Section 408.11273. Design of arc welding machines.

(1) A controller integrally mounted in an  electric  motor driven welder shall have the capacity for carrying rated motor current and shall be capable of making and interrupting stalled rotor current  of  the motor.

(2)   Control apparatus shall be enclosed except for the operating wheels, levers, or handles. The handles and wheels shall be large  enough  to  be grasped by a gloved hand.

(3)   Input power terminals, tap change devices, and live metal parts connected to input circuits shall be completely   enclosed   and   accessible only by use of tools.

(4)   Welding lead terminals shall be protected from accidental electrical contact by personnel or metal objects. If a welding lead terminal normally used for connection to the work is connected to a   grounded  enclosure,    it shall be done by a conductor at least 2 sizes smaller than  the  grounding conductor and it shall be so marked.

(5)   Portable control  devices,  such  as  push  buttons,  shall  not   be connected to an AC circuit of more than 120 volts. Exposed metal parts of a portable control device operating above 50 volts shall be grounded.

(6)   Auto transformers or AC reactors shall not be used to draw welding current directly from any AC power source having a voltage of more than 80 volts.

History: 1979 AC.