GB 15579.11-1998 Safety requirements for arc welding equipment Part 11: Electric welding tongs
Some standard content:
GB 15579. 11—1998
This standard is equivalent to IEC974/11:1992, and only the wet heat treatment conditions, rated current levels and cable cross-section range in EC974/11 are appropriately modified.
my country has a vast territory, and the summer in the south is a typical high temperature and high humidity climate. Therefore, this standard stipulates that the temperature of wet heat treatment is 40°C according to the requirements of GB/T 2423.3. This is in line with national conditions and is consistent with relevant standards such as GB/T8118 in the electric blasting machine industry. Electric welding clamps are used in conjunction with arc welding machines. If the rated current level is different from the rated current level of the welding machine, it will cause misunderstanding. Therefore, the rated current level of this standard is divided into grades according to GB/T8118, and the current level of IEC974/11 is retained in brackets. IEC974/11 and IEC974/12 respectively stipulate the cables used for welding tongs and welding relay couplers. However, the specified welding current is different from the corresponding cable cross-sectional area, and the former is one level larger than the latter. Since both devices are installed at the output end of the arc welding power source, the cable cross-sectional area should be consistent. According to the actual domestic use, this standard reduces the cable cross-sectional area corresponding to the welding current by one level, which is the same as IEC974/12.
Compared with JB7107-93, this standard has made major changes in the following aspects. From the industry standard to the national standard;
-Cancel the clamping tension clause:
Modify the protection level requirements of welding tongs!
-Increase the depth requirements for the insulation of the welding cable embedded in the welding tongs, and modify the temperature rise test method
Add marking and instruction manual requirements.
For the convenience of using this standard, Chapter 6 and Article 8.2 of IEC 974/11 are compiled as Appendix A for reference by users. This standard will be abolished from the date of entry into force of JB7107-93. Appendix A of this standard is a reminder appendix. This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China and is under the jurisdiction of the National Technical Committee for Standardization of Electric Welding Machines. The drafting unit of this standard: Chengdu Electric Welding Machine Research Institute. The main drafter of this standard: Pan Ying.
GB 15579. 11-1998
IEC Foreword
IEC (International Electrotechnical Commission) is a worldwide standardization organization composed of all national electrotechnical committees (IEC National Committees). The mission of IEC is to promote international cooperation on standard issues involved in the fields of electrical and electronic engineering. The final and additional business is to publish international standards, which are drafted by technical committees. Any IEC National Committee interested in its work items can participate in the drafting work. Both official and unofficial international organizations can contact IEC to participate in the drafting of standard projects. IEC and the International Organization for Standardization (ISO) work closely together in accordance with the principles agreed upon by the two organizations. EC's formal resolutions or agreements on technical issues are drafted by technical committees based on the participation of all interested national committees and after reaching international consensus as much as possible. Internationally, they are usually recommended to countries around the world in the form of published standards, technical reports or guidelines, and are indicated to be received by national committees. In order to promote international unification, IEC National Committees should ensure that IEC international standards and regional standards are implemented to the greatest extent possible within their own countries. Any differences between IFC and the corresponding national or regional standards should be clearly marked afterwards. The standards provided by IEC do not indicate the voting procedure, and cannot be responsible for any equipment that claims to comply with a certain standard. The international standard IEC974/11 was drafted by the 26th Technical Committee of IEC. The provisions of this standard are based on the following documents: DIS
26(CO)27
Voting Report
26(CD)30
Full information on the voting for this standard can be found in the voting report listed in the above table. 1 Applicable Scope
National Standard of the People's Republic of China
Safety requirements for arc welding equipment
Part 1:Electrode holders
Part I General
This standard specifies the safety and structural requirements for electrode holders. GB 15579. 11—1998
eq IEC 974/11:1992
This standard applies to electrode holders for manual arc welding with an electrode diameter of less than 10 mm (hereinafter referred to as electrode holders). This standard does not apply to electrode holders for underwater welding. 2 Referenced standards
The clauses contained in the following standards constitute the clauses of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2423.3-93 Basic environmental test procedures for electric and electronic products Test Ca; Steady damp heat test method (eqv IEC 68-2-3: 1984)
GB4208-93 Enclosure protection degree (IP code) (egv IEC529: 1989) 3 Environmental conditions
a) Ambient temperature: maximum 40℃
b) Relative air humidity of 90% at 20℃. 4 Definitions
This standard adopts the following definitions.
4.1 Welding clamps
Hand-held insulating device used to clamp and knead the electrode during manual arc welding and ensure electrical connection with the electrode. 4.2 Welding clamp head
Parts with holes, claws or equivalent structures on the welding clamp for inserting, positioning or clamping the welding rod. 4.3 Handle
Parts on the welding clamp for the operator to hold. 4.4 Joystick
Parts installed on the welding clamp to control the clamping device. 4.5 Rated current
The current that the welding clamp can withstand when it does not exceed its upper limit value specified by the manufacturer. Approved by the National Technical Supervision Bureau on January 19, 1998, implemented on October 1, 1998
4.6 Type A welding clamp
GB 15579. 11--1998
According to GB4208. Welding clamp whose internal live parts cannot be touched by the test finger. 4.7 Type B welding clamp
Different from type A, the live parts of the welding clamp head cannot be touched by the test ball. The diameter of the test ball should be selected according to the diameter of the electrode, see 8.1b.
4.8 Duty cycle
The ratio of the agreed load duration to the full cycle time. Part II Requirements and Tests
5 Test Parts
The test items specified in this standard are all type test items, and the factory inspection items are specified by the enterprise standard. At an ambient temperature of 10 to 40°C, the new, dry, fully assembled welding tongs with welding cables installed are tested according to the following requirements: 5.1 Measuring instrument accuracy requirements
8) Electrical measuring instruments: Class 0.5:
b) Temperature measuring device: ±2 K.
5.2 specifies the order of some tests.
5.2 Test sequence
The tests given below shall be carried out in the following order: a) general visual inspection;
b) temperature rise (see 9.1) #
c) impact resistance (see 10.4);
d) insulation resistance (see 8.2);
e) dielectric strength (see 8.3).
Other tests not mentioned above may be carried out in any conventional order. 6 Marking
Welding faults shall be marked with the rated current. The rated current corresponds to the minimum range of welding rods and welding cables specified in Table 1. Table 1 Relationship between the rated current of welding clamps and the specifications of welding rods and welding cables Rated current of welding clamps
160(150)
315(300)
Minimum range of welding rod diameter
2. 0~3. 2
2. 5 ~~4. 0
3. 2~~ 5. 0
4. 0 ~ 6. 3
5. 0 ~~ 8. 0
6.3--10.0
Minimum range of welding cable that can be assembled
Note: The current value refers to the rated value at 60% load duration. At 35% load duration, the current can be taken as the higher rated value in the next row of the table, so the maximum current value at 35% load duration is 630A. Check whether it is qualified by testing the mother.
7 Operation
Welding tongs should be able to:
GB 15579.11—1998
a) Safely and quickly install the electrode and remove the remaining electrode stubs; b) Clamp the electrode at any specified position to weld until only 50mm is left; c) Clamp the electrode of various diameters specified by the manufacturer without any external force applied by the operator! ) When the electrode is bonded to the workpiece, the electrode can be separated from the workpiece. Use the manual welding method to operate the clamping device, visual inspection and test d) to check whether it is qualified. 8 Protection against electric shock
8.1 Protection against direct contact
When the welding clamp is not clamped with the electrode and only equipped with the welding cable of the minimum cross-section specified by the manufacturer, it should be able to prevent accidental contact with its live parts. For type A welding clamps, this requirement is also valid for the electrode section inserted in the welding clamp. Use the minimum and maximum diameters of the welding rod specified by the manufacturer for inspection.
Use the following method to check whether it is qualified or not:
a) Use the standard test finger specified in GB4208 to check: 1) Type A welding clamp
2) Parts other than the welding clamp head of Type B welding clamp. b) The welding clamp head of Type B welding clamp is tested with the following test ball: 1) When the diameter of the welding rod used is less than or equal to 6.3 mm, according to GB 4208, the diameter of the metal test ball is (12.5+g *5) mm
2) When the diameter of the welding case used is more than 6.3 mm, the diameter of the metal test ball is (+0%) mm, which is twice the diameter of the thickest welding rod that can be used according to the manufacturer's regulations.
Apply a force of 30N±10% to the test ball in the jaws. The spring that does not transmit welding current should be insulated from other metal parts on the welding clamp. Check whether it is qualified or not by visual inspection.
8.2 Insulation resistance
The insulation resistance of the welding clamp after wet heat treatment should not be less than 1M. The following test is used to check whether it is qualified or not: Place the welding clamp without cable in a constant wet heat room for mixed heat treatment. The environmental conditions and methods of wet heat treatment are in accordance with GB/T2423.3. The temperature of the effective working space in the wet heat room should be maintained between (40±2)℃, and the relative humidity should be maintained within the range of (93)%. The welding clamp is first preheated at 40℃ in the wet heat room. When the welding clamp reaches a stable temperature, it is wetted again to prevent the welding clamp from falling off. After the welding pin is wet heat treated for 48 hours, wipe off the moisture on its surface, restore it under normal atmospheric conditions for 1~2 hours, and then wrap the outer surface of the welding clamp insulator with a metal box, and apply a 500V DC voltage between the welding clamp conductor and the metal box, measure the insulation resistance, and read the data after stabilization. 8.3 Dielectric strength
The insulating part of the welding clamp shall be able to withstand an AC test voltage of 1000V with no flashover or breakdown. The judgment shall be whether the applied voltage is reduced. Any instantaneous discharge that does not reduce the voltage can be ignored. The following test shall be used to check whether it is qualified or not: After the insulation resistance test, an AC test voltage of a near-sine waveform with a peak value not exceeding 1.45 times the effective value and a frequency of 50 Hz or 60 Hz shall be applied between the welding clamp conductor and the metal box for 1 min. 9 Thermal rating
9. 1 Temperature rise
GB 15579. 11--1998
After the welding clamp is equipped with an unplated copper welding relay of the largest cross-section and a round rod with the same diameter as the thickest electrode as specified in Table 1, the rated current shall be passed. The temperature rise of the hottest point on the outer surface of the handle shall not exceed 40K. Compliance is checked by the following test (see Figure 1): Two welding tongs of the same specification are each equipped with a welding relay of at least 2 II length. A clean, non-oxidised mild steel round bar is clamped between two welding tongs clamping devices at an angle of 180° to each other, with the height between the two welding tongs clamping devices being 50 mm.
The welding tongs connected by the round bar are suspended horizontally by their welding cables between two wooden frames 1 m apart. The clamped round bar is between the two wooden frames, 200 mm above the ground. The test area should be free of air flow. A direct current of 75 % of the rated current value (approximately 60 % duty cycle) is passed through the welding tongs until the rate of temperature rise does not exceed 2 K/h. The average temperature rise is calculated from the temperature rise of the hottest point of each of the two welding tongs. This test should be carried out 5 times, each time using a new pair of welding tongs and a new mild steel bar. 1000
Figure 1 Temperature rise test installation diagram
9.2 Heat resistance
After the temperature rise test according to 9.1, the insulation of the welding clamp head shall not show blistering, deep carbonization or cracking, especially the area where the electrode is clamped.
Check its compliance by visual inspection.
9.3 Welding spatter resistance
The insulating material of the handle shall be able to withstand normal amount of welding spatter without completely penetrating or burning. All parts of the welding clamp shall be made of flame retardant materials and will not cause combustion under normal working conditions. Check its compliance according to the device shown in Figure 2. Pass a current of about 25A through the heating rod to make it reach a thermal stability state of (300+5)C: measure the temperature with a thermometer or thermocouple. Then place the heating rod in a horizontal position on the insulating surface of the handle for 2 minutes. The depth of the heating rod entering the insulation layer should not exceed 1.5m, and it cannot touch the live parts. The depth of entry is measured from the outer surface of the main body of the insulation layer, excluding the auxiliary strips and other protruding parts. Use electric sparks or a small flame to ignite the gas escaping from the contact part. If the gas is flammable, the flame should go out immediately as the heating rod leaves.
10 Mechanical requirements
10.1 Welding cable entry
GB 15579. 11—199
J8—8CrNi steel
300-c
Welding wax handcart
100±0.5mmbzxz.net
Figure 2 Welding flying object resistance test device
The welding cable entry on the welding clamp should be designed to prevent the cable from being damaged due to bending. Through the test, check whether it is qualified or not.
10.2 Depth of welding cable insulation embedded in the welding clamp
The depth of the insulation of the welding cable into the welding clamp shall be at least twice the outer diameter of the cable, but at least 30°. The welding cable with the largest cross-sectional area specified by the manufacturer shall be measured to check whether it is qualified or not. 10.3 Connection of welding relay
The welding clamp shall be designed to be able to replace the welding relay within the area specified by the manufacturer, and its connection shall be able to withstand the tensile test without being disengaged.
Check its compliance through self-test and the following test: After the welding clamp is equipped with the welding cable with the largest cross-sectional area according to the requirements of the instruction manual, a tensile force of 40N/mm is applied to the connection according to the cross-sectional size of the welding cable, but the maximum tensile force is 2000N, and 10 tensile tests are performed. Each time the tensile force is gradually increased from 0 to the specified value within 1s, and it lasts for more than 1 second.
After the test, the cable shall not have obvious displacement. Repeat the above test with the welding cable with the smallest cross-sectional area. If there is more than one way to connect the welding cable, each connection method should be tested. 10.4 Mechanical impact resistance
After the welding clamp is subjected to the mechanical impact test, there should be no obvious or functional changes in the electrode clamping device or its operating parts, and the insulating part should not have cracks or breakdown, but small debris or scratches on the surface are allowed. Check whether it is qualified by the following tests: a) Vertical drop
The welding clamp is suspended by its welding cable so that the end of the welding clamp head is 1m above the impact plane. The impact plane is a low-carbon steel plate placed on the ground with a thickness of at least 9m.
Release the welding clamp with the cable and let it fall freely. Each welding clamp should be tested three times. b) Impact
The test method is shown in Figure 3. The welding clamp is suspended by its cable and moved to position A in a direction perpendicular to the surface. Release the welding clamp at zero initial velocity and make it hit the pad under the following conditions: The pad is a 40mm×40mm×5mm low-carbon angle steel with a top angle radius of 5mm. The suspension point of the welding cable is adjusted to 1m above the top angle of the angle steel so that the part of the welding clamp that is hit in the free hanging state just contacts the top angle of the angle steel; During the test, the welding clamp is offset and raised from the vertical position to 400mm. The welding clamp should hit the angle steel 6 times: twice on the welding clamp head, twice on the middle of the handle and twice on the joystick. If the welding clamp does not have a joystick, then hit the weak part of the welding clamp twice. 0001
Figure 3 Impact test device
11 Marking
Each welding tongs shall be clearly and permanently marked with the following: a) manufacturer's name, registered trademark or dealer's name; b) type (mark) given by the manufacturer; c) rated current;
d) number of this standard.
View the marking content,Check whether it is qualified or not. 12 Instructions for use
Each welding tongs should be provided with an instruction manual including the following contents: a) The range of holding welding rods;
b) The correct connection method of welding cables;
c) The selection of welding cable types and cross-sectional sizes; d) The relationship between welding power and duty cycle; e) Spare parts list.
Read the instructions for use and check whether it is qualified or not. 40×40×5
6 Dongji
GB15579.11—1998
Appendix A
(Reminder Appendix)
Article 6 and Article 8.2 of LEC 974/11 The rated current of welding tongs shall be marked. The rated current corresponds to the minimum range of welding rods and welding cables specified in Table A1. Table A1 Relationship between rated current of welding tongs and specifications of welding rods and welding cables Rated current of welding tongs Minimum range of welding rod diameter 1. 6-2. 5
2. 0 ~ 3. 2
2. 5~~4. 0
3. 2~ 5. 0
4. 0~ 6- 3
5. 0~-8. 0
Minimum range of welding cable that can be assembled mma
95~120
Note that these current values refer to the rated values at 60% duty cycle. At 35% duty cycle, the current can be taken as the higher rated value in the next row of the table, so the maximum current value at 35% duty cycle is 600A. Check whether it is qualified by measurement.
2 Insulation resistance
The insulation resistance of the welding clamp after wet heat treatment should not be less than 1M. Check whether it is qualified by the following test: a) The temperature t of the wet heat chamber should be maintained between 20 and 30℃, with an error of ±1K, and its relative humidity should be maintained within the range of 91% to 95%. First, make the welding clamp without cable reach the temperature between t~(t+4)℃, and then place it in the hot box for 48h. b) Insulation resistance measurement
After wet heat treatment, wipe the welding clamp dry immediately and wrap the outer surface of the welding clamp insulator with a metal box. Apply 500V DC voltage between the welding clamp conductor and the metal foil to measure the insulation resistance and read the data after it stabilizes.
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