Lincoln Electric LN-25 Service Manual Download Page 68

Page: 68 / 90

TROUBLESHOOTING AND REPAIR

F-31

LN-25

REPAIR PROCEDURE

1. Open the case door. Remove the wire

reel by removing the retaining collar.
See Figure F.1.

2. Remove the three screws holding the

control box cover in place and remove
the control box cover. See Figure F.1.

NOTE: If only the gas solenoid valve needs
replacing, it may not be necessary to
disconnect all of the wiring. Disconnect
wiring only as needed.

3. For codes 10148 and above, remove

plug J11 from the solenoid PC board.
Also, disconnect the two solenoid
leads from the gas solenoid valve,
and disconnect the purge switch
leads. See Figure F.17.

GAS SOLENOID VALVE AND/OR SOLENOID PC BOARD

REPLACEMENT

(continued)

FIGURE F.17 – GAS SOLENOID ASSEMBLY WIRING (CODES 10148 AND ABOVE).

SOLENOID

PC BOARD

GAS SOLENOID

VALVE

SOLENOID
LEADS

PLUG J11

PURGE SWITCH

LEADS

Summary of Contents for LN-25

Page 1: ...ne 1995 Safety Depends on You Lincoln arc welding and cutting equipment is designed and built with safety in mind However your overall safety can be increased by proper installation and thoughtful operation on your part DO NOT INSTALL OPERATE OR REPAIR THIS EQUIPMENT WITHOUT READ ING THIS MANUAL AND THE SAFETY PRECAUTIONS CON TAINED THROUGHOUT And most importantly think before you act and be caref...

Page 2: ...ng the electrode electrode reel welding head nozzle or semiautomatic welding gun are also electrically hot 1 d Always be sure the work cable makes a good electrical connection with the metal being welded The connection should be as close as possible to the area being welded 1 e Ground the work or metal to be welded to a good electrical earth ground 1 f Maintain the electrode holder work clamp weld...

Page 3: ... prevent the welding sparks from starting a fire Remember that welding sparks and hot materials from welding can easily go through small cracks and openings to adjacent areas Avoid welding near hydraulic lines Have a fire extinguisher readily available 4 b Where compressed gases are to be used at the job site special precautions should be used to prevent hazardous situations Refer to Safety in Wel...

Page 4: ...ventilated areas or vent the engine exhaust fumes outdoors ____________________________________________________ 7 c Do not add the fuel near an open flame welding arc or when the engine is run ning Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on contact with hot engine parts and igniting Do not spill fuel when filling tank If fuel is spilled wipe it...

Page 5: ...ppropriés et non inflammables 4 Des gouttes de laitier en fusion sont émises de l arc de soudage Se protéger avec des vêtements de protection libres de l huile tels que les gants en cuir chemise épaisse pan talons sans revers et chaussures montantes 5 Toujours porter des lunettes de sécurité dans la zone de soudage Utiliser des lunettes avec écrans lateraux dans les zones où l on pique le laitier ...

Page 6: ...Accessories Section C LN 25 Option Chart C 2 Optional Accessories C 3 Remote Output Control Options and Control Cable Assemblies C 4 Maintenance Section D Safety Precautions D 2 Routine Maintenance D 2 Circuit Protection and Automatic Shutdown D 2 Adjusting Speed Sensor Module D 2 Calibration of LN 25 Wire Speed Dial D 3 Theory of Operation Section E General Description E 2 Control Circuit Operati...

Page 7: ...NOTES vi ...

Page 8: ...tion A 3 DC 250 A 3 DC 400 and CV 400 A 3 DC 600 A 4 R3S 325 A 4 SAM 400 650 A 4 SA 200 250 or SAE 300 400 A 4 Invertec CV300 and other newer Lincoln Power Sources A 4 Gun Cable Connection to Feeder A 4 Weld Cable Connection A 5 Electrode Cable Connection A 5 Work Cable Connection A 5 Wire Feed Drive Roll and Guide Tube Kits A 5 Section A ...

Page 9: ...WIRE SPEED RANGE 50 700 Inches Per Minute IPM RECOMMENDED ELECTRODE WIRE SIZES Diameter Wire Type 023 to 1 16 SOLID STEEL WIRE 035 to 5 64 CORED WIRE 035 to 1 16 ALUMINUM WIRE PHYSICAL DIMENSIONS HEIGHT WIDTH DEPTH WEIGHT Handle Down w o Options 14 Inches 7 4 Inches 21 Inches 28 lbs 354 mm 187 mm 531 mm 13 kg RATED CURRENT WIRE FEED SPEED PHYSICAL DIMENSIONS WIRE DIAMETERS VOLTAGE TECHNICAL SPECIF...

Page 10: ...SAFETY PRECAUTIONS Unless an optional output control or contactor is used with the LN 25 the electrode circuit including welding wire wire drive and welding gun is electrically hot when the welding power source is on The gun trigger controls wire feed only Disconnect or shut off welding power source before making connections or installations to the LN 25 Welding gun should be stored in the insulat...

Page 11: ......

Page 12: ...ut and bolt provided Tape the bolted connection WORK CABLE CONNECTION Connect a work lead of sufficient size between the proper output stud on the power source and the work Be sure the connection to the work makes tight metal to metal electrical contact Poor work lead connections can result in poor welding performance WIRE FEED DRIVE ROLL AND GUIDE TUBE KITS Turn off power source before installing...

Page 13: ...NOTES A 6 A 6 LN 25 ...

Page 14: ...el Coils B 5 Mounting 10 to 30 lb Spools B 5 Mounting 13 or 14 lb Innershield Coils B 5 Loading Wire Drive B 6 Idle Roll Pressure Setting B 6 Presetting Wire Feed Speed B 7 Setting Constant Wire Feed Speed CV Mode B 7 Setting Arc Sensing Wire Feed Speed VV CC Mode B 7 Making a Weld B 8 Welding B 9 Procedure at End of Coil B 9 Open Arc Welding with a Constant Current Power Source B 9 Automatic Prot...

Page 15: ...pplications in virtually any environment RECOMMENDED PROCESSES AND EQUIPMENT When combined with the quality drive roll kits and accessories available for use with the LN 25 a versatile portable welding system can be provided to meet the specific needs of Innershield submerged arc or gas metal arc welding applications within the wire feed capabilities of the LN 25 The LN 25 provides constant wire f...

Page 16: ... provides constant wire feed speed mode for use with constant voltage CV welding power sources The backward ÒVV CC Ó position provides arc sensing wire feed speed mode for use with constant current formerly variable voltage welding power sources WIRE SPEED DIAL AND RANGE SWITCH The Wire Speed control dial on the front panel of the LN 25 has two calibrated dial ranges selected by the HI LO Dial Ran...

Page 17: ... or K624 1 42V Remote Output Control Option or Internal Contactor K443 1 is not used NOTE The clip lead also serves as a work sensing lead for the LN 25 Voltmeter If the clip lead is extended by the user beyond the standard 15 ft length the voltmeter reading will be lower than the actual arc volts due to the LN 25 motor control cur rent flowing through the resistance of the extended lead To minimi...

Page 18: ...14 LB INNERSHIELD COILS Requires Optional K435 Spindle Adapter for 14 lb Coils a Remove the locking collar and the Readi Reel adapter shipped on the 2 diameter spindle adapter is not required b Mount K435 Spindle Adapter and Innershield coil per the Instructions S18256 included with the K435 LOADING ELECTRODE MOUNTING 22 TO 30 LB READI REEL COILS The LN 25 is factory equipped with a K363 P Readi R...

Page 19: ...until the reel turns freely but with little or no overrun when wire feeding is stopped Do not overtighten Keep gun in LN 25 gun holder when not feeding wire to prevent accidental arcing IDLE ROLL PRESSURE SETTING The idle roll pressure is set at the factory backed out two turns from full pressure This is an approximate setting For small wire sizes and aluminum wire the optimum idle roll pressure v...

Page 20: ...wer source welding performance is im proved using arc sensing wire feed speed CC VV mode In this wire feed mode the wire speed increases if arc voltage increases and decreases if arc voltage decreases but remains constant at any specific voltage level The LN 25 permits accurate CC mode presetting of the desired wire feed speed for the desired arc voltage to be used by setting the Wire Speed dial i...

Page 21: ... 600 700 656 618 620 678 638 640 700 658 660 680 680 700 700 MAKING A WELD SETUP a Connect work cable to metal to be welded W ork cable must make good electrical contact to the work The work must also be grounded as stated in ÒArc Welding Safety Precautions Ó b Check that the LN 25 is properly connected to the power source for the polarity and process to be used and appropriate power source settin...

Page 22: ...commercial quality mild steel welding applications PROCEDURE AT END OF COIL When the wire on the reel is used up the following procedure is to be followed for removing the old wire from the gun cable and loading a new reel a Shut off power source if a Remote Output Control Option or internal contactor is not used b Cut the end of the electrode off at the gun end Do not break it off by hand since t...

Page 23: ...lectrode shorts to the work the arc voltage will essentially drop to zero and the short circuit current supplied by the CC power source may not provide enough power to re establish the arc especially with steeper slope machines Under this condition the LN 25 feeder will stop as if the trigger was released and not restart until the short has been opened Arc shorting is more difficult to avoid when ...

Page 24: ...emote Output Control Options and Control Cable Assemblies C 4 K431 1 Remote Output Control Kit C 4 K433 Power Source Remote Box C 4 K432 Remote Control Cable Assembly C 4 K439 Remote Extension Cable Assembly C 5 K624 1 42V Remote Output Control Module C 5 K625 K626 K627 Remote Control Cable Assembly C 5 K444 K444 1 or K444 2 Remote V oltage Control Kit C 5 K557 1 Rear Handle Kit C 5 Section C Sect...

Page 25: ...Y NOTE This wire feeder provides ÒCOLDÓ electrode when gun trigger is released if equipped with K431 1 or K624 1 remote output control system or K443 1 internal contactor kit This feature and the use of a DC Constant V oltage welder provide an added margin of safety when welding must be performed under electrically hazardous conditions such as Damp locations While wearing wet clothing On metal str...

Page 26: ... Safety in Welding and Cutting published by the American Welding Society CYLINDER may explode if damaged Keep cylinder upright and chained to support Keep cylinder away from areas where it may be dam aged Never lift welder with cylinder attached Never allow welding electrode to touch cylinder Keep cylinder away trom welding or other live electrical circuits See GMA Gun Cable Gas Connection Install...

Page 27: ...te PC board and control cable receptacle which mount and connect inside the LN 25 control box per the Installation Instructions M17584 included with the kit NOTE If the K431 1 Remote Output Control Kit is installed but the LN 25 is to be used without the K432 Remote Control Cable Assembly then the Remote Board harness plug must be removed from the 12 pin receptacle on the Control Board and the jum...

Page 28: ...ASSEMBLY Requires K624 1 Remote Output Control Module installed in LN 25 The K625 K626 K627 control cable assemblies include an electrode cable and a 8 conductor control cable The cable assembly end with the socket pin connector connects to the LN 25 per the Instructions M17253 included with the K624 1 Kit The cable assembly end with the male pin connector connects to the power source per the Inst...

Page 29: ...OTE Connector part with 749 747 diameter should be made from brass if it is to be part of the welding current carrying circuit SWITCH REQUIREMENTS 1 Ú 2 Amp AC 24 Volts Ð Inductive 1 Ú 2 Amp DC 24 Volts Ð Inductive CONNECTOR MUST BE INSULATED IN THIS AREA STYLE A STYLE B LN 25 Connector for 1 16 062 through 5 64 Wire LN 25 Cable Connector for 023 through 052 Wire For all other dimensions see above...

Page 30: ...e Rolls and Guide Tubes D 2 Wire Reel Spindle D 2 Control Box D 2 Wire Drive Motor and Gearbox D 2 Gun and Cable Maintenance D 2 Circuit Protection and Automatic Shutdown D 2 Control PC Board Fuse D 2 Automatic Protection Shutdown D 2 Adjusting Speed Sensor Module D 2 Calibration of LN 25 Wire Speed Dial D 3 Section D ...

Page 31: ...it as necessary Do not use a solvent for cleaning the idle roll because it may wash the lu bricant 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 The drive rolls for 045 and 052 cored electrode and 1 16 068 and 5 64 electrode have a...

Page 32: ...d the dial is recalibrated as follows NOTE Knob set screw does not seat on shaft flat 1 Be sure the Wire Speed potentiometer mounting nut is securely tightened then rotate the potentiometer shaft so its flat faces about to the 100 mark on the LO range calibrated dial 2 Set DIAL RANGE switch to LO and WIRE FEED MODE switch to CV position 3 Press gun trigger to feed wire and measure the wire feed sp...

Page 33: ...NOTES D 4 D 4 LN 25 ...

Page 34: ... Theory of Operation Section E General Description E 2 Control Circuit Operation E 2 Input Power Circuit E 2 Welding Current Circuit E 2 Feedback and Control Circuits E 3 Trigger Circuit E 3 Optional Circuits E 4 Contactor E 4 Gas Solenoid E 4 Section E ...

Page 35: ...UT POWER CIRCUIT CONTROL CIRCUIT OPERATION INPUT POWER CIRCUIT The DC arc voltage from the power source is applied to the LN 25 through the electrode cable and work sensing lead This DC voltage is connected to the polarity switch which allows the wire feeder to be used in either electrode positive or electrode negative polarity The voltage is then coupled to the voltmeter and control board A wire ...

Page 36: ...rrent process To accomplish this the control board monitors the command voltage the feedback signal from the hall ef fect module and the arc voltage These three factors are monitored and compared and then the appropriate armature voltage is applied to the wire feed motor TRIGGER CIRCUIT When the gun trigger is closed the control board is ÒsignaledÓ to apply armature voltage to the drive motor and ...

Page 37: ...ode wire can be fed through the gun with the gun tip electrically ÒCOLDÓ See Figure E 3 GAS SOLENOID The gas solenoid feature permits the LN 25 to be used for gas metal arc welding GMA W processes When the gun trigger circuit is activated the control board signals the solenoid PC board to activate the gas solenoid which allows shielding gas to flow through the gun to the arc FIGURE E 3 Ð OPTIONAL ...

Page 38: ...alve and Solenoid PC Board Test F 7 Hall Effect Module Test F 12 Wire Drive Motor Test F 15 Contactor Test F 17 Component Replacement Procedures F 20 Contactor PC Board Replacement F 20 Control PC Board Replacement F 24 Contactor Replacement F 27 Gas Solenoid Valve and or Solenoid PC Board Replacement F 30 Drive Motor And Gearbox Replacement and Access to Hall Effect Module F 34 Retest After Repai...

Page 39: ...describes the symptom that the machine is exhibiting Symptoms are grouped according to feeding problems and function problems Step 2 PERFORM EXTERNAL TESTS The second column labeled POSSIBLE AREAS OF MISADJUSTMENT S lists the obvious external possibilities that may contribute to the machine symptom Perform these tests checks in the order listed In general these tests can be conducted without remov...

Page 40: ...t set the PC board on or near paper plastic or cloth which could have a static charge If the PC board can t be installed immediately put it back in the static shielding bag If the PC board uses protective shorting jumpers don t remove them until installation is complete If you return a PC board to The Lincoln Electric Company for credit it must be in the static shielding bag This will prevent furt...

Page 41: ... isolated and or eliminated from the troubleshooting procedure F 4 TROUBLESHOOTING AND REPAIR F 4 LN 25 PROBLEMS SYMPTOMS POSSIBLE AREAS OF MISADJUSTMENT S RECOMMENDED COURSE OF ACTION When gun trigger is pulled there is no wire feed 1 Check to see if the drive rolls are turning when the gun trigger is pulled If the drive rolls are turning then check for a mechanical restriction in the wire feed p...

Page 42: ... board then the control board may be faulty Replace 3 If more than 5 amps is indicated then the motor is drawing too much armature current Check and or replace the motor brushes 4 The motor or gearbox may be faulty Replace 1 If the LN 25 is connected to a constant current power source the arc voltage may be dipping below the 15 VDC threshold that is essential for proper LN 25 operation 2 Try conne...

Page 43: ...or board or remote control board if used may be faulty 4 The control board may be faulty Replace F 6 TROUBLESHOOTING AND REPAIR F 6 LN 25 PROBLEMS SYMPTOMS POSSIBLE AREAS OF MISADJUSTMENT S RECOMMENDED COURSE OF ACTION The wire feed motor runs very fast and there is no control 1 Make sure the mode switch S3 is in the CV mode 2 Make sure the wire speed control and the wire speed range switch S2 are...

Page 44: ...ctory trained personnel Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty For your safety and to avoid electrical shock please observe all safety notes and precautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to perform the test repair...

Page 45: ...s onta l line for DES IRED IN M IN Sele ct diag onal line for ARC VOL TS USE D Dete rmin e verti cal line whe re lines cros s This verti cal line is CC WIR E SPE ED SET TING on fron t dial Set swit ch to CC and set prop er ARC VOL TS while weld i See exam ple for 375 IN M IN at 29 VOL TS WIR E SPE ED CAL IBRA TED IN IN M IN WIR E SPE ED CAL IBRA TED PER GRA PH VAR IABL E WIR E SPE ED FOR CC POW ER...

Page 46: ...d then apply 12 VDC to the gas solenoid 5 If the solenoid activates and allows gas flow then the solenoid valve is good NOTE There should not be any gas flow until the solenoid is activated 6 If the solenoid does not activate and allow gas flow then the solenoid is faulty Replace 7 The normal solenoid resistance is approximately 20 to 27 ohms GAS SOLENOID VALVE AND SOLENOID PC BOARD TEST continued...

Page 47: ... lead Make sure the polarity switch is set to match the polarity of the electrode cable For example if the electrode cable is positive and the work sensing lead is negative set the polarity switch to positive See Figure F 3 GAS SOLENOID VALVE AND SOLENOID PC BOARD TEST continued FIGURE F 3 Ð APPLIED VOL TAGE POLARITY ELECTRODE CABLE POLARITY SWITCH WORK SENSING LEAD ...

Page 48: ...olenoid valve is functional the solenoid PC board may be faulty 6 If the above voltage checks are not correct the control board contactor board if used remote control board if used and or wiring harness may be faulty Refer to the wiring diagrams in the Electrical Diagrams Section The appropriate jumper plugs may be used to isolate and check suspect contactor or remote control boards GAS SOLENOID V...

Page 49: ...Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty For your safety and to avoid electrical shock please observe all safety notes and precautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to perform the test repairs safely contact the Lin...

Page 50: ...ocate the three hall effect leads 500 512 and 555 incorporated in plug J4 on the control board for codes 9812 and below the leads connect directly to the control board Do not remove the leads from the control board See Figure F 6 and Figure F 7 HALL EFFECT MODULE TEST continued FIGURE F 6 CONTROL PC BOARD CODES 10148 AND ABOVE FIGURE F 7 CONTROL PC BOARD CODES 9812 AND BELOW J4 J3 J1 J2 541 539 55...

Page 51: ...ulty 6 Activate the LN 25 trigger circuit make sure the drive motor is running and check for the presence of approximately 6 0 VDC from lead 555 to lead 500 The value of 6 0 VDC represents the correct feedback voltage from the hall ef fect device to the control board 7 If the above voltage reading is not correct the hall ef fect device may need to be adjusted see the Maintenance Section or replace...

Page 52: ... Unauthorized repairs performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty For your safety and to avoid electrical shock please observe all safety notes and precautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to perform the test repairs safely contact the Li...

Page 53: ...motor leads 539 white and 541 black from the control PC board See Figure F 7 4 Apply a variable DC voltage to the drive motor from lead 541 black to lead 539 white 5 When the supply voltage is varied from 2 to 23 VDC the drive motor speed RPM should vary accordingly If the motor does not run or vary in speed the motor gearbox or motor brushes may be faulty Check or replace 6 Check the resistance b...

Page 54: ...s performed on this equipment may result in danger to the technician or machine operator and will invalidate your factory warranty For your safety and to avoid electrical shock please observe all safety notes and precautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to perform the test repairs safely contact the Lincoln Electric servi...

Page 55: ...holding the control box cover in place and remove the control box cover See Figure F 1 3 Separate the two in line connectors located behind the reel stand assembly See Figure F 9 For codes 9812 and below remove the two contactor coil leads from the contactor PC board See Figure F 10 CONTACTOR TEST continued FIGURE F 9 Ð CONT ACTOR LEAD IN LINE CONNECTORS IN LINE CONNECTORS ...

Page 56: ...ctor activated The resistance should be very low 0 to 1 ohm 7 If the resistance is high or open between the two large terminal studs when the contactor is activated the contactor is faulty Replace 8 If the contactor activates and the resistance between the terminals is low when the 12 VDC is applied the contactor is good NOTE When the contactor is not activated the resistance between the terminals...

Page 57: ...S REQUIRED Phillips head screwdriver ELECTRIC SHOCK can kill Observe all safety precautions detailed throughout this manual Turn of f input power to the wire feeder Only qualified technicians should perform installations maintenance and troubleshooting work on the machine WARNING ...

Page 58: ...oor Remove the wire reel by removing the retaining collar See Figure F 1 3 Remove the three screws holding the control box cover in place and remove the control box cover See Figure F 1 4 For codes 10148 and above remove plug J9 and plug J7 from the contactor PC board See Figure F 11 CONTACTOR PC BOARD REPLACEMENT continued FIGURE F 11 Ð CONT ACTOR PC BOARD CODES 10148 AND ABOVE J6 J7 J9 S21415 S2...

Page 59: ...or coil leads and plug J7 from the contactor PC board See Figure F 10 Also for codes 9812 and below remove plug J3 from the control PC board See Figure F 12 CONTACTOR PC BOARD REPLACEMENT continued FIGURE F 12 Ð CONTROL PC BOARD PLUG LOCA TIONS CODES 9812 AND BELOW J1 J2 J3 J4 G1757 G1757 ...

Page 60: ...7 onto the contactor PC board See Figure F 11 9 For codes 9812 and below install the contactor coil leads and plug J7 onto the contactor PC board See Figure F 10 Also for codes 9812 and below install plug J3 onto the control PC board See Figure F 12 10 Install the control box cover and secure by installing the three screws See Figure F 1 11 Install the wire reel and retaining collar and close the ...

Page 61: ... REQUIRED Phillips head screwdriver ELECTRIC SHOCK can kill Observe all safety precautions detailed throughout this manual Turn of f input power to the wire feeder Only qualified technicians should perform installations maintenance and troubleshooting work on the machine WARNING ...

Page 62: ...A 5 For codes 9812 and below remove the four plugs J1 J2 J3 and J4 Also tag and remove the five individual leads three hall ef fect leads 500 512 and 555 and two drive motor leads 539 and 541 connected to the control PC board See Figure F 14B 6 On older codes the control PC board is larger If necessary perform the Contactor PC Board Replacement procedure to remove the contactor PC board If install...

Page 63: ... PC board See Figure F 14A 10 For codes 9812 and below install the four Molex type plugs J1 J2 J3 and J4 Also connect the five individual leads to the control PC board If necessary refer to the wiring diagrams in the Electrical Diagrams Section See Figure F 7 11 Install the control box cover and secure by installing the three screws See Figure F 1 12 Install the wire reel and retaining collar and ...

Page 64: ...s head screwdriver 5 16 nutdriver 11 16 wrench ELECTRIC SHOCK can kill Observe all safety precautions detailed throughout this manual Turn off input power to the wire feeder Only qualified technicians should perform installations maintenance and troubleshooting work on the machine WARNING ...

Page 65: ...x cover See Figure F 1 3 Remove the baf fle from in front of the contactor See Figure F 16 4 Remove the 5 16 screw holding the contactor in place 5 Remove the two 1 1 16 brass nuts holding voltage sensing lead 67 and the welding cables to the contactor CONTACTOR REPLACEMENT continued FIGURE F 16 CONTACTOR REPLACEMENT VOLTAGE SENSING LEAD 67 WELDING CABLES CONTACTOR BAFFLE 5 16 SCREW REEL STAND ASS...

Page 66: ...behind the reel stand assembly See Figure F 16 For codes 9812 and below install the contactor coil leads onto the contactor PC board See Figure F 10 11 Install the welding cables and voltage sensing lead 67 to the contactor and secure with the two 1 1 16 brass nuts See Figure F 16 NOTE Be sure brass nuts are tight 11 ft lb torque is recommended 12 Install the 5 16 screw to secure the contactor in ...

Page 67: ...OOLS REQUIRED Phillips head screwdriver 3 4 wrench Pliers ELECTRIC SHOCK can kill Observe all safety precautions detailed throughout this manual Turn of f input power to the wire feeder Only qualified technicians should perform installations maintenance and troubleshooting work on the machine WARNING ...

Page 68: ...eds replacing it may not be necessary to disconnect all of the wiring Disconnect wiring only as needed 3 For codes 10148 and above remove plug J11 from the solenoid PC board Also disconnect the two solenoid leads from the gas solenoid valve and disconnect the purge switch leads See Figure F 17 GAS SOLENOID VALVE AND OR SOLENOID PC BOARD REPLACEMENT continued FIGURE F 17 GAS SOLENOID ASSEMBLY WIRIN...

Page 69: ...he solenoid PC board to the assembly bracket Remove the solenoid PC board 9 Install the replacement solenoid PC board onto the assembly bracket and secure with the two mounting screws 10 Install the replacement gas solenoid valve onto the assembly bracket and secure with the two mounting screws 11 Install the gas solenoid assembly bracket into the case and secure with the two mounting screws 12 In...

Page 70: ...screws See Figure F 1 16 Install the wire reel and retaining collar and close the case door See Figure F 1 TROUBLESHOOTING AND REPAIR F 33 F 33 LN 25 GAS SOLENOID VALVE AND OR SOLENOID PC BOARD REPLACEMENT continued FIGURE F 19 GAS SOLENOID VALVE AND SOLENOID PC BOARD REPLACEMENT BRASS FITTING GAS SOLENOID ASSEMBLY MOUNTING SCREW GAS SOLENOID VALVE MOUNTING SCREW SOLENOID PC BOARD PC BOARD MOUNTIN...

Page 71: ...D Phillips head screwdriver 3 4 wrench 5 8 wrench 7 16 wrench Slot head screwdriver ELECTRIC SHOCK can kill Observe all safety precautions detailed throughout this manual Turn of f input power to the wire feeder Only qualified technicians should perform installations maintenance and troubleshooting work on the machine WARNING ...

Page 72: ...the control box cover See Figure F 1 4 For codes 10148 and above separate both in line connectors behind the mylar insulation See Figure F 20 For codes 9812 and below remove the two armature leads 539 and 541 and the three hall ef fect module leads 500 512 and 555 from the control board See Figure F 7 DRIVE MOTOR AND GEARBOX REPLACEMENT AND ACCESS TO HALL EFFECT MODULE continued FIGURE F 20 Ð WIRE...

Page 73: ...the three screws flat washers and lockwashers Install the rear end plate lockwashers and screws 10 Position the wire drive assembly inside the case and secure to the bottom of the case with the four bolts Secure the electrode cable to the conductor block with the 1 2 bolt See Figure F 20 11 For codes 10148 and above connect both in line connectors and position them behind the mylar insulation See ...

Page 74: ... 25 DRIVE MOTOR AND GEARBOX REPLACEMENT AND ACCESS TO HALL EFFECT MODULE continued FIGURE F 21 Ð DRIVE MOTOR REPLACEMENT DRIVE MOTOR GEARBOX REAR END PLATE LOCKWASHER END PLATE MOUNTING SCREW FLAT WASHER LOCKWASHER DRIVE MOTOR MOUNTING SCREW ...

Page 75: ...ristics must be replaced or if any electrical components are repaired or replaced the machine must be retested and meet the following standards Wire Feed Speed 50 through 700 Inches Per Minute Voltmeter Must be operative from 0 through 40 VDC Gas Solenoid optional Must operate when gun trigger is activated Contactor optional Must operate when gun trigger is activated ...

Page 76: ...agrams Codes 10148 and Above G 3 Codes 9812 and Below G 4 Operating Schematics Codes 10148 and Above G 5 Codes 9812 and Below G 6 Control PC Board Layout Codes 10148 and Above G 7 Codes 9812 and Below G 9 Contactor PC Board Layout Codes 10148 and Above G 11 Codes 9812 and Below G 13 Section G ...

Page 77: ...NOTES G 2 G 2 LN 25 ...

Page 78: ...GHER PART NO CONTROL PC BOARD WHEN A CONTACTOR IS NOT USED THE 67 LEAD TO THE POLARITY SWITCH COMES FROM THE CONDUCTOR BLOCK AND THE INPUT CABLE CONNECTS DIRECTLY TO THE CONDUCTOR BLOCK N H TOGGLE SWITCH USED ON EARLIER UNITS N G JUMPER PLUG MUST BE INSTALLED UNLESS OPTIONAL TIMER IS USED N A N B WHEN A CONTACTOR IS NOT USED THE JUMPER PLUG MUST BE INSTALLED UNLESS OPTIONAL REMOTE KIT IS BEING USE...

Page 79: ... SWITCH S3 WIRE FEED MODE SWITCH S4 COLD INCH SWITCH INPUT CABLE NOTES N A WHEN A CONTACTOR IS NOT USED THE JUMPER PLUG MUST BE INSTALLED UNLESS OPTIONAL REMOTE KIT IS BEING USED N B CONNECTIONS AS VIEWED FROM BACK OF RHEOSTAT AND SWITCHES N D ITEM FACTORY INSTALLED ON SOME MODELS AND OPTIONAL EQUIPMENT ON SOME MODELS N E CONTACTOR CAN BE INSTALLED IN UNITS WITH A G1757 3 OR HIGHER PART NO CONTROL...

Page 80: ...ES LM224 X6 4 11 40V 600mA Q13 100K R61 1 00K R83 X8 13 11 10 18 15V C25 1 00K R100 4N35 OCI1 1 2 22 1K R82 1 00K R81 22 1K R79 D29 D28 512 NUMBER 22 1K R80 X8 1 7 6 C39 LM2901 X8 3 12 C40 MC14013B X10 7 14 1 0 35V C29 100V 100p C48 C38 LM224 X5 4 11 10K R60 22 1K R90 200mA 7 5 9 0 V Q15 4 7 35V C45 2 43K R88 1W 12V DZ1 40V 600mA Q14 C47 D7 20 50V C10 5W 4700 R14 X5 3 1 2 4 7 35V C27 26 7K R59 40V...

Page 81: ...K 2 8K 2 1 2 3 X5 1 R56 26 7K SET SPEED SCALER BUFFER 22 1K R71 R74 R77 R73 R76 R78 D23 15 0K 15 0K X7 5 4 2 10K D25 33 2K Q12 200mA 30V 512 R79 22 1K TRIGGER SENSING D24 C32 1 0 35V R75 26 7K R72 3 3K 5W D29 D22 X7 X7 14 13 9 8 11 10 15 0K R70 R69 OVER VOLTAGE SHUT DOWN 26 7K D21 D20 C31 1 8 20V D19 R68 22 1K R67 22 1K 512 C30 1 8 20V 10K D13 500p R63 R62 R65 R64 667 150K 509 13 7K R66 150K 7 6 X...

Page 82: ... from Lincoln Electric This information is provided for reference only Lincoln Electric dis courages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician Improper PC board repairs could result in damage to the machine CONTROL PC BOARD LAYOUT CODES 10148 AND ABOVE CONTROL X X X X X X X X X X X X X X X...

Page 83: ...INI PCB 16 PIN C1 CAPACITOR CD 05 600V 80 20 C26 CAPACITOR PEF 0 1 400V 10 R47 RESISTOR WW 7W 0 100 1 DZ2 DZ3 DZ4 ZENER DIODE 1W 16V 5 1N4745A DZ1 ZENER DIODE 1W 12V 5 1N4742A Q3 Q4 Q5 Q6 Q10 Q12 Q13 Q14 TRANSISTOR N T226 0 5A 40V 2N4401 Q7 Q11 TRANSISTOR P T226 0 5A 40V 2N4403 D12 DIODE AXLDS 3A 600V 1N5406 TP1 MOV 150VRMS 45J 14MM CRIMPED R13 R14 RESISTOR WW 5W 4 7K 5 SQ R38 RESISTOR WW 5W 68 5 ...

Page 84: ...rom Lincoln Electric This information is provided for reference only Lincoln Electric dis courages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician Improper PC board repairs could result in damage to the machine CONTROL PC BOARD LAYOUT CODES 9812 AND BELOW LN 25 CONTROL X X X X X X X X X X X X X ...

Page 85: ...ACITOR PEF 0 1 400V 10 R47 RESISTOR WW 7W 0 100 1 DZ2 DZ3 DZ4 ZENER DIODE 1W 16V 5 1N4745A DZ1 ZENER DIODE 1W 12V 5 1N4742A Q7 Q11 TRANSISTOR P T226 0 2A 30V 2N4125 D12 DIODE AXLDS 3A 600V 1N5406 R1 RESISTOR CC 2W 10 10 B539 B541 CONNECTOR TAB QC VERTICAL 1 4 B500 B512 B555 CONNECTOR TAB QC VERTICAL 3 16 J3 PC BD PLUG ASBLY TP1 MOV 150VRMS 45J 14MM CRIMPED R13 R14 RESISTOR WW 5W 4 7K 5 SQ R38 RESI...

Page 86: ...mponents are not available from Lincoln Electric This information is provided for reference only Lincoln Electric dis courages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician Improper PC board repairs could result in damage to the machine CONTACTOR PC BOARD LAYOUT CODES 10148 AND ABOVE X X X X X...

Page 87: ...50V 10 R19 RESISTOR WW 1W 1 0 1 R30 RESISTOR WW 7W 2 7 5 DZ1 DZ2 ZENER DIODE 1W 16V 5 1N4745A Q1 TRANSISTOR N T220 5A 450V MJE16002 Q8 TRANSISTOR NMF T247 20A 500V RFP460 D1 DIODE AXLDS 3A 600V 1N5406 R31 R32 RESISTOR WW 5W 2 7 5 C1 CAPACITOR ALEL 5600 35V 30 10 R3 R11 R29 RESISTOR MF 1 4W 100 1 R16 RESISTOR MF 1 4W 10 0K 1 R14 RESISTOR MF 1 4W 100K 1 R4 R24 RESISTOR MF 1 4W 15 0K 1 R20 RESISTOR M...

Page 88: ...ents are not available from Lincoln Electric This information is provided for reference only Lincoln Electric dis courages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician Improper PC board repairs could result in damage to the machine CONTACTOR PC BOARD LAYOUT CODES 9812 AND BELOW X X X X X X X ...

Page 89: ...10 X1 X2 IC VOLT REF ADJ PRECISION 431I C10 CAPACITOR CEMO 0 1 50V 10 R19 RESISTOR WW 1W 1 0 1 R30 RESISTOR WW 7W 2 7 5 DZ1 DZ2 ZENER DIODE 1W 16V 5 1N4745A Q1 TRANSISTOR N T220 5A 450V MJE16002 Q8 TRANSISTOR NMF T247 20A 500V RFP460 D1 DIODE AXLDS 3A 600V 1N5406 R31 R32 RESISTOR WW 5W 2 7 5 C1 CAPACITOR ALEL 5600 35V 30 10 R3 R11 R29 RESISTOR MF 1 4W 100 1 R16 RESISTOR MF 1 4W 10 0K 1 R14 RESISTO...

Page 90: ...NOTES G 15 G 15 LN 25 ...

Search results

Summary of Contents for LN-25

Reviews:

Related manuals for LN-25

Brands by name

Popular brands

Lincoln Electric LN-25, Service Manual

Search results

Summary of Contents for LN-25

Reviews:

Related manuals for LN-25

Brands by name

Popular brands