1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 977 Fused Power-Circuit Devices STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHO
2、RIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Fused Power-Circuit Devices, UL 977 Fifth Edition, Dated April 30, 2012 Summary of Topics: This revision to ANSI/UL 977 is being issued to reaffirm approval as an American National Standard. No chang
3、es in requirements are involved. The new requirements are substantially in accordance with Proposal(s) on this subject dated June 3, 2016. The revisions dated July 29, 2016 include a reprinted title page (page 1) for this Standard. Text that has been changed in any manner or impacted by ULs electron
4、ic publishing system is marked with a vertical line in the margin. Changes in requirements are marked with a vertical line in the 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.
5、No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, 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
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7、of or the inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibility of such 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 versio
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9、rchasers computer system. JULY 29, 2016 UL 977 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JULY 29, 2016 UL 977 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION
10、 FROM UL APRIL 30, 2012 (Title Page Reprinted: July 29, 2016) 1 UL 977 Standard for Fused Power-Circuit Devices First Edition June, 1973 Second Edition October, 1976 Third Edition June, 1984 Fourth Edition November, 1994 Fifth Edition April 30, 2012 This ANSI/UL Standard for Safety consists of the F
11、ifth Edition including revisions through July 29, 2016. The most recent designation of ANSI/UL 977 as a Reaffirmed American National Standard (ANS) occurred on July 29, 2016. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. T
12、he Department of Defense (DoD) has adopted UL 977 on August 28, 1984. The publication of revised pages or a new edition of this Standard will not invalidate the DoD adoption. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submi
13、tted 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 and all copyrights, ownerships, and rights re
14、garding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2016 UNDERWRITERS LABORATORIES INC. ANSI/UL 977-2012 (R2016)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL APRIL 30, 2012 FUSED POWER-CIRCUIT DEVICES - UL
15、 977 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .5 2 Components .6 3 Units of measurement .7 4 References 7 CONSTRUCTION 5 General 7 6 Enclosure 9 6.1 General 9 6.2 Rainproof enclosure
16、s .9 7 Ventilation 11 8 Sheet-Metal Enclosures 12 9 Doors and Covers .12 10 Hinges 14 11 Latches 14 12 Operating Mechanism 15 12.1 General .15 12.2 Electrical operators 16 13 Ground Fault Protection .17 14 Insulating Material .19 15 Current-Carrying Parts .19 16 Wiring Terminals 20 17 Control Circui
17、t .21 18 Lockout 21 19 Fusing .21 20 Spacings .26 21 Wiring Space .27 22 Disconnecting Means 30 23 Provision for Grounding 31 24 Provision for Bonding 31 PERFORMANCE 25 General 32 26 Temperature Test .35 27 Strength of Insulating Base and Support .37 28 Overvoltage Test 38 29 Water Spray Test 38 30
18、Operation Test 38 31 Endurance Test .41 32 200-Percent Overload 41 33 Dielectric Voltage-Withstand Test 42 34 Close-Open Test 44 35 Dielectric Voltage-Withstand (Repeated) Test After the Close-Open Test .45 36 Contact Opening Test 45 37 Dielectric Voltage-Withstand (Repeated) Test After the Contact
19、Opening Test 46 38 Short-Circuit Withstand Test 46 APRIL 30, 2012 FUSED POWER-CIRCUIT DEVICES - UL 977 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 39 Closing Test 50 40 Low-Level Dielectric Voltage-Withstand Test 51 41 Metallic Coating
20、Thickness Test .51 INSTRUMENTATION AND CALIBRATION OF HIGH-CAPACITY CIRCUITS 42 Galvanometers .52 43 Circuit Measurement Verication 53 44 Calibration of Test Circuit .54 44.1 Details 54 44.2 Current 54 44.3 Voltage 56 44.4 Power factor 56 44.5 Recovery voltage 56 MANUFACTURING AND PRODUCTION TEST 45
21、 Operation 58 RATINGS 46 Current 59 47 Voltage .59 48 Withstand 60 49 Control Circuit .60 MARKING 50 Details .60 INSTALLATION TEST PROCEDURES 51 Details .64 APPENDIX A Standards for ComponentsA1 APRIL 30, 2012 FUSED POWER-CIRCUIT DEVICES - UL 977 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER R
22、EPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover fused power-circuit devices to be employed in accordance with the National Electrical Code. 1.2 Fused power-circuit devices, as covered by these requirements, are considered to be either bolted p
23、ressure contact switches or high-pressure butt-type contact switches. 1.3 Bolted-pressure contact switches are devices in which the blade-jaw connections have an additional pressure or clamping action provided at both ends of the switch blades when the blades are in the fully closed position. 1.4 Hi
24、gh-pressure butt-type contact switches are devices having butt-type contacts and a spring-charged mechanism. 1.5 These requirements do not apply to low-voltage AC power circuit protectors as covered by the Standard for Low Voltage AC Power Circuit Protectors Used in Enclosures, ANSI/IEEE C37.29, or
25、to low-voltage AC integrally fused power circuit breakers as covered by the Standard for Low-Voltage AC Power Circuit Breakers Used in Enclosures, ANSI/IEEE C37.13. 1.6 Fused power-circuit devices may be manually or electrically operated and may incorporate electrical tripping means. 1.7 An electric
26、ally tripped device is one whose closing is performed manually or electrically but contact opening is performed by a release energized by a separate source of voltage. 1.8 A device with an electrical operator is one whose contact closing and opening is performed by electrical means. 1.9 Fused power-
27、circuit devices have continuous current ratings of more than 600 A and voltage ratings of 600 V or less AC, DC, or both. Devices rated AC are intended for use on circuits having maximum available short-circuit currents of 100,000, 150,000, or 200,000 A (rms symmetrical). Devices rated DC are intende
28、d for use on circuits having maximum available short-circuit currents of 20,000, 50,000, 100,000, 150,000, or 200,000 A DC. 1.10 Fused power-circuit devices have provisions for mounting (or are intended to be used with upstream) Class L fuses or Class T fuses rated more than 600 A. 1.11 These requir
29、ements cover complete, enclosed fused power-circuit devices in which the switch is integral with the enclosure; open-type fused power-circuit devices intended for mounting in other equipment, such as switchboards or in a separately shipped enclosure; and enclosures intended for mounting open-type fu
30、sed power-circuit devices. JULY 29, 2016 FUSED POWER-CIRCUIT DEVICES - UL 977 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 1.12 These requirements also cover electrically tripped and/or operated devices that have been investigated to det
31、ermine their acceptability for ground-fault protection when combined with ground-fault sensing and relaying equipment as follows: a) Switches for use with Class I ground-fault sensing and relaying equipment including those devices that are capable of interrupting 12 times their rated current or that
32、 have integral means intended to prevent disconnecting at levels of fault current exceeding the contact interrupting capability of the switch. b) Switches for use with Class II ground-fault sensing and relaying equipment are capable of interrupting at 10 times their rated current and are for use in
33、ground-fault protection systems where means intended to prevent disconnecting levels at fault current exceeding the contact interrupting capabilities of the switch are incorporated within the ground-fault sensing and relaying equipment. 1.13 A product that contains features, characteristics, compone
34、nts, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of re, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements to determine that the level of safety a
35、s originally anticipated by the intent of this standard is maintained. A product whose features, characteristics, components, materials, or systems conict with specic requirements or provisions of this standard shall not be judged to comply with this standard. Where appropriate, revision of requirem
36、ents shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard. 2 Components 2.1 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
37、 covering components generally 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 supersede
38、d by a requirement in this standard. APRIL 30, 2012 FUSED POWER-CIRCUIT DEVICES - UL 977 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Units of measurement 3.1 If a value for measurement is followed by a value in other units, the use or
39、 recognition of either value can be expected to provide equivalent results in the application of such requirements. 4 References 4.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or stan
40、dard. CONSTRUCTION 5 General 5.1 A fused power-circuit device shall employ materials throughout that are acceptable for the particular application, and shall be made and nished with the degree of uniformity and grade of workmanship practicable in a well-equipped factory. 5.2 The construction of a fu
41、sed power-circuit device shall be such as to provide ample strength and rigidity. 5.3 All parts of a fused power-circuit device shall be properly assembled in place when shipped from the factory, except as noted in 5.4, 5.6, 5.7, 5.8, and 5.9. 5.4 If a fused power-circuit device is acceptable for us
42、e without a neutral assembly as well as with such assembly, the neutral assembly need not be shipped from the factory with the switching unit provided that: a) The neutral assembly is shipped from the factory completely assembled with the necessary barriers and all other accessories that are require
43、d for its installation and use; and b) The neutral assembly and switch are marked in accordance with 50.12. 5.5 With reference to 5.4, hardware for mounting the neutral assembly must be furnished with that assembly but need not be assembled in place. 5.6 External operating handles need not be assemb
44、led in place but in place of such assembly, they are to be packaged and shipped with the switching unit. 5.7 When a fused power-circuit device without enclosure is shipped for assembly in a switchboard or similar equipment, the load fuse terminal assembly need not be mounted in place when all the fo
45、llowing conditions are met: a) All poles of the load fuse terminal assembly are secured to a common base that can be installed as a single unit by a simple assembly operation; b) Assembly instructions and markings are provided; c) The construction is such that alignment of fuse mounts will be assure
46、d; d) Barriers or stops intended to prevent over-sized fusing will continue to be effective; and e) The load fuse terminal assembly is packaged and shipped with the switching unit. APRIL 30, 2012 FUSED POWER-CIRCUIT DEVICES - UL 977 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR
47、 DISTRIBUTION WITHOUT PERMISSION FROM UL 5.8 If the proper operation or installation of an open type fused power-circuit device is dependent upon an insulating barrier, liner, shield or similar member being mounted on the device or elsewhere, the insulating barrier shall be provided with the device
48、and a marking as specied in 50.29 shall be provided. 5.9 If a fused power-circuit device is intended for use with or without an accessory assembly, the assembly need not be shipped from the factory with the fused power-circuit device provided that: a) The fused power-circuit device is acceptable for
49、 use with or without the accessory. b) Each accessory is acceptable for the intended use. c) Installation instructions for the proper installation operation, and necessary adjustments are provided: 1) With the accessory; 2) With the fused power-circuit device; or 3) The accessory is marked with reference to a specic installation instruction drawing unless the construction makes the installation obvious. If a ling, drilling, or cutting operation is involved the instructions include a caution statement, that such operation i
