Lincoln Electric IM901-A manual Wire Feed Speed Validation, Model gearing, Board

D-2 MAINTENANCE D-2

The LN-25™ PRO flow meter cannot be calibrated. If the flow meter reads incorrectly, check for leaks or kinks in the gas hose. Replace the flow meter if neces- sary.

Wire Feed Speed Validation

(See Figure D.1)

Calibration of the LN-25™ PRO may be required when the p.c. board, wire feed speed potentiometer or motor is replaced or serviced. Calibration matches the scale on the name plate to the actual wire feed speed.

Tools required:

•RPM meter

•Constant voltage DC welding power source (DC-400, V-350, CV-400 or equivalent)

•7/16" open end wrench

To verify if calibration is necessary:

1.	Turn power OFF.
2. Set the wire feed speed per the table.
Model gearing		Wire Feed Speed	Acceptable Range
Standard Speed		400 in/min	69 - 77 rpm
Extra Torque		150 in/min	25 - 31 rpm
3.	Remove the plastic cover from the lower portion of the
	wire drive with a 7/16" wrench.
4.	Connect the LN-25™ PRO to the constant voltage DC
	welding power source. The work lead of the LN-25™
	PRO must be connected to the work terminal of the
	power source.
5.	Turn power ON.

6. Measure the motor rpm when the COLD FEED button is pressed.

7. Verify the rpm is within the acceptable range.

FIGURE D.1

MOTOR

SHAFT

To change the wire feed speed calibration: (See Figure D.2)

Tools required:

•5/16" nut driver

•RPM meter

•Shorting plug. The shorting plug shorts pins 4 & 8 of connector J3 on the Control P.C. Board. J3 is a 8 pin molex connector.

1.Turn power OFF.

2.Remove the 4 screws holding the rear cover inside the feeder and remove the cover.

3.Open the idle arm.

4.Set the wire feed speed per the table.

Model gearing	Wire Feed Speed
Standard Speed	400 in/min
Extra Torque	150 in/min

5.Connect the LN-25™ PRO to the constant voltage DC welding power source. The work lead of the LN-25™ PRO must be connected to the work terminal of the power source.

6.Turn power ON.

7.Insert the shorting plug into connector J3 on the Control P.C. Board. The shorting plug shorts pins 4

&8.

8.Remove the shorting plug.

9.Turn power OFF.

10.Replace the cover and secure with the screws.

FIGURE D.2

COVER

COVER

P.C. bOARD

LN-25™ PRO ACROSS THE ARC MODEL