Routine Maintenance; Periodic Maintenance; Calibration Specification - Lincoln Electric LN-25 SVM179-B Service Manual

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SAFETY PRECAUTIONS
WARNING
ELECTRIC SHOCK can kill.
• Do not operate with covers
removed.
• Turn off power source before
installing or servicing.
• Do not touch electrically hot
parts.
• Turn the input power to the welding power
source off at the fuse box before working in the
terminal strip.
• Only qualified personnel should install, use or
service this equipment.
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ROUTINE MAINTENANCE

• Check weld cables and gas hoses for cuts.
• Clean and tighten all weld terminals.

PERIODIC MAINTENANCE

• Clean drive rolls and inner wire guide and replace if
worn.
• Blow out or vacuum the inside of the feeder.

CALIBRATION SPECIFICATION

The voltmeter and flow meter are not calibrated and
are for reference purposes only.
Voltmeter Validation, Across the Arc Analog Meter
Models
Tools required:
• DC voltmeter reference standard
• Constant voltage DC welding power source with
adjustable no-load voltage (DC-400, V-350, CV-400
or equivalent).
To verify the analog voltmeter accuracy:
1. Turn power OFF.
2. 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 ter-
minal of the power source.
3. Connect the reference voltmeter between the brass
block of the LN-25™ PRO and the work lead.
4. Turn power ON.
MAINTENANCE
5. Energize the output circuit of the power source.
Adjust the power source output to 20±1 VDC as
measured on the reference meter.
6. Verify that LN-25™ PRO voltmeter reads between
19 and 21 volts.
If the voltmeter reading is out of range, check for loose
connections or replace the voltmeter. There is no cal-
ibration adjustment for the LN-25™ PRO voltmeter.
Flow Meter Validation
Tools required:
• Flow meter reference standard.
• Constant voltage DC welding power source (DC-
400, V-350, CV-400 or equivalent).
To verify the flow meter accuracy:
1. Turn power OFF.
2. 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 ter-
minal of the power source.
3. Connect a supply of CO2 to the wire feeder. Do not
exceed the maximum inlet pressure of the wire
feeder.
4. Disconnect the shielding gas hose that connects to
the gun bushing.
5. Connect the shielding gas hose to flow meter refer-
ence standard.
6. Orient the LN-25™ PRO in a vertical position.
7. Turn power ON.
8. Adjust the flow meter on the LN-25™ PRO to 40
scfh while pressing the GAS PURGE button.
9. Measure the gas flow with the calibrated flow meter
while pressing the GAS PURGE button.
10. The measured flow rate should be between 35
and 45 scfh.
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.
LN-25™ PRO
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