Lincoln Electric IM803-B - Manual (Page 14)

B-4 OPERATION B-4
OVERLOAD PROTECTION
The machine is electrically protected from producing
high output currents. Should the output current
exceed 300A, an electronic protection circuit will
reduce the current to less than 200A. The machine
will continue to produce this low current until the pro-
tection circuit is reset. Reset occurs when the output
load is removed.
Note: When TIG welding with the Output Knob at or
above 275 Amps the Arc may go out.
THERMAL PROTECTION
Thermostats protect the machine from excessive
operating temperatures. Excessive temperatures may
be caused by a lack of cooling air or operating the
machine beyond the duty cycle and output rating. If
excessive operating temperature should occur, the
thermostats will prevent output voltage or current.
Thermostats are self-resetting once the machine cools
sufficiently.
FAN
The cooling fan on the ES 275i operates once 15
amps of welding current is drawn and for 7 minutes
after the output current has stopped flowing.
The fan will also run anytime the machine has over
heated.
POWER-UP SEQUENCE
At power up the thermal light (and Power light on
codes 11164 and above) turns on and the fans run for
approximately 3 seconds. This is the pre-charge time
for the main capacitors. After this time the fans and
thermal light turn off and the pre-charge relay closes
to apply full line power to the capacitors. At this time
the machine is ready to weld.
ES 275i