D-1

MAINTENANCE

D-1

 

 

 

SAFETY PRECAUTIONS

WARNING

ELECTRIC SHOCK can kill.

Only qualified personnel should per- form this maintenance.

Turn the input power OFF at the dis- connect switch or fuse box before working on this equipment.

Do not touch electrically hot parts.

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WARNING

To avoid receiving a high frequency shock, keep the TIG torch and cables in good condition.

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ROUTINE AND PERIODIC MAINTENANCE

1.Disconnect power supply lines to machine before performing periodic maintenance.

2.Periodically clean the inside of the machine with a low pressure air system. Be sure to clean the fol- lowing components thoroughly.

Main Transformer

Electrode/Gas Output Receptacle

Polarity Switch

Rectifier Assembly

Arc Starter/Spark Gap Assembly

PC Boards

Fan Blades

3.Inspect welder output and control cables for fraying, cuts, and bare spots.

4.Keep TIG torch and cables in good condition.

5.Clean air louvers to ensure proper air flow and cool- ing.

6.The fan motor has sealed ball bearings which require no maintenance.

7.SPARK GAP ADJUSTMENT

The spark gap .020(.5mm) is set at the factory to a gap of 0.015 inches (0.4mm) See Figure D.1. This setting is adequate for most applications. Where less high frequency is desired, the setting can be reduced to 0.015 inches (0.4mm).

WARNING

Use extreme caution when working with circuit of the high frequency. The high voltages developed can be lethal. Turn the input power off using the disconnect switch or fuse box before working inside machine. This is particularly important when working on the secondary circuit of the high voltage transformer (T3) because the output volt- age is dangerously high.

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Refer to figure D.1. Note in highly dirty environments where there is an abundance of conductive contami- nants, use a low pressure air stream or a firm piece of paper to clean the spark gap. Do not disturb the facto- ry setting.

To check the spark gap:

-Turn off input power as specified above.

-Remove the right side panel from the machine, the spark gap box is located on the lower right side.

-Check the spark gap with a feeler gauge.

If adjustment is needed:

-Adjust the gap by loosening the allen head screw in one of the aluminum blocks, near the front of the unit and tighten the screw in the new position.

If the gap is correct:

-Replace the wraparound.

8.Inspect gas hose and inlet fitting for cracks or leaks.

9.Replace any unreadable labels or decals.

10.Verify that the machine and welding circuit is prop- erly grounded.

FIGURE D.1 SPARK GAP

.020 Spark Gap

FAN MOTOR OR FAN BLADE REPLACEMENT When installing a new fan blade or fan motor be sure to maintain proper shaft spacing per Figure D.2 below.

.30

FIGURE D.2

PRECISION TIG 185

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Lincoln Electric TIG 185 manual Routine and Periodic Maintenance, Spark GAP Adjustment