Of course we all weld with two stop watches to monitor our weld time and cool down time so we don't exceed the duty cycle of our welder Those who want to brag about their 100% duty cycle industrial power sources - please go haunt some other thread. I do not have a 100% duty cycle machine and this question is not about 100% duty cycle machines.

Miller included a feature on many of their machines which they call "fan on demand" which runs the cooling fan only as required to maintain the temperature of the machine. If I operate my Diversion 165 at an amperage corresponding to its 30% duty cycle rating for 3 minutes I am, in theory, supposed to wait 7 minutes for it to cool. However, the "fan on demand" will shut off the fan after perhaps 3 - 4 minutes.

So my question, (any Miller reps on the forum?) is...

Is it safe to consider that the necessary cool down period has elapsed when the "fan on demand" shuts off the cooling fan - thus allowing me to start welding again?