1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULAUGUST 11, 20151UL 2808Outline of Investigation for Energy Monitoring Current TransformersIssue Number: 2August 11, 2015Summary of TopicsThis is the second issue of the Outline of Investigation f
2、or EnergyMonitoring Current Transformers, UL 2808. Updates include the following:1. Revised spacing requirements in accordance with UL 61010-1 basicinsulation requirements in lieu of requiring full reinforced levels2. Addition of requirements for enclosed-type current transformersintended for outdoo
3、r use3. Addition of requirements to address Rogowski coil type constructions4. Addition of requirements for terminal blocks and industrial cableassemblies for alternative wiring methods5. Addition of requirements for Signal Gathering/Multiplexer Accessoriesto allow multiple current transformers to b
4、e connected together withina panel to send the signal down one pair of conductors to the meter6. Increasing the maximum primary voltage rating to include 1,000 Vacand 1,500 Vdc circuitsULs Outlines of Investigation are copyrighted by UL. Neither a printed norelectronic copy of an Outline of Investig
5、ation should be altered in any way. All ofULs Outlines of Investigation and all copyrights, ownerships, and rights regardingthose Outlines of Investigation shall remain the sole and exclusive property of UL.COPYRIGHT 2015 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTH
6、ER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULAUGUST 11, 2015UL 28082No 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 Gl
7、ossary .5CONSTRUCTION6 General 67 Case and Potting Materials .68 Spacings .89 Field wiring 1210 Burden Components 13PERFORMANCE11 Mold Stress Relief Test 1412 Dielectric Voltage-Withstand Test 1413 Lead Securement Test 1514 Permanence of Marking Test .1515 Temperature Test 1516 Permissible Limit Tes
8、t .1917 Outdoor Use Submersion Test .1918 Outdoor Use Cold Impact Test .19MARKINGS19 General 20INSTALLATION INSTRUCTIONS20 General 21ACCESSORIES21 Signal Gathering/Multiplexer Accessories 22APPENDIX AStandard for Components.A1AUGUST 11, 2015 UL 2808 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHE
9、R REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These 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
10、as panelboards, switchboards, industrial control equipment, and energymonitoring/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 transformer
11、s intended for outdoor use.1.2 These current transformers are rated to measure current 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 Cu
12、rrent transformer conductor leads under the scope of this Outline are considered 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 d
13、oes not include investigation of the function of the controlled equipment.1.5 These 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 t
14、emperature of 0 40C (32 104F)unless specifically indicated for use in other conditions.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
15、and marked “Service Entrance”, these current transformers areevaluated for installation 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 req
16、uirements 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, orb) Is superseded by a requirement in this Outline.2.3 A component
17、shall be used in accordance with its rating established for the intended conditions ofuse.AUGUST 11, 2015UL 28084UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL2.4 Specific components are incomplete in construction features or restricted in p
18、erformance capabilities.Such components are 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 pa
19、rentheses are explanatory orapproximate information.4 Undated References4.1 Any undated 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 fo
20、llowing definitions apply.5.2 BURDEN COMPONENT A resistor or other component that 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
21、CIRCUIT The portion of the wiring system between the load side of a Class 2 powersource 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 in
22、stallation between the service point and the line sideof the service equipment.Note: 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
23、 installation in an environment where only non-conductive POLLUTION occurs, exceptthat 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
24、.AUGUST 11, 2015 UL 2808 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION 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 with
25、in an insulating material and comply with the spacingrequirements within this Outline.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 equ
26、ipment having a maximumline-to-line voltage of 250 Vac, 600 Vac, 1000 Vac, or 1500 Vdc.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
27、otherwise recessed within theinsulating case to reduce the likelihood of creating a 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 elec
28、aPerformance level category (PLC)HWIb,cHAId,eCTIf,gV-2, VTM-2 Min. 105C 0, 1 or 2 0, 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
29、) value of a material is to be determined in accordance with the Standard forPolymeric 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 sha
30、ll not be exceededduring the Temperature Test.Hot Wire Ignition (HWI)bThe Hot Wire Ignition (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 mini
31、mum thickness atwhich the material is being used. When the thickness of an insulating 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 valu
32、e greater (worse) than the valuerequired by Table 7.1 shall be subjected to the Glow 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
33、 by test in accordance the Standard for Polymeric Materials - Short TermProperty Evaluations, 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 co
34、rresponding to a HAIvalue, the material is evaluated as in footnote e.eA material without 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
35、 ElectricalEquipment Evaluations, UL 746C.Comparative Tracking Index (CTI)AUGUST 11, 2015UL 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
36、 (PLC)HWIb,cHAId,eCTIf,gfThe Comparative Tracking Index (CTI) PLC value of a material 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 ma
37、terial is being used. When the thickness of an insulating material is less than the minimumspecified 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 (wors
38、e) than the value required by Table 7.1 shall have aproof tracking index of 175 as determined 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 accordan
39、ce with 19.5 do not require molded case materials with HAI or HWI ratings, and thecase 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 7.3 or Table 7.1, if it can bedemonstrated that a minimum of 0.8 mm of void and bubble free pott
40、ing material is provided between theexternal surface and all internal metal parts.7.3 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
41、 Term Property Evaluations, UL 746B. Examples of suitable generic material include:Epoxy, Melamine-Phenolic, Phenolic, Unfilled Nylon and Unfilled Polycarbonate.7.4 Potting materials that are entirely encased shall comply with the requirements in Table 7.1, thegeneric material requirements in 7.3, o
42、r Table 7.2.Table 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 7.1.7.5 If provided in multiple pieces, except where it would interfere with the intended motion of
43、 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 case material.7.6 When mounted as intended, there shall be no vent
44、ilation or other openings in the case that wouldallow contaminants into areas with live parts.7.7 Flexible case materials such as the Rogoski Coil shall meet the insulation requirements for field wiringleads described in 9.1 and 9.3, except the exterior-most insulating material shall be rated at lea
45、st 105C.AUGUST 11, 2015 UL 2808 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7.8 For enclosed-type current transformers, the case shall be molded of materials suitable for outdoor use(f1) with respect to exposure to Ultraviolet Light, Wate
46、r Exposure and Immersion in accordance with theStandard for Polymeric 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 th
47、e Tensile Strength and Elongation Tests, andCompression Tests of the 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
48、 6P of UL 50E.8 Spacings8.1 Electrical spacings for an uncontrolled 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 ra
49、ting of 4 is assumed.Table 8.1Uncontrolled environment spacings to 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 47.2aSee 8.4 for possible increas
