Cranes and hoists: the installation of electrical equipment and wiring for cranes, monorail hoists, hoists and runways needs a readily accessible disconnecting means between the power supply and the runway contact conductors, and a second disconnecting means that can be locked open in the leads from the runway conductors or other supply on every crane or monorail hoist. If that second disconnect cannot readily be reached from the operating station, the station must have a way to cut power to every motor of the crane or hoist. The second disconnect may be omitted for a floor-controlled installation (a monorail hoist or a crane bridge moved by hand) within view of the power supply disconnect with no fixed work platform for servicing. Every hoisting mechanism needs a limit switch or similar device that keeps the load block from travelling beyond its safe upper limit. Where live parts may be serviced while energized, the working space toward them is at least 2 feet 6 inches, and control cabinet doors open at least 90 degrees or are removable, or equivalent access is provided. All exposed metal parts of cranes, hoists and accessories including pendant controls are joined into a continuous conductor and grounded per 1926.404(f); metal-to-metal bearing surfaces count as connected, and trolley and bridge frames count as grounded through their wheels and tracks unless paint or insulation prevents reliable contact, in which case a separate bonding conductor is fitted. Elevators, escalators and moving walks each need a single means to disconnect all ungrounded main supply conductors, and control panels not in the drive machine space are in cabinets that lock. Electric welders: each motor-generator arc welder, and each AC transformer or DC rectifier arc welder without an integral disconnect, needs a disconnecting means in its supply circuit; each resistance welder and its controls need a switch or circuit breaker to isolate them, rated at no less than the supply conductor ampacity. X-ray equipment needs a supply disconnect operable from a place readily reached from the X-ray control (a grounding-type plug and receptacle may serve for 120-volt circuits of 30 amperes or less), a high-voltage switch or equivalent for each unit or group on a shared high-voltage circuit placed or enclosed to prevent contact, and radiographic and fluoroscopic units must be effectively enclosed or interlocked to de-energize and prevent ready access to live parts.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.