1、May 7, 20041SUBJECT 2419OUTLINE OF INVESTIGATIONFORELECTRICALLY CONDUCTIVE CORROSION RESISTANT COMPOUNDSIssue Number: 1MAY 7, 2004Summary of TopicsThis is the First Issue of the Outline of Investigation for ElectricallyConductive Corrosion Resistant Compounds.The UL Foreword is no longer located wit
2、hin the UL Standard. For informationconcerning the use and application of the requirements contained in thisStandard, the current version of the UL Foreword is located onULStandardsInfoNet at: http:/ 2004 UNDERWRITERS LABORATORIES INC.MAY 7, 2004SUBJECT 24192No Text on This PageCONTENTSINTRODUCTION1
3、 Scope .42 General 42.1 Units of Measurement .42.2 Undated References 43 Glossary .4CONSTRUCTION4 General 5PERFORMANCE5 Material Identification 56 Electrical Resistance Test 57 Corrosion Resistance Test .68 Compatibility with Different Insulation 68.1 Specimen preparation .68.2 Physical properties t
4、est 6MARKINGS9 General 7MAY 7, 2004 SUBJECT 2419 3INTRODUCTION1 Scope1.1 These requirements cover electrically conductive corrosion resistant compounds for use on thethreads of Rigid Metal Conduit (RMC) and Intermediate Metal Conduit (IMC). These compounds areintended to resist corrosion and provide
5、 electrical conductivity in accordance with Section 300.6(a) of theNational Electrical Code, NFPA 70-2002 when used in accordance with the manufacturerss installationinstructions.1.2 These compounds are not suitable for use on conduit intended for use in Hazardous Locations asdefined by the National
6、 Electrical Code, NFPA 70.1.3 In addition to the requirement as specified in this outline, these compounds are to be evaluated fortheir suitability with the specific conduit type used and the specific application.2 General2.1 Units of Measurement2.1.1 Values stated without parentheses are the requir
7、ement. Values in parentheses are explanatory orapproximate information.2.2 Undated References2.2.1 Any undated reference to a code or standard appearing in the requirements of this standard shallbe interpreted as referring to the latest edition of that code or standard.3 Glossary3.1 For the purposes
8、 of this outline, the following definitions apply.3.2 COMPOUND A combination of elements used to coat conduit threads that provides corrosionresistance and conductivity.3.3 INTERMEDIATE METAL CONDUIT Conduit that is for use as a metal raceway for the installationof wires and cables as defined in the
9、 Standard for Electrical Intermediate Metal Conduit Steel, UL 1242.3.4 RIGID METAL CONDUIT Conduit that is for use as a metal raceway for the installation of wires andcables as defined in the:a) Standard for Electrical Rigid Metal Conduit Steel, UL 6; andb) Standard for Electrical Rigid Metal Condui
10、t Aluminum, Red Brass, and Stainless Steel, UL6A.MAY 7, 2004SUBJECT 24194CONSTRUCTION4 General4.1 A compound shall be evaluated for its compatibility with the different types of wire insulation that areto be encountered in the conduit application.4.2 When a manufacturer specifies that a compound is
11、not suitable for a particular type of insulation, thelimitation shall be printed on the container used to package the compound. See Markings, Section 9.4.3 Compounds shall be subjected to the tests in Sections58.PERFORMANCE5 Material Identification5.1 An electrically conductive compound that is to b
12、e used on threads of conduit shall be subjected to theInfrared Spectroscopy (IR) tests specified in the Standard for Polymeric Materials Short Term PropertyEvaluations, UL 746A.6 Electrical Resistance Test6.1 The electrical resistance of the connection between adjacent sections of conduit joined by
13、a couplingshall not exceed 0.005 ohm. Tests are to be conducted first on three specimens that are not provided withthe corrosion-resistant compound on the threads. The tests are to be repeated on the same specimensthat are provided with the compound.6.2 The conduit is to be cut, threaded and joined
14、to the coupling of an additional section of conduit in theintended manner, and a direct current of 30 A is to be passed between adjacent sections of the conduit.The resulting voltage drop is to be measured between points (file marks) on two adjacent sections 1/16inch (1.6 mm) from the connection of
15、the conduit. The resistance is to be calculated by dividing themeasured voltage drop by the current passing through the conduit. The conduit is to be removed from thefitting, the coating applied to the threads in the intended manner and the conduit reassembled to thefitting. The conduit is to be wip
16、ed clean to ensure there is no excess compound at the connection. Thevoltage drop is then to be re-measured and the resistance calculated.6.3 The two maximum resistance measurements are to be compared. The resistance measurement ofthe conduit connection provided with the compound shall not be greate
17、r than that of the specimen withoutthe compound.MAY 7, 2004 SUBJECT 2419 57 Corrosion Resistance Test7.1 A compound shall be evaluated for its ability to provide corrosion resistance on a conduit thread asspecified in 7.2 7.5.7.2 Three conduit specimens are to be cut, threaded, and provided with the
18、 corrosion-resistant compoundto be tested. The specimens are to be free of grease and dirt before being placed in the test environment.7.3 The test apparatus is to be an insulated specimen chamber, such as a Cleveland cabinet. It is tocontain a temperature-controlled water reservoir, pump, spray cha
19、mber for humidifying the air, anair-circulating fan, provision for heating the air, specimen supports, and the necessary means of control.7.4 The dry bulb temperature of the test chamber is to be maintained at 60 1C (140 2F) and therelative humidity is to be maintained at 98 2 percent throughout the
20、 test. The specimens are to besupported in racks at an angle of 15 degrees from the vertical.7.5 The test is to be conducted for 48 hours. There shall be no evidence of rust on the threads after theexposure.8 Compatibility with Different Insulation8.1 Specimen preparation8.1.1 Specimens of the insul
21、ation used in the intended application shall be subjected to this test.Exception: Insulation not specifically intended for use with a compound, as noted in 4.2, need not betested. The compound container shall be marked as specified in 9.2.8.1.2 Specimens of rubber and thermoplastic insulation are to
22、 be prepared as specified in the StandardTest Method for Tensile Properties of Plastics, ASTM D 638 and then coated with a 1/64 inch (0.40 mm)thick layer of the compound to be evaluated. The specimens are to be conditioned in an air-circulatingoven at a temperature equal to the temperature rating of
23、 the insulation for three separate periods of 7, 14,and 51 days. Separate specimens of the insulation without the compound are to be simultaneouslyconditioned as well.8.1.3 At the end of each exposure period, the compound is to be wiped off and the specimens kept atroom temperature 25C (77F) for 3 d
24、ays to allow absorbed moisture to evaporate. After the third day, thespecimens are to be subjected to the physical properties test specified in 8.2.8.2 Physical properties test8.2.1 The specimens conditioned as described in 8.1 shall be subjected to tensile strength and elongationtests noted in eith
25、er 8.2.2 or 8.2.3.8.2.2 Rubber insulation specimens are to be tested as specified in the Standard Test Methods forVulcanized Rubber and Thermoplastic Elastomers Tension, ASTM D 41298a.MAY 7, 2004SUBJECT 241968.2.3 Thermoplastic insulation specimens are to be tested as specified in the Standard Test
26、Method forTensile Properties of Plastics, ASTM D 638.8.2.4 Exposure to the compound shall not result in greater than a 10 percent reduction of physicalproperties when compared to unexposed specimens.MARKINGS9 General9.1 The following markings shall be on the smallest unit container: Manufacturers na
27、me, compound,designation, batch number, and date code or fill date.9.2 When a compound is not intended for use with a particular type of insulation, as specified in 4.2 andthe exception to 8.1.1, the container shall detail the type of insulation and convey the message in amanner that is evident to the user.MAY 7, 2004 SUBJECT 2419 7MAY 7, 2004SUBJECT 24198No Text on This Page
