I. How to adjust the current of an electric welding machine
(I) Theoretical Formula for Current Regulation
How is the welding machine current adjusted? Generally, it can be adjusted using the empirical formula I=(35-55)d. In this formula, I is the welding current (A) and d is the electrode diameter (mm). Calculate an approximate welding current, then perform trial welding on the steel plate to adjust it until the appropriate current is determined.
(II) How to adjust the current of an electric welding machine
1. The adjustment of welding machine current is generally divided into two levels:
(1) Level 1 is coarse adjustment. It is commonly used to change the connection of the output wire (connection in position I or position II) to change the number of turns of the internal coil and thus achieve a wide range of current adjustment. Coarse adjustment should be performed with the power off to prevent electric shock.
(2) The other level is fine adjustment, which is usually achieved by changing the position of the "movable iron core" (movable iron core type) or "movable coil" (moving coil type) inside the welding machine. Fine adjustment is achieved by rotating the handle. When the handle is rotated counterclockwise, the current value increases, and when the handle is rotated clockwise, the current decreases. Fine adjustment should be performed under no-load conditions.
2. Adjustable welding current of AC welding machines
To accommodate welding requirements of different materials and plate thicknesses, the welding current can be adjusted from tens of amperes to hundreds of amperes, and the required current value can be arbitrarily adjusted according to the thickness of the workpiece and the diameter of the welding rod used. The coarse and fine adjustment ranges for various welding machine models can be found on the nameplate.
II. The difference between electric welding machines and electric welding machines
Spot welding machine:
Resistance spot welding, or spot welding for short, is a resistance welding method in which workpieces are assembled into lap joints and pressed between two electrodes, and the base metal is melted by resistance heat to form a weld point.
During operation, the two electrodes press the workpiece, causing the two layers of metal to form a certain contact resistance under the pressure of the two electrodes. When the welding current flows from one electrode to the other electrode, an instantaneous thermal fusion is formed at the two contact resistance points. The spot welding machine has a short heating time and concentrated heat, so the heat-affected zone is small, and the deformation and stress are also small. Usually, there is no need to arrange straightening and heat treatment processes after welding.
The welding process requires no filler metals such as welding rods or wires, nor welding materials such as oxygen, acetylene, or argon. It is low-cost, more environmentally friendly, simple to operate, and easily mechanized and automated, thus reducing labor costs. It boasts high productivity and produces no noise or harmful gases, making it suitable for mass production.
Electric welding machine:
Electric welding machines use electrical energy, instantly converting electrical energy into heat energy. They are suitable for working in dry environments with few requirements. Due to their small size, simple operation, ease of use, and high speed, they are highly favored by the market. They are particularly useful for parts requiring high strength, as they can instantly connect similar or dissimilar metal materials. The only difference is the welding method. After heat treatment, the weld has the same strength as the base material and better sealing performance. This solves the sealing and strength problems in the manufacture of gas and liquid storage containers.
The above is an introduction to the differences between spot welding machines and electric welding machines. We hope this information is helpful. For more detailed information, please follow Ster Technology.
III. Causes of Electric Shock Accidents During Welding
(a) Direct cause
1) During the replacement of welding rods, electrodes and welding operations, the hands and some parts of the body come into contact with live objects, while the feet or other parts of the body are not insulated from the ground and metal structures.
2) When connecting wires, adjusting welding current, or moving welding equipment, the hand or any part of the body comes into contact with a live conductor.
3) Contact with high-voltage power grids or improper connection of low-voltage power grids when welding at heights.
(ii) Indirect causes
1) Leakage in welding equipment, cables, machine covers, etc.
2) The welding equipment or circuit malfunctioned.
3) Improper welding operation can cause a circuit to form between the live conductor and the human body.
4) Welding equipment, cables and metal structures in the factory form a welding circuit.
IV. Safety Protection Measures for Electric Welding
1. The welding power source must be used independently and have sufficient capacity to ensure compatibility with the welding operation.
2. The welding machine casing must have complete insulation protection, the wiring joints must not be exposed, and all parts of the welding machine must be securely connected and must not be loose.
3. The welding machine must be protectively grounded, and a neutral grounding device should be installed if necessary.
4. The welding machine should automatically shut off after being unloaded for a certain period of time.
5. The area around the welding machine should be well-ventilated and have good heat dissipation.
6. Welding clamps should be checked frequently to ensure they are easy to use, secure, have good contact, are correctly connected, and that the welding rod can be clamped within the specified angle.
7. The connecting cable must be flexible, oil-resistant, heat-resistant, corrosion-resistant, and meet specifications. The length should be 20 to 30 meters.
8. Welders must strengthen personal protection. Work clothes, insulating gloves, insulating shoes, mats, etc. must be used and kept in good condition.
9. During welding, the area around the welding point should be safely isolated from flammable and explosive hazardous materials. If there is no barrier, the spatial distance should be at least 25 meters.
10. A work plan should be prepared before welding operations, and good lighting and ventilation should be ensured.
11. In the event of an electric shock, first, disconnect the power supply; second, immediately provide first aid, including artificial respiration, and never stop abruptly.
