Electrode holders used must be purpose-built for arc welding and cutting and rated to carry the maximum current the electrodes need; current-carrying parts running through the grip and the outer jaw surfaces are fully insulated against the maximum voltage to ground. Welding and cutting cables are the fully insulated flexible type sized for the maximum current of the job, allowing for the duty cycle. The 10 feet of cable nearest the electrode holder must be free of repairs and splices, except standard insulated connectors or splices insulated as well as the cable. Cable lengths are joined only with substantial insulated connectors of at least the cable's capacity; lug connections are fastened tight for good contact with exposed metal fully insulated. Cables needing repair are not used, and elsewhere than that lead section, bare spots from wear are covered with rubber and friction tape or equivalent. Ground return cables carry safely at least the maximum output of the unit served, or of all units combined when one cable serves several. Pipelines holding gas or flammable liquid and conduits holding electrical circuits may not serve as ground returns; welding on natural gas pipelines follows DOT 49 CFR part 192. Where a structure or pipeline is used as a ground return, electrical contact at every joint is verified, and any arc, spark or heating at a joint rules it out; where used continuously, all joints are bonded and periodic inspections confirm no electrolysis or fire hazard. Machine frames are grounded through a third wire in the supply cable or a separate wire grounded at the source, and grounding circuits other than via the structure are checked to show resistance low enough to trip the fuse or breaker. All ground connections are inspected to confirm they are electrically adequate for the current and mechanically sound. The employer must instruct workers in safe arc welding: remove electrodes from unattended holders and place holders where they cannot touch people or conductive objects; never dip hot holders in water; open the machine power switch when leaving work for an appreciable time or moving the machine; report faulty equipment to the supervisor; and see 1926.406(c). Wherever practicable, arc work is shielded by noncombustible or flameproof screens protecting nearby people from direct arc rays.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.