What general requirements apply to resistance welding equipment?
(1) All equipment must be installed by a qualified electrician according to the requirements of chapter 296-307 WAC Part T. There must be a safety-type disconnecting switch or a circuit breaker or circuit interrupter to open each power circuit to the machine, conveniently located at or near the machine, so that the power can be shut off when the machine or its controls are to be serviced. (2) Ignitron tubes used in resistance welding equipment must have a thermal protection switch. (3) Employees designated to operate resistance welding equipment must have been properly instructed and judged competent to operate such equipment. (4) Controls of all automatic or air and hydraulic clamps must be arranged or guarded to prevent the operator from accidentally activating them.
