1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 1008A Medium-Voltage Transfer SwitchesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FUR
2、THER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Medium-Voltage Transfer Switches, UL 1008A First Edition, Dated March 30, 2012 SUMMARY OF TOPICS This revision of UL 1008A is being issued to incorporate an effective date for requirements in 5.7, 7.9, 14.1.1, 44
3、 45, 47.2.1, and 47.5.3 originally published March 30, 2012. No changes in requirements are involved. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. Changes in requirements are marked with a vertical line in the
4、margin and are followed by an effective date note indicating the date of publication or the date on which the changed requirement becomes effective. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic,
5、mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, including but not limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be liable
6、for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibility of suc
7、h damage. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, liability, dam
8、age, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. The requirements in this Standard are now in effect, except for those paragraphs, sections, tables, gure
9、s, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effective date are located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS noti
10、ce. The following table lists the future effective dates with the corresponding reference. APRIL 17, 2013 UL 1008A tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Future Effective Dates References April 17, 2015 5.7, 7.9, 14.1.1, 44 45, 4
11、7.2.1, and 47.5.3 APRIL 17, 2013 UL 1008A tr2UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MARCH 30, 2012 (Title Page Reprinted: April 17, 2013) HISTORICAL NOTE Prior to the publication of this rst edition these requirements were covered b
12、y the Outline of Investigation for Transfer Switch Equipment, Over 600 Volts, UL 1008A. 1 UL 1008A Standard for Medium-Voltage Transfer Switches First Edition March 30, 2012 This ANSI/UL Standard for Safety consists of the First edition including revisions through April 17, 2013. The most recent des
13、ignation of ANSI/UL 1008A as an American National Standard (ANSI) occurred on March 30, 2012. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. Comments or proposals for revisions on any part of the Standard may be submitted t
14、o UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards an
15、d all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2013 UNDERWRITERS LABORATORIES INC. ANSI/UL 1008A-2012UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MARCH 30,
16、2012 MEDIUM-VOLTAGE TRANSFER SWITCHES - UL 1008A 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .6 2 Components 7 3 Units of Measurement .7 4 Undated References 7 5 Glossary .8 CONSTRUCTIO
17、N 6 General 9 7 Enclosure .10 8 Insulating Material .12 9 Mounting of Parts 12 10 Guarding and Accessibility of Live Parts .13 11 Current-Carrying Parts 13 12 Field Wiring Terminals for Control Circuits .13 13 Internal Wiring 15 13.1 General .15 13.2 Barriers dening wireways .15 13.3 Wiring in circu
18、its 750 V and below 16 13.4 Wiring in circuits above 750 V .17 14 Isolation .18 14.1 Isolating means 18 14.2 Isolation of circuits 19 15 Grounding and Bonding .19 16 Operating Mechanism .21 16.1 General .21 16.2 Transfer switch operator interlocks .22 16.3 Location and protection of transfer control
19、 circuits 22 16.4 Transfer switches for emergency use .23 17 Ground-Fault Protection .23 18 Receptacles 25 19 Spacings 25 19.1 General .25 19.2 Spacings on printed-wiring boards operating at 1500 V or less .27 20 Wiring Space .29 21 Interlocking 29 22 Transfer Switches for Service Equipment Use 30 2
20、3 Additional Requirements for Transfer Switches Comprised of Circuit Breakers in Switchgear .32 24 Additional Requirements for Transfer Switches Comprised of Contactors 33 25 Additional Requirements for Transfer Switches Comprised of Load Interrupting Switches in Metal Enclosed Switchgear 33 PERFORM
21、ANCE 26 General 33 27 Transfer Switches Comprised of Circuit Breakers in Switchgear 35 28 Transfer Switches Comprised of Contactors 36 29 Transfer Switches Comprised of Load Interrupting Switches in Metal Enclosed Switchgear . .36 MARCH 30, 2012 MEDIUM-VOLTAGE TRANSFER SWITCHES - UL 1008A 3UL COPYRI
22、GHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 30 Other Transfer Switches .36 31 Normal Operation Test 37 32 Overvoltage Test .38 33 Undervoltage Test 38 34 Overload Test 38 35 Temperature Test .40 36 Mechanical Endurance Test 43 37 Dielectric Volta
23、ge-Withstand Test .44 38 Contact Opening Test .45 39 Dielectric Voltage-Withstand Test (Repeated) 46 40 Withstand Test .46 41 Closing Test .51 42 Short-Time Current Rating Test 51 43 Dielectric Voltage-Withstand Test (Repeated) 53 44 Switching Capability Test 53 45 Isolation Means Interlock Integrit
24、y Test 53 46 Transfer Switch Operator Interlock Integrity Test 54 47 Impulse Voltage Withstand Test 54 47.1 General .54 47.2 Impulse voltage withstand test methods .54 47.3 Impulse voltage withstand test sequence 55 47.4 Evaluation .56 47.5 Power-frequency voltage withstand test .56 MANUFACTURING AN
25、D PRODUCTION TESTS 48 Ground-Fault Protection .57 RATINGS 49 Details .58 MARKINGS 50 Content 59 51 Service Equipment Markings .61 52 Permanence of Marking .61 INSTALLATION TEST PROCEDURES 53 Details .61 TRANSFER SWITCHES FOR FIRE PUMP SERVICE GENERAL 54 Scope .62 CONSTRUCTION 55 General 62 MARCH 30,
26、 2012 MEDIUM-VOLTAGE TRANSFER SWITCHES - UL 1008A 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL PERFORMANCE 56 General 63 RATING 57 Details .63 MARKINGS 58 Details .63 APPENDIX A Standards for ComponentsA1 MARCH 30, 2012 MEDIUM-VOLTAGE TR
27、ANSFER SWITCHES - UL 1008A 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover automatic, non-automatic, and manual transfer switches, operating at above 750 V AC, and intended for use in ordina
28、ry locations to provide for power as follows: a) Automatic transfer switches for use in emergency systems in accordance with Articles 517- Health Care Facilities, 700-Emergency Systems, 701-Legally Required Standby Systems, and 702-Optional Standby Systems of the National Electrical Code, ANSI/NFPA
29、70; and the Standard for Health Care Facilities, ANSI/NFPA 99. b) Transfer switches for use in optional standby systems in accordance with Article 702 of the National Electrical Code, ANSI/NFPA 70. c) In legally required standby systems in accordance with Article 701 of the National Electrical Code,
30、 ANSI/NFPA 70. d) Automatic transfer switches for use in accordance with the National Fire Protection Association Standard for Centrifugal Fire Pumps, ANSI/NFPA 20. e) Non-Automatic transfer switches for use in accordance with Articles 517-Health Care Facilities, and 702-Optional Standby Systems of
31、the National Electrical Code, ANSI/NFPA 70; and the Standard for Health Care Facilities, ANSI/NFPA 99. 1.2 An automatic transfer switch for use in a legally required stand-by system shall comply with the requirements for a transfer switch for emergency systems. 1.3 These requirements cover transfer
32、switches rated greater than 750 Volts, up to 46 kV. 1.4 These requirements cover transfer switches together with their associated control devices including, but not limited to, voltage sensing relays, frequency sensing relays, and time delay relays. 1.5 An automatic transfer switch as covered by the
33、se requirements is a device that automatically transfers a common load from a normal supply to an alternate supply in the event of failure of the normal supply, and automatically returns the load to the normal supply when the normal supply is restored. An automatic transfer switch may be provided wi
34、th a logic control circuit that inhibits automatic operation of the device from either a normal to an alternate supply, or from an alternate to a normal supply when the switch reverts to automatic operation upon loss of power to the load. 1.6 A non-automatic transfer switch as covered by these requi
35、rements is a device, operated manually by a physical action, or electrically by a remote control, for transferring a common load between a normal and alternate supply. 1.7 A transfer switch may incorporate overcurrent protection for the main power circuits. MARCH 30, 2012 MEDIUM-VOLTAGE TRANSFER SWI
36、TCHES - UL 1008A 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 1.8 These requirements only cover completely enclosed transfer switches. 1.9 Transfer switches are rated in amperes and are considered to be acceptable for total system transf
37、er, which includes control of motors, electric-heating loads, and transformer loads. 2 Components 2.1 Except as indicated in 2.2, a component of a product covered by this Standard shall comply with the requirements for that component. See Appendix A for a list of standards covering components genera
38、lly used in the products covered by this standard. 2.2 A component is not required to comply with a specic requirement that: a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard, or b) Is superseded by a requirement in this
39、standard. 2.3 A component shall be used in accordance with its rating established for the intended conditions of use. 2.4 Specic components are incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as c
40、ertain temperatures not exceeding specied limits, and shall be used only under those specic conditions. 3 Units of Measurement 3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 4 Undated References 4.1 Any undated reference t
41、o a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. MARCH 30, 2012 MEDIUM-VOLTAGE TRANSFER SWITCHES - UL 1008A 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PE
42、RMISSION FROM UL 5 Glossary 5.1 For the purpose of this standard the following denitions apply. 5.2 ACCESSIBLE PART A part located so that it can be contacted by a person, either directly or by means of a probe or tool during user servicing, or that is not recessed the required distance behind an op
43、ening. 5.3 BARRIER A partition for the insulation or isolation of electric circuits, for the isolation of electric arcs, or for isolation of moving parts or hot surfaces. In this respect, a barrier may serve as a portion of an enclosure or as a functional part. 5.4 CONTROL CIRCUIT A circuit that car
44、ries electric signals directing the performance of a transfer switch. A control circuit does not carry main power current. 5.5 ENCLOSURE That portion of a transfer switch that reduces the accessibility and unintentional contact of a part that may involve a risk of re, electric shock or injury to per
45、sons, or reduces the risk of propagation of ame, sparks, and molten metal initiated by an electrical disturbance occurring within. 5.6 LIVE PART Denotes metal or conductive parts that, during intended use, have a potential difference with respect to ground or any other conductive part. 5.7 OPERATING
46、 DUTY CLASS The minimum number of operations a transfer switch can be expected to perform over the life of the equipment. The three operating duty classes are: a) Class A 2000 operations, b) Class B 1000 operations, and c) Class C 400 operations. Revised 5.7 effective April 17, 2015 5.8 OPERATOR Tra
47、ined persons having familiarity with the construction and operation of the equipment, and the risks involved, including, but not limited to, persons who may periodically open a transfer switch to repair or maintain electrical or mechanical components. 5.9 POLLUTION DEGREE1N opollution or only dry, n
48、onconductive pollution occurs. The pollution has no inuence. 5.10 POLLUTION DEGREE 2 Normally, only nonconductive pollution occurs; however, temporary conductivity caused by condensation may be expected. 5.11 POLLUTION DEGREE 3 Conductive pollution occurs, or dry, nonconductive pollution occurs that
49、 becomes conductive due to condensation that is expected. 5.12 PRIMARY CIRCUIT Wiring and components that are conductively connected to the preferred or alternate source of supply or another branch circuit. 5.13 PRINTED-WIRING BOARD The nished combination of a pattern of conductive paths either on, in, or both on and in (multilayer) a sheet of insulating material, including printed components, and the base material. APRIL 17, 2013 MEDIUM-VOLTAGE TRANSFER SWITCHES - UL 1008A 8UL COPYRIGHTED MA
