14
WWW.FORNEYIND.COM
Performance Data Plate and Duty Cycle
On the machine, there is a plate that includes all the operating specifications for your new unit. The serial number of the
product is also found on this plate.
The duty cycle rating of a welder defines how long the operator can weld and how long the welder must rest and be
cooled. Duty cycle is expressed as a percentage of 10 minutes and represents the maximum welding time allowed. The
balance of the 10-minute cycle is required for cooling.
For example, a welder has a duty cycle rating of 30% at the rated output of 90A. This means with that machine, you can
weld at 90 A output for three (3) minutes out of 10 with the remaining seven (7) minutes required for cooling. The duty
cycle of your new welder can be found on the data plate affixed to the machine. It looks like the diagram below. Referring
to the sample below, the “X” row lists duty cycle percentages while the “I2” row lists the
amp draw corresponding to the duty cycle. Various duty cycles at other amperages are listed on your data plate.
(Example Data Plate)
If you exceed the duty cycle of the welder, the thermal protection system will engage, shutting off all welder output. After
cooling, the thermal protector will automatically reset and the welding functions can resume. This is normal and automatic
behavior of the machine, and does not require any user action. However, you should wait at least ten minutes after the
thermal protector engages before resuming welding. You must do this even if the thermal protector resets itself before the
ten minutes is up or you may experience less than specified duty cycle performance.
CAUTION: DO NOT REGULARLY EXCEED THE DUTY CYCLE OR DAMAGE TO THE WELDER
CAN RESULT.
Operation
Internal Thermal Protection
IP21S
