Lincoln Electric IM620-B manual Routine Maintenance, Circuit Protection and Automatic Shutdown

D-1 MAINTENANCE D-1

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.

CONTROL BOX

Every six months open and inspect the control sec- tion. The accumulated dirt should be gently blown off all of the electrical components. Be sure the air that is being used is dry. Check that lead plugs are secure in their receptacles.

WIRE DRIVE MOTOR AND GEAR BOX

Every year examine the gear box. Paint the gear teeth with molydisulfide filled grease. Lincoln specification E2322. Do not use a graphite grease.

Check the motor brushes. Replace if they are worn down to 1⁄4’’ or less. When ordering feed motor brushes, give all information from the motor nameplate.

GUN AND CABLE MAINTENANCE

See IM manual provided with the gun and cable assembly.

ROUTINE MAINTENANCE

DRIVE ROLLS AND GUIDE TUBES

After feeding every coil of wire, inspect the drive roll section. Clean it as necessary. Do not use a solvent for cleaning the idle roll because it may wash the lubricant out of the bearing. The drive roll, idle roll and guide tubes are stamped with the wire sizes they will feed. If a wire size other than that stamped on the rolls is to be used, the rolls and guide tubes must be changed.

CIRCUIT PROTECTION AND AUTOMATIC SHUTDOWN

CONTROL PC BOARD

The Control P.C. Board has electronic protection for trigger circuit faults to the electrode circuit.

AUTOMATIC PROTECTION SHUTDOWN

(See Automatic Protection Shutdown Section.)

The drive rolls for .035 through .052 cored electrode and 1⁄16 through 5⁄64 electrode have a double set of teeth so they can be reversed for additional life. Drive rolls for .023 through .052 solid electrode and aluminum sizes have no teeth but use two grooves so they also can be reversed for additional life.

See Wire Feed Drive Roll and Guide Tube Kits Sec- tion for roll changing instructions.

WIRE REEL SPINDLE

No routine maintenance required. Do not lubri- cate spindle.

LN-25

ADJUSTING SPEED

SENSOR MODULE

The LN-25 Speed Sensor Module is a three lead Hall Effect switch device encased in an externally threaded housing which is screwed into a mounting plate on the motor side of the wire drive gearbox.

Proper positioning of this module is critical to proper operation of the LN-25 wire feed speed control. If the device is not screwed in far enough, the LN-25 motor speed could be unstable or run at full speed with no control. If screwed in too far, it will rub a moving part inside the gearbox.

The module is properly mounted to the gearbox as shipped from the factory. If the device is ever removed or replaced, proper mounting technique is as follows: