1、NEMA Standards PublicationNational Electrical Manufacturers AssociationANSI/NEMA KS 2-2013Distribution Equipment Switch Application Guide, A Users ReferenceANSI/NEMA KS 2-2013 American National Standard Distribution Equipment Switch Application Guide, A Users Reference Secretariat: National Electric
2、al Manufacturers Association ANSI Approved: January 29, 2013 Published: February 1, 2013 American National Standards Institute, Inc. KS 2-2013 Page ii Copyright 2013 by tNational Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically
3、 sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document. American National Standards Institute (
4、ANSI) standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or seeks out the views of persons who have an interest in the topic covered by this public
5、ation. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in i
6、ts standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this d
7、ocument. NEMA disclaims and makes no guaranty or warranty, express or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA does not undert
8、ake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render professional or other services for or on behalf of any person or entity, nor is NEM
9、A undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. Inf
10、ormation and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it undertake to police or enforce compliance with the content
11、s of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safetyrelated information in this document shall not be attributable to NEMA and is solely the responsi
12、bility of the certifier or maker of the statement.KS 2-2013 Page iii Copyright 2013 by the National Electrical Manufacturers Association. Table of Contents FOREWORD . ivv Section 1 GENERAL . 1 1.1 Scope 1 1.2 References . 1 Section 2 DESCRIPTIONS OF SWITCHES AND TYPES OF SWITCH CONSTRUCTION 2 Sectio
13、n 3 RATINGS AND SERVICE EQUIPMENT USE OF SWITCHES . 4 3.1 Ratings 4 3.1.1 Voltage Rating . 4 3.1.2 Frequency Rating 4 3.1.3 Current Rating . 4 3.1.4 Horsepower Rating 4 3.1.5 Fuses . 4 3.1.6 Short-circuit Current Rating . 5 3.2 Service Equipment 5 Section 4 APPLICATION INFORMATION 6 4.1 General . 6
14、4.1.1 Environmental Conditions 6 4.1.2 Usual Service Conditions 6 4.1.3 Unusual Service Conditions 6 4.2 Selection and User Information 6 4.2.1 Enclosed Switches 7 4.2.2 Ampere or Ampere and Horsepower Ratings . 8 4.2.3 Fusible and Nonfusible Switches 8 4.2.4 Double Throw Switches . 8 4.2.5 Togging
15、or Plugging9 4.3 Switch Enclosure Information . 9 4.3.1 General 9 4.3.2 Common uses of Enclosure Types . 9 4.4 Switch Accessories . 11 4.4.1 Enclosed Switch Accessories 11 4.4.2 Fused Power-Circuit Device Accessories . 12 4.4.3 Wire Connector Kit 12 4.5 Conductor and Termination Information . 12 4.5
16、.1 Conductor Temperature Rating . 12 4.5.2 Termination Information . 12 KS 2-2013 Page iv Copyright 2013 by National Electrical Manufacturers Association FOREWORD This publication is a guide of practical information containing instructions for the proper selection, installation, and operation of dis
17、tribution equipment switches rated 600 volts or less. These instructions do not purport to cover all details or variations in equipment, nor to provide for every possible contingency regarding installation and operation. Refer to NEMA KS 3 for Inspection and Preventive Maintenance guidelines. It is
18、recommended that work described in this set of instructions be performed only by qualified personnel familiar with the construction and operation of distribution equipment switches and that such work be performed only after reading this complete set of instructions. For specific information not cove
19、red by these instructions, you are urged to contact the manufacturer of the switch directly. In the preparation of this Application Guide input of users and other interested parties has been sought and evaluated. Inquiries, comments, and proposed or recommended revisions should be submitted to the c
20、oncerned NEMA product section by contacting the following: Senior Technical Director, Operations National Electrical Manufacturers Association 1300 North 17th Street Rosslyn, Virginia 22209 These recommendations will be reviewed periodically and updated as necessary. This Application Guide was devel
21、oped by the Switch Voting Classification. Approval of the guide does not necessarily imply that all voting classification members voted for its approval or participated in its development. At the time it was approved, the Switch Voting Classification was composed of the following members: ABB Contro
22、l, Inc.New Berlin, WI Boltswitch, Inc.Crystal Lake, IL Cooper BussmannSt. Louis, MO Eaton ElectricalPittsburgh, PA GE Industrial SystemsPlainville, CT Hubbell Incorporated Shelton, CT Mersen USA LLCNewburyport, MA Siemens Industry, Inc. Norcross, GA Square D Company/Schneider Electric Palatine, IL K
23、S 2-2013 Page 1 Copyright 2013 by National Electrical Manufacturers Association Section 1 GENERAL 1.1 SCOPE This publication covers application information for distribution equipment switches that are: a) Rated at not more than 600V and 6000A with or without a horse-power rating b) With or without p
24、rovision for fuses c) With current-carrying parts and mechanisms enclosed in metallic or non-metallic cases, or that are enclosed when mounted in an enclosed switchboard, panelboard, or the like d) Manually operable by means of external handles NOTEThese devices may also be automatically operable by
25、 means of shunt trips, electrical operators, ground fault devices, or other mechanisms. This publication does not cover: a) The common form of snap switches b) Switching devices having features intended primarily for the starting and running protection of electric motors c) Circuit-breaker-type powe
26、r circuit protectors d) Molded case switches e) Transfer switches 1.2 REFERENCES In this publication, reference is made to the latest edition of the standards listed below. Copies are available from the indicated sources. National Electrical Manufacturers Association 1300 North 17th Street Rosslyn,
27、Virginia 22209 KS-1 Enclosed and Miscellaneous Distribution Equipment Switches (600V Maximum) KS-3 Guidelines for Inspection and Preventive Maintenance of Switches Used in Commercial and Industrial Applications NEMA 250 Enclosures for Electrical Equipment (1000V Maximum) National Fire Protection Ass
28、ociation Batterymarch Park Quincy, MA 02269 NFPA 70 National Electrical Code NFPA 70B Recommended Practice for Electrical Equipment Maintenance NFPA 70E Electrical Safety in the Workplace Underwriters Laboratories Inc. (UL) 333 Pfingsten Road Northbrook, IL 60062 UL 50 Enclosures for Electrical Equi
29、pment UL 98 Enclosed and Dead-Front Switches UL 977 Fused Power-Circuit Devices UL 1429 Pullout Switches KS 2-2013 Page 2 Copyright 2013 by National Electrical Manufacturers Association Section 2 DESCRIPTIONS OF SWITCHES AND TYPES OF SWITCH CONSTRUCTION bolted pressure contact switch: A switch that
30、has blade and jaw type contacts and, when the switch is closed, all blade joints are subjected to high clamping pressure by means of bolt, cam or similar mechanical action. (see also Fused Power-Circuit Device) dead-front switch: A switch that has all current carrying parts enclosed when it is mount
31、ed in an enclosed panelboard, deadfront switchboard, or the like. double-break switch: A switch that employs two switching contacts that make and break the circuit simultaneously for each pole. On fusible switches, a contact may be located on each side of the fuse, thus completely isolating the fuse
32、 from the circuit when the switch is in the off position. double-throw switch: A switch by means of which a change in circuit connections can be obtained by operating the switch into either of two closed positions or into an open position. enclosed switch: A switch with or without fuseholders, havin
33、g all current carrying parts completely enclosed, that is operable without opening the enclosure. fused power-circuit device: A fused switch having a 100% continuous current rating usually of a bolted pressure contact or high pressure contact design. Commonly available with a shunt trip operator tha
34、t is suitable for use with ground fault sensing element, or with ground fault sensing element that is integral to the device. general-duty switch: Infers that the product meets the minimum construction and performance requirements. heavy-duty switch: Infers that certain construction and performance
35、requirements exceed the requirements of general-duty. high-pressure butt-type contacts: A switch construction that employs butt contacts and, when the switch is closed, the butt contacts are compressed under pressure by means of a spring charged mechanism. Interlocked receptacle switch: An interlock
36、ed receptacle switch is an enclosed switch that has either a receptacle or receptacle poles wired to the line or load end of the switch. The switch operating mechanism is interlocked with the receptacle or receptacle door latch so that the mating plug(s) can neither be installed or removed if the sw
37、itch contacts are in the closed position. This type of switch is designed primarily for use in connecting portable equipment for special application use. interlock (mechanical): A mechanism that limits the operations of a switch to a specified sequence. isolating switch: A switch intended for isolat
38、ing an electric circuit from the source of power. It has no short-circuit current rating, and is intended to be operated only after the circuit has been opened by some other means. jogging; inching: The quickly repeated opening and closing of a circuit to stop and start a motor from rest for the pur
39、pose of accomplishing small movements of the driven machine. knife switch: A switch construction that employs switch blades that engage with contact plates, not aided by a bolted pressure mechanism. KS 2-2013 Page 3 Copyright 2013 by National Electrical Manufacturers Association miscellaneous switch
40、: Term used for such products as a panelboard switch or an open type switch that is intended to be mounted in a switchboard, enclosure or the like. Commonly, the component switch assembly of an “enclosed switch” may be referred to as a “miscellaneous switch”. plugging: A control function that provid
41、es braking by reversing the motor line voltage polarity or phase sequence so that the motor develops a counter-torque that exerts a retarding force. pullout switch: A switch, enclosed or non-enclosed, which is operated to open a circuit by manually separating the movable contact from the stationary
42、contact, and is operated to close a circuit by manually reconnecting the movable contact and the stationary contact. safety switch: Another term for an “enclosed switch” but usually also implies side operated, wall mounted, and cable connected. Usually further described as “general duty” or “heavy d
43、uty”. shunt trip; electrical trip: A means for releasing energy previously stored in a mechanism to open the switch upon the application of a specified voltage. tie switch: A switch that can be electrically fed from either direction, specifically for use in a multi-ended switchboard. Usually a tie s
44、witch is non-fusible, has key interlock provisions, and has special safeguards because either side of the switch may be energized, depending upon which main devices in the switchboard are closed. ventilated (the term): Indicates that an enclosure has been so constructed as to provide for the circula
45、tion of external air through the enclosure to remove excess heat, fumes, or vapors. KS 2-2013 Page 4 Copyright 2013 by National Electrical Manufacturers Association Section 3 RATINGS AND SERVICE EQUIPMENT USE OF SWITCHES 3.1 RATINGS Switches are selected based upon the electrical characteristics ava
46、ilable at their intended point of installation. Their ratings include the following: 3.1.1 Voltage Rating Switches may be available with voltage ratings up to 600 V AC and/or DC. Some switches may be suitable for use on circuits where all of the poles of the switch will not be used. In addition to t
47、he standard voltage rating, these switches may have one or more applicable voltage ratings intended for a switch having fewer poles. A switch with a 120/240 or 125/250 voltage rating is suitable only for use on a 3-wire AC or DC circuit having a grounded neutral except as noted below. A 120/240 V AC
48、 or a 125/250 V DC switch marked “For special water-heater applications ” may be suitable for use on 2-wire 240V AC or 250V DC water-heater circuit derived from an Edison 3-wire system having a grounded neutral when used with equipment to provide off-peak electric power service. 3.1.2 Frequency Rati
49、ng The frequency rating of AC switches is 60 Hz unless otherwise marked. Switches having a DC rating are marked DC. 3.1.3 Current Rating Switches are rated 30, 60, 100, 200, 400, 600, 800, 1200, 1600, 2000, 2500, 3000, 4000, 5000, or 6000 A. NOTE Some nonfusible switches are permitted to be used with overcurrent protection devices that have a continuous current rating above the current rating of the switch. In such cases, the switch is marked in combination with the overcurrent protective devices. 3.1.4 Horsepower Rating Switches eva
