Welding Machine Safety Operating Procedures

1. Basic Regulations for Routine Management and Usage of Welding Machines

The daily usage of welding machines should follow a dedicated management model of “assigned personnel, assigned location, and assigned responsibility.” The specific requirements are as follows:

• Certified Special Operations: Operators must undergo specialized national safety technical training and strictly hold a valid “Special Operations Certificate for Welding” before turning on and operating the equipment.
• Fixed Positioning Management: Equipment is subject to regionalized fixed-point management with clearly defined workstations. After use, machines must be cleaned and neatly placed in the designated safety planning area of the workshop.
• Responsibility-based Maintenance: The user of the welding machine is the primary safety person-in-charge for that equipment. They are responsible for routine pre-startup inspections and basic maintenance, and must immediately shut down and report for repair if any abnormality is detected.
• Standardized Cable Recovery: After using the secondary welding cables and ground wires, casually throwing them on the floor or tangling them around other electrical equipment is strictly prohibited. They must be promptly and properly coiled and securely stored by the user.

2. Professional Periodic Inspection and Electrical Insulation Testing System

To grasp the health status of the welding machines and avoid accidents caused by internal aging, the factory must establish a regular professional technical testing cycle:

• Quarterly Inspection and Technical Maintenance: The workshop should organize a special technical inspection and internal dust removal for all active welding machines at least once a quarter, promptly tightening any internal components loosened by vibration.
• Establish a Special Testing Team: For technical experiments and resistance performance testing, a joint testing team composed of full-time electricians, safety officers, and team leaders must be formed. Blind testing by ordinary operators is strictly prohibited.
• Mandatory Semi-Annual Insulation Resistance Testing: A system insulation resistance test must be mandatorily performed every six months. The testing scope covers: insulation resistance of the primary winding to ground, secondary winding to ground, and between the primary and secondary windings. All test data and resistance records must be duplicated and properly archived in the workshop team’s safety production ledger.

3. Welding Machine Safety Operating Procedures (14 Core Rules)

1. Verify Nameplate Voltage: Before welding, carefully check and confirm that the primary and secondary wiring are completely correct. The input power supply voltage must perfectly match the rated voltage on the welding machine’s nameplate. After the power is connected, touching or exposing the live electrical parts of the primary circuit is strictly prohibited.
2. Tighten Copper Connection Plates: The secondary tap connection copper plates must be tightly compressed, and the terminal locations must be equipped with spring washers and flat washers. Before throwing the switch, meticulously check that all wiring nuts, bolts, and components are complete, intact, and free of any looseness.
3. Balance Three-Phase Load: When multiple welding machines are used centrally in the same area, they must be reasonably and separately connected to the three-phase power network to ensure the three-phase load is generally balanced. Meanwhile, the grounding devices of multiple welders must be independently routed from the main grounding electrode; series grounding is strictly prohibited.
4. Dragging Prohibited: The upstream power supply must be cut off first before moving the welding machine. Forcibly dragging the machine by pulling the welding cables is strictly prohibited. If a sudden power outage occurs during operation, immediately turn off the welding machine’s power switch.
5. Field Environment Protection: When conducting outdoor operations in the field, the welding machine must be properly placed inside a protective shed that is rainproof, moisture-proof, sun-shaded, and well-ventilated.
6. Improvised Grounding Prohibited: During welding, a standard dedicated earth cable must be firmly clamped onto the workpiece. Substituting standard ground wires with randomly placed iron plates, steel bars, or other improvised bridging materials is strictly prohibited.
7. Proper Enclosure Grounding: The metal enclosure of the welding machine must have a reliable protective grounding or zero-connection network. The installation and removal of the primary power line in front of the machine must be performed by a dedicated professional holding an electrician’s certificate. The insulation resistance value between the primary and secondary windings, and between the windings and the iron core/enclosure, must absolutely not be less than 0.5 megohms (MΩ).
8. Clear Flammables and Explosives: Storing any flammable, explosive, or hazardous chemical materials within a 10-meter radius of the welding site is forbidden. Operators performing arc welding must wear a full set of Personal Protective Equipment (PPE) according to national labor protection regulations, including insulating shoes, a welding face shield, and heavy-duty welding gloves.
9. Strictly Control Cable Length: The primary input power cable length for general industrial AC arc welders should not exceed 5 meters; the total length of the secondary welding loop cable should not exceed 30 meters to prevent excessive voltage drop from affecting the weld bead profile.
10. Proper Insulation and Environmental Protection: The connection between the electrode holder and the torch cable must be excellently insulated and securely tightened. When replacing consumables like welding electrodes, dry insulating gloves must be worn. If working in highly conductive environments prone to electric shock, such as damp areas or dense metal plates, you must stand on a paved insulating rubber mat or a dry wooden board.
11. Welding Under Pressure Prohibited: Directly welding on pressurized vessels, fully loaded pipelines under normal pressure, or structural workpieces under mechanical stress is strictly prohibited. Upstream main power must be thoroughly cut off before welding electrically active equipment.
12. Clean Special Storage Tanks: Before welding containers, closed vessels, or chemical pipelines that have stored flammable, explosive, or toxic chemicals, they must undergo strict chemical cleaning, steam purging, and gas concentration testing. Only after confirming they are completely clean can all handholes, orifices, and valves be opened to commence welding.
13. Confined Space Monitoring: When welding inside structurally enclosed metal vessels (such as boiler liners, ship cabins, or large-diameter pipes), the vessel’s exterior must maintain absolutely reliable safety grounding. Forced mechanical ventilation and fume extraction must be applied internally, and a dedicated person must be stationed outside for continuous, uninterrupted monitoring. Introducing oxygen into such confined spaces as a ventilation source is strictly prohibited.
14. Preheating and Thermal Protection: When welding special carbon steel or non-ferrous metal workpieces that require extensive localized or overall preheating, perfect thermal insulation and anti-burn measures, such as laying asbestos cloth and setting up heat shields, must be taken in the surrounding area.