1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJUNE 21, 20061SUBJECT 2049OUTLINE OF INVESTIGATIONFORRESIDENTIAL PIPE HEATING CABLEIssue Number: 4June 21, 2006Summary of TopicsThis fourth issue of the Subject 2049 Outline of Investigation forR
2、esidential Pipe Heating Cable includes revisions to the Flexing Test forthe heating section of the cable.The UL Foreword is no longer located within the UL Standard. For informationconcerning the use and application of the requirements contained in thisStandard, the current version of the UL Forewor
3、d is located onULStandardsInfoNet at: http:/ 2006 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJUNE 21, 2006SUBJECT 20492No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDIS
4、TRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .4CONSTRUCTION2 Heating Conductors .43 Grounding Component .44 Jacket .55 Nonheating Leads .56 Thermostats 5PERFORMANCE7 Heating Section Tests .58 Complete Cable Tests .69 Permanence of Cord Tag and Marking Tests .7MARKING10 Details 811
5、 Installation Instructions 11JUNE 21, 2006 SUBJECT 2049 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 This outline covers residential pipe heating cable intended to reduce the likelihood of water freezingin exposed pi
6、pes of residences. These devices are considered appliances in accordance with Article 422of the National Electrical Code, NFPA 70.1.2 Cable units employing different heating conductors, insulation, or other forms of construction may beexamined and tested in accordance with the intent of this outline
7、, and if found to be substantiallyequivalent, may be covered.1.3 Residential pipe heating cables may be installed on metal or rigid plastic pipes. Plastic pipes areconsidered to have a maximum long-term thermal exposure limit of 50C absolute.1.4 These heating cables are limited to applications where
8、 they are not exposed to weather unlessadditionally evaluated for outdoor use.CONSTRUCTION2 Heating Conductors2.1 The heating conductors shall be insulated with a suitable insulating compound acceptable for use at75C (167F) or higher in wet locations. The minimum thickness of the insulation shall no
9、t be less than1/32 inch (0.8 mm) when not provided with a nylon jacket and not less than 1/64 inch (0.4 mm) whenprovided with a 4 mil or thicker nylon jacket.2.2 Heating cables which utilize self-regulating positive temperature coefficient (PTC) materials shall beevaluated in accordance with the req
10、uirements for such materials. Reference is made to the Appendix tothe Subject 1434 bulletin dated February 9, 1978, or to more current PTC requirements as appropriate.3 Grounding Component3.1 The heating section shall be provided with a grounding component that consists of a metallic sheathor braid.
11、 If the heating section consists of more than one conductor, the grounding component may beincorporated on each conductor or all conductors may be enclosed with a common sheath or braid. If thegrounding component consists of the braid, it shall provide at least 80 percent coverage and shall employma
12、terial that is corrosion resistant. The grounding component shall have a current-carrying capacity equalto or greater than that of the unit but not less than that of an 18 AWG (0.82 mm2) copper conductor. Thegrounding braid shall be connected to the grounding lead of the non-heating leads.JUNE 21, 2
13、006SUBJECT 20494UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL4 Jacket4.1 An optional insulating jacket may be employed over the grounding component.5 Nonheating Leads5.1 The heating section shall be connected to nonheating leads consisting
14、of Type SJ or heavier flexiblecord acceptable for outdoor use that are at least 2 feet (0.61 m) in length. The flexible cord shall not bemore than 6 feet (1.8 m) in length and shall be terminated by a grounding type attachment plug.6 Thermostats6.1 A thermostat for temperature control may be include
15、d in the cable assembly. The thermostat shallcomply with the applicable requirements of the Standard for Temperature-Indicating and -RegulatingEquipment, UL 873.PERFORMANCE7 Heating Section Tests7.1 The heating section of the cable shall be subjected to the tests specified in Table 7.1.Table 7.1Test
16、s for heating section of the cableTest ResultsFlexing test The heating cable shall comply with the Flexing of ShieldedCable Test of the Reference Standard for Electrical Wires,Cables, and Flexible Cords, UL 1581.Conductors shall not open in fewer than 15, 000 cycles.Impact test A. With flat plate, 5
17、 pounds, 1-1/4 inch diameter cylindricalweight, 3 feet height.Shall withstand ten impacts at different locations.B. On 3/4 inch drill rod, 5 pounds, 1-1/4 inch diametercylindrical weight, 1 foot height.Shall withstand ten impacts at different locations.Crushing test 500 pounds: reference Subject 158
18、8, Outline ofInvestigation for Roof and Gutter De-Icing Cable Units.Shall withstand the crushing force specified.Abrasion testaConducted only when insulating jacket is employed overgrounding component. Samples abraded by No. 1/2 emerycloth mounted on a curved plate, 3-1/2 inch radius, withsample sup
19、porting a 3/4 pound weight.Shall withstand 4000 cycles.Ground component ampacity The ground component shall be caused to carry a currentof (1) 135 percent of the branch circuit overload protectionfor 1 hour, and (2) 200 percent of the branch circuitoverload protection for 2 minutes.There shall be no
20、 damage to the insulation on the heatingsection.Cold bend The heating section shall be cooled to minus 35C (minus31F) for 1 hour and then wrapped around a metal mandrel3/8 inch (9.5 mm) in diameter.The insulation shall not crack.Flame test JUNE 21, 2006 SUBJECT 2049 5Table 7.1 Continued on Next Page
21、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 7.1 ContinuedTest ResultsThe heating section shall be subjected to the flame test inaccordance with the Standard for Thermoplastic-InsulatedWires and Cables, UL 83.The insulation shall not
22、flame more than 1 minute after thefinal application of the test flame nor shall flame beconveyed during, between, or after any application of thetest flame.aMay be omitted for units having outer braid or metallic sheath.8 Complete Cable Tests8.1 The complete cable shall be subjected to the tests spe
23、cified in Table 8.1. Tests on PVC pipe areconsidered representative of metal pipe as well.Table 8.1Tests for complete cablesTest ResultsInput The input shall be within 5 percent of the rated input valueof the unit when in the normal operating air temperature.Temperature Installed per manufacturers i
24、nstructions with minimum wrapspacing, tested at operating temperature on 1/2 inch PVCpipe filled with stagnant water.No material shall be exposed to a temperature over itsrating. References to be made to the Standard for ElectricHeating Appliances, UL 499. Temperature on the pipe shallnot exceed 50C
25、 absolute.Dielectric voltage-withstand Twice rated voltage plus 1000 volts. There shall be no indication of dielectric breakdown.Abnormal operation A. Installed on empty pipe with no spacing betweenadjacent turns and covered with (1) thermal insulation and(2) loosely wadded tissue paper.There shall
26、be no fire or other conditions that may involve arisk of electric shock or injury to persons.B. Installed on empty pipe with heating section crossingitself and covered with (1) thermal insulation and (2) looselywadded tissue paper.There shall be no fire or other conditions that may involve arisk of
27、electric shock or injury to persons.C. One-half of the heating section shall be installed onempty pipe in accordance with the manufacturersinstructions and the remaining section of the heating unitallowed to fall at random in a steel pail and covered withtissue paper.There shall be no fire or other
28、conditions that may involve arisk of electric shock or injury to persons.D. Installed on empty pipe with no spacing betweenadjacent turns and no insulation.No accessible part shall exceed 60C.E. Installed on empty pipe with heating section crossingitself and no insulation.No accessible part shall ex
29、ceed 60C.JUNE 21, 2006SUBJECT 20496UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL9 Permanence of Cord Tag and Marking Tests9.1 To determine compliance with 10.3, representative samples are to be subjected to the conditioningdescribed in Tabl
30、e 9.1 and then are to be tested in accordance with 9.2 9.5. Upon completion of thetesting, each cord tag sample shall comply with the following requirements:a) The tag shall not tear more than 1/16 inch (1.6 mm) at any point;b) The tag shall not separate from the power-supply cordc) The tag shall no
31、t slip or move along the length of the power-supply cord more than 1/2 inch(12.7 mm);d) The tag shall not permanently shrink, deform, crack, or result in any other condition thatwould render the markings or illustrations on the tag illegible; ande) Overlamination on the tag shall remain in place and
32、 not be torn or otherwise damaged, andthe printing shall remain legible.Table 9.1Exposure conditionsExposure conditions Time of evaluationAt least 72 hours in a standard atmosphere.aFollowing the exposure period, under the exposureconditions.At least 24 hours in a standard atmosphereafollowed byimme
33、rsion in demineralized water for 48 hours at 23C(73F).While still wet after removal from the water.bAt least 24 hours in a standard atmosphereafollowed by 10days in a circulating-air oven at the test temperaturecorresponding to the rated surface temperature (60C).After cooling in a standard atmosphe
34、re.aAt least 24 hours in a standard atmosphereafollowed by 7hours in a cold box at the lowest temperature (minus 35C)intended for use.Immediately upon removal from the cold box, avoidingwarming as much as possible.At least 24 hours in a standard atmosphereafollowed byexposure to ultraviolet light an
35、d water for 720 hours.Following the exposure period.baStandard atmosphere, 23 2C (73.4 3.6F) and a relative humidity of 50 5 percent.bLabels as attached to porous surfaces are to be dried at 40C (104F).9.2 In determining compliance with 9.1(d), manipulation is permissible, such as straightening of t
36、he tagby hand.9.3 For each type of conditioning specified in Table 9.1, three samples of the tag applied to the powersupply cord in the intended manner are to be used. If tags are applied by an adhesive, tests are to beconducted no sooner than 24 hours after application of the tag.9.4 Each sample is
37、 to consist of a length of power supply cord to which the tag has been applied. Thepower supply cord, with the attachment plug pointing up, is to be held tautly in a vertical plane. A force of5 pounds (22.2 N) is to be applied for 1 minute to the upper most corner of the tag farthest from the powers
38、upply cord, within 1/4 inch (6.4 mm) of the vertical edge of the tag. The force is to be applied verticallydownward in a direction parallel to the major axis of the cord.JUNE 21, 2006 SUBJECT 2049 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM
39、 UL9.5 To determine compliance with 9.1 (e), each sample is to be scraped ten times across printed areasand edges, with a force of approximately 2 pounds (8.9 N), using the edge of a 5/64 inch (2.0 mm) thicksteel blade held at a right angle to the test surface.MARKING10 Details10.1 Each complete uni
40、t shall be provided with a cord tag located not more than 3 inches (76.2 mm) fromthe attachment plug of the flexible cord. The cord tag shall be legibly and permanently marked with themarkings detailed in 10.2, and the illustrations shown in Figure 10.1. For other than the word WARNING,equivalent ma
41、rkings and illustrations may be used.Exception No. 1: A cable construction that self-regulates the maximum temperature on the surface of thecable to a temperature of 90C (194F) or less when subjected to the temperature and abnormal operationtests need not be marked concerning adjacent, twisted, or c
42、rossed-over turns.Exception No. 2: A cable construction that is not affected by twisting, such as a round construction, neednot have the reference to twisting in the marking.This is generated text for figtxt.JUNE 21, 2006SUBJECT 20498UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR
43、DISTRIBUTION WITHOUT PERMISSION FROM ULFigure 10.1Cord tag for residential pipe heating cableJUNE 21, 2006 SUBJECT 2049 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL10.2 Required markings on the cord tag include:a) Manufacturers name or tr
44、adename.b) Residential Pipe Heating Cable.c) Do not use an extension cord.d) Read installation instructions thoroughly and install only as directed.e) Do not remove this tag.f) WARNING! If cable is improperly installed a fire may result. Follow installation instructions.g) Install only in accessible
45、 locations, do not install behind walls or where hidden.h) Do not run through walls, ceilings, or floors.10.3 The cord tag shall be permanently attached to the flexible cord and shall be made of substantialmaterial (cardboard, cloth, plastic, or the equivalent) to provide mechanical strength and to
46、prevent easyremoval. The cord tag shall comply with the requirements in Section 9.10.4 The markings and illustrations shall be:a) paint-stenciled, die-stamped, molded, or indelibly stamped;b) in the form of a pressure-sensitive label; andc) in a form that has been determined to be equivalent.10.5 A
47、pressure-sensitive label shall comply with the applicable requirements for labels for outdoor usein the Standard for Marking and Labeling Systems, UL 969. Rated surface temperatures are consideredto be 60C (140F) for high temperature and minus 35C (minus 31F) for low temperature.10.6 The word WARNIN
48、G on the cord tag shall be in letters not less than 3/32 inch (2.4 mm) high. Theremaining statements shall be in letters not less than 1/16 inch (1.6 mm) high.10.7 All statements and illustrations shall be printed or illustrated so as to contrast with the background.JUNE 21, 2006SUBJECT 204910UL COP
49、YRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL11 Installation Instructions11.1 Installation instructions shall be provided with each complete unit and shall include a statement thatan extension cord shall not be employed to reach the receptacle.11.2 The instructions shall provide complete and clear guidance for all phases of installation.JUNE 21, 2006 SUBJECT 2049 11UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTI
