R 408.11283 Portable welding guns.

Rule 1283. (1) Unless the design makes it unnecessary, a portable welding gun shall be counterbalanced including the cables. (2) All suspended portable welding gun equipment, except the gun assembly, shall be equipped with a safety chain or cable capable of supporting the total shock load in event of failure of any component of the supporting system. (3) When a trolley is used to support a portable welding machine with a clevis for attachment to a safety chain, the clevis shall be wrought or forged steel and capable of supporting the shock load in event of failure of the trolley. (4) The movable holder shall have such clearance where it enters the welding gun frame that a shear action cannot take place if the operator's fingers are placed on the operating movable holder or guarding shall be provided. (5) The secondary and case of a portable welding transformer shall be grounded by a center tapped secondary or by a center tapped grounding reactor connected across the secondary.