1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULDecember 21, 20061SUBJECT 1615OUTLINE OF INVESTIGATIONFORREFRIGERANT HEAT RECOVERY UNITSIssue Number: 3DECEMBER 21, 2006Summary of TopicsThis new issue of SU 1615 is being issued through ULs elec
2、tronicpublishing system to ensure format uniformity between the PDF andHTML versions of the document. No substantive changes have beenincorporated in the document.The UL Foreword is no longer located within the UL Standard. For informationconcerning the use and application of the requirements contai
3、ned in thisStandard, the current version of the UL Foreword is located onULStandardsInfoNet at: http:/ 2006 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULDECEMBER 21, 2006SUBJECT 16152No Text on This PageUL COPY
4、RIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTS1 General 42 Electrical Requirements 43 Heat Exchangers .43.1 General .43.2 Double wall separation with vented interface .43.3 Double wall redundancy .54 Temperature Controls .55 Tests 66 Markin
5、gs .77 Installation Instructions 7DECEMBER 21, 2006 SUBJECT 1615 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL1 General1.1 The following covers the requirements for refrigerant heat recovery units which are intended forinstallation in conj
6、unction with air conditioning or refrigerating systems to extract heat from the refrigerantfor heating potable water. Generally these units include a heat exchanger and water temperature controlcomponents. They may include additional components such as hot water storage tanks and watercirculating pu
7、mps.1.2 The efficiency of the units, the feasibility of interconnection with air conditioning or refrigeratingsystems, and the effect of the units on the operation of the air conditioning and refrigerating systems arenot part of the investigation for coverage of these units under Classification Serv
8、ice.2 Electrical Requirements2.1 The electrical requirements normally applied to refrigerating and air conditioning equipment areapplicable to these units. This includes requirements for electrical enclosures, field wiring connections,internal wiring, separation of circuits, bonding for grounding, m
9、ounting of components, guarding ofuninsulated live parts, insulating materials, motors and motor overcurrent protection, switches andcontrollers, transformers, overcurrent protection for control circuit conductors, and electrical spacings.Requirements in the Standard for Refrigeration and Air Condit
10、ioning Condensing and Compressor Units,UL 303, are considered applicable and will be applied for investigation of the refrigerant heat recoveryunits.3 Heat Exchangers3.1 General3.1.1 The heat exchangers used in refrigerant heat recovery systems for heating potable water arerequired to be of a design
11、 which minimizes the risk of contamination of potable water. A design whichprovides double wall separation between the potable water and the refrigerants is considered ascomplying with this requirement. Such design may incorporate either a vented interface or redundancy asdescribed below.3.2 Double
12、wall separation with vented interface3.2.1 The concept of the vented interface is that if leakage develops in the heat exchanger wall whichcontains the refrigerant, it will not pressurize the interface and therefore will not exert pressure on theouter wall, which may result in failure also of the ou
13、ter wall thus allowing the refrigerant to leak into thepotable water. It would therefore be required that the interface be maintained at near atmosphericpressure, requiring that the venting path be continuous over the entire length of the heat exchanger. Thecontinuity of the venting path is determin
14、ed by use of water at a pressure not higher than 10 psig.3.2.2 In the heat exchanger of vented interface design the wall which contains the refrigerant shall becapable of withstanding a hydrostatic pressure equivalent to five times the maximum rated designpressure for the refrigerant side, with the
15、water side maintained at atmospheric pressure. Similarly, thewater side shall be capable of withstanding a hydrostatic pressure of at least 300 psig which is the sameas the requirement for water heater storage tanks in Standards for Household Electric Storage-TankWater Heaters, UL 174, and Oil-Fired
16、 Storage Tank Water Heaters, UL 732.DECEMBER 21, 2006SUBJECT 16154UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL3.3 Double wall redundancy3.3.1 The concept of double wall redundancy is that if leakage develops through a wall of the heatexcha
17、nger, it may be expected to occur at a point of minute material impurity which may result in a pinhole passage. With a double wall construction it is extremely unlikely that such impurities in the two wallswill coincide. Therefore, to avoid a potential leakage path developing through both walls, the
18、 refrigerantleaking through a pin hole in the wall containing the refrigerant shall not be able to travel in the interfaceto find an impurity and weak spot in the wall containing the water. For that purpose the interface needsto be completely leaktight, meaning that in tube-inside-tube heat exchange
19、r the refrigerant cannot travellongitudinally. Conformance with this requirement is to be determined by application of hydrostaticpressure to the interface at 1-1/2 times the maximum rated design pressure for the refrigerant side. Noleakage shall occur over a 6 inch distance.3.3.2 For a redundant do
20、uble wall heat exchanger the refrigerant side of each wall separately shall becapable of withstanding the hydrostatic pressure of five times the maximum rated design pressure, withthe water side maintained at atmospheric pressure. The water side of the heat exchanger is to besubjected to 300 psig hy
21、drostatic pressure, same as the requirement in the standards of UL 174 and UL732 referenced above.4 Temperature Controls4.1 If the heat reclaimer unit includes a hot water storage tank, the heat reclaimer shall be provided withappropriate temperature controls to prevent excessive temperature and pre
22、ssure in the storage tank.These requirements parallel the requirements for water heaters included in standards UL 174 and UL 732referenced above. Accordingly, the system shall include (1) a temperature-regulating control which limitsthe temperature of water in the storage tank to not higher than 85C
23、 (185F), and (2) a temperature limitcontrol, which is permitted to function only in the event the regulating control fails or malfunctions. The limitcontrol shall limit the temperature of water in the upper 6 inches of the tank to 99C (210F). When testingfor conformance with the above requirements i
24、t is normally assumed that the refrigerant flowing throughthe refrigerant side of the heat exchanger will attain a temperature of 250F, which will be simulated byflow of water entering the heat exchanger at that temperature. A temperature limiting control would not berequired if, by tests, it is det
25、ermined that the heat reclaimer is not capable for producing a watertemperature higher than 99C and neither limit control nor regulating control would be required if the watertemperature in the tank will not exceed 85C. During these tests there will be no draw of water from thestorage tank.4.2 If a
26、water storage tank is not part of the heat reclaimer unit and water exiting the heat reclaimer canattain higher temperatures than indicated above, as determined by tests described below underOperation Tests, respective regulating and/or limit controls would be required to prevent deliver of waterat
27、higher temperatures then permitted for water heaters. In lieu of providing a limit control, a warningmarking may be provided on the unit indicating that the installer may need to provide a limit control toprevent excessive water temperature.4.3 The regulating and limit controls used to prevent exces
28、sive temperatures shall conform to appropriaterequirements for water heater regulating and limit controls as included in the Standards for Limit Controls,UL 353, or Temperature-Indicating and -Regulating Equipment, UL 873.DECEMBER 21, 2006 SUBJECT 1615 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FUR
29、THER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL5 Tests5.1 A complete test program applicable to a refrigerant heat reclaimer can be determined only byreviewing the design, construction, operation, and intended installation method of the heat reclaimer. It isexpected that at least the fol
30、lowing tests will be necessary.5.2 POWER INPUT The current draw at rated input voltage measured with suitable meters, shall be notmore than 110 percent of the rated value marked on the unit nameplate.5.3 TEMPERATURE TEST Temperatures of materials and electrical components will be measured withthe sy
31、stem operated at rated voltage and conditions stabilized with water flowing through the refrigerantside at a temperature not more than 5F below the temperature which causes the regulating control tooperate. Tests may be conducted also under other operating conditions if it is determined that they ma
32、yproduce higher temperatures on components and materials. All temperatures shall be within the ratings ofthe materials and components involved. Temperature limits for commonly used materials and componentsare included in Table 29.1 of standard UL 303 referenced above.5.4 UNDERVOLTAGE AND OVERVOLTAGE
33、 TEST Tests will be conducted at 85 and 110 percentrated input voltages, based on the standard test voltages such as 120, 208, 240, and 480 volts. Normaloperation of electromagnetic switching devices (contactors, relays) is expected at 85 percent rated inputvoltage. 110 percent rated voltage shall n
34、ot cause any damage to electrical components. Conformancewith this requirement is determined by operating the system at 110 percent rated input voltage untiltemperatures stabilize, and then operating the system at rated input voltage, at which normal operationshall be observed.5.5 DIELECTRIC WITHSTA
35、ND TEST Dielectric potential of twice rated voltage plus 1000 volts will beapplied between high-voltage parts and grounded parts and between high-voltage and low-voltage parts,and 500 volts will be applied between low-voltage and grounded metal parts for 1 minute. There shall beno dielectric breakdo
36、wn.5.6 HYDROSTATIC STRENGTH TEST These will be conducted on the heat exchanger as discussedabove under the heading Heat Exchangers. These tests are conducted in accordance with the Standardfor Refrigerant-Containing Components and Accessories, Nonelectrical, UL 207.5.7 OPERATIONAL TESTS Tests will b
37、e conducted to determine that the temperature-regulatingand/or limit controls, if provided, will prevent the water from attaining higher temperatures than indicatedabove under the heading of Temperature Controls. For these tests the unit will be operated such thatwater temperature is gradually incre
38、ased. The temperature in the upper 6 inches of the tank will bemonitored by thermocouples and shall not exceed 85C (185F) with the temperature regulating control inoperation. With the regulating control bypassed, the temperature shall not exceed 99C (210F). If astorage tank is not included as part o
39、f the heat reclaimer unit, the heat reclaimer will be connected to thesmallest storage tank specified in the installation instructions with piping runs as short as possible andinsulated with 1 inch thick fiberglass insulation.5.8 RAIN AND INSULATION RESISTANCE TESTS This test will be conducted on ou
40、tdoor useequipment only in accordance with Section 52 of above-referenced standard UL 303.DECEMBER 21, 2006SUBJECT 16156UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL5.9 For all these tests it is expected that Listed and/or Recognized Compon
41、ents are being employed andestablished ratings and use conditions are compatible with the application. If this is not the case, thecomponents may need to be separately investigated and tested to determine their suitability.6 Markings6.1 The heat reclaimer units shall be marked with at least the foll
42、owing information.a) Subscribers name.b) Model, catalog number, and the like designation.c) Electrical ratings.d) Pressure rating of the refrigerant and water sides.e) Types of refrigerants.f) Identification of water and refrigerant inlet and outlet connections.g) Identification of terminals and req
43、uired hook-up information for electrical connections.h) Warning markings for the need of temperature limiting control, if applicable (seeTemperature Controls above).6.2 Additional markings may be required if this becomes evident during the investigation. All markingsshall be of permanent type, eithe
44、r metal plates or Recognized Marking and Labeling Systems (PGDQ2)suitable for the temperatures and surfaces involved.7 Installation Instructions7.1 Installation instructions shall be furnished with the heat reclaimer units, which shall include allinformation necessary to accomplish the installation
45、in the intended manner. It is expected that at leastthe following shall be included:a) Types of air conditioning or refrigerating systems with which the heat reclaimer units may beinstalled.b) Instructions for accomplishing the interconnection with the refrigerating equipment with whichit may be ins
46、talled. If this involves cutting refrigeration lines of air conditioning or refrigerationsystem and punching holes into cabinets for passage of piping or conduit, instructions shall beincluded for location of such holes and how to caulk or seal such openings, if required.c) Instructions for accompli
47、shing the interconnection with water piping and/or with the hot waterstorage tank, if applicable.d) If the heat reclaimers are intended to electrical interconnect with existing equipment and/orbe powered from other equipment, instructions shall be provided for making the determinationthat current ra
48、tings of existing controls and/or wiring is not exceeded when the heat reclaimer isinstalled.e) All warning statements and any informative information included in marking shall also beincluded in installation instructions.DECEMBER 21, 2006 SUBJECT 1615 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7.2 Draft copies of installation instructions are to be submitted to UL review as part of investigation forClassification.DECEMBER 21, 2006SUBJECT 16158
