Lincoln Electric LF-72-74 User Manual

For use with machines having Code Number : 11075 thru 11293

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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.

OPERATE OR REPAIR THIS EQUIPMENT WITHOUT READING THIS MANUAL AND THE SAFETY PRECAUTIONS CONTAINED THROUGHOUT.

most importantly, think before you act and be careful.

DO NOT INSTALL,

And,

SVM171-A

January, 2007

LF-72/74

View Safety Info View Safety Info View Safety Info View Safety Info

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Cleveland, Ohio 44117-1199 U.S.A. TEL: 1-888-935-3877 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com

SERVICE MANUAL

• World's Leader in Welding and Cutting Products •

• Sales and Service through Subsidiaries and Distributors Worldwide •

SAFETY

WARNING

CALIFORNIA PROPOSITION 65 WARNINGS

Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.

The Above For Diesel Engines

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.

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 Gasoline Engines

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 vaporizing 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.h. To avoid scalding, do not remove the radiator pressure cap when the engine is hot.

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

___________________________________________________

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.

Mar ‘95

possible to the area being welded.

2.d.5. Do not work next to welding power source.

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SAFETY

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.

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.

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. The operation of welding fume control equipment is affected by various factors including proper use and positioning of the equipment, maintenance of the equipment and the specific welding procedure and application involved. Worker exposure level should be checked upon installation and periodically thereafter to be certain it is within applicable OSHA PEL and ACGIH TLV limits.

5.c.

Do not weld in locations near chlorinated hydrocarbon coming from degreasing, cleaning or spraying operations. The heat and rays of the arc can react with solvent vapors form phosgene, a highly toxic gas, and other irritating products.

5.d. 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.

vapors

5.e. 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.f. Also see item 1.b.

AUG 06

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iii

SAFETY

iii

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.

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 been “cleaned”. For information, purchase “Recommended Safe Practices for the 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.

Sparks and spatter are thrown from the welding arc. Wear oil

6.f. 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 circuits. This can create fire hazards or overheat lifting chains or cables until they fail.

6.h. Also see item 1.c.

Remember that welding sparks and hot

though

they have

Preparation

for Welding and Cutting of

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.

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.

Mar ‘95

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SAFETY

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 suivantes:

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.

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 levage, 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.

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 rayonnement 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, pantalons 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

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 debrancher à l’interrupteur à la boite de fusibles.

4. Garder tous les couvercles et dispositifs de sûreté à leur place.

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Mar. ‘93

MASTER TABLE OF CONTENTS FOR ALL SECTIONS

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Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-iv

Installation LF-72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section A

Installation LF-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section AA

Operation LF-72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section B

Operation LF-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section BB

Accessories LF-72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section C

Accessories LF-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section CC

Maintenance LF-72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section D

Maintenance LF-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section DD

Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section E

Troubleshooting and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F

Electrical Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section G

Parts Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P501 Series (LF-72)

P518 Series (LF-74)

LF-72/74

Section A-1 Section A-1

TABLE OF CONTENTS

- INSTALLATION SECTION -

Installation ..............................................................................................................Section A

Technical Specifications...............................................................................................A-2

Safety Precautions .......................................................................................................A-3

Location ..................................................................................................................A-3

Mounting .................................................................................................................A-3

Bench Mount ..........................................................................................................A-4

Swivel Mount ..........................................................................................................A-4

Boom Mount ...........................................................................................................A-4

Suspended..............................................................................................................A-4

Weld Cable Sizes....................................................................................................A-5

Coaxial Weld Cables...............................................................................................A-6

Weld Cable Connections ........................................................................................A-6

Analog Control Cable Connections..............................................................................A-7

Analog Miller Control Cable Adapter ...........................................................................A-8

Welding Gun/Wire Feeder Trigger Connector.........................................................A-9

High Frequency Protection.....................................................................................A-9

Remote Sense Lead Specifications........................................................................A-9

Wire Drive Systems ......................................................................................................A-9

Welding Guns, Torches and Accesories ....................................................................A-10

Procedure for Changing Drive and Idle Roll Sets......................................................A-11

Wire Drive Configuration..............................................................................A-11/A-12

Pressure Arm Adjustment.....................................................................................A-12

Wire Reel Loading.................................................................................................A-13

Weld Wire Routing ................................................................................................A-14

Sheilding Gas Connections........................................................................................A-15

Installing Electrode Conduit Kits................................................................................A-16

Aluminum Wire Preperations......................................................................................A-17

Base Model, Bench Model Standard Duty and Bench Model Heavy Duty...............A-18

Typical System Configurations...................................................................................A-19

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LF-72/74 SINGLE/DUAL

A-2

TECHNICAL SPECIFICATIONS

SPEC.# TYPE WIRE FEED SPEED RANGE

LF-72 Speed Solid Cored

INSTALLATION

LF-72 Wire Feeder

A-2

Wire Size

K2327-1 K2327-4 K2327-2 Bench Model 50-800 IPM .023 - 1/16 in. .035 - 5/64 in

K2327-3 Bench Mode

SPEC.# TYPE

Input Voltage Dimensions

K2327-1

K2327-4

K2327-2

K2327-3

LF-72 11.1“ 10.2“ 12.9“ (19.7 Kg.)

Base Model

LF-72

Bench 9 AMPS ( 320 mm) (277 mm) (572 mm) (23.8 Kg.) (-10°C to 40°C) (-40°C to 85°C) Standard Duty

LF-72

Bench ( 389 mm) (330 mm) (704 mm) (30.6 Kg.) Heavy Duty

INPUT POWER

24-42VAC 12.6“ 10.9“ 22.5“ 52.5 Lbs 14°F to 104°F -40°F to 85°F

Base Model

Standard Duty

Heavy Duty

(1.27-20.3 m/m) (0.6 - 1.6 mm) (0.9 - 2.0 mm)

CONTROL BOX, WIRE DRIVE AND COMPLETE UNITS

PHYSICAL SIZE• TEMPERATURE RATING

and Current Height Width Depth Weight Operating Storage

( 282 mm) (259 mm) (328 mm)

Dimensions ∆

Height Width Depth Weight

Dimensions ∆

Height Width Depth Weight

15.3“ 13.0“ 27.7“ 67.5 Lbs

43 Lbs

26.5 Lbs (12.0 Kg)

WELDING CAPACITY RATING

Amp Rating Duty Cycle

500 A 60% 400 A 100%

∆ Dimensions do not include wire reel.

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LF-72/74

A-3 A-3

INSTALLATION

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 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.

----------------------------------------------------------------------------------------

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.

MOUNTING

For location and size,

Mounting Holes (See Figure A.1) and for Mounting Holes (See Figure A.2).

LF-72 Bench Model Rear

FIGURE A.1

Bottom

FIGURE A.2

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LF-72/74

A-4 A-4

INSTALLATION

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 welding power source (CV-xxx and DC-xxx product family only).

Bench Mount

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.

Swivel Kit and Bench Model, Standard Duty

Swivel Kit and Base Model LF-72

WARNING

Alternative methods for hanging the wire feeder must not be used unless insulation is provided between the wire feeder enclosure and the hanging device.

------------------------------------------------------------------------

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LF-72/74

A-5 A-5

INSTALLATION

SAFETY PRECAUTION

ELECTRIC SHOCK can kill.

• Only qualified personnel should perform this installation.

• Do not touch electrically hot parts.

----------------------------------------------------------------------

WELD CABLE SIZES

Table A.1 has the copper cable sizes recommended for different currents and duty cycles. Lengths stipulated 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 minimizing voltage in the welding circuit.

Amperes

200 200 225 225 250

250 250 250 300

325 350 400 400 500

TABLE A.1

RECOMMENDED CABLE SIZES (RUBBER COVERED COPPER - RATED 75°C)**

CABLE SIZES FOR COMBINED LENGTHS OF ELECTRODE AND WORK CABLES

Percent

Duty

Cycle

100

40 & 30

40 60

100

60 60

100

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

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

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

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

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

** 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.

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LF-72/74

A-6 A-6

El ectrode

Work

Power Source

Work

Electrode

Wire Feeder

Electrode

Work

Coaxial Weld Cable

INSTALLATION

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 connections can result in poor welding performance.

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LF-72/74

A-7 A-7

POWER SOURCE WIRE FEEDER

INSTALLATION

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 environment.

The wire feeder power requires overcurrent protection. 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

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between the wire feeder and power source.

LF-72/74

A-8 A-8

IRE FEEDERPOWER SOURCE

NOTES

ANALOG MILLER CONTROL CABLE ADAPTER K2335-1

This Lincoln Electric wire feeder may be mounted to a limited 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.

MILLER POWER SOURCE

Pin Function

A 24 VAC to feeder

Pin Function

I 42 VAC feeder

LINCOLN WIRE FEEDER

D Welding Output Control B Welding Output Control C +10VDC to feeder for remote control

C Welding Output Control

E Remote Voltage Control ("+" supply, from

power source)

D Remote control common

G Remote Voltage Control ("-" supply, from

power source)

E 0-10VDC from feeder for remote control.

F Remote Voltage Control (control signal from

feeder or remote.)

F Current feedback to feeder.

J Reserved for future use. Scaled 0-10V. 1 V = 100 amps. Referenced to pin D.

G 24 VAC common. H Arc Voltage feedback to feeder.

K 42 VAC to feeder

L Reserved for future use. Scaled 0-10V. 1 V = 10 Arc volts. Referenced to pin D.

I J K L M N

Miller is a registered trademark not owned or licensed by The Lincoln Electric Company.

N Electrode voltage to power source (67)

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LF-72/74

A-9 A-9

elding Gun

ire Feeder

mphenol

Trigger Lead

INSTALLATION

WELDING GUN/WIRE FEEDER TRIGGER CONNECTOR

Wire Feeder

Pin Function A Gun Trigger BC Common DE-

HIGH FREQUENCY PROTECTION

Locate the LF-72 away from radio controlled machinery. The normal operation of the LF-72 may adversely affect the operation of RF controlled equipment, which may result in bodily injury or damage to the equipment

REMOTE SENSE LEAD SPECIFICATIONS

Refer to the power source instruction manual for instructions for connecting the wire feeder for STT welding.

WIRE DRIVE SYSTEMS

Drive Roll Kits are designed to feed specific types and wire sizes. The LF-72 Bench Model comes with the combo not included, but are available for ordering from the following tables:

Drive Roll Kits, Steel Wires

Includes: 2 Smooth V groove drive rolls and an inner wire guide.

Drive Roll Kits, Cored Wires

Includes: 2 Knurled drive rolls and an inner wire guide.

KP1696-1. All other Drive Roll Kits listed are

KP1696-030S .023-.030 (0.6-0.8mm) KP1696-035S .035 (0.9mm) KP1696-045S .045 (1.2mm) KP1696-052S .052 (1.4mm) KP1696-1/16S 1/16 (1.6mm)

KP1696-1 .035, .O45 (0.9, 1.2mm)

KP1696-2 .040 (1.0mm)

KP1697-035C .030-.035" (0.8-0.9mm) KP1697-045C .040-.045" (1.0-1.2mm) KP1697-052C .052" (1.4mm) KP1697-1/16C 1/16" (1.6mm) KP1697-068 .068-.072" (1.7-1.8mm) KP1697-5/64C 5/64" (2.0mm)

Drive Roll Kits, Aluminum Wire

Includes: 2 polished U groove drive rolls, outer wire guide and an inner wire guide.

KP1695-035A .035" (0.9 mm) KP1695-040A .040" (1.0mm) KP1695-3/64A 3/64" (1.2mm) KP1695-1/16A 1/16" (1.6mm)

DRIVE ROLLS INNER WIRE GUIDE

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LF-72/74

A-10 A-10

WIRE DRIVE UNIT

GUN RECEIVER BUSHING (INTERCHANGABLE)

TRIGGER RECEPTACLE

LF-72 BASE MODEL

GUN TRIGGER

CONNECTOR

CABLE CONNECTOR END K466-10

GUN NOZZLE

GUN HANDLE

GUN TUBE

GUN AND CABLE

INSTALLATION

WELDING GUNS, TORCHES AND ACCESSORIES

GUN RECEIVER BUSHING

The LF-72 wire feeder comes with a K1500-2 gun receiver bushing.

MAGNUM GUN AND CABLE ASSEMBLIES

The LF-72 wire feeder model will accept a number of optional gun and cable assemblies. An example of installing the Gun and Cable is shown in Figure A.3 with a 15 ft. (4.6m) long Magnum 400 gun and cable.

1. Turn off power at the welding power source.

2. Unscrew Thumb screw on Wire Drive Unit, until tip of screw no longer protrudes into gun bushing hole as seen from the front of machine.

FIGURE A.3

3. Fully insert the gun cable connector end into the gun receiver bushing and gently tighten the thumb screw as show in Figure A.3 below.

4. Connect the gun trigger connector to the trigger receptacle. Make sure that the key ways are aligned and insert.

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LF-72/74

A-11 A-11

GUN RECEIVER BUSHING

LOOSEN TIGHTEN

THUMB SCREW

OUTER WIRE GUIDE

SOCKET HEAD CAP SCREW

CONNECTOR BLOCK

INSTALLATION

PROCEDURE FOR CHANGING DRIVE AND IDLE ROLL SETS

(See Figure A.4 )

WARNING

ELECTRIC SHOCK can kill.

• Turn the input power OFF at the welding power source before installation or changing drive rolls and/or guides.

• Do not touch electrically live parts.

• When inching with the gun trigger, electrode and drive mechanism are "hot" to work and ground and could remain energized several seconds after the gun trigger is released.

• Only qualified personnel should perform maintenance work.

-----------------------------------------------------------------------

1. Turn power off at the welding power source.

2. Release the idle roll pressure arm.

3. Remove the outer wire guide by turning the knurled

thumbscrews counter-clockwise to unscrew them from the feed plate.

4. Rotate the triangular lock and remove the drive

WIRE DRIVE CONFIGURATION

(See Figure A.5)

Changing the Gun Receiver Bushing

WARNING

ELECTRIC SHOCK can kill.

• Turn the input power OFF at the disconnect switch or fuse box before attempting to connect or disconnect input power lines, output cables or control cables.

• Only qualified personnel should perform this installation.

------------------------------------------------------------------------

Tools required:

• 1/4" hex key wrench

Note: Some gun bushings do not require the use of

the thumb screw.

1. Turn power off at the welding power source.

2. Remove the welding wire from the wire drive.

3. Remove the thumb screw from the wire drive.

4. Remove the welding gun from the wire drive.

5. Remove the inner wire guide.

6. Insert the new inner wire guide, groove side out,

7. Install a drive roll on each hub assembly secure

8. Install the outer wire guide by aligning it with the

9. Close the idle arm and engage the idle roll pressure

rolls.

FIGURE A.4

over the two locating pins in the feed plate.

with the triangular lock.

pins and tightening the knurled thumbscrews.

arm. Adjust the pressure appropriately.

5. Loosen the socket head cap screw that holds the connector bar against the gun bushing. Important: Do not attempt to completely remove the socket head cap screw.

6. Remove the outer wire guide, and push the gun bushing out of the wire drive. Because of the precision fit, light tapping may be required to remove the gun bushing.

FIGURE A.5

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LF-72/74

A-12 A-12

ALUMINUM

OUTERSHIELD

METALSHIEL D INNERSHIELD

STEEL

STAINLESS

COR E D WI RES

SOLID WIRES

INSTALLATION

7. Disconnect the shielding gas hose from the gun bushing, if required.

8. Connect the shielding gas hose to the new gun bushing, if required.

9. Rotate the gun bushing until the thumb screw hole aligns with the thumb screw hole in the feed plate. Slide the gun receiver bushing into the wire drive and verify the thumb screw holes are aligned.

10. Tighten the socket head cap screw.

11. Insert the welding gun into the gun bushing and

tighten the thumb screw.

Gun Receiver For use With Bushing

K1500-1 K466-1 Lincoln gun connectors;

Innershield and Subarc guns)

K1500-2 K466-2, K466-10 Lincoln gun

connectors; Magnum 200/300/400 guns and compatible with Tweco® #4)

PRESSURE ARM ADJUSTMENT

WARNING

ELECTRIC SHOCK can kill.

• Turn the input power OFF at the welding power source before installation or changing drive rolls and/or guides.

• Do not touch electrically live parts.

• When inching with the gun trigger, electrode and drive mechanism are "hot" to work and ground and could remain energized several seconds after the gun trigger is released.

• Only qualified personnel should perform maintenance work.

------------------------------------------------------------------------

The pressure arm controls the amount of force the drive rolls exert on the wire. Proper adjustment of the pressure arm gives the best welding performance.

Set the pressure arm as follows (See Figure A.6):

Aluminum wires between 1 and 3 Cored wires between 3 and 4 Steel, Stainless wires between 4 and 6

K1500-3 K1637-7 Lincoln gun connectors;

Magnum 550 guns and compatible with Tweco® #5)

K1500-4 K466-3 Lincoln gun connectors;

compatible with Miller® guns.)

K1500-5 (Compatible with Oxo® guns.)

K489-7 ( Lincoln Fast-Mate guns.)

FIGURE A.6

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LF-72/74

A-13 A-13

INSTALLATION

WIRE REEL LOADING

WARNING

• Keep hands, hair, clothing and tools away from rotating equipment.

• Do not wear gloves when threading wire or changing wire spool.

• Only qualified personnel should install, use or service this equipment.

-----------------------------------------------------------------------

Loading 10 to 15 lb. (4.5 – 6.8kg) Spools

A K468 spindle adapter is required for loading 2" wide spools on 2" (51mm) spindles. Use a K468-1 spindle adapter for loading 2-1/2" (64mm) wide spools. (See figure A.7 and figure A.8)

1. Squeeze the release bar on the retaining collar and remove it from the spindle.

2. Place the spindle adapter on the spindle, aligning the spindle brake pin with the hole in the adapter.

3. Place the spool on the spindle and align the adapter brake tab with one of the holes in the back side of the spool. An indicator mark on the end of the spindle shows the orientation of the brake tab. Be certain the wire feeds off of the spool in the proper direction.

4. Re-install the retaining collar. Make sure that the release bar snaps out and that the retaining collar fully engages the groove on the spindle.

FIGURE A.7

Adapter

Spindle Placement

The wire reel stand provides two mounting locations for the spindle. Each mounting location consists of a tube in the center of the mast and locating slots.

Loading 16 to 44 lb. (7.3 – 20kg) Spools

(See figure A.8)

1. Squeeze the release bar on the retaining collar and remove it from the spindle.

2. Place the spool on the spindle, aligning the spindle brake pin with one of the holes in the back side of the spool. An indicator mark on the end of the spindle shows the orientation of the brake holding pin. Be certain the wire feeds off of the spool in the proper direction.

3. Re-install the retaining collar. Make sure that the release bar snaps out and that the retaining collar fully engages the groove on the spindle.

FIGURE A.8

Retaining Collar

Loading 30 lb. (13.6 kg) Readi-Reels

(See Figure A.9)

A K363-P Readi-Reel adapter is required for loading these spools on 2" (51mm) spindles.

1. Squeeze the release bar on the retaining collar and remove it from the spindle.

2. Place the Readi-Reel adapter on the spindle, aligning the spindle brake pin with one of the holes in the adapter.

3. Re-install the retaining collar. Make sure that the release bar snaps out and that the retaining collar fully engages the groove on the spindle.

4. Rotate the spindle and adapter until the retaining spring is at the 12 o’clock position.

5. Position the Readi-Reel so that electrode de-reels in the proper direction.

6. Set one of the Readi-Reel inside cage wires on the

slot in the retaining spring.

7. Lower the Read-Reel to depress the retaining

spring and align the other inside cage wires with the grooves in the adapter.

8. Slide the cage all way onto the adapter until the

retaining spring "pops up" fully.

Removing a Readi-Reel

1. To remove a Readi-Reel from the an adapter, depress the retaining spring with a thumb while pulling the Readi-Reel cage from the adapter with both hands. Do not remove the adapter from the spindle.

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LF-72/74

A-14 A-14

INSTALLATION

FIGURE A.9

WELD WIRE ROUTING

The electrode supply may be either from reels, ReadiReels, spools, or bulk packaged drums or reels. Observe the following precautions:

a) The electrode must be routed to the wire drive unit

so that the bends in the wire are at a minimum, and also that the force required to pull the wire from the reel into the wire drive unit is kept at a minimum.

b) The electrode is “hot” when the gun trigger is

pressed and must be insulated from the boom and structure.

c) If more than one wire feed unit shares the same

boom and are not sharing the some power source output stud, their wire and reels must be insulated from each other as well as insulated from their mounting structure.

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LF-72/74

A-15 A-15

INSTALLATION

SHIELDING GAS CONNECTION

CYLINDER may explode if damaged.

• Keep cylinder upright and chained to support.

• Keep cylinder away from areas where it may be damaged.

• Never lift welder with cylinder attached.

• Never allow welding electrode to touch cylinder.

• Keep cylinder away from welding or other live electrical circuits.

------------------------------------------------------------------------

BUILD-UP OF SHIELDING GAS may harm health or kill.

• Shut off shielding gas supply when not in use.

SEE AMERICAN NATIONAL STANDARD Z-49.1, "SAFETY IN WELDING AND CUTTING" PUBLISHED BY THE AMERICAN WELDING SOCIETY.

------------------------------------------------------------------------

Maximum inlet pressure is 100 psi. (6.9 bar.)

5. Attach one end of the inlet hose to the outlet fitting of the flow regulator. Attach the other end to the welding system shielding gas inlet. Tighten the union nuts with a wrench.

6. Before opening the cylinder valve, turn the regulator adjusting knob counterclockwise until the adjusting spring pressure is released.

7. Standing to one side, open the cylinder valve slowly a fraction of a turn. When the cylinder pressure gage stops moving, open the valve fully.

8. The flow regulator is adjustable. Adjust it to the flow rate recommended for the procedure and process being used before making a weld.

Install the shielding gas supply as follows:

1. Secure the cylinder to prevent it from falling.

2. Remove the cylinder cap. Inspect the cylinder valves and regulator for damaged threads, dirt, dust, oil or grease. Remove dust and dirt with a clean cloth. DO NOT ATTACH THE REGULATOR IF OIL, GREASE OR DAMAGE IS PRESENT! Inform your gas supplier of this condition. Oil or grease in the presence of high pressure oxygen is explosive.

3. Stand to one side away from the outlet and open the cylinder valve for an instant. This blows away any dust or dirt which may have accumulated in the valve outlet.

4. Attach the flow regulator to the cylinder valve and tighten the union nut(s) securely with a wrench. Note: if connecting to 100% CO

ulator adapter between regulator and cylinder valve. If adapter is equipped with a plastic washer, be sure it is seated for connection to the CO

cylinder, insert reg-

cylinder.

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LF-72/74

A-16 A-16

"O" RING

INSTALLATION

INSTALLING ELECTRODE CONDUIT KITS

WARNING

ELECTRIC SHOCK can kill.

• Turn the input power OFF at the disconnect switch before working on this equipment.

• Do not touch electrically hot parts.

------------------------------------------------------------------------

Electrode conduit is used when feeding wire drums, from boxes or large reels. For best feeding results, use the shortest conduit length possible and avoid bends.

(For Codes 11075, 11076, 11077)

Tools required: (See Figure A.10a)

• Snap Ring Pliers

To install Lincoln conduit:

sharp

(For Codes 11209, 11210, 11211 and above)

To install Lincoln conduit:

1. Turn off power at the welding power source.

2. Remove the “O” ring holding the ball bushing assembly to the back of the wire feeder. Remove the ball bushing assembly.

(See Figure A.10b)

FIGURE A.10b

1. Turn off power at the welding power source.

2. Remove the snap ring holding the ball bushing assembly to the back of the wire feeder. Remove the ball bushing assembly.

FIGURE A.10a

3. Place a K1546-xx conduit connector into the back of the wire drive. Rotate the conduit connector to a position where the thumb screw does not interfere with the idle arm or door.

4. Tighten the set screw to secure the conduit connector in the wire drive.

5. Insert conduit through the sheet metal of the LF-72 and into the conduit connector. Secure with the thumb screw.

FIGURE A.11

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LF-72/74

A-17 A-17

"O" RING

INSTALLATION

ALUMINUM WIRE PREPARATIONS

WARNING

ELECTRIC SHOCK can kill.

• Turn the input power OFF at the disconnect switch before working on this equipment.

• Do not touch electrically hot parts.

-----------------------------------------------------------------------Welding with aluminum filler wires requires extra care. Aluminum wire is softer and not as stiff as steel wires, it is important to keep aluminum wire free of dirt and scratches. Limit gun length to 10 Ft.(3.0 m) for best results and use a spool cover if feeding from a spool.

To prevent scratching of the aluminum wire, remove the ball bearings from the ball housing as follows.

(For Codes 11075, 11076, 11077)

Tools required: (See Figure A.12a)

• Snap Ring Pliers

• 9/64" Hex key wrench

FIGURE A.12a

(For Codes 11209, 11210, 11211 and above)

Tools required: (See Figure A.12b)

• 9/64" Hex key wrench

1. Turn off power at the welding power source.

2. Remove the snap ring holding the ball bushing assembly to the back of the wire feeder. Remove the ball bushing assembly.

1. Turn off power at the welding power source.

2. Remove the snap ring holding the ball bushing assembly to the back of the wire feeder. Remove the ball bushing assembly.

FIGURE A.12b

3. Remove the three socket head cap screws from the

ball bushing assembly. Caution: as the screws are

being loosened, the balls may fall free from the assembly.

4. Place the ball bushing housing into the wire feeder case and secure with the snap ring or “O” ring depending on which code your machine uses.

Remove the balls and the steel washer.

FIGURE A.13

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LF-72/74

A-18 A-18

INSTALLATION

BASE MODEL

BENCH MODEL STANDARD DUTY

BENCH MODEL HEAVY DUTY

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LF-72/74

A-19 A-19

INSTALLATION

TYPICAL SYSTEM CONFIGURATIONS

The LF-72 is capable of welding with many different welding processes. These processes may require reconfiguring 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)

---

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LF-72/74

A-20 A-20

NOTES

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LF-72/74

Section B-1 Section B-1

TABLE OF CONTENTS

- OPERATION SECTION -

Operation ................................................................................................................Section B

Safety Precautions .......................................................................................................B-2

Graphic Symbols..........................................................................................................B-2

Common Welding Abbreviations..................................................................................B-3

Product Description......................................................................................................B-3

Recommended Processes and Required Equipment..................................................B-3

Front Panel Controls and Connections........................................................................B-4

1. Remote Voltage Control Kit (Optional)................................................................B-5

2. Burnback and Postflow Timer Kit (Optional) ......................................................B-5

3. Thermal LED, Motor Overload............................................................................B-5

4. Cold Feed/Gas Purge Switch .............................................................................B-5

5. 2 Step - Trigger Interlock Switch.................................................................B-5/B-6

6. Wire Feed Speed Knob ......................................................................................B-6

7. Gun Receiver Bushing ........................................................................................B-6

8. Trigger Connector 5-Pin Amphenol ....................................................................B-6

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LF-72/74 SINGLE/DUAL

B-2 B-2

OPERATION

SAFETY PRECAUTIONS

Read this entire section of operating instructions before operating the machine.

WARNING

ELECTRIC SHOCK can kill.

• Unless using cold feed feature, when feeding with the gun trigger, the electrode and drive mechanism are always electrically energized and could remain energized several seconds after welding ceases.

• Do not touch electrically live parts or electrodes with your skin or wet clothing.

• Insulate yourself from the work and ground.

• Always wear dry insulating gloves.

-------------------------------------------------------------

ONLY QUALIFIED PERSONS SHOULD INSTALL, USE OR SERVICE THIS EQUIPMENT. READ AND FOLLOW THE MANUFACTURER’S INSTRUCTIONS, EMPLOYER’S SAFETY PRACTICES AND MATERIAL SAFETY DATA SHEETS (MSDS) FOR CONSUMABLES.

The serviceability of a product or structure utilizing the LF-72 wire feeder is and must be the sole responsibility of the builder/user. Many variables beyond the control of The Lincoln Electric Company affect the results obtained in using the LF-72 wire feeder. These variables include, but are not limited to, welding procedure, plate chemistry and temperature, weldment design, fabrication methods and service requirements. The available range of the LF-72 wire feeder may not be suitable for all applications, and the builder/user is and must be solely responsible for welding settings.

GRAPHIC SYMBOLS THAT APPEAR ON THIS MACHINE OR IN THIS MANUAL

COLD FEED

POSITIVE OUTPUT

NEGATIVE OUTPUT

-----------------------------------------------------------

READ THIS WARNING, PROTECT YOURSELF & OTHERS.

FUMES AND GASES can be dangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust at the arc, or both, to keep fumes and gases from your breathing zone and general area.

WELDING SPARKS can cause fire or explosion.

• Do not weld near flammable material.

• Do not weld on containers which have held flammable material.

ARC RAYS can burn.

• Wear eye, ear, and body protection.

PROTECTIVE GROUND

WARNING OR CAUTION

DANGEROUS VOLTAGE

SHOCK HAZARD

WELDING FUMES

EXPLOSION

GAS INPUT

-----------------------------------------------------------

Observe additional guidelines detailed in the beginning of this manual.

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LF-72/74

WORK CONNECTION

B-3 B-3

OPERATION

PROCESS LIMITATIONS

COMMON WELDING ABBREVIATIONS

• Rated for up to 1/16(1.6 mm) solid electrode and 5/64

WFS

• Wire Feed Speed

• Constant Voltage

GMAW (MIG)

• Gas Metal Arc Welding

FCAW (Cable Innershield or Outershield)

• Flux Core Arc Welding

(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) diameter; 4 inch (100mm)

• For K2327-3 Bench model, heavy duty: Maximum spool size = 60 lb. (27.2 kg)

REQUIRED EQUIPMENT

PRODUCT DESCRIPTION

General Physical Description

Lincoln’s LF-72 is designed for use with the CV and DC family of power sources. These include:

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 combine to make an easy to install, easy to use wire feeder 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 components 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 welding 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.

• 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.

RECOMMENDED PROCESSES

• GMAW .023-1/16 (0.6 - 1.6 mm) steel electrodes.

• FCAW .035 -5/64 (0.9 - 2.0mm) cored electrodes

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LF-72/74

B-4 B-4

OPERATION

FRONT PANEL CONTROLS AND CONNECTIONS

FIGURE B.1 CASE FRONT CONTROLS

ITEM DESCRIPTION

3 Thermal LED, Motor Overload.

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

5 2 step - Trigger Interlock switch.

6 Wire Feed Speed Knob.

Location for Optional

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

Press the switch down for gas flow with weld output off.

Remote Voltage Control

(See Accessory Section For Kit Number).

7 Gun Receiver Bushing.

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

for detail.

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