Tweco 170Pi Transtig - Manual (Page 16)

TRANSTIG 170Pi
INTRODUCTION 2-4 Manual 0-5241
2.09 Duty Cycle
The rated duty cycle of a Welding Power Source, is a statement of the time it may be operated at its rated
welding current output without exceeding the temperature limits of the insulation of the component parts.
To explain the 10 minute duty cycle period the following example is used. Suppose a Welding Power Source
is designed to operate at a 30% duty cycle, 170 amperes at 26.8 volts. This means that it has been designed
and built to provide the rated amperage (170A) for 3.0 minutes, i.e. arc welding time, out of every 10 minute
period (30% of 10 minutes is 3.0 minutes). During the other 7.0 minutes of the 10 minute period the Welding
Power Source must idle and be allowed to cool.
A-11644
Figure 2-1: Transtig 170Pi Duty Cycle