Arc Welding Arc welding involves the use of a powerful electric arc to make and repair plain, coated, or treated metal items. Welders can be stationary, electric powered or portable, diesel/gas powered. Install electric-powered arc welders to code. Ground equipment and place it on an independent circuit with the correct-sized fuse or circuit breaker. Overloading circuits or improper installation can lead to fire, a ground fault, or equipment failure. Mount a safety disconnect switch near the user work area. Operate diesel/gas powered arc welders in well-ventilated areas to control combustion fumes. Do not add fuel to the engine while it is running...