1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJULY 19, 20161UL 2877Outline of Investigation for Power Supplies, Medium VoltageIssue Number: 2July 19, 2016Summary of TopicsThis second issue of the Outline of Investigation for Power Supplies,M
2、edium Voltage, UL 2877, covers requirements for power supplies withinput voltage ratings greater than 1000 V, to 15 kV.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 of Inve
3、stigation 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 ULJULY 19, 2016UL 28772No Te
4、xt on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .52 Glossary .53 Components 64 Units of Measurement and Undated References 65 Normal and Special Service Conditions 65.1 Normal service conditions .65.2
5、 Special service conditions .7CONSTRUCTION6 General 77 Enclosures .78 Grounding and Bonding 119 Protective Devices .1210 Isolating Means .1311 Interlocking 1311.1 Isolating means interlocks .1311.2 Drawout element interlocks 1311.3 Door interlocks .1512 Automatic Restarting 1513 Wiring and Connectio
6、ns .1614 Insulating Materials .1914.1 General .1914.2 Isolation of semiconductor devices .2015 Field Installed Accessories .2016 Spacings 2016.1 General .2016.2 Circuits of 1000 V or less to ground 2216.3 Spacings to SELV circuits .2316.4 Spacings for printed wiring boards in accordance with the Sta
7、ndard for InsulationCoordination Including Clearances and Creepage Distances for Electrical Equipment, UL840 .2317 Current Carrying Parts 2518 SELV Circuits 2618.1 General requirements .2618.2 Voltages under normal conditions 2618.3 Voltages under single fault conditions .2618.4 Separation from haza
8、rdous voltages 2619 Modular Constructions .27PERFORMANCE20 General 2721 Temperature Test .2821.1 General .2821.2 Test conditions .3022 Overload Test 3123 Overvoltage Test .31JULY 19, 2016 UL 2877 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM
9、UL24 Mechanical Tests .3225 Output Short Circuit Test 3226 Dielectric Voltage-Withstand Tests (Power Frequency and Impulse) 3426.1 Power-frequency voltage withstand test .3426.2 Impulse withstand tests .3627 Switching Capacity Test - Isolating Means .3827.1 Non-interlocked isolating means 3827.2 Int
10、erlocked isolating means 3928 Mechanical Tests of Viewing Panes .3929 Rod Entry Test .3930 Enclosure Ground Integrity Test 4031 Driven Rain Test 4032 Shutter Integrity Test 4033 Inoperative Blower Motor Test 4034 Clogged Filter Test 4035 Breakdown of Components Test .4036 Verification of SELV Circui
11、ts Test .42RATING37 General 42MARKING38 General 4339 General Markings for Power Supplies .4340 Conditional Markings 4441 Additional Equipment Information .46JULY 19, 2016UL 28774UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Sco
12、pe1.1 These requirements cover power supplies having ac or dc input voltage ratings above 1000 V, up to15 kV, and ac or dc output voltage ratings up to 15 kV.1.2 These power supplies may have one or more circuits that are classified as safety extra low voltage(SELV).1.3 These requirements cover equi
13、pment intended for use in ordinary locations in accordance with theNational Electrical Code.1.4 These requirements also cover open type, or partially enclosed power supplies intended to beinstalled in equipment where the overall assembly is investigated using this outline of investigation, oranother
14、 applicable standard for medium voltage equipment.2 Glossary2.1 The definitions in UL 347 are applicable. Where definitions in this outline conflict with definitions inUL 347, the definitions in this outline take precedence.2.2 SELV CIRCUIT A secondary circuit with voltages that do not exceed a safe
15、 value under normaloperating conditions and single fault conditions.NOTE: The voltage limits for SELV circuits are specified in 18.1.2.3 BASIC INSULATION Insulation to provide protection against electric shock.2.4 DOUBLE INSULATION Insulation consisting of basic insulation, plus supplementary insula
16、tion.2.5 MODULAR CONSTRUCTION POWER SUPPLIES Power supplies using multiple modules, eachwith low voltage input and output voltage ratings. Refer to 19.1.2.6 REINFORCED INSULATION A single insulation that provides equivalent protection against electricshock as double insulation.2.7 REMOVABLE MODULE A
17、 portion of a modular construction power supply that is capable of beingremoved for replacement without opening the power supply enclosure or disassembly of parts other thanthose within the removable portion.2.8 STANDBY CURRENT The current that flows in the input circuit of a power supply when the p
18、owersupply is connected to a source of rated voltage, but is not delivering load current.2.9 SUPPLEMENTARY INSULATION Insulation that is independent of, and in addition to, basicinsulation, that provides the same level of insulation as the basic insulation, should the basic insulationfail.JULY 19, 2
19、016 UL 2877 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL3 Components3.1 A component of a product covered by this Outline shall comply with the requirements for thatcomponent and shall be used in accordance with its recognized rating and o
20、ther limitations of use. SeeAppendix A for a list of standards covering components used in the products covered by this outline. Acomponent 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 theproduc
21、t covered by this outline, orb) Is superseded by a requirement in this outline.3.2 Components that provide isolation between medium voltage circuits and low voltage circuits (such astransformers, optical isolators, and the like) shall be provided with sufficient insulation to withstand therated powe
22、r frequency dielectric voltage and rated impulse voltage between the circuits.3.3 Components that provide isolation between medium voltage circuits and SELV circuits shall beprovided with double or reinforced insulation, and the insulation shall be sufficient to withstand 160% ofthe rated power freq
23、uency dielectric voltage and 160% of the rated impulse voltage between the circuits.4 Units of Measurement and Undated References4.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory orapproximate information.4.2 Any undated reference to a code or standard
24、appearing in the requirements of this outline shall beinterpreted as referring to the latest edition of that code or standard.5 Normal and Special Service Conditions5.1 Normal service conditions5.1.1 Apparatus within the scope of this standard shall be capable of operation within its performancespec
25、ifications under the following conditions:a) For equipment that is cooled by air, either ventilated or nonventilated, the temperature of theair outside of the enclosure and the ambient temperature is above 0C but does not exceed40C, and its average value, measured over a period of 24 h, does not exc
26、eed 35C, andb) The equipment is located where:i) the influence of solar radiation is not significant, such as indoors or similarly protectedlocations;ii) the altitude does not exceed 1 000 m (3 300 ft);iii) the ambient air is not significantly polluted by dust, smoke, corrosive and/orflammable gases
27、, vapors, or salt, andiv) the average value of the relative humidity, measured over a period of 24 h, does notexceed 95% non-condensing.JULY 19, 2016UL 28776UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL5.2 Special service conditions5.2.1 Al
28、titude5.2.1.1 Installation at altitudes above 1000 m up to 3000 m is also recognized in this standard. Variationsin the design will in some cases be required. For example, considerations should be made for temperaturerise, insulation level, and mechanical parameters affected by lower ambient pressur
29、es. In such cases, themanufacturer shall supply de-rating factors to be applied to the normal service condition ratings and anynecessary setting adjustments.5.2.2 Solar radiation5.2.2.1 If the effects of solar radiation are significant, the principles stated in ANSI/IEEE C37.24, Guidefor Evaluating
30、the Effect of Solar Radiation on Outdoor Metal-Enclosed Switchgear, may be used forguidance.CONSTRUCTION6 General6.1 Equipment as covered by this outline shall:a) Be so constructed as to provide for compliance with the rules for installation and use of suchequipment as given in the National Electric
31、al Code, ANSI/NFPA 70; andb) Employ materials that are acceptable for the particular use.7 Enclosures7.1 This section does not apply to open type power supplies. For partially enclosed power supplies, thissection applies to any portion of the power supply that may form part of the overall assembly e
32、nclosurewhen assembled into other equipment.7.2 In addition to the following, the enclosure requirements of UL 50 and UL 50E apply. If there is aconflict between the requirements in this outline and UL 50 or UL 50E, the requirements in this outlineapply.7.3 Enclosures shall be metallic, and built to
33、 the requirements of UL 50 and UL 50E, except thatenclosure thickness shall be in accordance with 7.15. External parts of the power supply may be ofinsulating material, provided that all medium-voltage parts are completely enclosed by grounded metallicpartitions having material thickness equivalent
34、to that required for the enclosure. This does not precludethe use of inspection windows or ventilation openings as detailed in 7.4 and 7.5, respectively.7.4 Inspection windows may be provided and form part of the enclosure when all of the followingconditions are met:a) The window shall an infrared v
35、iewport that complies with UL 50V, or shall be of clear safety-type glass, wire-reinforced glass, or another clear material found suitable with respect toflammability and UV resistance in accordance with UL 746C;b) The window shall be secured in such a manner that it cannot be removed without tools;
36、 andJULY 19, 2016 UL 2877 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULc) The window shall meet the requirements of the impact and pressure tests for viewing panesspecified in Section 28.7.5 Ventilation openings may be provided when they c
37、omply with the following:a) Ventilation openings, including perforations, louvers, and openings protected by means ofwire screening, expanded metal, or a perforated cover, shall comply with the rod entry testspecified in Section 29.b) Barriers shall be provided behind all ventilating openings into m
38、edium-voltage compartments.The barrier shall be effectively secured in place and shall prevent drawing a straight line fromany point outside the enclosure to any medium voltage live part, including insulated parts.c) The diameter of the wires of a screen covering a ventilation opening shall be not l
39、ess than1.3 mm (0.050 in) if the screen openings are 320 mm2(0.497 in2) or less in area, and shall benot less than 2.06 mm (0.081 in) for larger screen openings.d) Perforated sheet steel and sheet steel employed for expanded metal mesh shall be not lessthan 1.07 mm (0.042 in) thick for mesh openings
40、 or perforations 320 mm2(0.497 in2) or less inarea, and shall be not less than 2.03 mm (0.080 in) thick for larger openings.7.6 Enclosures with forced ventilation shall comply with 7.7 and 7.8.7.7 When ventilation is accomplished by one or more blowers within the enclosure that provide a positiveint
41、ake and exhaust, the ventilation openings shall be located such that the exhaust air is not directedtoward the area occupied by the equipment operator.7.8 When equipment incorporates a blower motor, it shall comply with the Inoperative Blower Motor Test,Section 33.7.9 When a power supply is provided
42、 with filters for ventilation openings, the construction shall complywith the Clogged Filter Test, Section 34, and with (a) or (b) below:a) The filters shall be located in a medium voltage compartment so that the filters cannot bereplaced without opening a door or cover to the compartment. The door
43、of the compartmentshall be interlocked in accordance with Section 11, Interlocking.b) The filters shall be located outside of a medium voltage compartment, so that the filters maybe replaced without opening the medium voltage compartment. During any period of filterreplacement, including with a filt
44、er access cover open and no filter installed, the constructionshall comply with 7.5.7.10 Enclosures shall comply with the rod entry test of Section 29.7.11 Doors and covers shall be provided with means such as latches, locks, interlocks, bolts or screwsfor firmly securing them in place. Covers of co
45、mpartments containing medium-voltage components shallbe bolted closed.JULY 19, 2016UL 28778UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7.12 If uninsulated live parts are exposed by the opening of a door or cover, means shall be provided to
46、secure it in the closed position. This securement means shall require the use of a tool other than a keyto open the door or cover. If parts operating above 1000 V are exposed by the opening of a cover or door,a warning marking shall be provided in accordance 40.1(a).7.13 Parts mounted on the interio
47、r of a door shall be effectively guarded or enclosed to provide protectionagainst unintentional contact when the door is opened for maintenance of the equipment.7.14 The following requirements shall apply to power supplies intended for outdoor use:a) External hinged doors or covers shall be provided
48、 with stops to hold them in the openposition;b) Enclosures shall be subjected to the driven rain test described in Section 31 in addition toany test requirements for the Type designation marked on the enclosure in accordance with UL50E;c) Enclosures shall have provisions for locking to prevent acces
49、s to medium-voltagecompartments; andd) Consideration should be given to prevention of condensation and entry of snakes, rodents,etc.7.15 The thickness of a sheet-metal enclosure at points to which a wiring system is to be connected shallbe not less than 0.8 mm thick for uncoated steel, 0.9 mm thick for zinc-coated steel, and 1.2 mm thick fornon-ferrous metal. Enclosure thickness at points other than where a wiring system is to be connected shallbe not less than that specified in Table 7.1 or Table 7.2. With reference to Table 7.1 and Table 7.2, asupporting frame
