1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJUNE 10, 20161UL 2808Outline of Investigation for Energy Monitoring Current TransformersIssue Number: 3June 10, 2016Summary of TopicsThis third issue of the Outline of Investigation for Energy Mo
2、nitoringCurrent Transformers, UL 2808, includes revised requirements for thecase and potting material of current transformers.ULs Outlines of Investigation are copyrighted by UL LLC. Neither a printed norelectronic copy of an Outline of Investigation should be altered in any way. All ofULs Outlines
3、of Investigation and all copyrights, ownerships, and rights regardingthose Outlines of Investigation shall remain the sole and exclusive property of ULLLC.COPYRIGHT 2016 UL LLCUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJUNE 10, 2016UL 280
4、82No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Components 43 Units of Measurement .54 Undated References 55 Glossary .5CONSTRUCTION6 General 67 Case and Potting Materials .68 Spacings .89
5、Field wiring 1310 Burden Components 14PERFORMANCE11 Mold Stress Relief Test 1412 Dielectric Voltage-Withstand Test 1513 Lead Securement Test 1514 Permanence of Marking Test .1615 Temperature Test 1616 Permissible Limit Test .2017 Outdoor Use Submersion Test .2018 Outdoor Use Cold Impact Test .20MARK
6、INGS19 General 21INSTALLATION INSTRUCTIONS20 General 22ACCESSORIES21 Signal Gathering/Multiplexer Accessories 23APPENDIX AStandard for Components.A1JUNE 10, 2016 UL 2808 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 T
7、hese requirements cover open-type current transformers and their associated signal level combinerand/or multiplexer board accessories thereto intended for field installation within distribution and controlequipment such as panelboards, switchboards, industrial control equipment, and energymonitoring
8、/management equipment, to measure current on a branch circuit. Installation is in accordancewith the National Electrical Code, ANSI/NFPA 70. These requirements also cover Service Entranceenclosed-type current transformers intended for outdoor use.1.2 These current transformers are rated to measure c
9、urrent in a maximum 250 Vac, 600 Vac, or 1000Vac line-to-line circuits or in a maximum 1500 Vdc circuit. Transformers rated for use in an AC circuit mayalso be used in DC circuits that do not exceed the Vac rating.1.3 Current transformer conductor leads under the scope of this Outline are considered
10、 a Class 1 circuit,as defined by the National Electrical Code, ANSI/NFPA 70, and are intended to be installed with NFPA 70Chapter 3 wiring methods. Isolation for the user is provided at the termination.1.4 This Outline does not include investigation of the function of the controlled equipment.1.5 Th
11、ese current transformers have not been evaluated for accuracy or use with emergency controlsystems where the function of the control could affect safety.1.6 These current transformers are intended for use in an ambient temperature of 0 40C (32 104F)unless specifically indicated for use in other cond
12、itions.1.7 These current transformers are intended for use at altitudes up to 2000 meters (6562 ft) and in ahumidity tolerance of095percent, unless indicated for use in other conditions.1.8 Unless specifically evaluated and marked “Service Entrance”, these current transformers areevaluated for insta
13、llation within equipment on the load side of the service equipment overcurrent device.2 Components2.1 Except as indicated in 2.2, a component of a product covered by this Outline of Investigation shallcomply with the requirements for that component.2.2 A component is not required to comply with a sp
14、ecific requirement that:a) Involves a feature or characteristic not required in the application of the component in theproduct covered by this Outline, orb) Is superseded by a requirement in this Outline.2.3 A component shall be used in accordance with its rating established for the intended conditi
15、ons ofuse.JUNE 10, 2016UL 28084UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL2.4 Specific components are incomplete in construction features or restricted in performance capabilities.Such components are intended for use only under limited co
16、nditions, 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 information.4 Undated References4.1 Any un
17、dated reference to a code or standard appearing in the requirements of this Outline shall beinterpreted as referring to the latest edition of that code or standard.5 Glossary5.1 For the purposes of this Outline, the following definitions apply.5.2 BURDEN COMPONENT A resistor or other component that
18、limits open circuit voltage of the currenttransformer.5.3 CLASS 1 CIRCUIT The portion of the wiring system between the load side of the overcurrent deviceor power-limited supply and the connected equipment.5.4 CLASS 2 CIRCUIT The portion of the wiring system between the load side of a Class 2 powers
19、ource and the connected equipment.5.5 OPEN-TYPE DEVICE A device that is not provided with a complete enclosure and is intended tobe placed in a suitable end-product enclosure.5.6 SERVICE ENTRANCE That portion of the installation between the service point and the line sideof the service equipment.Not
20、e: Service entrance correlates with Overvoltage Category IV, or CAT IV, as defined in IEC 60364 andIEC 60664-1.5.7 CONTROLLED ENVIRONMENT Also known as Pollution Degree 2. Indicates current transformersare intended for installation in an environment where only non-conductive POLLUTION occurs, except
21、that occasionally a temporary conductivity caused by condensation is expected.5.8 ENCLOSED-TYPE DEVICE A device that is provided with a complete enclosure and may beinstalled outside of a separate end-product enclosure.JUNE 10, 2016 UL 2808 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODU
22、CTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONSTRUCTION6 General6.1 In order to reduce the likelihood of creating a risk of electric shock, all metallic parts shall becompletely encased or otherwise recessed within an insulating material and comply with the spacingrequirements within this Outlin
23、e.6.2 Unless otherwise noted, all insulating materials shall be rated with an Electrical Relative ThermalIndex (RTI Elec) of 105C, minimum.6.3 These current transformers shall be evaluated for installation within equipment having a maximumline-to-line voltage of 250 Vac, 600 Vac, 1000 Vac, or 1500 V
24、dc.6.4 These current transformers shall not contain any radio signal generators or other intentional signalemitters.7 Case and Potting Materials7.1 All metallic parts of the current transformer shall be insulated or otherwise recessed within theinsulating case to reduce the likelihood of creating a
25、risk of electric shock within the installation. Materialsfor a molded insulating case shall comply with Table 7.1.Table 7.1Material characteristics for current transformer case and exposed pottingFlame class RTI elecaPerformance level category (PLC)HWIb,cHAId,eCTIf,gV-2, VTM-2 Min. 105C 0, 1 or 2 0,
26、 1 or 2 0, 1, 2 or 3V-1, VTM-1 Min. 105C 0, 1, 2 or 3 0, 1, or 2 0, 1, 2 or 3V-0, VTM-0 or 5V Min. 105C 0, 1, 2, 3 or 4 0, 1, 2 or 3 0, 1, 2 or 3Relative Thermal Index (RTI)aThe Electrical Relative Thermal Index (RTI) value of a material is to be determined in accordance with the Standard forPolymer
27、ic Materials - Long Term Property Evaluations, UL 746B, by test or by use of the generic RTI table. This materialcharacteristic is dependent upon the minimum thickness at which the material is being used. The RTI shall not be exceededduring the Temperature Test.Hot Wire Ignition (HWI)bThe Hot Wire I
28、gnition (HWI) value of a material is to be determined by test in accordance with the Standard for PolymericMaterials - Short Term Property Evaluations, UL 746A. This material characteristic is dependent upon the minimum thickness atwhich the material is being used. When the thickness of an insulatin
29、g material is less than the minimum specified thicknesscorresponding to a HWI value, the material is evaluated as in footnote c.cA material without an HWI Performance Level Category (PLC) value or with a HWI PLC value greater (worse) than the valuerequired by Table 7.1 shall be subjected to the Glow
30、 Wire End-Product Test specified in the Standard for Polymeric Materials -Use in Electrical Equipment Evaluations, UL 746C.High Current Arc Resistance to Ignition (HAI)dThe HAI value of a material is to be determined by test in accordance the Standard for Polymeric Materials - Short TermProperty Eva
31、luations, UL 746A. This material characteristic is dependent upon the minimum thickness at which the material isbeing used. When the thickness of an insulating material is less than the minimum specified thickness corresponding to a HAIvalue, the material is evaluated as in footnote e.eA material wi
32、thout an HAI PLC value or with an HAI PLC value greater (worse) than the value required by Table 7.1 shall besubjected to the end-product Arc Resistance Test specified in the Standard for Polymeric Materials - Use in ElectricalEquipment Evaluations, UL 746C.Comparative Tracking Index (CTI)JUNE 10, 2
33、016UL 28086Table 7.1 Continued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 7.1 ContinuedFlame class RTI elecaPerformance level category (PLC)HWIb,cHAId,eCTIf,gfThe Comparative Tracking Index (CTI) PLC value of a material
34、is to be determined by test in accordance with the Standard forPolymeric Materials - Short Term Property Evaluations, UL 746A. This material characteristic is not dependent upon theminimum thickness at which the material is being used. When the thickness of an insulating material is less than the mi
35、nimumspecified thickness corresponding to a CTI value, the material is evaluated as having the same CTI value found for the greaterthickness.gA material without a CTI PLC value or with a CTI PLC value greater (worse) than the value required by Table 7.1 shall have aproof tracking index of 175 as det
36、ermined by the end-product Proof Tracking Test specified in the Standard for PolymericMaterials - Use in Electrical Equipment Evaluations UL 746C.Basic Insulated TransformershCurrent transformers marked in accordance with 19.5 do not require molded case materials with HAI or HWI ratings, and thecase
37、 shall have a CTI rating of 0, 1, 2, 3 or 4.7.2 One side of the case may consist of a potting material complying with 7.4 or Table 7.1, if it can bedemonstrated that a minimum of 0.8 mm of void and bubble free potting material is provided between theexternal surface and all internal metal parts.7.3
38、The whole case may consist of a potting material complying with Table 7.1, if it can be demonstratedthat a minimum of 0.8 mm of void and bubble free potting material is provided between the externalsurface and all internal metal parts. In addition, a molding procedure shall be provided to demonstrat
39、e thereliability and repeatability. This construction shall be subjected to the Outdoor Use Cold Impact Test,Section 18, but at 5C ambient, then followed by the Dielectric Voltage-Withstand Test, Section 12.Note: The Outdoor Use Cold Impact Test may be conducted at a lower temperature if requested b
40、y themanufacturer.7.4 Potting material shall be at least 0.8 mm thick and void and bubble free. Any generic potting materialmay be used whose Electrical RTI is a minimum 105 C, as determined by the Standard for PolymericMaterials - Long Term Property Evaluations, UL 746B. Examples of suitable generi
41、c material include:Epoxy, Melamine-Phenolic, Phenolic, Unfilled Nylon and Unfilled Polycarbonate.7.5 Potting materials that are entirely encased shall comply with the requirements in Table 7.1, thegeneric material requirements in 7.4, or Table 7.2.JUNE 10, 2016 UL 2808 7UL COPYRIGHTED MATERIAL NOT A
42、UTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 7.2Additional material characteristics allowed for internal pottingFlame class RTI elec Performance level category (PLC)HWIaHAIaCTIaHB Min 90C 0, 1 or 2 0 or 1 0, 1, 2 or 3aSee Table 7.1.7.6 If provided in multiple pie
43、ces, except where it would interfere with the intended motion of a split-corebobbin, the case parts shall be reliably secured together by ultrasonic welding, solvent welding, snap-fit,glue, or other suitable means. If glue is used, it shall be rated minimum 105C and evaluated for adhesionwith the ca
44、se material.7.7 When mounted as intended, there shall be no ventilation or other openings in the case that wouldallow contaminants into areas with live parts.7.8 Flexible case materials such as the Rogoski Coil shall meet the insulation requirements for field wiringleads described in 9.1 and 9.3, ex
45、cept the exterior-most insulating material shall be rated at least 105C.7.9 For enclosed-type current transformers, the case shall be molded of materials suitable for outdoor use(f1) with respect to exposure to Ultraviolet Light, Water Exposure and Immersion in accordance with theStandard for Polyme
46、ric Materials - Use in Electrical Equipment Evaluations, UL 746C. Potting materialshall also be evaluated for exposure to Ultraviolet Light, Water Exposure and Immersion in accordancewith UL 746C. Gasket materials shall comply with the Tensile Strength and Elongation Tests, andCompression Tests of t
47、he Standard for Enclosures for Electrical Equipment, EnvironmentalConsiderations, UL 50E. The case shall restrict water access to interior parts. Exposed metal parts shallmeet the outdoor and additional corrosion requirements for Type 6P of UL 50E.8 Spacings8.1 Electrical spacings for an uncontrolle
48、d environment from any external surface to any internal live partshall comply with Table 8.1. Over-surface distances depend on the Comparative Tracking Index (CTI) ofthe insulation material. If the CTI value is not known, a CTI PLC rating of 4 is assumed.Table 8.1Uncontrolled environment spacings to
49、 coilFrom any external surface to coil, exposed conductor ends inside case or any other live parta,b,c,dMarked primaryvoltageThrough-airmmOver-surfaceemmComparative Tracking Index (CTI)PLC 0 PLC 1 PLC 2 or 3fNon-service entrance250 Vac 5.9 6.4 7.2 8.0600 Vac 10.5 15.2 17.1 19.01000 Vac 14.3 25.0 28.0 32.01500 Vdc 19.4 37.8 41.7 47.2Service entrance250 Vac 10.5 10.5 10.5 10.5600 Vac 14.3 15.2 17.1 19.01000 Vac 24.3 25.0 28.0 32.01500 Vdc 31.4 37.8 41.7 47.2JUNE 10, 2016UL 28088Table 8.1 Continued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED F
