Lincoln Electric IM727 SAE400 SEVERE DUTY - Manual (Page 16)

B-4 OPERATION B-4
WELDER CONTROLS
POLARITY SWITCH
Turn the Arc Polarity switch to electrode positive or
electrode negative as required for each particular
application.
CONTROL OF WELDING CURRENT
Purpose of Controls
The continuous “ Current Control ” is the main current
adjuster. The “ Job Selector ” is both a fine current
adjuster and the continuous Open Circuit Voltage
adjuster. Open Circuit Voltage (OCV) controls the arc
characteristics.
“Job Selector”
The “ Job Selector ” dial is divided into four colored sec-
tions providing OCV ranges as follows:
Color Title OCV Range
White Large Electrodes High OCV
Black Normal Welding Medium OCV
Red Overhead & Vertical Low OCV
Grey Special Applications Extra-Low OCV
The “ Job Selector ” is usually set in the black range
because it provides a soft “ Buttering “ arc desired for
most welding. Some operators prefer to set the “ Job
Selector ” in the red range for a snappy “ Digging ” arc
when welding vertical up or overhead.
“Current Control”
Do not adjust the “ Current Control ” while welding
because this can damage the control.
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The “ Current Control ” dial is calibrated in amperes on
three separate colored dials corresponding to the
white, black and red ranges of the
“ Job Selector ” dial.
For example: when the “ Job Selector ” is set on the
black range, the approximate welding current is indi-
cated on the black scale of the
“ Current Control ” dial.
How to Set the Controls
Assume you want a normal soft arc and about 135
amps, using a 5/32
” (4.0 mm) electrode:
1. Set the “ Job Selector ” at the center of the black
range.
2. Set the “ Current Control ” to read 135 amps on the
black dial.
3. Start to weld.
4. If you want a little more current, turn the “ Job
Selector ” up (counterclockwise) to increase cur-
rent. If you want a little less current, turn the “ Job
Selector ” down (clockwise) to decrease current.
5. If dialing the desired current with the “ Job
Selector ” moves the setting outside the black
range causing undesirable arc characteristics, turn
the
“ Job Selector ” back to the center of the black
range. Then turn the “ Current Control ” up or down
a little as needed. Readjust the “ Job Selector ” for
the exact characteristics and current desired.
REMOTE CONTROL
A receptacle and “ Local/Remote ” control switch on the
lower front control panel and a remote control box with
100 ft. (30.5 m) of cord for adjusting the OCV at the
welding site are standard. Putting the switch in the
“ REMOTE ” position allows fine current control at the
remote control box while placing the switch in the
“ LOCAL ” position allows fine current control at the “ Job
Selector ” on the machine.
AUXILIARY POWER CONTROLS
Note: GFCI receptacles our an option and if installed,
see the “ MAINTENANCE SECTION ” for detailed
information on testing and resetting the GFCI
receptacle.
115 VAC Receptacle
One 20 amp, 115 VAC duplex receptacle provides 115
VAC for auxiliary power. A total of 26 amps can be
drawn from this receptacle.
230 VAC Receptacle
One 15 amp, 230 VAC duplex receptacle provides 230
VAC for auxiliary power. A total of 13 amps can be
drawn from this receptacle.
Circuit Breakers
The circuit breakers provide separate overload current
protection for each half of the 115 V duplex receptacle.
The circuit breakers provide overload current protec-
tion in both current carrying wires of the 230 V duplex
receptacle.
Ground Stud
Provides a connection point for connecting the
machine to earth ground. For the safest grounding pro-
cedure refer to
“ Machine Grounding ” in the INSTALLA-
TION section of this manual.
SAE-400 SEVERE DUTY
CAUTION