1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSeptember 18, 20091SUBJECT 1247AOUTLINE OF INVESTIGATIONFORVARIABLE SPEED LIMITING CONTROLS INSTALLED WITH DIESELENGINES FOR DRIVING STATIONARY FIRE PUMPSIssue No. 2September 18, 2009Summary of T
2、opicsThis second issue of Subject 1247A, Outline of Investigation for VariableSpeed Limiting Controls Installed With Diesel Engines for DrivingStationary Fire Pumps covers the construction and performancerequirements for a variable speed pressure limiting control (VSPLC) andvariable speed suction li
3、miting control (VSSLC) intended to be installedon a diesel engine for driving a stationary fire pump at the enginemanufacturing location.COPYRIGHT 2009 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSEPTEMBER 18,
4、 2009SUBJECT 1247A2No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTS1 Scope .42 Components 43 Units of Measurement .44 Undated References 55 Glossary .56 Variable Speed Limiting Controls .57 Performance Tests 77.1 VS
5、PLC Performance rating 77.2 VSSLC Performance test 87.3 Engine endurance at lowest operating speed 87.4 VSPLC Operation test 97.5 VSSLC Operation test 97.6 Pressure Transducer (Sensor) Tests .107.7 Hydrostatic strength .127.8 Elastomeric parts (except gaskets) test 137.9 Cycling test .137.10 Contami
6、nated water cycle test .147.11 Stress-corrosion cracking of brass parts test .147.12 Stress-corrosion cracking of stainless steel parts test .157.13 Deposit loading test 167.14 10-day corrosion test .168 Variable Speed Limiting Control Production Tests 179 Marking .18SEPTEMBER 18, 2009 SUBJECT 1247A
7、 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL1 Scope1.1 These requirements cover the construction and performance requirements for a variable speedpressure limiting control (VSPLC) and variable speed suction limiting control (VSSLC) inten
8、ded to beinstalled on a diesel engine for driving a stationary fire pump at the engine manufacturing location. Inaddition to complying with the requirements described herein, the engine with VSPLC or VSSLC shallcomply with the applicable requirements of the Standard for Diesel Engines for Driving St
9、ationary FirePumps, UL 1247.1.2 The engines covered by these requirements are intended for installation and use in accordance withthe Standard for the Installation of Stationary Fire Pumps for Fire Protection, NFPA 20.2 Components2.1 Except as indicated in 2.2, a component of a product covered by th
10、is Outline of Investigation shallcomply with the requirements for that component.2.2 A component is not required to comply with a specific requirement that:a) Involves a feature or characteristic not required in the application of the component in theproduct covered by this Outline of Investigation,
11、 orb) Is superseded by a requirement in this Outline of Investigation.2.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.2.4 Specific components are incomplete in construction features or restricted in performance capabilities.Such components ar
12、e intended for use only under limited conditions, such as certain temperatures notexceeding specified limits, and shall be used only under those specific conditions.3 Units of Measurement3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory orapproximate in
13、formation.SEPTEMBER 18, 2009SUBJECT 1247A4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL4 Undated References4.1 Any undated reference to a code or standard appearing in the requirements of this Outline ofInvestigation shall be interpreted as
14、 referring to the latest edition of that code or standard.5 Glossary5.1 For the purpose of this outline of investigation, the following definitions apply.5.2 CORROSION-RESISTANT MATERIAL A material having resistance to corrosion equivalent to orexceeding that of a brass, bronze, monel, or series 300
15、 stainless steel alloy.5.3 RATED PRESSURE The maximum working pressure intended for the device.5.4 SET PRESSURE The internal pressure at which a variable speed limiting control device isintended to begin to decrease engine speed.5.5 SYSTEM PRESSURE The pressure that is measured on the discharge side
16、 of the fire pump (theresult of the suction supply pressure, pump curve and engine speed droop) at any flow condition.5.6 VARIABLE SPEED PRESSURE LIMITING CONTROL (VSPLC) A factory installed engineattachment intended to limit system pressure by reducing the pump driver speed from rated speed.Where r
17、eferenced in this standard, the VSPLC device is the primary variable speed control device thatis connected to the engine throttle or electronically controls the engine throttle.5.7 VARIABLE SPEED SUCTION LIMITING CONTROL (VSSLC) A factory installed engineattachment intended to maintain a minimum pos
18、itive suction pressure by reducing the pump driverspeed from rated speed. Where referenced in this standard, the VSSLC device is the primary variablespeed control device that is connected to the engine throttle or electronically controls the engine throttle.6 Variable Speed Limiting Controls6.1 A VS
19、PLC shall not decrease engine speed unless system pressure exceeds the set pressure.6.2 A VSSLC shall not decrease engine speed unless the suction pressure drops below the set pressure.6.3 A VSPLC shall not increase engine speed above the rated speed for the purpose of increasingsystem pressure.6.4
20、A mechanical VSPLC or VSSLC shall be factory preset, and provided with a means such as afastening nut to secure the intended setting and a tamper indicator such as a seal.6.5 An electronic VSPLC or VSSLC shall be factory preset and shall not be field programmable.6.6 A VSPLC or VSSLC shall be provid
21、ed with a stop having a tamper indicator or other feature that willnot permit the engine to be operated at a speed below the lowest operating speed permitted by the enginemanufacturer.SEPTEMBER 18, 2009 SUBJECT 1247A 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WIT
22、HOUT PERMISSION FROM UL6.7 A VSPLC or VSSLC device shall be constructed for use at a rated pressure of at least 175 psig (1.21Mpa).6.8 A part that bears against, rotates within, or slides on stationary parts, and that must be free to moveduring operation, shall be made of compatible corrosion-resist
23、ant material, or shall be fitted with bushings,inserts, or other parts made of these corrosion-resistant materials at those points where freedom of motionis required.6.9 An interior bolt or screw shall be made of bronze or other corrosion-resistant material.6.10 An internal spring used in a VSPLC or
24、 VSSLC device shall be made of material having corrosionresistance equivalent to that of phosphor bronze and shall not be susceptible to stress corrosion.6.11 Clearance shall be provided between working parts and between working and stationary parts sothat corrosion or deposits of foreign matter wil
25、l not result in sluggish action or otherwise impairedoperation of the VSPLC or VSSLC device.6.12 If an orifice with a diameter less than 3/16 inch (4.8 mm) is used in operation of the device, a screenor strainer with corrosion resistance equivalent to brass shall be provided. The total area of the o
26、peningsin the screen or strainer shall be not less than 20 times the cross-section area of the opening that thescreen or strainer is intended to protect. The largest dimension of the screen or strainer openings shallnot exceed 1/32 inch (0.8 mm) less than the diameter of the protected orifice.6.13 A
27、 VSPLC or VSSLC shall be provided with means to accept a 1/2 inch (12.7 mm) pipe for sensingpressure.6.14 A mechanical VSPLC or VSSLC device shall be constructed with a return spring or similar featuresuch that in the event of a failure of the pressure limiting control, the engine shall return to ra
28、ted speed.6.15 An electronic VSPLC or VSSLC device shall be constructed such that in the event of a failure of thepressure limiting control, the engine shall return to rated speed.6.16 A pressure sensing line connected to a VSPLC or VSSLC device shall not incorporate a manualshutoff unless the shuto
29、ff valve has provisions to be locked in the open position.6.17 A VSPLC shall not have a set pressure less than 100 psig (0.69 Mpa).6.18 A VSSLC shall not have a set pressure less than 5 psig (34.5 kPa).6.19 A pressure-sensing device shall have a minimum orifice diameter of 1/8 inch (3.2 mm).6.20 A p
30、ressure transducer (sensor, transmitter) shall be field replaceable.6.21 An engine provided with a VSSLC shall be provided with a switch or means to activate alow-pressure signal when the suction pressure falls between 80 to 100 percent of the set pressure. Thesignal to the terminal and switch shall
31、 comply with the applicable requirements of the Standard for DieselEngines for Driving Stationary Fire Pumps, UL 1247.SEPTEMBER 18, 2009SUBJECT 1247A6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7 Performance Tests7.1 VSPLC Performance rati
32、ng7.1.1 When tested as specified in 7.1.2 7.1.6, a performance rating shall be established for the VSPLCand when subjected to these tests, a VSPLC shall begin to decrease the speed of the engine from ratedspeed with an inlet pressure at no less than 100 percent of the set pressure and no more than 1
33、05 percentof the set pressure.7.1.2 A mechanical VSPLC shall be tested at each set pressure and at least the minimum and maximumspeed ratings.7.1.3 An electronic VSPLC shall be tested at least at the minimum and maximum set pressures and theminimum and maximum speed ratings.7.1.4 The VSPLC shall be
34、attached to the engine such that it is operational. A stable inlet pressure, witha media of water, shall be created by means of an external source and shall be plumbed to the inlet of theVSPLC device. If a positive displacement pump is used to establish the inlet pressure, dampers orsnubbers are to
35、be used to stabilize the pressure.7.1.5 With the engine running and no load applied, inlet water pressure shall be applied to the VSPLCdevice starting at 90 percent of the set pressure. The inlet pressure shall then be gradually increased to115 percent of the set pressure or until the minimum engine
36、 speed has been achieved. Inlet waterpressure and engine speed shall be recorded.7.1.6 A VSPLC rating shall be established at each set pressure and representative engine speed ratingsbased upon the lowest VSPLC value achieved at:a) 110 percent of the set pressure;b) Rated pressure of the components
37、intended for use with the engine; orc) The lowest operating speed permitted by the engine manufacturer using the followingcalculation.VSPLC Rating,Z=1(N2)/(N1)2in which:Z is the rating of VSPLC. When the VSPLC is fully engaged, this is a value that is to bemultiplied by the maximum pressure on the c
38、orrected pump speed curve to obtain the maximumamount of trim pressure available using the VSPLC device;N1is the engine rated speed (RPM); andN2is the reduced engine speed (RPM).SEPTEMBER 18, 2009 SUBJECT 1247A 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT P
39、ERMISSION FROM UL7.2 VSSLC Performance test7.2.1 When tested as specified in 7.2.2 7.2.5, a VSSLC shall begin to decrease the speed of the enginefrom rated speed with an inlet pressure at no more than 100 percent of the set pressure and no less than95 percent of the set pressure.7.2.2 A mechanical V
40、SSLC shall be tested at each set pressure and at least the minimum and maximumspeed ratings.7.2.3 An electronic VSSPLC shall be tested at least at the minimum and maximum set pressures and theminimum and maximum speed ratings.7.2.4 The VSSLC shall be attached to the engine such that it is operationa
41、l. A stable inlet pressure, witha media of water, shall be created by means of an external source and shall be connected to the inlet ofthe VSSLC device. If a positive displacement pump is used to establish the inlet pressure, dampers orsnubbers are to be used to stabilize pressure.7.2.5 With the en
42、gine running and no load applied, inlet water pressure shall be applied to the VSSLCdevice starting at 115 percent of the set pressure. The inlet pressure shall then be gradually decreasedto 90 percent of the set pressure or until the minimum engine speed has been achieved. Inlet waterpressure and e
43、ngine speed shall be recorded.7.3 Engine endurance at lowest operating speed7.3.1 An engine equipped with a VSPLC or VSSLC shall comply with 20.2 of UL 1247 and 7.3.2 when a1-hour endurance test is conducted at the lowest engine operating speed permitted by the enginemanufacturer.7.3.2 The endurance
44、 performance test shall be conducted per 20.2 of UL 1247 at the lowest operatingspeed and the maximum sustainable power output shall be no less than the power (HPL) determined asfollows:HPL=1.1*HPR*(NL/NR)3in which:HPLis the maximum sustainable power output required to be generated at the lowest ope
45、ratingspeed permitted by the manufacturer as referenced in 7.3.1;HPRis the rated power at the lowest rated speed for a given engine model;NRis the lowest rated speed for a given engine model; andNLis the lowest operating speed permitted by the engine manufacturer as referenced in 7.3.1.SEPTEMBER 18,
46、 2009SUBJECT 1247A8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7.4 VSPLC Operation test7.4.1 When tested as specified in 7.4.3 through 7.4.5, a VSPLC shall maintain the system pressure suchthat within 5 seconds after the set pressure has b
47、een exceeded, the system pressure is to be maintainedat not less than 98 percent nor more than 110 percent of the set pressure. In addition, the systempressure shall be at least 98 percent of the set pressure within 20 seconds after the engine is started. Theengine speed shall return to the highest
48、rated speed when the VSPLC is disabled.7.4.2 After 20 seconds from engine start-up, an electronic VSPLC shall maintain a stable systempressure such that the system pressure does not fluctuate more that 3 percent of the set pressure.Momentary pressure fluctuations outside the specified pressure band
49、that do not last more than 3 secondsshall be permitted.7.4.3 A VSPLC shall be connected to an engine driven centrifugal pump that will generate systempressure to accommodate VSPLC testing at a minimum of 95 percent of the Z-rating.7.4.4 With the engine set at its highest rated speed, the engine shall be started while connected to acentrifugal pump:a) That generates system pressure at the rated speed determined as follows; andSystem Pressure = Set Pressure * (1+Z)b) With a churn load of less than 30 percent of the nameplate power rating of the engine.7.4.5 The suc
