Page 2 - SAFETY; WARNING; CALIFORNIA PROPOSITION 65 WARNINGS
FOR ENGINEpowered equipment. 1.a. Turn the engine off before troubleshooting and maintenance work unless the maintenance work requires it to be running. ____________________________________________________ 1.b. Operate engines in open, well-ventilated areas or vent the engine exhaust fumesoutdoors. ...
Page 3 - ii; ELECTRIC SHOCK can kill.
ii SAFETY ii ARC RAYS can burn. 4.a. Use a shield with the proper filter and cover plates to protect your eyes from sparks andthe rays of the arc when welding or observingopen arc welding. Headshield and filter lensshould conform to ANSI Z87. I standards. 4.b. Use suitable clothing made from durable...
Page 4 - iii
FOR ELECTRICALLYpowered equipment. 8.a. Turn off input power using the disconnect switch at the fuse box before working onthe equipment. 8.b. Install equipment in accordance with the U.S. National Electrical Code, all local codes and the manufacturerʼsrecommendations. 8.c. Ground the equipment in ac...
Page 5 - iv; PRÉCAUTIONS DE SÛRETÉ
iv SAFETY iv PRÉCAUTIONS DE SÛRETÉ Pour votre propre protection lire et observer toutes les instructions et les précautions de sûreté specifiques qui parraissent dans ce manuel aussi bien que les précautions de sûreté générales suiv- antes: Sûreté Pour Soudage A LʼArc 1. Protegez-vous contre la seco...
Page 6 - Thank You; Please Examine Carton and Equipment For Damage Immediately
v v Thank You for selecting a QUALITY product by Lincoln Electric. We want you to take pride in operating this Lincoln Electric Company product •••as much pride as we have in bringing this product to you! Read this Operators Manual completely before attempting to use this equipment. Save this manual...
Page 7 - TABLE OF CONTENTS
TABLE OF CONTENTS Page . Installation ..........................................................................................................Section A Technical Specifications ........................................................................................A-1,A-2Safety Precautions .. .......
Page 8 - INSTALLATION; RATED INPUT - SINGLE PHASE ONLY; Duty Cycle-Applications
A-1 INSTALLATION PRECISION TIG 375 A-1 TECHNICAL SPECIFICATIONS-PRECISION TIG 375 (K2624-1 Domestic Package*-60Hz) (K2622-1 Domestic,K2622-2 Canadian-60Hz) Voltage + 10% 208/230/460 230/460/575 Max. Amps With Power Factor Capacitor 112/102/51 139/126/63 102/92/46 128/116/58 80/72/36 104/92/47 68/62/...
Page 9 - ADDITIONAL OUTPUT CAPACITY; Amps DC; PHYSICAL DIMENSIONS; TEMPERATURE RANGES
K2622-1, -2 K2624-1 A-2 INSTALLATION PRECISION TIG 375 A-2 ADDITIONAL OUTPUT CAPACITY Output Current Range 2Amps DC to 420Amps AC-DC * Type of Output CC (Constant Current) AC/DC (GTAW) Stick (SMAW) Maximum Open Circuit Voltage (STICK AND TIG) AC/DC OCV: 80 Auxiliary Power 15Amp Circuit Breaker and N...
Page 10 - SAFETY PRECAUTIONS; SELECT SUITABLE LOCATION; GRINDING; STACKING; The Precision TIG 375's cannot be stacked .; UNDERCARRIAGE LIFTING AND MOVING; Keep the welder power supply lines as short as pos-
A-3 INSTALLATION PRECISION TIG 375 A-3 SAFETY PRECAUTIONS SELECT SUITABLE LOCATION Place the welder where clean cooling air can freely cir-culate in through the top rear vents and out through thebottom rear vents. Dirt, dust or any foreign materialthat can be drawn into the welder should be kept at ...
Page 11 - INPUT and GROUNDING CONNECTIONS; CAUTION
INPUT and GROUNDING CONNECTIONS Be sure the voltage, phase, and frequency of the inputpower is as specified on the rating plate, located on therear of the machine. Remove the reconnect panel cover located near theback of the left case side to reveal the reconnect panel.Welder supply line entry provi...
Page 12 - WORK CABLE CONNECTION; If the Precision TIG is equipped with an Under-; STICK ELECTRODE CABLE CONNECTION; Export model has a voltage range for
A-5 INSTALLATION PRECISION TIG 375 A-5 Recommended Cable Sizes for Combined Lengths ofCopper Work and Electrode Cables using 75 o C Wire: Machine Rating 0 to 100 Ft . 101 to 200 Ft 201 to 250 Ft 375A/40% #1 (42.4 mm2) 1/0 (53.5 mm2) 2/0 (67.4 mm2) WORK CABLE CONNECTION A 15ʼ (2/0) weld cable with cl...
Page 13 - TIG TORCH CONNECTION; The Precision TIG provides an insulated Torch; chained to a support.
A-6 INSTALLATION PRECISION TIG 375 A-6 TIG TORCH CONNECTION The Precision TIG torch connection box, located on theright side of the machine, provides all the input andoutput connections for the installation of both air-cooled and water-cooled TIG torches with fittings con-forming to Compressed Gas A...
Page 14 - AUXILIARY POWER CONNECTIONS; Export models
A-7 INSTALLATION PRECISION TIG 375 A-7 AUXILIARY POWER CONNECTIONS The Precision TIG machines provide a standard NEMA5-15R duplex receptacle, located on the upper caseback on the torch side of the machine: • The bottom outlet of this duplex receptacle provides switched 115VAC power for the Under-Coo...
Page 15 - ROBOTIC INTERFACE CONNECTION
A-8 INSTALLATION PRECISION TIG 375 A-8 ROBOTIC INTERFACE CONNECTION Robotic interface can be made at the RemoteReceptacle (See Operation Section B-2). The machineis shipped with the remote receptacle circuit internallyconnected to receptacle J5 of the Control board forstandard Amptrol operation. In ...
Page 16 - OPERATION; PRODUCT DESCRIPTION; II Technology, Presettable; PIPE THAWING
B-1 OPERATION B-1 PRODUCT DESCRIPTION The Precision TIG 375 is part of a new family of indus-trial arc welding power sources providing constant cur-rent, single range square wave AC/DC TIG (GTAW)with patented Micro-Start TM II Technology, Presettable Min. and Max. Output controls, and built-in high ...
Page 17 - RECOMMENDED PROCESSES; User provided
B-2 OPERATION B-2 RECOMMENDED PROCESSES ANDEQUIPMENT RECOMMENDED PROCESSES The Precision TIG 375 is recommended for the TIG(GTAW) and Stick (SMAW) welding processes withinits output capacity range of 2 amps DC, or 5 amps AC,to 420 amps AC/DC. It is compatible with mostMagnum TIG accessories (refer E...
Page 18 - POLARITY SWITCH –; CONTROLS AND SETTINGS
B-3 OPERATION B-3 1. POWER SWITCH - Input line switch turns input power ON or OFF, as indicated by the on or off sta-tus of the front panel displays. 2. POLARITY SWITCH – The 3-position rotary power switch has detente positions for DC-, AC and DC+selections for the Electrode output welding polarity....
Page 19 - AC BALANCE CONTROL; MINIMUM OUTPUT CONTROL AND DISPLAY SWITCH
B-4 OPERATION B-4 • When the Polarity Switch is set to DC (- or +), the TIG mode provides high frequency only for starting. Hi-Freq. turns on after pre-flow time with the arcstart switch closure, and turns off when the arc isestablished. * • Also functions for DC+ polarity to permit "balling"...
Page 20 - DIGITAL DISPLAY; DISPLAY; exit
B-5 OPERATION B-5 PRECISION TIG 375 DIGITAL DISPLAY DIGITAL DISPLAY (SET) DISPLAY (SELECT) DISPL AY 7a MENU BUTTON AND DISPLAY SWITCH – Pressing and holding the (Menu) Button for about 5 seconds enters the menu display which allows: • Selection of up to seven programmable parameters(Preflow, Upslope...
Page 21 - ADVANCED PANEL CONTROLS
B-6 OPERATION B-6 PRECISION TIG 375 8. DIGITAL METER AND DISPLAY SWITCH – A (3- digit) LED meter is used to monitor the preset andactual welding procedure based on the Display(momentary) switch position: • Before welding with Display switch in center (normal) position, the digital meter displays the...
Page 23 - INTERNAL SET UP CONTROLS; – Does not function; TIG WELDING FEATURES; – Doubles the time ranges.
B-8 OPERATION B-8 INTERNAL SET UP CONTROLS Precision TIG 375 Advanced Panel has the followingadditional control features which are set up using theDIP Switch (S1) provided on the internal panel of thisoption. Access to this internal panel is obtained by removingthe two screws securing the top corner...
Page 26 - TIG WELD CYCLE CHART
B-11 OPERATION B-11 SETUP GUIDELINES FOR TIG WELDINGWITH AN AMPTROL Both the Hand and Foot Amptrols work in a similar manner. They are meant to be used for remote currentcontrol for TIG welding using the machineʼs 2-Step trigger mode (See Item 12). The Amptrol is capable of controlling the output of...
Page 28 - RECOMMENDED ELECTRODE AMPERAGE RANGES - Precision TIG 375; SMAW Process; MAKING A TIG WELD WITH AN AMPTROL
B-13 OPERATION B-13 PRECISION TIG 375 RECOMMENDED ELECTRODE AMPERAGE RANGES - Precision TIG 375 SMAW Process ELECTRODE POLARITY 3/32" 1/8" 5/32" Fleetweld 5P, Fleetweld 5P+ DC+ 40 - 70 75 - 130 90 - 175 Fleetweld 180 DC+ 40 - 80 55 - 110 105 - 135 Fleetweld 37 DC+ 70 - 95 100 - 135 145 -...
Page 29 - ACCESSORIES; OPTIONAL EQUIPMENT; FACTORY INSTALLED OPTIONS
C-1 ACCESSORIES C-1 OPTIONAL EQUIPMENT FACTORY INSTALLED OPTIONS The basic Precision TIG 375 machine is factoryequipped with: • K2621-1 Precision TIG Advanced Control Panel. Provides 2/4-step trigger with adjustable Pulser con-trols and Down slope timer for TIG welding. Alsoincludes adjustable Hot S...
Page 30 - MAINTENANCE; OVERLOAD PROTECTION
D-1 MAINTENANCE D-1 PRECISION TIG 375 ELECTRIC SHOCK can kill. • Only qualified personnel should perform this maintenance. • Turn the input power OFF at the disconnect switch or fuse boxbefore working on thisequipment. • Do not touch electrically hot parts. To avoid receiving a high frequency shock,...
Page 31 - SERVICE PROCEDURES; Input Reconnect Panel; SPARK GAP ADJUSTMENT
D-2 MAINTENANCE D-2 SERVICE PROCEDURES Operation of the Precision TIG should be trouble-freefor the life of the machine. Should a malfunction occur,however, the following procedures will be useful totrained service personnel with experience in repairingarc welding equipment: COMPONENT ACCESS The fol...
Page 32 - DO NOT; use a volt-ohm meter to measure output voltages in TIG mode. The; TROUBLESHOOTING; Local; for technical troubleshooting assistance before you proceed.; Step 3. RECOMMENDED COURSE OF ACTION; HOW TO USE TROUBLESHOOTING GUIDE
DO NOT use a volt-ohm meter to measure output voltages in TIG mode. The High Frequency Arc Starter voltage can damage the meter. CAUTION E-1 TROUBLESHOOTING E-1 PRECISION TIG 375 If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact yo...
Page 33 - OUTPUT PROBLEMS
E-2 TROUBLESHOOTING E-2 PRECISION TIG 375 Observe all Safety Guidelines detailed throughout this manual 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 troublesho...
Page 34 - METER PROBLEMS
E-3 TROUBLESHOOTING E-3 PRECISION TIG 375 Observe all Safety Guidelines detailed throughout this manual 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 troublesho...
Page 35 - PROBLEMS
E-4 TROUBLESHOOTING E-4 PRECISION TIG 375 Observe all Safety Guidelines detailed throughout this manual 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 troublesho...
Page 36 - PRESET & OUTPUT CONTROL PROBLEMS
E-5 TROUBLESHOOTING E-5 PRECISION TIG 375 Observe all Safety Guidelines detailed throughout this manual 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 troublesho...
Page 37 - STICK WELDING PROBLEMS
E-6 TROUBLESHOOTING E-6 PRECISION TIG 375 Observe all Safety Guidelines detailed throughout this manual 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 troublesho...
Page 38 - TIG PROBLEMS
E-7 TROUBLESHOOTING E-7 PRECISION TIG 375 Observe all Safety Guidelines detailed throughout this manual 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 troublesho...
Page 39 - WIRING DIAGRAM
F-1 WIRING DIAGRAM F-1 PRECISION TIG 375 NOTE: This diagram is for r efer ence only . It may not be accurate for all machines cover ed by this manual. The specific diag ram for a particular code is pasted inside the machine on one of the enclosur e panels. If the diagram is illegible, write to the S...
Page 41 - DIMENSION PRINT; CKAGE
F-3 DIMENSION PRINT F-3 PRECISION TIG 375 K2624-1 DOMESTIC P A CKAGE