Lincoln Electric IM870-A manual Welder Controls, Remote Control, Auxiliary Power Controls

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 sections 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

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.

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”

CAUTION

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

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.

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 recepta- cle. The circuit breakers provide overload current pro- tection 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 procedure refer to “Machine Grounding” in the INSTALLATION section of this manual.

SAE-400 SEVERE DUTY