in. Could you paste it for me? 6.5.3 Mass Elastic System 6.5.3.1* For a separately coupled‐type pumps driven by a diesel engine, a torsional coupling shall be used and mounted on the engine side of the flexible coupling or flexible connecting shaft. A.6.5.3.1 Torsional couplings are very useful at moving harmful stresses out of the operating speed ranges of these pump systems. However, if the stiffness or damping characteristic of the coupling is not selected correctly it can actually make the system torsional activity worse at operating speed. 6.5.3.1.1* For drive systems that include a diesel engine, a torsional coupling, and a horizontal shaft pump, the pump manufacturer shall provide at minimum a 2–mass torsional frequency calculation indicating that the speed at which engine firing frequency excites the system resonance is at minimum 30% below rated pump operating speed. 6.5.3.1.1.1* The torsional frequency calculation specified in 6.5.3.1.1 shall include the mass elastic characteristics for a wetted pump with the specific impeller(s) trim, the torsional coupling, flexible coupling or flexible connecting shaft, and the engine.

2

A.6.5.3.1.1.1 TWO MASS MODEL HORIZONTAL SHAFT PUMP WITH FLYWHEEL MOUNTED TORSIONAL COUPLING When using a torsional coupling which has a torsional spring rate much less than the torsional spring rate of the flexible connecting shaft and pump shaft, the system should be considered as two lumped inertias (M1, M2) connected by a spring (K) as per Figure 1.

Figure A.6.5.3.1.1 lumped inertia definition (HSC or ES with torsional coupling) where: E1 ‐ total inertia of engine and flywheel (kgm2) E2 ‐ torsional coupling primary inertia (kgm2) P1 ‐ torsional coupling secondary inertia (kgm2) P2 ‐ flexible connecting shaft total inertia (kgm2) – if present P3 ‐ inertia of companion flange (kgm2) – if present P4 ‐ wetted inertia of pump impeller (kgm2) K ‐ dynamic torsional stiffness of torsional coupling element (Nm/rad) 6.5.3.1.2* When the calculations required in 6.5.3.1.1 indicate that critical speeds are found to fall within 30% above or within 30% below of pump rated speed, then a further detailed set of forced response calculations are required of the components indicating there are no damaging vibratory stresses or torques within the pump shaft, coupling or flexible connecting shaft, engine crankshaft stress or excessive crankshaft damper heat dissipation. A.6.5.3.1.2 The calculated forced response results should be compared against manufacturers’ recommended limits for each component. For torsional couplings this comparison would include vibratory torque and heat dissipation if the spring element is a viscoelastic material. 6.5.3.1.2.1* The torsional analysis specified in 6.5.3.1.2 shall include the mass elastic characteristics required in 6.5.3.1.1.1 plus; (a) the excitation characteristics of the specific engine and rating (b) a fully flexible lumped parameter model having multiple elements along the length of the engine crankshaft, the horizontal shafting, and pump impeller (c) include the effect of engine misfire

M1 = E1 + E2 M2 = P1 + P2 + P3 + P4

3

A.6.5.3.1.2.1 As a result of the influence of emission laws engine combustion processes have changed considerably over the years. The cylinder and injection pressures of modern diesel engines are very different than older engines. Therefore when doing the calculations of 6.5.3.1.2 it is desirable to have specific engine manufacturer and rating excitation data. Older hand books that provide diesel engine excitation data are typically inadequate for these calculations. This is often referred to as a multi‐mass analysis. 6.5.3.1.3 For a system defined in 6.5.3.1 that use a variable speed diesel driver the operating speed for the analytical speeds shall be define as a minimum of 30% above pump rated speed and 30% below the lowest possible speed of the variable speed driver. 6.5.3.1.4 The torsional coupling required in par. 6.5.3.1 shall be permitted to be omitted when the system or an identical sample system, with same specific impeller trim, has been tested from 0 to 150% flow at the pressures on the flow curve for the pump shaft peak to peak vibratory torque stress has been measured and the following conditions are met; a) peak to peak stresses shall be measured at all speeds from 25% above pump rated speed to 25% below pump rated speed or 25% below the lowest possible speed of a variable speed system and there are no stresses greater than 75% of the calculated stress capability of each of the components in the system, b) all vibratory torque measurements shall have remained positive . Problem and Substantiation Torsional failures of horizontal pump systems typically resulting in broken pump shafts have been happening too often the last few years. There is no obvious smoking gun at this time, therefore I am proposing a solution equal to the requirements in chapter 7 for Vertical Turbine pumps that been developed over a number NFPA 20 revision cycles.

Public Comment No. 25-NFPA 20-2017 [ Section No. 7.5.1.6.1.7 ]

7.5.1.6.1.7 *

In addition to the requirements of 7.5.1.6.1.3, results shall include engine critical response, i .e. crankshaftstress, crankshaft damper heat dissipation.


This language was a part of the original Proposals but did not make it into TerraView text.

Related Item

FR-44




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: The Technical Committee agrees that this language is more appropriate in the body of thestandard than in the annex.


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8.1.5 * Pump Materials.

Materials used in pump construction shall be selected based on the corrosion potential of the environment,fluids used, and operational conditions. (See 3.3.11 12 for definition of corrosion-resistant materials.)


As stated in our ballot comment for the First Draft, the definition of "Corrosion-Resistant Material" is now in Section 3.3.12. This comment is being submitted for correlation to get this link corrected in the second draft.

Related Item

FR-92




Street Address:

City:

State:

Zip:


Committee Statement

Committee Action: Accepted


Statement: This revision corrects the cross-reference to the definition of corrosion-resistant material.


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9.1.8.3

Arc-resistant equipment shall be permitted. The front of the fire pump controller enclosure shall be arc-resistant with pressure relieving vents on the top or sides per IEEE C37.20.7, or equivalent standard.


As stated in our ballot comments on the First Revision, it is a good first step for this panel to allow or permit arc-resistant equipment. This, however, does not go far enough to protect persons that have to interact with this equipment. The panel should either require arc-resistant equipment or allow other methods to reduce arc flash energies without compromising the reliability of the source.

Related Item

FR-61

PI-175




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Rejected

Resolution: Requirements for reduction of arc-flash should be performance based. Any such requirements needto be coordinated with the upstream protection for the fire pump controller and motor. A studyseeking a system solution for the fire pump electrical installation is recommended. A task group hasbeen formed to address the issue of arc flash in fire pump equipment.


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Public Comment No. 8-NFPA 20-2017 [ Section No. 9.2 ]

9.2* Normal Power.

9.2.1

An electric motor–driven fire pump shall be provided with a normal source of power as a continuallyavailable source.

9.2.2

The normal source of power required in 9.2.1 and its routing shall be arranged in accordance with one ofthe 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:

(5) The protected facility is part of a multibuilding campus-style arrangement.

(6) A backup source of power is provided from a source independent of the normal source of power.

(7) It is impractical to supply the normal source of power through the arrangement in 9.2.2(1) ,9.2.2(2) , or 9.2.2(3) .

(8) The arrangement is acceptable to the authority having jurisdiction.

(9) The overcurrent protection device(s) in each disconnecting means is selectively coordinated withany other supply side overcurrent protective device(s).

(10) Dedicated transformer connection directly from the service meeting the requirements of Article 695 ofNFPA 70

9.2.3

For fire pump installations using the arrangement in 9.2.2(1), 9.2.2(2), 9.2.2(3), or 9.2.2(5) for the normalsource of power, no more than one a single disconnecting means and associated overcurrent protectiondevice shall be installed in the power supply to the fire pump controller.

9.2.3.1

Where the single disconnecting means permitted required by 9.2.3 is installed, the disconnecting meansshall meet all of the following requirements:

(1) It shall be identified as being suitable for use as service equipment have a rating of not less than 125percent of the sum of the fire pump motor full load current .

(2) It shall be lockable in both the closed position and the open position.

(3)

(4)

(5) It shall be marked “Fire Pump Disconnecting Means” in letters that are no less than 1 in. (25 mm) inheight and that can be seen without having to open enclosure doors or covers.

9.2.3.2

Where the single disconnecting means permitted required by 9.2.3 is installed, a placard shall be placedadjacent to the fire pump controller stating the location of this disconnecting means and the location of anykey needed to unlock the disconnect.

* It shall be located remote from other building disconnecting means.

* It shall be located remote from other fire pump source disconnecting means.


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9.2.3.3

Where the single disconnecting means permitted required by 9.2.3 is installed, the disconnect shall besupervised in the closed position by one of the following methods:

(1) Central station, proprietary, or remote station signal device

(2) Local signaling service that will cause the sounding of an audible signal at a constantly attendedlocation

(3) Locking the disconnecting means in the closed position

(4) Where the disconnecting means is located within fenced enclosures or in buildings under the control ofthe owner, sealing the disconnecting means and performing approved weekly recorded inspections

9.2.3.4

Where the overcurrent protection permitted single disconnecting means required by 9.2.3 is installed , the overcurrent protection device shall be rated to carry indefinitely the sum of the locked rotor current ofthe largest fire pump motor and the full-load current of all of the other pump motors and accessoryequipment .

9.2.3.4.1

Alternatively, compliance with 9.2.3.4 shall be based on an assembly listed for fire pump service thatcomplies with the following:

(1) The overcurrent protection device shall not open within 2 minutes at 600 percent full-load current.

(2) The overcurrent protection device shall not open with a restart transient of 24 times the full-loadcurrent.

(3) The overcurrent protection device shall not open within 10 minutes at 300 percent full-load current.

(4) The trip point for circuit breakers shall not be field adjustable.

9.2.3.4.2 Overcurrent Device Selection.

An instantaneous trip circuit breaker shall be permitted in lieu of the overcurrent devices specified in10.8.2.2(2) provided it is part of a transfer switch assembly listed for fire pump service and complies with9.2.3.4.1.


There has been an issue between safety and reliability for the electric service for fire pump controllers since I can remember. Now there is conflict between what is in NFPA 70E, and NFPA 25 as I see it, that can be resolved by requiring a way to isolate the power into the fire pump controller without compromising the reliability. There are requirements in NFPA 25 2017 edition specifically 8.1.1.2.2 and 8.1.1.2.16 that require electrical connections and control power wiring connections to be "checked" annually. We are also told that there is no "safe" way to work on controllers and no level of PPE exists to work on, check or perform maintenance on a controller for arc flash or shock protection while power is live into the controller. If this portion of what was initially PI#174 is not acceptable, then representatives from NFPA 20,25,70,and 70E should all get together and figure out a way to be safe while not compromising reliability without conflicting and confusing requirements between the standards for the majority of regular users of the standards.

Related Item

PI 174-NFPA 20-2016


Submitter Full Name: David Baron

Organization: Global Fire Protection Company

Street Address:

City:

State:

Zip:


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Committee Statement

CommitteeAction:

Rejected

Resolution: Requirements for reduction of arc-flash should be performance based. Any such requirements needto be coordinated with the upstream protection for the fire pump controller and motor. A studyseeking a system solution for the fire pump electrical installation is recommended. A task group hasbeen formed to address the issue of arc flash in fire pump equipment. The proposed solution mayresult in the unintended consequences of reducing the reliability of the delivery of power to the firepump. There are other solutions to reducing the arc flash hazard present in the fire pump room.


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Public Comment No. 19-NFPA 20-2017 [ New Section after 10.4.7.2 ]

TITLE OF NEW CONTENT

10.4.7.2.5 Alternate Source Isolating Switch or Circuit Breaker Oper

Where two sources of power are supplied to meet the requirements of 9.3.2, a signal shall be provided toindicate that the Alternate Source Isolating Switch or Circuit Breaker is open or tripped.


Renumbered 10.4.7.2.5 should be added since paragraph 10.8.3.12.2 only permits the Alternate Source Isolating Switch or Circuit Breaker Open alarm to be monitored, it does not require it. It should be required since a left open Isolating Switch or Circuit Breaker will prevent the fire pump from running on Alternate power.

Related Item

FR 75


Submitter Full Name: Vince Baclawski

Organization: Nema

Street Address:

City:

State:

Zip:

Submittal Date: Fri May 05 13:54:04 EDT 2017

Committee Statement

CommitteeAction:

Accepted


Statement: This section is added because paragraph 10.8.3.12.2 permits the alternate source isolating switchor circuit breaker open alarm to be monitored, but does not require it. This should be requiredbecause an isolating switch or circuit breaker that is left open will prevent the fire pump fromrunning on alternate power.


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10.4.7.2.5 6 Controller or System Trouble.

A controller or system trouble alarm shall actuate whenever a ground-fault alarm, when required (see10.4.5.9), a pressure-sensing device alarm (see 10.5.2.1.3.1 and 10.5.2.1.3.2), or a fail-to-start alarm (see10.5.2.7.5), or a locked rotor overcurrent protection (see 10.6.9.1 ) occurs.


The revisions to re-numbered 10.4.7.2.6, add clarification that the ground fault alarm is only to be included when a ground fault alarm is used. Also, the locked rotor overcurrent protection required in 10.6.9.1 does not require an alarm.

Related Item

FR 75



Organization: Nema

Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: This revision clarifies that the ground fault signal is only to be included when a ground fault signal isprovided. Also, the locked rotor overcurrent protection required in 10.6.9.1 does not require analarm, so this provision has been removed. The term "alarm" has been revised to "signal", as this isthe appropriate terminology.


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10.5.2.1 * Water Pressure Control.

10.5.2.1.1 Pressure-

Sensing Device

Actuated Switches .

10.5.2.1.1.1

A pressure-sensing device, either a pressure-actuated switch or electronic pressure sensor, havingadjustable high- and low-calibrated set-points

A there shall be provided as part of the controller two pressure-actuated switch switches or electronic two pressure sensor sensing devices having adjustablehigh - and low - calibrated set - points shall be provided as part of the controller .

10.5.2.1.1.2

*

Water piping shall not be extended into the controller.

10.5.2.1.1.3

For multistage multiport pumps, a dedicated pressure-

sensing device

actuated switch or electronic pressure sensor as described

in

in 10.5.2.1.1.1

shall

shall be provided for each discharge port of the pump as part of the controller.

10.5.2.1.1.

4

3

For multistage multiport pumps, a dedicated pressure recorder as described

in

in 10.5.2.1.8.2

shall

shall be provided for each discharge port of the pump as part of the controller.

10.5.2.1.1.

5

4

The requirements

of

of 10.5.2.1.1.1

and

and 10.5.2.1.1.

3 shall

2 shall not apply in a non-pressure-actuated controller, where the pressure-

sensing device

actuated switch shall not be required.


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10.5.2.1.2

There shall be no pressure snubber or restrictive orifice employed within the

sensing device

pressure switch or pressure responsive means .

10.5.2.1.

3 *

Where an electronic pressure sensor is used to automatically control fire pump operation, the fire pumpcontroller shall monitor

this electronic pressure sensor

the transducer during automatic testing.

3 pressure actuation

10.5.2.1.3.1

*

Where the

electronic

transducer pressure

sensor

reading exceeds 10 psi (0.68 bar) during any automatic pump start that was initiated by the solenoiddrain valve, as required by

If two pressure-actuated switches are used, they shall be electrically connected in such a way thateither switch will start the pump

10.5.2.

7

1 .

8. 3 , the controller shall activate a visual and audible alarm , that can be silenced.

3.2

If two electronic pressure devices are used, any pressure reading below set points will start thepump

10.5.2.1.3.

2 *


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Where an

3

If two electronic pressure

sensor is used to control fire pump operation, the fire pump controller shall monitor for and provide asignal for the following electronic pressure sensor conditions:

Any time the

electronic pressure sensor

transducer output is less than 10 percent of rated span or below its rated zero pressure output

Any time the electronic pressure sensor reading is more than 10 percent above its rated full-scale output

devices are used, any pressure deviance between electronic pressure devices more than 10 psitriggers a visual and audible alarm on the controller.

10.5.2.1.4

There shall be no valve or other restrictions within the controller ahead of the pressure

-sensing device

switch or pressure responsive means .

10.5.2.1.5

This

pressure-sensing device

switch shall be responsive to water pressure in the fire protection system.

10.5.2.1.6

The pressure

-

sensing

device

element of the switch shall be capable of withstanding a momentary surge pressure of 400 psi (27.6 bar)or 133 percent of fire pump controller rated operating pressure, whichever is higher, without losing itsaccuracy.

10.5.2.1.7

Suitable provision shall be made for relieving pressure to the pressure-

sensing device

actuated switch to allow testing of the operation of the controller and the pumping unit. [

See

See Figure A.4.31(a)

and

and Figure A.4.31(b) .]

10.5.2.1.8

Water pressure control shall be in accordance

with


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with 10.5.2.1.8.1

through

through 10.5.2.1.8.6 .

10.5.2.1.8.1

Pressure

-sensing element of the pressure-sensing device

switch actuation at the low adjustment setting shall initiate pump starting sequence (if pump is notalready in operation).

10.5.2.1.8.2 *

A pressure

-

recording device shall record the pressure in each fire pump controller pressure-sensing line at the inputto the controller.

10.5.2.1.8.3

The pressure recorder shall be listed as part of the controller or shall be a separately listed unit installedto sense the pressure at the input of the controller.

10.5.2.1.8.4

The recorder shall be capable of

storing events

operating for at least 7 days without being reset or rewound .

10.5.2.1.8.5

The pressure

-

sensing element of the recorder shall be capable of withstanding a momentary surge pressure of at least400 psi (27.6 bar) or 133 percent of fire pump controller rated operating pressure, whichever is greater,without losing its accuracy.

10.5.2.1.8.6

For variable speed pressure limiting control,

a

a 1 ⁄ 2 in. (12.7 mm) nominal size inside diameter pressure line shall be connected to the dischargepiping at a point recommended by the variable speed control manufacturer. The connection shall bebetween the discharge check valve and the discharge control valve.

10.5.2.1.8.7

Access to the recorder data shall not require opening the controller , nor require taking the controller outof service.


WIth all respect for the comittee, I disagree with the statement resolution for proposal 133.This statement was : This standard makes provisions for safeguards against failed transducers.- probably in reference with article 10.5.2.1.3. which is the only article that states about transducer failure.

By the explanation below, the article 10.5.2.1.3 should be removed from the next edition and be replaced by the introduction of a second pressure transducer.

The current standard is written like this :


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10.5.2.1.3* Where an electronic pressure sensor is used to automatically control fire pump operation, the fire pump controller shall monitor the transducer during automatic testing.10.5.2.1.3.1* Where the transducer pressure reading exceeds 10 psi (0.68 bar) during any automatic pump start that was initiated by the solenoid drain valve, as required by 10.5.2.1.8.3, the controller shall activate a visual and audible alarm, that can be silenced.10.5.2.1.3.2* Where an electronic pressure sensor is used to control fire pump operation, the fire pump controller shall monitor for and provide a signal for the following electronic pressure sensor conditions:(1) Any time the transducer output is less than 10 percent of rated span or below its rated zero pressure output(2) Any time the pressure transducer reading is more than 10 percent above its rated full-scale output

Here are my comments on the actual statement that it is not clear, nor precise, nor consistent with the installation.

10.5.2.1.3* Where an electronic pressure sensor is used to automatically control fire pump operation, the fire pump controller shall monitor the transducer during automatic testing.

It means that the transducer is not monitored continuously. By this wording, the monitoring of the transducer depends on a human operation during periodic testing.As per NFPA 25 code, this period is one week, but in certain cases could be one month.A defective pressure transducer can compromise the entire firefighting system out of order for 7 days – if inspection is done regularly.Certainly, some sites are not inspected periodically that compromises the real benefit of this monitoring.

10.5.2.1.3.1* Where the transducer pressure reading exceeds 10 psi (0.68 bar) during any automatic pump start that was initiated by the solenoid drain valve, as required by 10.5.2.1.8.3, the controller shall activate a visual and audible alarm, that can be silenced.

A.10.5.2.1.3.1 When the solenoid valve drain opens, the restricting orifice in the pressure sensing line will keep the pressure at the transducer near zero while the solenoid valve is open. This is the time when the transducer can be verified to be less than 10 psi.

The pressure on the pressure transducer while solenoid valve is open depends of many factors, and this pressure can, in certain cases, be much higher than 10 psi.

As there are no real technical requirements for the solenoid valve, the K indice of the solenoid valve can be of any value as this is not mentioned in this standard. Some current manufacturers install a strainer between the pressure transducer and the solenoid valve to avoid debris in the solenoid valve. The strainer can be clogged, so the pressure at pressure transducer point raises when ‘cloggage’ increases.There are also no requirements for the drain piping. The contractor installs this drain piping according to the pump room environment (waste pit can be far from controller). A long drain pipe will also raise this pressure.

By this, the value of 10 psi is unjustified. Even on some installations, it is not possible to drop the pressure below cut-in pressure threshold.

The pressure transducer monitoring should not depend of the design of the pressure sensing line including the drain section.

This alarm should not be ‘silencable’. If this alarm appears, the transducer is faulty and the installation can be considered out of order. By silencing this alarm, the technician that tests the installation can leave it out of order for another period if it not reacts accordingly. Again, with a silencable alarm, the firefighting installation depends on a human factor.

10.5.2.1.3.2* Where an electronic pressure sensor is used to control fire pump operation, the fire pump controller shall monitor for and provide a signal for the following electronic pressure sensor conditions:(1) Any time the transducer output is less than 10 percent of rated span or below its rated zero pressure output


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(2) Any time the pressure transducer reading is more than 10 percent above its rated full-scale output

A.10.5.2.1.3.2 The purpose of monitoring the pressure reading from a pressure transducer is to detect and correct a transducer that is operating outside of the expected pressure range.

Concerning paragraph (1) :At this level of pressure (10% of rated span), the controller has already started the pump because the cut-in threshold is above this value. So, because of a down drift of the pressure transducer, the pump is running on a closed circuit. Running the pump on a closed circuit may cause damages of the pump. Also, this start is seen by the controller as a ‘real’ start, so the engine will be destroyed if any mechanical problem.There are no reasons to start the engine because of a transducer drift.

Also, the wording below its rated zero pressure output is difficult to understand the technical meaning. How can a 0 to 10v transducer produce an electrical signal below 0v?

Concerning paragraph (2)In this sentence, pressure transducer reading is the pressure displayed on the screen (after conversion of the electrical signal of the transducer)?Above its rated full scale output…GEMS pressure transducer drift was reported on the past. The drift was slow approximatively 10 psi per week. Having this problem, the alarm is only active when the drift reaches the top range of the pressure transducer. That can be several weeks. Is it normal to wait several weeks although the drift can be seen by having two pressure transducers.

The article doesn’t mention the possibility of a fixed output – that could be caused by a problem of the pressure transducer or even by the analog input of the electronic board. In that case, the pressure reading is steady at a certain pressure and so avoid starting. Having two pressure transducers – then two analog input on the electronic board – is redundant and increase drastically the reliability of this type of measurement.

In the NFPA 20, everything is focused to start the pump- in electric : no thermic protection; double power sources if one is not enough reliable; emergency handle; on variable speed , back up starter in case of frequency drive failure.- in diesel : two batteries; two battery chargers; two power relays, emergency handle on power relays; possibility to start the engine from the engine control panel.

And the most important feature to start the pump which is the pressure transducer, there is no backup.

Related Item

Public Input No. 133-NFPA 20-2016 [ Section No. 10.5.2.1 ]


Submitter Full Name: Daniel Gendebien

Organization: Tornatech

Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Rejected


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Resolution: The standard has addressed the problem noted by the submitter with the present requirement fortesting the transducer via monitoring pressure level under certain conditions. This mechanism issufficient to determine transducer failure. Providing two or more transducers is permitted but it isnot necessary for the standard to specifically say this.


34 of 45 12/21/2017, 10:14 AM


11.2.7.2.1.2

Lead Flooded lead -acid batteries shall be furnished in a moist or dry charge condition with electrolyte liquidin a separate container. Valve regulated lead acid (VRLA) batteries shall be furnished in a completed,charged condition.


Original text only allows for flooded lead acid batteries. Adding statement for VRLA batteries creates option for users to use lower maintenance batteries in their application. Lower maintenance is achieved by not needing to periodically check electrolyte levels that is needed in flooded batteries. This reduction in maintenance potentially reduces the overall cost of ownership of the stationary pump.Other NFPA standards specifically mention VRLA and flooded lead acid batteries as options, i.e. NFPA 70E-2015 320.2 and NFPA 110-2016 3.3.7.

Related Item

Battery Type


Submitter Full Name: Sean Sullivan

Organization: EnerSys

Street Address:

City:

State:

Zip:

Submittal Date: Tue Mar 21 08:44:56 EDT 2017

Committee Statement

CommitteeAction:

Accepted


Statement: This standard has to date specifically specified dry charge batteries with separate electrolytebecause of the typical extended time before the batteries are put into service when the pump set iscommissioned. This was not intended to preclude low maintenance batteries, but to take advantageof the dry charge feature. Should low maintenance batteries have the necessary capacity to meetthe performance requirements of the standard and the engine manufacturer’s requirements withoutsetting dormant on site for an extended period of time, this standard is open to their use. The annexmaterial has been added to explain the differences between flooded and VRLA lead-acid batteriesand their use.


35 of 45 12/21/2017, 10:14 AM


11.2.7.2.1.4 *

At 40°F (4°C), battery unit A shall have the capacity sufficient to maintain the cranking speed recommendedby the engine manufacturer, which is during six consecutive cycles of 15 seconds of cranking and15 seconds of rest.


This is editorial as a result of changes made during Proposals so text will read correctly.

Related Item

FR-50




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: As a result of the First Revision on this section, this editorial correction is necessary for the textto read correctly.


36 of 45 12/21/2017, 10:14 AM


11.2.7.2.1.5

At 40°F (4°C), battery unit B shall have the capacity sufficient to maintain the cranking speed recommendedby the engine manufacturer, which is six during six consecutive cycles of 15 seconds of cranking and 15seconds of rest.


This is editorial as a result of changes made during Proposals so text will read correctly.

Related Item

FR-50




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: As a result of the First Revision on this section, this editorial correction is necessary for the textto read correctly.


37 of 45 12/21/2017, 10:14 AM


11.2.7.2.1.6 *

Battery unit A and battery unit B, combined, shall be sized, based on calculations, to have capacity to carrythe loads defined in 11.2.7.2.3 for 72 hours of standby power followed by six three consecutive cycles of15 seconds of cranking and 15 seconds of rest, without ac power being available for battery charging.


Somehow during the Proposal change “three” was changed to “six” inadvertently. This is to correct it back to three.

Related Item

FR-50




Street Address:

City:

State:

Zip:


Committee Statement

Committee Action: Rejected

Resolution: The Committee determined that the language resulting from the First Draft is correct.


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Public Comment No. 18-NFPA 20-2017 [ Section No. 12.6 ]

12.6 Battery Chargers.

The requirements for battery chargers shall be as follows:

(1) Chargers shall be specifically listed for fire pump service and be part of the diesel fire pump controller.

(2) Additional chargers also listed for fire pump service shall be permitted to be installed external to thediesel fire pump controller for added capacity or redundancy.

(3) The rectifier shall be a semiconductor type.

(4) The charger for a lead-acid battery shall be a type that automatically reduces the charging rate to lessthan 500 mA when the battery reaches a full charge condition.

(5) The battery charger at its rated voltage shall be capable of delivering energy into a fully dischargedbattery in such a manner that it will not damage the battery.

(6) The battery charger shall restore to the battery 100 percent of the battery's reserve capacity orampere-hour rating within 24 hours.

(7) The charger shall be marked with the reserve capacity or ampere-hour rating of the largest capacitybattery that it can recharge in compliance with 12.6(4).

(8) Means shall be provided on the exterior of the controller to read the voltage and charging current ofeach battery within an accuracy of ±2 percent.

(9) The charger shall be designed such that it will not be damaged or blow fuses during the cranking cycleof the engine when operated by an automatic or manual controller.

(10) The charger shall automatically charge at the maximum rate whenever required by the state of chargeof the battery.

(11) The battery charger shall be arranged to indicate loss of current output on the load side of the directcurrent (dc) overcurrent protective device where not connected through a control panel. [See12.4.1.4(2).]

(12) The charger(s) shall remain in float mode or switch from equalize to float mode while the batteries areunder the loads in 11.2.7.2.5.2.

(13) The charger(s) shall not inhibit the engine alternator from charging the batteries while the engine isrunning.


Either the battery charger in the fire pump controller, or the alternator on the engine, or both will charge the batteries depending on the the battery voltage. Since the charging sources are in parallel, the batteries will take current from either source.On a discharged battery, the battery voltage is low so both sources will charge the batteries. As the battery is charged, the voltage increases. As the voltage increases, the voltage regulators on the battery charger and the alternator will start cutting back the current to the battery. But if the battery charger has a higher regulation voltage than the alternator, the alternator will cut back first. It doesn't matter which one cuts back first as long as both have a high enough voltage to charge the battery. Also, if one fails, the other will take over and keep the batteries charged while the engine is running.

Since either the charger or alternator will dominate depending on the settings, and it doesn't matter which one does, this paragraph will cause confusion with an AHJ in the field. Further, it will be difficult for the Laboratories to verify.

Related Item

FR 84


39 of 45 12/21/2017, 10:14 AM



Organization: Nema

Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: This revision ensures that the alternator is the primary means of charging because it rechargesthe batteries faster. It is required to recharge the battery in 30 minutes.


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Public Comment No. 16-NFPA 20-2017 [ Section No. A.4.13.1 ]

A.4.13.1

A fire pump that is inoperative for any reason at any time constitutes an impairment to the fire protectionsystem. It should be returned to service without delay.

Rain , intense and intense heat from the sun , blown freezing rain, blowing sand or dust, flood, rodents,insects, and vandals are adverse conditions to equipment not installed in a completely protective buildingor enclosure. At a minimum, equipment installed outdoors should be shielded by a roof or deck.


As stated in our ballot comments for the First Revision, there was insufficient technical substantiation given to justify elimination of outdoor fire pumps currently listed and allowed for the purpose. If allowed to continue, the panel should add an exception for pumps installed prior to the date of adoption of this code so that repair or replacement of said pumps is not hindered.



Public Comment No. 13-NFPA 20-2017 [Section No. 4.13.1.2] companion proposal

Related Item

FR-89




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted


Statement: During the First Draft stage, there was insufficient technical substantiation provided to justify theelimination of outdoor fire pumps if properly rated for such installation and approved by the authorityhaving jurisdiction. This revision reverses the change that was made at the First Draft. The term "acompletely" was changed to "an acceptable" because fire pumps might not need to be in a fullyenclosed building to be adequately protected.


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A.4.13.1

A fire pump that is inoperative for any reason at any time constitutes an impairment to the fire protectionsystem. It should be returned to service without delay.

Rain, intense heat from the sun, blown freezing rain, blowing sand or dust, flood, rodents, insects, andvandals are adverse conditions to equipment not installed in a completely an acceptable protectivebuilding or enclosure.


In Southern climates, mild year round temperatures do not subject pumps to freezing conditions. In mild climates, adequate protection can be provided without the need for 4 solid walls. Many of our power plants and industrial facilities are outdoors on structural platforms with no walls including critical equipment such as Steam Turbines, Feed Pumps, and miscellaneous cooling pumps. Fire Pumps may not need a fully enclosed building to be adequately protected. Further, a fully enclosed building creates adverse affects on ambient conditions, making it hard to maintain interior temperatures below equipment maximums without supplemental building cooling. Outdoor pumps would not be the norm, but at least they would not be prohibited and used only under AHJ Approval. NFPA 37 allows Stationary Engines to be installed outdoors with appropriate protective enclosures. NFPA 37 adequately defines such enclosures as: "A cover intended to protect an engine and related equipment." and states Enclosures are neither a structure nor a room. This change adds consistency with NFPA 37 in that it gives an option for location in either a building or enclosure as long as it is acceptable to the AHJ. In accordance with NFPA 37, an enclosure is not a building.



Public Comment No. 29-NFPA 20-2017 [Section No. 4.13.1.2.3]

Related Item

FR-21

FR-89





Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Accepted



42 of 45 12/21/2017, 10:14 AM

Statement: During the First Draft stage, there was insufficient technical substantiation provided to justify theelimination of outdoor fire pumps if properly rated for such installation and approved by the authorityhaving jurisdiction. This revision reverses the change that was made at the First Draft. The term "acompletely" was changed to "an acceptable" because fire pumps might not need to be in a fullyenclosed building to be adequately protected.


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A.9.3.2

A reliable power source possesses the following characteristics:

(1) The source power plant has not experienced any shutdowns longer than 10 continuous hours in theyear prior to plan submittal. NFPA 25 requires special undertakings (i.e., fire watches) when a water-based fire protection system is taken out of service for longer than 10 hours. If the normal sourcepower plant has been intentionally shut down for longer than 10 hours in the past, it is reasonable torequire a backup source of power. With the exception of areas with a history of unplanned poweroutages for longer than 10 hours where fire protection systems could not be supplied through the firedepartment connection due to mulitple facilities being impacted by the same regional event.

(2) Power outages have not routinely been experienced in the area of the protected facility caused byfailures in generation or transmission. This standard is not intended to require that the normal source ofpower be infallible to deem the power reliable. NFPA 20 does not intend to require a backup source ofpower for every installation using an electric motor–driven fire pump.

(3) The normal source of power is not supplied by overhead conductors outside the protected facility. Firedepartments responding to an incident at the protected facility will not operate aerial apparatus nearlive overhead power lines, without exception. A backup source of power is required in case thisscenario occurs and the normal source of power must be shut off. Additionally, many utility providerswill remove power to the protected facility by physically cutting the overhead conductors. If the normalsource of power is provided by overhead conductors, which will not be identified, the utility providercould mistakenly cut the overhead conductor supplying the fire pump.

(4) Only the disconnect switches and overcurrent protection devices permitted by 9.2.3 are installed in thenormal source of power. Power disconnection and activated overcurrent protection should occur only inthe fire pump controller. The provisions of 9.2.2 for the disconnect switch and overcurrent protectionessentially require disconnection and overcurrent protection to occur in the fire pump controller. Ifunanticipated disconnect switches or overcurrent protection devices are installed in the normal sourceof power that do not meet the requirements of 9.2.2, the normal source of power must be considerednot reliable and a backup source of power is necessary.

Typical methods of routing power from the source to the motor are shown in Figure A.9.2. Otherconfigurations are also acceptable. The determination of the reliability of a service is left up to the discretionof the authority having jurisdiction.

For more information on the determination of reliability, see the following publications:

(1) IEEE 493, Recommended Practice for the Design of Reliable Industrial and Commercial PowerSystems

(2) “Reliability engineering applied to Critical Operations Power Systems (COPS),” a paper presented atthe 2011 IEEE Industrial and Commercial Power Systems Conference (I&CPS)

(3) “Reliability analysis for power to fire pump using Fault Tree and RBD,” in IEEE Transactions onIndustry Applications

(4) “Risk analysis for NEC Article 708 Critical Operations Power Systems,” paper presented at the 2009Industry Applications Society Annual Meeting and published by IEEE

(5) “NEC Article 708,” in IEEE Industry Application Magazine, Jan.-Feb. 2011


Additional sentence added to 9.3.2 (1) addresses unplanned outages. The current language does not address unplanned outages, which can affect a region versus an individual facility. These unplanned outages have a higher risk for a fire, and during a region wide event the fire department may not be able to respond to all facilities affected.


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Related Item

FR-86


Submitter Full Name: Kyle Tingle

Organization: Clarke Fire Protection

Street Address:

City:

State:

Zip:


Committee Statement

CommitteeAction:

Rejected

Resolution: The proposed text does not appear to address the submitter's substantiation. This is primarily dueto the added text being an incomplete sentence. The proposed text appears to provide anexception to the need for a reliable power source for areas with a history of unplanned poweroutages which conflicts with the substantiation provided.


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Public Comment No. 5-NFPA 20-2017 [ Section No. 2.3.6 ] · .4, Rotodynamic Centrifugal Pumps for...

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Transcript of Public Comment No. 5-NFPA 20-2017 [ Section No. 2.3.6 ] · .4, Rotodynamic Centrifugal Pumps for...