How to prevent electric shock accidents in welders?

Accident Summary:

A welder at a factory was performing welding operations at a temporary outdoor work site. During operation, he discovered that the welding machine lacked a power switch box. He then disconnected the insulation from the ends of each conductor in the cable and connected them to the exposed power grid. However, he mistakenly connected the neutral wire to the live wire. When he adjusted the welding current and touched the casing, he was electrocuted and died.

Comprehensive Measures to Prevent Electrocution Accidents in Welders

The risk of electric shock during welding operations needs to be controlled collaboratively from three aspects: equipment, operation, and environment. Specific measures are as follows:

I. Equipment Safety
Insulation and Grounding: The welding machine casing must be reliably grounded. The insulation layers of cables and welding clamps must be undamaged, with an insulation resistance ≥1MΩ.

Leakage Protection: Install a two-stage leakage protection device with an operating current ≤30mA.

Automatic Power Cut-off: The equipment should be equipped with an automatic power-off function under no-load conditions, cutting off the power supply when the equipment is not in use or moved.

II. Operating Procedures
Certified Worker: Welders must undergo professional training; unlicensed operation is prohibited. Power-off Operation: Power must be disconnected before replacing welding rods or repairing equipment. Avoid operating the circuit breaker under load.

Protective Equipment: Wear insulated gloves, insulated shoes, and dry work clothes. Do not wipe welding rods with a damp cloth.

III. Environmental Management
Dry and Ventilated: The humidity of the working environment should be ≤85%. Avoid working in damp, enclosed, or flammable/explosive locations.

Safe Distance: Maintain a distance of ≥0.5m between live parts and the ground/equipment. Minimize the length of power cords.

Through multi-level control through technical protection (grounding, leakage protection), management measures (certified operation), and personal protective equipment (insulation equipment), the risk of electric shock can be effectively reduced.