ESAB EMP 320ic - Understanding Duty Cycle

5 OPERATION
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5.5.3 GTAW (TIG) 400 V
V = Output voltage
A = Welding current (Amps)
5.6 Duty cycle
The EMP 255ic has a welding current output of 255 A at 40% duty cycle. The EMP 320 has a
welding current output of 320 A at 40% duty cycle. A self-resetting thermostat will protect the
power source if the duty cycle is exceeded.
Example: If the power source operates at a 40% duty cycle, it will provide the rated
amperage for a maximum of 4 minutes out of every 10-minute period. The remaining time, 6
minutes, the power source must be allowed to cool down with fans running.
A different combination of duty cycle and welding current can be selected. Use the graphs
below to determine the correct duty cycle for a given welding current.