Duty Cycle And Overheating - Miller Electric Shopmaster 300 AC/DC Owner's Manual

2-3. Duty Cycle And Overheating

A. AC Mode
B. DC Mode
(CV or CC)
Overheating
OM-322 Page 10
AC Mode: 40% Duty Cycle At 200 Amperes
4 Minutes Welding
DC Mode: 50% Duty Cycle At 300 Amperes
5 Minutes Welding
0
Minutes
6 Minutes Resting
5 Minutes Resting
15
OR
Reduce Duty Cycle
Duty Cycle is percentage of 10 min-
utes that unit can weld at rated load
without overheating.
If unit overheats, thermostat opens,
output stops, and cooling fan runs.
Wait fifteen minutes for unit to cool.
Reduce amperage or duty cycle be-
fore welding.
Y Exceeding duty cycle can
damage unit and void
warranty.
A
duty1 4/95 / 127 200-A / 127 199-A