1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULAUGUST 28, 20151UL 1008MTRANSFER SWITCH EQUIPMENT, METER MOUNTEDIssue No: 2August 28, 2015Summary of TopicsThis Second Issue of Outline of Investigation for Transfer SwitchEquipment, Meter Mounte
2、d, UL 1008M, is being issued to incorporaterequirements for meter mounted transfer switches intended for use withpermanently connected generators.ULs Outlines of Investigations are copyrighted by UL. Neither a printed orelectronic copy of an Outline of Investigation should be altered in any way. All
3、 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 FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT
4、PERMISSION FROM ULAUGUST 28, 2015UL 1008M2No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Components .53 Units of Measurement 54 Undated References 5CONSTRUCTION5 General 56 Enclosure .67 Ins
5、ulating Material .68 Mounting of Parts .69 Guarding and Accessibility of Live Parts 710 Current-Carrying Parts .711 Field Wiring Terminals .712 Internal Wiring 813 Grounding and Bonding 814 Operating Mechanism 914.1 General 914.2 Location and protection of transfer control circuits 1015 Receptacles
6、1016 Inlets for Cord Connection to a Portable Generator .1117 Spacings 1117.1 General .1117.2 Spacings on printed wiring boards 12PERFORMANCE18 General 1319 Normal Operation Test 1320 Overvoltage Test .1421 Undervoltage Test 1422 Overload Test 1423 Temperature Test .1624 Endurance Test 1925 Dielectr
7、ic Voltage-Withstand Test 1926 Withstand 2027 Closing 22RATINGS28 Details .23MARKINGS29 Content 2330 Permanence of Marking .24AUGUST 28, 2015 UL 1008M 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These requirements c
8、over automatic and non-automatic (manual) transfer switch equipment,operating at 600 V ac less, and intended for installation in a utility meter base, in ordinary locations only.1.2 These devices are intended for use in optional standby systems only, and are not intended for use inEmergency or Legal
9、ly Required Standby Systems. These devices are intended for one of the followingapplications:a) Cord connection of a portable generator to power a premise wiring system, where theneutral (grounded circuit conductor) of the generator is not bonded to ground or the generatorframe, and bonding of the n
10、eutral (grounded circuit conductor) to ground will occur within themeter base orb) Permanent connection of a stationary generator to power a premise wiring system, wherethe generator is connected as a non-seperately derived system, where the neutral (groundedcircuit conductor) of the generator is no
11、t bonded to ground or the generator frame.1.3 These devices are connected between the meter mounting equipment and the electric utility meter,on the line side of the service disconnect. As such, the installation of these devices is intended to be underthe exclusive control of the serving utility, an
12、d these are not considered under the purview of the NationalElectrical Code, NFPA 70. Generators and associated wiring connected to the generator terminals of thetransfer switch are not considered under the exclusive control of the utility, and are under the purview ofNFPA 70.1.4 An automatic transf
13、er switch as covered by these requirements is a device that automaticallytransfers a common load from a normal supply to an alternate supply in the event of failure of the normalsupply, and automatically returns the load to the normal supply when the normal supply is restored. Anautomatic transfer s
14、witch may be provided with a logic control circuit that inhibits automatic operation ofthe device from either a normal to an alternate supply, or from an alternate to a normal supply when theswitch reverts to automatic operation upon loss of power to the load.1.5 A non-automatic transfer switch as c
15、overed by these requirements is a device, operated manually bya physical action, or electrically by a remote control, for transferring a common load between a normal andalternate supply.1.6 A transfer switch may incorporate overcurrent protection for the main power circuits.1.7 These requirements on
16、ly cover transfer switches which are completely enclosed when installed in ameter base in conjunction with the electrical utility meter.1.8 Transfer switches are rated in amperes and are considered to be acceptable for total system transfer,which includes control of motors, electric-heating loads, a
17、nd transformer loads.AUGUST 28, 2015UL 1008M4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL2 Components2.1 Except as indicated in 2.2, a component of a product covered by this Outline of Investigation shallcomply with the requirements for th
18、at 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 shall be used in
19、 accordance with its rating established for the intended conditions ofuse.2.4 Specific components are incomplete in construction features or restricted in performance capabilities.Such components are intended for use only under limited conditions, such as certain temperatures notexceeding specified
20、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 undated reference to a code or standard appearing in the require
21、ments of this outline shall beinterpreted as referring to the latest edition of that code or standard.CONSTRUCTION5 General5.1 Transfer switches shall employ materials throughout which are acceptable for the particular use, andshall be made and finished with the degree of uniformity and grade of wor
22、kmanship practicable in awell-equipped factory.AUGUST 28, 2015 UL 1008M 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6 Enclosure6.1 A transfer switch shall be provided with an enclosure, which complies with the requirements of theStandard
23、for Meter Sockets, UL 414.6.2 An external operating means such as those for a disconnect, a pilot device, or a resetting operation mounted on or through an enclosure shall withstand the tests specified for the enclosure.6.3 Marking and instructions on the exterior of the device shall be permanent. S
24、ee 30.1.6.4 Meter mounted transfer switches which are intended for outdoor use in wet locations shall complywith the requirements for Type 3, 3R, 3S, 4, 4X, 6, or 6P enclosures, as detailed in the Enclosure Sectionof the Standard for Transfer Switch Equipment, UL 1008. Transfer switches intended for
25、 cord connectionto portable generators, shall comply with these requirements with the cord connector installed as well aswith the connector withdrawn.6.5 Enclosures shall have provisions for padlocking or sealing by the serving utility, such that theenclosure may not be opened or removed without rem
26、oving the utility company padlock or breaking theutility company seal. This requirement does not apply to enclosures (such as generator termination boxes)that contain only wiring or components that are not connected to the utility conductors with the transferswitch in any position.7 Insulating Mater
27、ial7.1 Material for the support of uninsulated live parts shall be porcelain, phenolic or cold moldedcomposition, or other material acceptable for the support of such parts in accordance with the Standardfor Polymeric Materials Use in Electrical Equipment Evaluations, UL 746C, and shall be capable o
28、fwithstanding the most severe conditions likely to be met in service.7.2 Insulating material, including barriers between parts of opposite polarity (phase barriers) and materialthat may be subject to the influence of an arc formed by the opening of a switch, shall be acceptable forthe particular app
29、lication.8 Mounting of Parts8.1 All parts of transfer switches shall be securely mounted in position and prevented from loosening orturning if such motion may affect adversely the intended performance of the equipment, or may affect therisk of fire and injury to persons incident to the operation of
30、the equipment.8.2 Uninsulated live parts other than pressure wire connectors, shall be secured to their supportingsurfaces so that they will be prevented from turning or shifting in position if such motion may result in areduction of spacings to less than those indicated in Section 17. The security
31、of contact assemblies shallbe such as to provide the continued alignment of contacts.8.3 Friction between surfaces is not acceptable as a means to prevent turning, loosening, or shifting of apart as required in 8.1 and 8.2, but a lock washer, properly applied, may be accepted.AUGUST 28, 2015UL 1008M
32、6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL8.4 If the mechanism of a switching device is such that automatic operation of the transfer switch, oroperation of a remote or automatic tripping devices will permit sudden movement of an operat
33、ing handle,the motion of the handle shall be restricted or the handle shall be guarded to prevent injury to persons inthe vicinity of the handle.9 Guarding and Accessibility of Live Parts9.1 When the transfer switch is installed in a meter base in conjunction with an electrical utility meter,there s
34、hall be no uninsulated live parts accessible.9.2 Inlets for connection of portable generators shall be of the type with male blades, and shall bearranged such that they are not energized unless mated with the appropriate connector.10 Current-Carrying Parts10.1 A current-carrying part shall have mech
35、anical strength and current-carrying capacity for the service,and shall be of metal that is acceptable for the particular application.10.2 If parts are held together by screws, a threaded part shall have no fewer than two full, clean-cutthreads engaged. If the screw does not extend all the way throu
36、gh a threaded part, the taper or lead andthe first full thread are to be disregarded in a determination of the number of threads engaged.11 Field Wiring Terminals11.1 Transfer switch equipment shall be provided with blades and jaws for mating with a meter base andan electrical utility meter. These b
37、lades and jaws shall comply with the requirements of the Standard forMeter Sockets, UL 414.11.2 Meter mounted transfer switches for connection to a portable generator shall be provided only withan integral inlet for cord connection of a portable generator. Flexible cord shall not be an integral part
38、 ofthe transfer switch. Field wiring terminals for connection of a portable generator are not allowed.11.3 Meter mounted transfer switches for permanent connection to a stationary generator shall haveprovisions for permanent connection of wiring contained in appropriate flexible metal or non-metalli
39、cconduit in accordance with NFPA 70, the National Electrical Code. The use of non-flexible conduit is notpermitted.AUGUST 28, 2015 UL 1008M 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL12 Internal Wiring12.1 The internal wiring of transfer
40、 switches shall consist of general use wire or appliance wiring materialacceptable for the particular application when considered with respect to the temperature and voltage andconditions of service to which the wiring is likely to be subjected.12.2 Wireways shall be smooth and entirely free from sh
41、arp edges, burrs, fins, moving parts, and the like,which may cause abrasion of the conductor insulation.12.3 All joints and connections shall be mechanically secure and shall provide effective electrical contactwithout strain on connections and terminals.12.4 Stranded conductors clamped under wire-b
42、inding screws or similar parts shall have the individualstrands restrained by cupped washers or the equivalent to provide connections.12.5 A splice shall be provided with insulation equivalent to that of the wires involved.12.6 An opening in a barrier through which factory installed wiring passes, o
43、r through which field installedwiring may pass, shall be provided with a bushing, or shall be formed so that there are no sharp edgeswith which conductors may come in contact.12.7 A bushing employed as described in 12.6 shall be of glass, ceramic, hard fiber, phenoliccomposition, cold-molded composi
44、tion, or other polymeric material which has been investigated and foundsuitable for the application. Rubber, neoprene, and similar materials are not acceptable for this bushing.13 Grounding and Bonding13.1 Transfer switches shall have provision for grounding all dead metal parts that are exposed or
45、thatare likely to be touched by a person during adjustment or intended operation of the device, and that arelikely to become energized.13.2 Small, isolated (insulated) dead metal parts are not required to be grounded.13.3 A dead metal part is not considered likely to become energized if acceptable r
46、esults are obtainedduring dielectric voltage withstand with the part connected to ground during the tests.13.4 The equipment grounding conductor and neutral (grounded circuit conductor) from the generatorshall be bonded within the transfer switch enclosure to the neutral (grounded circuit conductor)
47、 of thenormal supply circuit. The size of the bonding conductor shall be based on the rating of the alternatesupply circuit in accordance with the main bonding jumper requirements from Table 17.1 of the Standardfor Transfer Switch Equipment, UL 1008.13.5 The bonding conductor required by 13.4 shall
48、be installed in the transfer switch, and shall haveprovisions for connection to the neutral terminal of the meter base.AUGUST 28, 2015UL 1008M8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL14 Operating Mechanism14.1 General14.1.1 The operati
49、ng mechanism of a transfer switch shall be constructed to provide reliable and positiveelectrical and mechanical performance under all conditions of intended operation.14.1.2 Provision shall be made to reduce the possibility of adjusting screws and similar adjustable partsfrom loosening under the conditions of actual use.14.1.3 An automatic transfer switch shall incorporate the required control equipment to initiate transferfrom the normal supply to the alternate supply upon the interruption of any or all phases of the normalsupply.14.1.4 An automatic transfer switch shall be
