Lincoln Electric 11075 User manual

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LF-72
OPERATOR’S MANUAL
IM847-B
December, 2005
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 thought-
ful operation on your part. DO
NOT INSTALL, OPERATE OR
REPAIR THIS EQUIPMENT
WITHOUT READING THIS
MANUAL AND THE SAFETY
PRECAUTIONS CONTAINED
THROUGHOUT. And, most
importantly, think before you act
and be careful.
For use with machines having Code Numbers: 11075, 11076, 11077
11209, 11210, 11211, 11227
11290, 11291, 11292, 11293
Copyright © 2005 Lincoln Global Inc.
IP21
IEC 60974-5
RETURN TO MAIN MENU

FOR ENGINE
powered 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 fumes
outdoors.
____________________________________________________
1.c. Do not add the fuel near an open flame
welding arc or when the engine is running.
Stop the engine and allow it to cool before
refueling to prevent spilled fuel from vaporiz-
ing on contact with hot engine parts and
igniting. Do not spill fuel when filling tank. If
fuel is spilled, wipe it up and do not start
engine until fumes have been eliminated.
____________________________________________________
1.d. Keep all equipment safety guards, covers and devices in
position and in good repair.Keep hands, hair, clothing and
tools away from V-belts, gears, fans and all other moving
parts when starting, operating or repairing equipment.
____________________________________________________
1.e. In some cases it may be necessary to remove safety
guards to perform required maintenance. Remove
guards only when necessary and replace them when the
maintenance requiring their removal is complete.
Always use the greatest care when working near moving
parts.
___________________________________________________
1.f. Do not put your hands near the engine fan.
Do not attempt to override the governor or
idler by pushing on the throttle control rods
while the engine is running.
___________________________________________________
1.g. To prevent accidentally starting gasoline engines while
turning the engine or welding generator during maintenance
work, disconnect the spark plug wires, distributor cap or
magneto wire as appropriate.
i
SAFETY
i
ARC WELDING CAN BE HAZARDOUS. PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH.
KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.
Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you
purchase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1” from the American Welding Society, P.O. Box
351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety” booklet E205 is available
from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.
BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE
PERFORMED ONLY BY QUALIFIED INDIVIDUALS.
WARNING
Mar ‘95
ELECTRIC AND
MAGNETIC FIELDS
may be dangerous
2.a. Electric current flowing through any conductor causes
localized Electric and Magnetic Fields (EMF). Welding
current creates EMF fields around welding cables and
welding machines
2.b. EMF fields may interfere with some pacemakers, and
welders having a pacemaker should consult their physician
before welding.
2.c. Exposure to EMF fields in welding may have other health
effects which are now not known.
2.d. All welders should use the following procedures in order to
minimize exposure to EMF fields from the welding circuit:
2.d.1.
Route the electrode and work cables together - Secure
them with tape when possible.
2.d.2. Never coil the electrode lead around your body.
2.d.3. Do not place your body between the electrode and
work cables. If the electrode cable is on your right
side, the work cable should also be on your right side.
2.d.4. Connect the work cable to the workpiece as close as
possible to the area being welded.
2.d.5. Do not work next to welding power source.
1.h. To avoid scalding, do not remove the
radiator pressure cap when the engine is
hot.
CALIFORNIA PROPOSITION 65 WARNINGS
Diesel engine exhaust and some of its constituents
are known to the State of California to cause can-
cer, birth defects, and other reproductive harm.
The engine exhaust from this product contains
chemicals known to the State of California to cause
cancer, birth defects, or other reproductive harm.
The Above For Diesel Engines The Above For Gasoline Engines

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 and
the rays of the arc when welding or observing
open arc welding. Headshield and filter lens
should conform to ANSI Z87. I standards.
4.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
the arc rays.
4.c. Protect other nearby personnel with suitable, non-flammable
screening and/or warn them not to watch the arc nor expose
themselves to the arc rays or to hot spatter or metal.
ELECTRIC SHOCK can
kill.
3.a. The electrode and work (or ground) circuits
are electrically “hot” when the welder is on.
Do not touch these “hot” parts with your bare
skin or wet clothing. Wear dry, hole-free
gloves to insulate hands.
3.b. Insulate yourself from work and ground using dry insulation.
Make certain the insulation is large enough to cover your full
area of physical contact with work and ground.
In addition to the normal safety precautions, if welding
must be performed under electrically hazardous
conditions (in damp locations or while wearing wet
clothing; on metal structures such as floors, gratings or
scaffolds; when in cramped positions such as sitting,
kneeling or lying, if there is a high risk of unavoidable or
accidental contact with the workpiece or ground) use
the following equipment:
• Semiautomatic DC Constant Voltage (Wire) Welder.
• DC Manual (Stick) Welder.
• AC Welder with Reduced Voltage Control.
3.c. In semiautomatic or automatic wire welding, the electrode,
electrode reel, welding head, nozzle or semiautomatic
welding gun are also electrically “hot”.
3.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.
3.e. Ground the work or metal to be welded to a good electrical
(earth) ground.
3.f.
Maintain the electrode holder, work clamp, welding cable and
welding machine in good, safe operating condition. Replace
damaged insulation.
3.g. Never dip the electrode in water for cooling.
3.h. Never simultaneously touch electrically “hot” parts of
electrode holders connected to two welders because voltage
between the two can be the total of the open circuit voltage
of both welders.
3.i. When working above floor level, use a safety belt to protect
yourself from a fall should you get a shock.
3.j. Also see Items 6.c. and 8.
FUMES AND GASES
can be dangerous.
5.a. Welding may produce fumes and gases
hazardous to health. Avoid breathing these
fumes and gases.When welding, keep
your head out of the fume. Use enough
ventilation and/or exhaust at the arc to keep
fumes and gases away from the breathing zone. When
welding with electrodes which require special
ventilation such as stainless or hard facing (see
instructions on container or MSDS) or on lead or
cadmium plated steel and other metals or coatings
which produce highly toxic fumes, keep exposure as
low as possible and below Threshold Limit Values (TLV)
using local exhaust or mechanical ventilation. In
confined spaces or in some circumstances, outdoors, a
respirator may be required. Additional precautions are
also required when welding on galvanized steel.
5.b.
Do not weld in locations near chlorinated hydrocarbon vapors
coming from degreasing, cleaning or spraying operations.
The heat and rays of the arc can react with solvent vapors to
form phosgene, a highly toxic gas, and other irritating prod-
ucts.
5.c. Shielding gases used for arc welding can displace air and
cause injury or death. Always use enough ventilation,
especially in confined areas, to insure breathing air is safe.
5.d. Read and understand the manufacturer’s instructions for this
equipment and the consumables to be used, including the
material safety data sheet (MSDS) and follow your
employer’s safety practices. MSDS forms are available from
your welding distributor or from the manufacturer.
5.e. Also see item 1.b.
Mar ‘95

FOR ELECTRICALLY
powered equipment.
8.a. Turn off input power using the disconnect
switch at the fuse box before working on
the equipment.
8.b. Install equipment in accordance with the U.S. National
Electrical Code, all local codes and the manufacturer’s
recommendations.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
CYLINDER may explode
if damaged.
7.a. Use only compressed gas cylinders
containing the correct shielding gas for the
process used and properly operating
regulators designed for the gas and
pressure used. All hoses, fittings, etc. should be suitable for
the application and maintained in good condition.
7.b. Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.
7.c. Cylinders should be located:
• Away from areas where they may be struck or subjected to
physical damage.
• A safe distance from arc welding or cutting operations and
any other source of heat, sparks, or flame.
7.d. Never allow the electrode, electrode holder or any other
electrically “hot” parts to touch a cylinder.
7.e. Keep your head and face away from the cylinder valve outlet
when opening the cylinder valve.
7.f. Valve protection caps should always be in place and hand
tight except when the cylinder is in use or connected for
use.
7.g. Read and follow the instructions on compressed gas
cylinders, associated equipment, and CGA publication P-l,
“Precautions for Safe Handling of Compressed Gases in
Cylinders,” available from the Compressed Gas Association
1235 Jefferson Davis Highway, Arlington, VA 22202.
iii
SAFETY
iii
Mar ‘95
WELDING SPARKS can
cause fire or explosion.
6.a. Remove fire hazards from the welding area.
If this is not possible, cover them to 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.
6.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 Welding and Cutting” (ANSI
Standard Z49.1) and the operating information for the
equipment being used.
6.c. When not welding, make certain no part of the electrode
circuit is touching the work or ground. Accidental contact
can cause overheating and create a fire hazard.
6.d. Do not heat, cut or weld tanks, drums or containers until the
proper steps have been taken to insure that such procedures
will not cause flammable or toxic vapors from substances
inside. They can cause an explosion even though they have
been “cleaned”. For information, purchase “Recommended
Safe Practices for the
Preparation for Welding and Cutting of
Containers and Piping That Have Held Hazardous
Substances”, AWS F4.1 from the American Welding Society
(see address above).
6.e. Vent hollow castings or containers before heating, cutting or
welding. They may explode.
6.f.
Sparks and spatter are thrown from the welding arc. Wear oil
free protective garments such as leather gloves, heavy shirt,
cuffless trousers, high shoes and a cap over your hair. Wear
ear plugs when welding out of position or in confined places.
Always wear safety glasses with side shields when in a
welding area.
6.g. Connect the work cable to the work as close to the welding
area as practical. Work cables connected to the building
framework or other locations away from the welding area
increase the possibility of the welding current passing
through lifting chains, crane cables or other alternate cir-
cuits. This can create fire hazards or overheat lifting chains
or cables until they fail.
6.h. Also see item 1.c.

iv
SAFETY
iv
Mar. ‘93
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 L’Arc
1. Protegez-vous contre la secousse électrique:
a. Les circuits à l’électrode et à la piéce sont sous tension
quand la machine à souder est en marche. Eviter toujours
tout contact entre les parties sous tension et la peau nue
ou les vétements mouillés. Porter des gants secs et sans
trous pour isoler les mains.
b. Faire trés attention de bien s’isoler de la masse quand on
soude dans des endroits humides, ou sur un plancher
metallique ou des grilles metalliques, principalement dans
les positions assis ou couché pour lesquelles une grande
partie du corps peut être en contact avec la masse.
c. Maintenir le porte-électrode, la pince de masse, le câble
de soudage et la machine à souder en bon et sûr état
defonctionnement.
d.Ne jamais plonger le porte-électrode dans l’eau pour le
refroidir.
e. Ne jamais toucher simultanément les parties sous tension
des porte-électrodes connectés à deux machines à souder
parce que la tension entre les deux pinces peut être le
total de la tension à vide des deux machines.
f. Si on utilise la machine à souder comme une source de
courant pour soudage semi-automatique, ces precautions
pour le porte-électrode s’applicuent aussi au pistolet de
soudage.
2. Dans le cas de travail au dessus du niveau du sol, se protéger
contre les chutes dans le cas ou on recoit un choc. Ne jamais
enrouler le câble-électrode autour de n’importe quelle partie
du corps.
3. Un coup d’arc peut être plus sévère qu’un coup de soliel,
donc:
a. Utiliser un bon masque avec un verre filtrant approprié
ainsi qu’un verre blanc afin de se protéger les yeux du ray-
onnement de l’arc et des projections quand on soude ou
quand on regarde l’arc.
b. Porter des vêtements convenables afin de protéger la
peau de soudeur et des aides contre le rayonnement de
l‘arc.
c. Protéger l’autre personnel travaillant à proximité au
soudage à l’aide d’écrans appropriés 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.
6. Eloigner les matériaux inflammables ou les recouvrir afin de
prévenir tout risque d’incendie dû aux étincelles.
7. Quand on ne soude pas, poser la pince à une endroit isolé de
la masse. Un court-circuit accidental peut provoquer un
échauffement et un risque d’incendie.
8. S’assurer que la masse est connectée le plus prés possible
de la zone de travail qu’il est pratique de le faire. Si on place
la masse sur la charpente de la construction ou d’autres
endroits éloignés de la zone de travail, on augmente le risque
de voir passer le courant de soudage par les chaines de lev-
age, câbles de grue, ou autres circuits. Cela peut provoquer
des risques d’incendie ou d’echauffement des chaines et des
câbles jusqu’à ce qu’ils se rompent.
9. Assurer une ventilation suffisante dans la zone de soudage.
Ceci est particuliérement important pour le soudage de tôles
galvanisées plombées, ou cadmiées ou tout autre métal qui
produit des fumeés toxiques.
10. Ne pas souder en présence de vapeurs de chlore provenant
d’opérations de dégraissage, nettoyage ou pistolage. La
chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs
du solvant pour produire du phosgéne (gas fortement toxique)
ou autres produits irritants.
11. Pour obtenir de plus amples renseignements sur la sûreté,
voir le code “Code for safety in welding and cutting” CSA
Standard W 117.2-1974.
PRÉCAUTIONS DE SÛRETÉ POUR
LES MACHINES À SOUDER À
TRANSFORMATEUR ET À
REDRESSEUR
1. Relier à la terre le chassis du poste conformement au code de
l’électricité et aux recommendations du fabricant. Le dispositif
de montage ou la piece à souder doit être branché à une
bonne mise à la terre.
2. Autant que possible, I’installation et l’entretien du poste seront
effectués par un électricien qualifié.
3. Avant de faires des travaux à l’interieur de poste, la debranch-
er à l’interrupteur à la boite de fusibles.
4. Garder tous les couvercles et dispositifs de sûreté à leur
place.

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 and keep it
handy for quick reference. Pay particular attention to the safety instructions we have provided for your protection.
The level of seriousness to be applied to each is explained below:
WARNING
This statement appears where the information must be followed exactly to avoid serious personal injury or
loss of life.
This statement appears where the information must be followed to avoid minor personal injury or damage to
this equipment.
CAUTION
Please Examine Carton and Equipment For Damage Immediately
When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims
for material damaged in shipment must be made by the purchaser against the transportation company at the
time the shipment is received.
Please record your equipment identification information below for future reference. This information can be
found on your machine nameplate.
Product _________________________________________________________________________________
Model Number ___________________________________________________________________________
Code Number or Date Code_________________________________________________________________
Serial Number____________________________________________________________________________
Date Purchased___________________________________________________________________________
Where Purchased_________________________________________________________________________
Whenever you request replacement parts or information on this equipment, always supply the information you
have recorded above. The code number is especially important when identifying the correct replacement parts.
vv
On-Line Product Registration
- Register your machine with Lincoln Electric either via fax or over the Internet.
• For faxing: Complete the form on the back of the warranty statement included in the literature packet
accompanying this machine and fax the form per the instructions printed on it.
• For On-Line Registration: Go to our
WEB SITE at www.lincolnelectric.com. Choose “Quick Links” and then
“Product Registration”. Please complete the form and submit your registration.

vi
vi TABLE OF CONTENTS
Page
Glossary of Terms and General information ...................................................................Section
Glossary of Terms....................................................................................................................1
Definitions of Welding Modes ...........................................................................................1
Common Welding Abbreviations ......................................................................................1
Product Description. .........................................................................................................2
Recommended Processes and Required Equipment.......................................................2
Base Model, Bench Model Standard Duty and Bench Model Heavy Duty .......................3
Base Model and Standard Wire Drive Features ...............................................................4
Technical Specifications ...................................................................................................5
Typical System Configurations .........................................................................................6
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
Installation.......................................................................................................................Section A
Safety Precautions ...............................................................................................................A-1
Location.........................................................................................................................A-1
Mounting .......................................................................................................................A-1
Bench Mount .................................................................................................................A-2
Swivel Mount.................................................................................................................A-2
Boom Mount..................................................................................................................A-2
Suspended ....................................................................................................................A-2
Safety Precautions ........................................................................................................A-3
Weld Cable Sizes..........................................................................................................A-3
Coaxial Weld Cables.....................................................................................................A-4
Weld Cable Connections...............................................................................................A-4
Analog Control Cable Connection ........................................................................................A-5
Analog Miller Control Cable Adapter ....................................................................................A-6
High Frequency.............................................................................................................A-7
Welding Gun/Wire Feeder Trigger Connector...............................................................A-7
Remote Sense Lead Specifications ..............................................................................A-7
Wire Drive Systems..............................................................................................................A-7
Welding Guns, Torches and Accessories ............................................................................A-8
Procedures For Changing Drive Rolls and Idle Roll Sets.....................................................A-9
Wire Drive Configuration ...............................................................................................A-9
Pressure Arm Adjustment ...........................................................................................A-10
Wire Reel Loading.......................................................................................................A-11
Weld Wire Routing .....................................................................................................A-12
Shielding Gas Connection..................................................................................................A-13
Installing Electrode Conduit Kits.........................................................................................A-14
Aluminum Wire Preparations..............................................................................................A-15
________________________________________________________________________________
Operation.........................................................................................................................Section B
Safety Precautions ...............................................................................................................B-1
Graphic Symbols .................................................................................................................B-1
Front Panel Controls and Connections...................................................................B-2 thru B-4
1. Remote Voltage Control Kit (Optional)......................................................................B-3
2. Burnback and Postflow Timer Kit (Optional) .............................................................B-3
3. Thermal LED, Motor Overload ..................................................................................B-3
4. Cold Feed / Gas Purge Switch..................................................................................B-3
5. 2-Step Trigger Interlock Switch .................................................................................B-3
6. Wire Feed Speed Knob.............................................................................................B-4
7. Gun Receiver Bushing ..............................................................................................B-4
8. Trigger Connector 5-pin Amphenol ...........................................................................B-4
________________________________________________________________________________
Accessories.....................................................................................................Section C
General Options / Accessories...............................................................C-1 Thru C-4
________________________________________________________________________

vii
TABLE OF CONTENTS
LF-72
vii
Page
Maintenance ....................................................................................................Section D
Safety Precautions ................................................................................................D-1
Routine ..................................................................................................................D-1
Periodic..................................................................................................................D-1
Calibration Specification........................................................................................D-1
________________________________________________________________________
Troubleshooting............................................................................................................E
Safety Precautions.................................................................................................E-1
How To Use Troubleshooting Guide......................................................................E-1
Troubleshooting .............................................................................................E-2, E-3
________________________________________________________________________
Wiring Diagram and Dimension Prints..........................................................Section F
________________________________________________________________________
Parts Lists................................................................................................................P501
________________________________________________________________________

11
GLOSSARY OF TERMS
COMMON WELDING ABBREVIATIONS
WFS
• Wire Feed Speed
CV
• Constant Voltage
GMAW (MIG)
• Gas Metal Arc Welding
FCAW (Cable Innershield or Outershield)
• Flux Core Arc Welding
LF-72

PROCESS LIMITATIONS
• Rated for up to 1/16(1.6 mm) solid electrode and
5/64 (2.0 mm) cored electrode.
• The maximum WFS is 800 in/min (20.3 M/min).
• The LF-72 is not recommended for GMAW-Pulse
(synergic), GTAW, GTAW-Pulse, SAW, CAG,
SMAW.
• Do not use push-pull equipment with the LF-72.
• For K2327-2 Bench model, std. duty: Maximum
spool size = 44 lb. (20 kg); 12 inch (300mm) diame-
ter; 4 inch (100mm)
• For K2327-3 Bench model, heavy duty: Maximum
spool size = 60 lb. (27.2 kg)
REQUIRED EQUIPMENT
Lincoln’s LF-72 is designed for use with the CV and
DC family of power sources. These include:
• CV-305 • DC-400
• CV-400 • DC-600
• CV-655 • Invertec™ V350
• Invertec™ V450
EQUIPMENT LIMITATIONS
• Maximum gun length =25 ft. (7.6m)
• Maximum conduit length = 30 ft. (9.1m)
• Maximum total control cable length = 100ft (31m)
• The LF-72 operates on 42VAC and not 115 VAC
• The K1733-1 wire straightener may not be used with
the LF-72
• Gun bushings are required for welding guns that do
not have a Magnum (Tweco #2-#4 compatible) back
end.
• The LF-72 does not attach to K303 wire reel stands.
2
GENERAL INFORMATION
LF-72
2
PRODUCT DESCRIPTION
General Physical Description
The LF-72 is optimized for .035 through .045 (0.9mm
through 1.2mm) GMAW welding. The powerful 2 roll
drive, heavy duty enclosure and wire reel stand com-
bine to make an easy to install, easy to use wire feed-
er for everyday welding. Powering the wire drive is a
high performance motor gearbox. A heavy duty
hinged door opens easily, which provides an ample
amount of room for assembling precision drive com-
ponents and the welding gun. Also under the door is a
convenient storage tray for contact tips and tools.
Three packages are available. The basic unit consists
of the wire drive box housing. The standard duty
bench model targets users of 12" (305 mm)diameter
spools. The heavy duty bench model satisfies the
needs of customers using 60 lb (27.2 kg) spools.
General Functional Description
• The LF-72 is a highly versatile and economical
choice of industrial feeders. Easy to use features are
a calibrated WFS knob, cold-feed/ gas purge switch
and trigger interlock.
• Several kits are available to expand the LF-72’s
welding capability. The timer kit allows adjustment of
burnback and postflow times. The remote voltage
control kit includes a 0 to 10 dial for setting the weld-
ing voltage at the wire feeder. The swivel kit mounts
to the lift bail of a power source and lets the feeder
freely rotate so the gun cable stays straight.
RECOMMENDED PROCESSES
• GMAW .023-1/16 (0.6 - 1.6 mm) steel electrodes.
• FCAW .035 -5/64 (0.9 - 2.0mm) cored electrodes

3
GENERAL INFORMATION
LF-72
3
BENCH MODEL STANDARD DUTY
BENCH MODEL HEAVY DUTY
BASE MODEL

4
GENERAL INFORMATION
LF-72
4
CALIBRATED
WIRE FEED
SPEED KNOB
DRIVE ROLLS
PATENTED SPLIT
WIRE GUIDE
PRESSURE ARM
STORAGE TRAY
BALL BEARING
INLET GUIDE
BUSHING ASSEMBLY
MOTOR THERMAL LED
TRIGGER CONNECTION
(5 PIN AMPHENOL)
GUN RECEIVER BUSHING
CONNECTION POINT
FOR GUN AND CABLE
ASSEMBLY
REMOTE KIT PANEL
TIMER KIT PANEL
2 STEP
TRIGGER INTERLOCK
TOGGLE SWITCH
COLD FEED
GAS PURGE
TOGGLE SWITCH
DOOR AND HINGE REMOVED
SEE INSTALLATION AND OPERATION SECTIONS FOR DETAILED INFORMATION
BASE MODEL AND STANDARD WIRE DRIVE FEATURES

5
GENERAL INFORMATION
LF-72
5
TECHNICAL SPECIFICATIONS
: LF-72 Wire Feeder
SPEC.# TYPE WIRE FEED SPEED RANGE
∆Dimensions do not include wire reel.
Wire Size
LF-72 Speed Solid Cored
K2327-1
K2327-4
K2327-2 Bench Model 50-800 IPM .023 - 1/16 in. .035 - 5/64 in
Standard Duty (1.27-20.3 m/m) (0.6 - 1.6 mm) (0.9 - 2.0 mm)
K2327-3 Bench Mode
Heavy Duty
CONTROL BOX, WIRE DRIVE AND COMPLETE UNITS
SPEC.# TYPE INPUT POWER PHYSICAL SIZE• TEMPERATURE RATING
Input Voltage Dimensions
and Current Height Width Depth Weight Operating Storage
43 Lbs
K2327-1 LF-72 11.1“10.2“12.9“(19.7 Kg.)
( 282 mm) (259 mm) (328 mm)
K2327-4
Base Model 26.5 Lbs
(12.0 Kg)
Dimensions ∆
Height Width Depth Weight
LF-72
K2327-2
24-42VAC 12.6“10.9“22.5“52.5 Lbs 14°F to 104°F -40°F to 185°F
Bench 9 AMPS ( 320 mm) (277 mm) (572 mm) (23.8 Kg.) (-10°C to 40°C)
( -40°C to 85°C)
Standard
Duty
Dimensions ∆
Height Width Depth Weight
LF-72
K2327-3 15.3“13.0“27.7“67.5 Lbs
Bench ( 389 mm) (330 mm) (704 mm) (30.6 Kg.)
Heavy
Duty
WELDING CAPACITY RATING
Amp Rating Duty Cycle
500 A 60%
400 A 100%
Base Model

6
GENERAL INFORMATION
LF-72
6
TYPICAL SYSTEM CONFIGURATIONS
The LF-72 is capable of welding with many different welding processes. These processes may require reconfig-
uring the LF-72 with other products that may or may not be included with the model you purchased. Use the
Table 1 below to identify the basic items which are included in the LF-72 to utilize the various Welding Processes
that the machine is capable of controlling.
TABLE 1
PART NO.
K2327-1
K2327-2
K2327-3
K2327-4
Description
Base Model
Bench Model,
Standard Duty
Bench Model,
Heavy Duty
Base Model
Wire
Feeder
LF-72
Gun
15', Magnum 400,
.035-.045 (0.9-1.2 mm)
---
Wire Reel Stand
---
Standard duty, up to
44 lb. (20 kg) spools.
Heavy Duty, up to
60 lb. (27.2 kg) coils.
---
Drive Roll Kit
.035-.045 combo
(0.9-1.2 mm)
CONTROL
CABLE
10’(3m)
---

A-1
INSTALLATION
LF-72
A-1
SAFETY PRECAUTION
LOCATION
The LF-72 may be placed on a bench or mounted on
top of a welding power source.
Place the LF-72 in a clean and dry location.
Do not stack the LF-72.
ELECTRIC SHOCK can kill.
• Only qualified personnel should
perform this installation.
• Turn off the input power to the
power source at the disconnect
switch or fuse box before working
on this equipment. Turn off the
input power to any other equipment
connected to the welding system at
the disconnect switch or fuse box
before working on this equipment.
• Do not touch electrically hot parts.
----------------------------------------------------------------------------------------
FIGURE A.1
FIGURE A.2
MOUNTING
For location and size, LF-72 Bench Model Rear
Mounting Holes (See Figure A.1) and for Bottom
Mounting Holes (See Figure A.2).

A-2
INSTALLATION
LF-72
A-2
BENCH MOUNT
The LF-72 mounts in a variety of configurations. As
shipped from the factory, the LF-72 is suitable for
bench mounting or placing directly on top of the weld-
ing power source (CV-xxx and DC-xxx product family
only).
SWIVEL MOUNT
Both the standard duty bench model and heavy duty
bench model may be mounted onto a swivel when a
top a welding power source.
BOOM MOUNT
When boom mounting, remove the wire reel stand (if
assembled) and secure the wire feeder directly to the
desired surface.
SUSPENDED
Only suspend the wire feeder by the lift bail of the
portability kit.
Alternative methods for hanging the wire feeder
must not be used unless insulation is provided
between the wire feeder enclosure and the hang-
ing device.
------------------------------------------------------------------------
Bench Mount
Swivel Kit and Bench Model, Standard Duty
Swivel Kit and Base Model LF-72
WARNING

A-3
INSTALLATION
LF-72
A-3
SAFETY PRECAUTION
ELECTRIC SHOCK can
kill.
• Only qualified personnel should
perform this installation.
• Turn off the input power to the power source at
the disconnect switch or fuse box before work-
ing on this equipment. Turn off the input power
to any other equipment connected to the weld-
ing system at the disconnect switch or fuse
box before working on this equipment.
• Do not touch electrically hot parts.
----------------------------------------------------------------------
** Tabled values are for operation at ambient temperatures of 40°C and below. Applications above 40°C
may require cables larger than recommended, or cables rated higher than 75°C.
Amperes
200
200
225
225
250
250
250
250
300
325
350
400
400
500
Percent
Duty
Cycle
60
100
20
40 & 30
30
40
60
100
60
100
60
60
100
60
200 to 250 Ft.
61 to 76 m
1/0
1/0
1/0
1/0
1/0
1/0
1/0
1/0
2/0
3/0
3/0
4/0
4/0
4/0
150 to 200 Ft.
48 to 61 m
1
1
1
1
1
1
1
1
1/0
2/0
2/0
3/0
3/0
3/0
100 to 150 Ft.
31 to 48 m
2
2
2
2
2
1
1
1
1
2/0
2/0
2/0
3/0
3/0
50 to 100Ft.
15 to 31 m
2
2
3
3
3
2
1
1
1
2/0
1/0
2/0
3/0
2/0
0 to 50 Ft.
0 to 15 m
2
2
4 or 5
3
3
2
1
1
1
2/0
1/0
2/0
3/0
2/0
RECOMMENDED CABLE SIZES (RUBBER COVERED COPPER - RATED 75°C)**
CABLE SIZES FOR COMBINED LENGTHS OF ELECTRODE AND WORK CABLES
WELD CABLE SIZES
Table A.1 has the copper cable sizes recommended
for different currents and duty cycles. Lengths stipu-
lated are the distance from the welder to work and
back to the welder again. Cable sizes are increased
for greater lengths primarily for the purpose of mini-
mizing voltage in the welding circuit.
TABLE A.1

A-4
INSTALLATION
LF-72
A-4
COAXIAL WELD CABLES
Coaxial welding cables are specially designed welding
cables for pulse welding or STT welding. Coaxial weld
cables feature low inductance, allowing fast changes
in the weld current. Regular cables have a higher
inductance which may distort the pulse or STT wave
shape. Inductance becomes more severe as the weld
cables become longer.
Coaxial weld cables are recommended for all pulse
and STT welding, especially when the total weld cable
length (electrode cable + work cable) exceeds 50 feet
(7.6m)
A coaxial weld cable is constructed by 8 small leads
wrapped around one large lead. The large inner lead
connects to the electrode stud on the power source
and the electrode connection on the wire feeder. The
small leads combine together to form the work lead,
one end attached to the power source and the other
end to the work piece.
(See Coaxial weld Cable below.)
WELD 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 connec-
tions can result in poor welding performance.
Electrode
Work
Work
Power Source
Work Electrode Wire Feeder
Electrode
Work
Coaxial Weld Cable

A-5
INSTALLATION
LF-72
A-5
ANALOG CONTROL CABLE
CONTROL CABLE CONNECTIONS
•All control cables can be connected end to end to
extend their length.
The control cable connecting the wire feeder to the
power source is specially made for the welding envi-
ronment.
The wire feeder power requires overcurrent protec-
tion. Connect the wire feeder only to power sources
with overcurrent protection of no more than 15 amps.
PIN FUNCTION LEAD#
A Unused -------
B Reserved -------
C Welding Output Control 2
(trigger from feeder)
D Welding Output Control 4
(trigger from feeder)
E Remote Voltage Control 77
(“+”supply from feeder or remote)
F Remote Voltage Control 76
(control signal from feeder or remote)
G Remote Voltage Control 75
(“-”supply from feeder or remote)
H Reserved
I 42 VAC 41
J Reserve for Future Use.
K 42 VAC 42
L Reserve for Future Use.
M Unused -------
N Electrode voltage from feeder 67
Do not use more than 100 ft (30.5 m) of control cable
between the wire feeder and power source.
AIH
G
B
F
E
D
C
J
KN
M
L
ABC
D
I
E
F
G
H
JKL
M
N
POWER SOURCE WIRE FEEDER

A-6
INSTALLATION
LF-72
A-6
ANALOG MILLER CONTROL CABLE
ADAPTER K2335-1
This Lincoln Electric wire feeder may be mounted to a limit-
ed number of Miller Electric power sources. The Miller
power source must have the amphenol pin definition shown
in the table below for proper operation of the wire feeder.
Operation of Lincoln wire feeders on Miller power sources
may result in lack of high speeds or reduce pull force on
high wire feed speeds. Maximum wire feed speed for the
LF-72 operating on a Miller power source is approximately
720ipm. Be sure the Miller power source provides 24 VAC
to the wire feeder and has overcurrent protection of no more
than 15 amps. The power source must not exceed 113VDC
peak.
AB
C
D
I
E
F
G
H
JKL
M
N
AI
H
G
B
F
E
D
C
J
K
N
M
L
WIRE FEEDERPOWER SOURCE
MILLER POWER SOURCE
Pin Function
A 24 VAC to feeder
B Welding Output Control
C +10VDC to feeder for remote control
D Remote control common
E 0-10VDC from feeder for remote control.
F Current feedback to feeder.
Scaled 0-10V. 1 V = 100 amps.
Referenced to pin D.
G 24 VAC common.
H Arc Voltage feedback to feeder.
Scaled 0-10V. 1 V = 10 Arc volts.
Referenced to pin D.
I
J
K
L
M
N
LINCOLN WIRE FEEDER
Pin Function
I 42 VAC feeder
D Welding Output Control
C Welding Output Control
E Remote Voltage Control ("+" supply, from
power source)
G Remote Voltage Control ("-" supply, from
power source)
F Remote Voltage Control (control signal from
feeder or remote.)
J Reserved for future use.
K 42 VAC to feeder
L Reserved for future use.
N Electrode voltage to power source (67)
Miller is a registered trademark not owned or licensed by The Lincoln Electric Company.