1、NEMA Standards Publication No. EW 3-1983 (R1995, R1999, R2002) Semiautomatic Wire Feed Systems for Arc Welding Published by: National Electrical Manufacturers Association 1300 North 17th Street, Suite 1847 Rosslyn, VA 22209 O Copyright 2002 by the National Electrical Manufacturers Association. All r
2、ights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions. NOTICE AND DISCLAIMER The information in this publication was con
3、sidered technically 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. The National Electri
4、cal Manufacturers Association (NEMA) 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 t
5、he topic covered by this publication. 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
6、of any judgments contained in its 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, app
7、lication, or reliance on this document. 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
8、 or needs. NEMA does not undertake 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 a
9、ny person or entity, nor is NEMA 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
10、in any given circumstances. Information 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 enfo
11、rce compliance with the contents 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 safety-related information in this document shall not be attributable to
12、 NEMA and is solely the responsibility of the certifier or maker of the statement. TABLE OF CONTENTS Page FOREWORD . i SCOPE . i Section 1 DEFINITIONS . i Section 2 SERVICE CONDITIONS General . 4 Usual Service Conditions 4 Unusual Service Conditions . 4 Section 3 MECHANICAL CONSTRUCTION REQUIREMENTS
13、 Frames and Enclosures-General Strength Considerations . 5 Enclosure of Live Parts . 5 Openings in Enclosures . 5 Enclosure Construction . 6 Rotating Parts . 6 Filler Wire Supply 6 Corrosion Protection . 6 Service Line Hoses . 6 Gun Assembly . 6 Water Cooling . 7 Drop Testing 7 Section 4 ELECTRICAL
14、CONSTRUCTION REQUIREMENTS Service Line Cords. Cables. and Connections Wire Feed Unit and Control . Gun Assembly and Gun Cable Assembly High-Potential Test and Insulation Resistance 8 8 9 9 Section 5 RATING AND PERFORMANCE Rating of Wire Feed System . 11 Performance 11 Temperature Testing . 11 Other
15、Performance Data 12 Section6 MARKINGS . Wire Feeder Nameplate . 13 Gun Assembly and Gun Cable Assembly Nameplate 13 O 1983 by the National Electrical Manufacturers Association NEMA Standards Publication EW 3-1983 (R1989, R1995) Semiautomatic Wire Feed Systems for Arc Welding Published by: National E
16、lectrical Manufacturers Association 1300 North 17th Street Rosslyn, VA 22209 O Copyright 1999 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Lit
17、erary and Artistic Works, and the International and Pan American Copyright Conventions. Foreword This standards publication was developed by the NEMA Arc Welding Section and it includes requirements for construction, ratings, and performance applying to certain wire feed systems used in semiautomati
18、c arc welding processes. They are based upon sound engineering principles, research, and records of tests and field experience. Also involved is an appreciation of the problems of manufacture, installation, and use derived from consultation with and information obtained from manufacturers and users,
19、 and others having specialized experience. Two 90-day public reviews for comments were solicited through the American Welding Society (AWS) Welding Journal and the NEMA Arc Welding Section canvass list, to ensure that the views of interested parties in the public and private sector have been given f
20、ull consideration. Their comments and suggestions, prior to final NEMA approval, provided vital user and general interest input, and resulted in a number of substantive changes being made in this publication. These standards will be reviewed periodically by the Arc Welding Section of NEMA for any ch
21、anges which may be necessary to keep them up to date. As future major revisions to this publication are proposed, it is intended to offer the same or similar individuals a further opportunity to participate in the development of this publication. Proposed or recommended revisions should be submitted
22、 to: Manager, Engineering Department National Electrical Manufacturers Association 2101 L Street, N.W. Washington, D.C. 20037 Scope This standards publication applies to wire feed systems used in semiautomatic arc welding processes such as gas-metal arc welding, flux-cored arc welding with gas, flux
23、-cored arc welding without gas, submerged arc welding, and gas-tungsten arc welding with the addition of filler wire. This publication does not apply to automatic arc welding systems or to gas- tungsten arc welding apparatus without the addition of filler wire. i EW 3-1 983 Page 1 Section 1 DEFINITI
24、ONS AUTOMATIC ARC WELDING may have integral provisions for the filler wire supply, or the filler wire supply may be remote from the wire feed unit with continuous pay-out Welding with equipment which performs the achieved by means of filler wire conduit, pulleys, entire welding operation without con
25、stant observa- tion and adjustment of the controls by an operator. rollers, etc. The equipment may or may not load and unload NEMA Standard 11-6-1975. the work. NEMA Standard 11-6-1975. FLUX CORED ARC WELDING (FCAW) CONTACT TUBE continuous electrode. A device which transfers welding current to a NEM
26、A Standard 1-11-1983. DRIVE ROLLS Rolls which contact the filler wire and transfer the mechanical power from the motor/gear portion of the wire-feed unit to the filler wire to feed the wire from the filler wire supply to the arc. NEMA Standard 11-6-1975. DUTY CYCLE The ratio (expressed as a percent)
27、 of arc time to total time. For the purpose of these standards, the time period of one complete cycle shall be 10 minutes. NEMA Standard 11-6-1975. ELECTRODE A component of the welding circuit in the form of continuous filler wire through which the welding current is conducted. It is melted by the a
28、rc and deposited in the weld seam. NEMA Standard 11-6-1975. FILLER METAL The metal to be added in making a weld. NEMA Standard 11-6-1975. FILLER WIRE Filler metal in wire form. NEMA Standard 1-11-1983, FILLER WIRE CONDUIT guides the filler wire. A flexible tubular member which insulates and/or NEMA
29、Standard 11-6-1975. FILLER WIRE SUPPLY The filler wire which is stored for continuous pay-out to the wire feed unit. The wire feed unit An arc welding process wherein coalescence is produced by heating with an arc between a contin- uous filler metal (consumable) electrode and the work. Shielding is
30、obtained from a flux contained within the tubular electrode. Additional shielding may or may not be obtained from an externally supplied gas or gas mixture. NEMA Standard 1-11-1983. GAS METAL ARC WELDING (GMAW) An arc welding process which produces co- alescence of metals by heating them with an arc
31、 between a continuous filler metal (consumable) electrode and the work. Shielding is obtained entirely from an externally supplied gas or gas mixture. Some methods of this process are called MIG or CO, welding (nonpreferred terms). NEMA Standard 1-1 1-1983. GUN ASSEMBLY A hand-held manipulated devic
32、e which guides the filler wire into the arc. It may include pro- visions for the transfer of welding current to the electrode, shielding, fume removal, filler wire supply, and control means for the welding process. NEMA Standard 11-6-1975. GUN CABLE ASSEMBLY The flexible supply lines necessary for t
33、he opera- tion of the gun assembly. It includes a cable which carries welding current and may also include a filler wire conduit means for conveying shielding medium, cooling medium, means for fume removal, control wires, and line for nonelectric drives. NEMA Standard 1-11-1983. GUN SWITCH stop, and
34、/or control the wire feed system. The part of the gun assembly that is used to start, NEMA System 11-6-1975. EW 3-1983 Page 2 INPUT CONTROL CURRENT The input current required to operate the wire feed system. NEMA Standard 1-11-1983. INPUT CONTROL FREQUENCY input control voltage. INPUT CONTROL POWER
35、feed system. The nominal frequency or frequencies of the NEMA Standard 1-11-1983. The input power required to operate the wire NEMA Standard 1-11-1983. INPUT CONTROL VOLTAGE source to operate the wire feed system. The input voltage required from an external NEMA Standard 1-1 1-1983. LIVE PARTS energ
36、ized during normal operation. Any parts which can be expected to be electrically NEMA Standard 11-6-1975. MANUFACTURER plate. The company whose name is shown on the name- NEMA Standard 11-6-1975. MAXIMUM LOAD The maximum mechanical load at the various rated wire feed speeds over the operating ranges
37、 of the equipment at which the wire feed unit and wire feed control can operate at the rated duty cycle withox causing the rated temperature rise of any component to be exceeded. NEMA Standard 11-6.1975. NOZZLE removes fumes from the welding arc. A device which directs shielding medium to or NEMA St
38、andard 1-11-1983. RATEDCURRENT The current at which a device can operate at the rated duty cycle without exceeding its rated tem- perature. NEMA Standard 11-6-1975. RATED SPEED RANGE The wire feed speed range in inches per minute or millimeters per second, or both, listed by the manufacturer for eac
39、h rated size of filler wire. NEMA Standard 11-6-1975. SEMIAUTOMATIC ARC WELDING Arc welding with equipment which controls on the feeding of the filler wire. The manipulation o the welding gun assembly is manually controlled. NEMA Standard 11-6-1975, ? SERVICE LINES The lines between the source of po
40、wer equipment or other equipment, or both, and the wire feed control or unit. These lines may consist of: 1. A welding cable to supply the welding power to the system. 2. Flexible cord(s) to supply input control power and to interconnect control circuits, such as that for the welding contactor, as r
41、equired. Hoses to supply shielding medium, cooling or fume removal. Hoses, lines, or conduits required for non- electric power or control. NEMA Standard 1-11-1983. 3. 4. SHIELDING MEDIUM Gas, flux, or other material which is used to shield the arc and molten weld metal from the atmosphere. b NEMA St
42、andard 1-11-198 SUBMERGED ARC WELDING (SAW) An arc welding process which produces coales- cence of metal by heating them with an arc or arcs between a bare metal electrode or electrodes and the work. The arc and molten metal are shielded by a blanket of granular, fusible materia1 on the work. NEMA S
43、tandard 1-11-1983. WELDING CURRENT the making of a weld. The current which is in the welding circuit during NEMA Standard 11-6-1975. WELDING POWER CIRCUIT Any part of the system which is electrically energized by the welding power of the welding power source. NEMA Standard 11-6-1975. WELDING POWER S
44、OURCE A source of welding current and voltage for arc welding. d NEMA Standard 11-6-197 EW 3-1 983 Page 3 WIRE FEED CONTROL The electrical apparatus or mechanical apparatus, or both, that control(s) the wire feed unit, the sequence of operations and the services as required. NEMA Standard 11-6-1975.
45、 O WIRE FEED SYSTEMS A system which applies a continuous filler wire to an arc or weld zone. The system usuaily includes the following elements: a gun assembly, gun cable assembly, wire feed unit, wire feed control, filler wire supply, and service line. NEMA Standard 11-6-1975. WIRE FEED UNIT The ap
46、paratus that converts control power to mechanical power and transfers it to the filler wire. It usually includes a motor, speed reducing means, drive rolls, and filler wire guides. It may also include the wire feed control and filler wire supply. NEMA Standard 11-6-1975. EW 3-1 983 Page 4 Section 2
47、SERVICE CONDITIONS 2.1 GENERAL Service conditions, other than those specified as usual, may have a detrimental effect on the welding apparatus. Such an effect depends upon the degree of departure from usual operating conditions and the severity of the environment to which the ap- paratus is exposed.
48、 Of principal concern are unusual service conditions which might cause abnormal deterioration of the insulation system, electrical breakdown or mechanical wear, resulting in pre- mature failure. Although past experience of the user may often be the best guide, the manufacturer of the welding equipme
49、nt should be consulted for further informa- tion regarding any unusual service conditions which may increase the mechanical or thermal stresses on the equipment and, as a result, increase the chances for failure and possible hazard. Authorized Engineering Information 11-6-1975. 2.2 USUAL SERVICE CONDITIONS Equipment conforming to these standards shall be capable of operating in accordance with its rating under the following conditions: 1. Where the ambient temperature is in the range of O “C to 40 OC. 2. Where the altitude is between sea level and 3300 feet (lo00 meters). 3. 4. When exposed t
