Michigan Administrative Code › Department - Labor and Economic Opportunity › MIOSHA › General Industry and Construction Safety and Occupational Health Standards › Construction Safety and Health Standard › Part 7 - WELDING AND CUTTING GENERAL PROVISIONS › ARC WELDING AND CUTTING › Section R. 408.40744 - Installation

Current through Vol. 24-12, July 15, 2024
Rule 744.
(1)
						The frame or case of a welding machine shall be grounded, unless the
						manufacturer does not recommend it.
(2) The work on which the operator welds
						shall be grounded. A wire used to ground a workpiece shall be capable of
						carrying the full welding current. Connections of the ground shall be
						mechanically sound and strong. When a single ground return cable services more
						than 1 unit, the safe current-carrying capacity of the cable shall equal or
						exceed the total maximum output capacities of all units which it
						services.
(3) A conduit containing
						an electrical conductor shall not be used for completing a work-lead
						circuit.
(4) A pipeline in service
						shall not be used as a permanent part of a work-lead circuit, but may be used
						during construction, extension, or repair if current is not carried through
						threaded joints, flanged bolted joints, or caulked joints and if special
						precautions are used to avoid sparking at the connection of the work-lead
						cable.
(5) Chains, wire ropes,
						cranes, hoists, and elevators used for carrying loads shall not be used to
						carry a welding current.
(6) A
						welding cable shall be protected against damage, entanglement, or contact with
						power supply or high-tension wires.
(7) A welding machine that is not provided
						with a controller or disconnect switch as an integral part shall have a
						controller or disconnect switch with overload protection provided. A disconnect
						switch with overload protection or overload disconnect protection, or
						equivalent, shall be provided for each outlet used by a portable welding
						machine, unless the machine is equipped with a disconnect switch and overload
						protection.
(8) The rated
						current-carrying capacity of the supply conductors for individual machines
						shall not be less than the rated primary current for the welding machine. The
						rated current-carrying capacity of the conductors for a group of welding
						machines may be less than the sum of the rated primary current of the welding
						machines supplied. The conductor rating shall be determined in each case
						according to the machine loading based on the use to be made of each welding
						machine and the allowance permissible if all the machines supplied by the
						conductor will not be in use at the same time.
(9) Where a welding machine is working
						sufficiently close to another machine so that a welding operator is likely to
						touch the exposed parts of more than 1 electrode holder simultaneously, the
						machine shall be connected so as to minimize shock hazard as follows:
(a) DC machine shall be connected with the
						same polarity.
(b) AC machine shall
						be connected to the same phase of the supply circuit and with the same
						instantaneous polarity.