Front Panel Controls and Connections | Lincoln Electric LF-72/74

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

B-4	OPERATION	B-4

FRONT PANEL CONTROLS AND CONNECTIONS

FIGURE B.1 CASE FRONT CONTROLS

6

1

2

7

3

4

5

8

ITEM	DESCRIPTION

1	Location for Optional Remote Voltage Control (See Accessory Section For Kit Number).

2	Location for Optional Burnback and Postflow Timer Kit (See Accessory Section For Kit Number).

3	Thermal LED, Motor Overload.

4	Cold Feed - Gas Purge Switch, press the switch up to feed wire with weld output off.
	Press the switch down for gas flow with weld output off.

5	2 step - Trigger Interlock switch.

6	Wire Feed Speed Knob.

7	Gun Receiver Bushing.

8	Trigger Connector 5-pin amphenol for connecting the MIG gun trigger. See Installation Section
	for detail.

LF-72/74

Image 30

Lincoln Electric LF-72/74 service manual Front Panel Controls and Connections, Figure B.1 Case Front Controls Description

Contents

LF-72/74 Safety Electric Shock can kill Welding Sparks can cause fire or explosion Iii Précautions DE Sûreté Sûreté Pour Soudage a L’Arc Master Table of Contents for ALL Sections Table of Contents Installation SectionSection A-1 Installation Amp Rating Duty Cycle Safety Precaution LocationMounting Boom Mount Bench MountSwivel Mount Suspended Weld Cable Sizes Coaxial Weld Cables Weld Cable Connection INSTALLATIONA-7 Analog Control CableControl Cable Connections Miller Power Source Lincoln Wire Feeder Analog Miller Control Cable Adapter K2335-1Pin Function Remote Sense Lead Specifications Wire Drive SystemsWelding GUN/WIRE Feeder Trigger Connector High Frequency Protection Welding GUNS, Torches and ACCES- Sories Magnum GUN and Cable Assemblies Procedure for Changing Drive and Idle Roll Sets Wire Drive ConfigurationRolls.FIGURE A.4 Pressure ARM Adjustment Gun Receiver For use With BushingSet the pressure arm as follows See Figure A.6 Wire Reel Loading Weld Wire Routing Figure A.9 Shielding GAS Connection Conduit Kits Installing ElectrodeTo install Lincoln conduit See Figure A.10b For Codes 11209, 11210, 11211 and above Aluminum Wire Preparations Figure A.12b INSTALLATIONA-18 Base Model Bench Model Standard Duty Bench Model Heavy Duty Typical System Configurations Cable LF-72/74 Operation Section Section B-1 Operation GAS Input Work Connection Common Welding Abbreviations Product DescriptionRecommended Processes Front Panel Controls and Connections Figure B.1 Case Front Controls Description Step Trigger Interlock Switch Burnback and Postflow Timer KITCold FEED/GAS Purge Switch Remote Voltage Control KIT GUN Receiver Bushing K1500-2 Wire Feed Speed KnobTrigger Connector 5-PIN Amphenol Trigger Interlock Accessories Section Section C-1 Accessories Optional Kits LF-72s Accessories Key LF-72/74 Maintenance Section Section D-1 Calibration Specification MaintenanceMaintenance Routine Maintenance Figure D.1 Figure D.3 Major Component Location Section AA-1 Section AA WFS Range Wire Sizes AA-2Model AA-3 Figure AA.1 AA-4 AA-5 AA-6 Coaxial Weld Cable INSTALLATIONAA-7 AA-7K1797-xx AA-8 Drive Roll Kits Steel or Cored Wires AA-9 AA-10 Figure AA.3 Lation or changing drive rolls and/or AA-11Changing the Gun Receiver Bushing Guides Assembly of Drive Rolls and Wire Guides AA-12 AA-13 Set the pressure arm as follows See Figure AA.8 AA-14 AA-15 Loading 16 to 44 lb .3 20kg Spools See figure AA.8 AA-16 Figure AA.11 AA-17 Figure AA.12a AA-18 Figure AA.12b AA-19 AA-20INSTALLATIONAA-20 Common Equipment SET-UPS Figure AA.15 High Volume Production AA-21 Figure AA.16 Portable Welding AA-22 Section BB-1 Section BB BB-2 Fcaw Innershield or Outershield Required Equipment BB-3 BB-4 Figure BB.1 Case Front Controls Description BB-5 K2426-1 and K2426-2 modelsK2426-3 model Switch BB-6 Section CC-1 CC-2 CC-3 CC-4 CC-5 CC-6 Section DD-1 Section DD When inching with gun trigger, electrode To verify the wire feed speedNal wiring WFS knob setting Could remain energized Several seconds MAINTENANCEDD-3 DD-3 Figure DD.3 Major Component Location DD-4 Theory of Operation Section Section E-1 Theory of Operation Return to Section Control Board LF-72/74 Troubleshooting & Repair Section Section F-1 Troubleshooting & Repair HOW to USE Troubleshooting Guide PC Board Troubleshooting Procedures Function Problems Function Problems Troubleshooting & Repair Drive Motor and Tach Feedback Test Test Description Test Procedure Troubleshooting and Repair GAS Solenoid Test Test Procedure Figure F.3 Leads 552, 552B Diode Bridge Test 552B + 552A Wire Speed Potentiometer Test Wire Speed Potentiometer Test 14F-14 PC Board Removal and Replacement Control PC Board Removal and Replacement Procedure Removal Procedure Replacement Procedure Troubleshooting and Repair Wire Drive Motor and Gear BOX Removal and Replacement Procedure Procedure Replacement Procedures SET UP Operation Verification LF-72/74 Electrical Diagrams Section Section G-1 Electrical Diagrams LF-72/74 Timer KIT Board Normal Speed Micro Internal panel Motor Connecter Summary High Torque Setting engages Schematic Common Analog Control PC Board G4559 Sheet Electrical Diagrams Electrical Diagrams PC Board Assembly Common Analog Control G4560-2E0