Lincoln LN-742H manual Troubleshooting

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E-4

TROUBLESHOOTING

E-4

 

 

 

 

Observe all Safety Guidelines detailed throughout this manual

 

 

 

 

PROBLEMS

(SYMPTOMS)

POSSIBLE

CAUSE

RECOMMENDED

COURSE OF ACTION

The LN-742 voltmeter does not

1.

Make sure the polarity switch on

function or read correctly when the

 

the Lincoln welding power

actual arc voltage is present. The

 

source is in the correct position

wire feeder is feeding wire correct-

 

for the welding process.

ly.

 

 

 

2.

Check or replace the control

 

 

cable. Check the continuity

 

 

(zero ohms) of leads #21 and

 

 

#67.

 

 

 

The LN-742 shuts down while

1.

Check for mechanical restric-

welding and the HXX symbol

 

tions in the wire feed path.

appears on the display.

 

 

 

 

 

The display and/or indicator lights

1.

Make sure the control cable is

do not change when the arrow or

 

connected to the welding power

select keys are pressed.

 

source correctly.

 

2.

Check the 42 VAC fuse or cir-

 

 

cuit breaker in the welding

 

 

power source.

 

 

 

The arrow keys do not change the

1.

If a remote control unit is con-

welding wire feed speed.

 

nected to the LN-742 the arrow

 

 

keys will not change welding

 

 

wire feed speed. Use the WFS

 

 

pot on the remote control unit or

 

 

disconnect the remote control

 

 

unit and use the arrow keys.

 

 

 

If all recommended possible areas of misadjustment have been checked and the problem persists, Contact your local Lincoln Authorized Field Service Facility.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

LN-742 & LN-742H

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Contents LN-742 & LN-742H Wire Feeders California Proposition 65 Warnings SafetyElectric Shock can kill Cylinder may explode if damaged Sûreté Pour Soudage a L’Arc Précautions DE SûretéThank You Table of Contents Technical Specifications LN-742 InstallationInput Cable Connections Mounting LocationFigure A.2 Strain Relief Clamp PIN Work Cable Table A.1 Work Lead SpecificationsGUN and Cable Assemblies GUN Cable ConnectionsFigure A.5 Water Connections Water Connections For Water Cooled GunsFigure A.6 Shielding GAS Hookup Gmaw Shielding GAS HookupOperation Safety PrecautionsOperating Instructions General DescriptionFigure B.1 Wire Feeder Controls Controls and SettingsDrive Roll Installation Acceleration SettingChanging Drive Rolls for TWO- Roll Wire Feeders English or Metric Speed Display UnitsGuide Tube Detail Changing Drive Rolls for FOUR- Roll Wire Feeders Figure B.3 Installing Drive Rolls on a FOUR-ROLL Feeder Figure B.4 Idle Roll Pressure Setting Idle Roll Pressure SettingFigure B.5a Threaded Locking Collar Wire LoadingInnershield Coils Electrode Feeding and Brake AdjustmentTo Mount a 50 or 60 LB Coil Adjustable Wire Reel BrakeFigure B.7 K1504-1 Coil Reel READI-REELS a K438 READI-REEL Adapter Must be UsedMaking a Weld Wire Reel ChangingTable C.1 LN-742 Accessories AccessoriesGeneral K163 Undercarriage K589-1 Remote Control KITK178-1 Mounting Platform Solenoid KITWelding Guns Power Input CablesSPINDLES, STANDS, Adapters Attaching the Wire Reel Stand Table C.2 Drive Roll KIT Numbers Drive Roll KitsRoutine Maintenance MaintenancePeriodic Maintenance HOW to USE Troubleshooting Guide TroubleshootingTroubleshooting Troubleshooting Troubleshooting Troubleshooting Troubleshooting Troubleshooting Diagrams LN-742 & LN-742H LN-742 & LN-742H LN-742 & LN-742H LN-742 & LN-742H Precaucion Warnung

LN-742, LN-742H specifications

The Lincoln LN-742H and LN-742 are renowned models in the realm of industrial welding equipment, specifically designed to cater to the needs of professional welders and fabricators. These machines stand out for their robustness, advanced technology, and ease of use, making them popular choices in various industries, including construction, automotive, and manufacturing.

One of the main features of the Lincoln LN-742H and LN-742 is their powerful Arc control capabilities. The machines are equipped with innovative technology that allows for consistent arc stability, which is crucial for achieving high-quality welds. The adjustable arc force enables users to tailor the welding parameters to their specific applications, facilitating optimal penetration and minimal spatter.

The LN-742H model is particularly notable for its enhanced portable design, making it easier for operators to transport the machine to different job sites. This portability does not compromise its power, as it offers a high output suitable for both thin and thicker materials. Moreover, the LN-742 model comes with a highly efficient cooling system that ensures the machine runs smoothly without overheating, even during prolonged use.

Both models feature an intuitive user interface that simplifies the welding process. The digital display offers real-time feedback on the welding parameters, allowing welders to make precise adjustments as needed. This feature is especially beneficial for beginners, who may be unfamiliar with optimal welding settings.

Another impressive characteristic of the Lincoln LN-742H and LN-742 machines is their versatility. They support various welding processes, including MIG, TIG, and stick welding, giving users the flexibility to choose the most suitable method for their projects. This adaptability makes these models an ideal solution for shops that handle a wide range of welding tasks.

Durability is a significant consideration in the design of the LN-742H and LN-742, as they are built with high-quality materials that withstand heavy use and challenging conditions. The rugged construction extends the lifespan of the machines, reducing the need for frequent repairs and servicing.

In summary, the Lincoln LN-742H and LN-742 welding machines exemplify advanced engineering and user-focused design. Their combination of powerful performance, portability, user-friendly features, and versatile applications makes them essential tools for professionals in the welding industry, paving the way for excellence in metal fabrication and repair.