Lincoln Electric IM502 User Manual

IM502-A

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LN-742 & LN-742H Wire Feeders

For use with machines having Code Numbers:

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.

NOT INSTALL, OPERATE OR
REPAIR THIS EQUIPMENT
WITHOUT READING THIS
MANUAL AND THE SAFETY
PRECAUTIONS CONTAINED
THROUGHOUT.

importantly, think before you act
and be careful.

And, most

DO

June, 2000

10029
10030
10234
10235
10236
10237
10046
10047

Date of Purchase:
Serial Number:
Code Number:
Model:
Where Purchased:

OPERATOR’S MANUAL

• World's Leader in Welding and Cutting Products •

• Sales and Service through Subsidiaries and Distributors Worldwide •

Cleveland, Ohio 44117-1199 U.S.A. TEL: [phone] FAX: [phone] WEB SITE: www.lincolnelectric.com

i

SAFETY

i

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.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.

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

possible to the area being welded.

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

Mar ‘95

ii

SAFETY

ii

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.

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.

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.

5.b.

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.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

vapors

to

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

iv

SAFETY

iv

PRÉCAUTIONS DE SÛRETÉ

Pour votre propre protection lire et observer toutes les instructions
et les précautions de sûreté specifiques qui parraissent dans ce
manuel aussi bien que les précautions de sûreté générales suiv-
antes:

Sûreté Pour Soudage A 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 branchéà 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 sûretéà leur
place.

Mar. ‘93

for selecting a QUALITY product by Lincoln Electric. We want you

Thank You

to take pride in operating this Lincoln Electric Company product

••• as much pride as we have in bringing this product to you!

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.

Model Name & Number _____________________________________

Code & Serial Number _____________________________________

Date of Purchase _____________________________________

Whenever you request replacement parts for or information on this equipment always supply the information
you have recorded above.

vv

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.

CAUTION

This statement appears where the information must be followed to avoid minor personal injury or damage to
this equipment.

TABLE OF CONTENTS

Page

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

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

Technical Specifications - LN-742 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Mounting Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

Input Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

Work Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5

Gun and Cable Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5

Gun Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5

Water Connections (For Water Cooled Guns) . . . . . . . . . . . . . . . . . . . . . A-6

GMAW Shielding Gas Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7

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

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Recommended Processes and Equipment . . . . . . . . . . . . . . . . . . . . . . . B-1

Controls and Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2

Acceleration Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

English or Metric Speed Display Units . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

Circuit Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

Drive Roll Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

Idle Roll Pressure Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7

Wire Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-8

Making a Weld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-12

Wire Reel Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-12

vi

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section C

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Flux System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2

Power Input Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

Welding Guns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3

Spindles, Stands, and Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4

Attaching the Wire Reel Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5

Drive Roll Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section D

Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Periodic Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Troubleshooting and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section E

How To Use Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2

Electrical Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F

Parts Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix

LN-742 & LN-742H

A-1

INSTALLATION

TECHNICAL SPECIFICATIONS – LN-742

INPUT VOLTAGE

40 to 42V ±10%, 50/60 Hz, 4.0 Amps

WIRE FEED SPEED

A-1

SYSTEM

LN-742

LN-742H

SYSTEM

LN-742
LN-742H
LN-742
LN-742H

OPERATING

STORAGE

BOTH LN-742 AND LN-742H

2 ROLL FEEDER
WITHOUT WIRE STAND

WIRE SPEED RANGE

50 in. to 770 in. per minute (1.25 to 19.5 m/min)

80 in. to 1200 in. per minute (2.00 to 30.5 m/min)

WIRE DIAMETERS

ELECTRODE

SOLID

SOLID
CORED
CORED

0.025 in. through 1/16 in. (0.6 through 1.6 mm)

0.025 in. through 0.045 in. (0.6 through 1.2 mm)

0.045 in. through 3/32 in. (1.2 through 2.4 mm)

DIAMETER

0.045 in. (1.2 mm)

TEMPERATURE RATING (ALL MODELS)

-4˚F to 104˚F (-20˚C to +40˚C)

-40˚F to 104˚F (-40˚C to +40˚C)

PHYSICAL DIMENSIONS

LENGTH

10.52 in.

(267 mm)

WIDTH

9.76 in.

(247 mm)

HEIGHT

10.89 in.

(277 mm)

TOTAL WEIGHT

LESS ELECTRODE

24.3 lbs

(11.1 kg)

2 ROLL FEEDER
WITH WIRE STAND (K377)

4 ROLL FEEDER
WITHOUT WIRE STAND

4 ROLL FEEDER
WITH WIRE STAND (K377)

ENVIRONMENTAL RATING (ALL MODELS)

21.58 in.

(548 mm)

11.50 in.

(292 mm)

22.56 in.

(573 mm)

IP21 (IEC 974-5)

LN-742 & LN-742H

9.76 in.

(247 mm)

11.60 in.

(295 mm)

11.60 in.

(295 mm)

17.00 in.

(432 mm)

11.11 in.

(282 mm)

17.00 in.

(432 mm)

34.3 lbs

(15.6 kg)

29.0 lbs

(13.2 kg)

39.0 lbs

(17.8 kg)

A-2

MOUNTING LOCATION

INSTALLATION

A-2

The LN-742 wire feeders can be mounted directly on
top of the power source providing that it is secure and
level. The LN-742 can also be mounted to an
undercarriage when portability is required. The LN-742
should be installed upright on a horizontal surface.

A K178-1 mounting platform is available for mounting
the LN-742 to the top of Idealarc power sources. Refer
to Section C, Accessories, for details.

INPUT CABLE CONNECTIONS

Refer to Section C, Accessories, for descriptions of
the various input cable assemblies available for the
LN-742 wire feeder.

WARNING

Turn input power off before connecting the LN-742
wire feeder.

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

For connecting an LN-742 to a specific Lincoln power
source, follow steps 1 through 5, and refer to the
connection diagram in Figure A.3. The welding cable
used must be sized according to the current and the
duty cycle of the application.

With input power disconnected at the source, install
the input cable per connection diagram A.3, and
complete the following instructions:

1. Connect the end of the control cable with the 14­pin cable plug to the mating receptacle on the
power source.

2. Connect the electrode lead to the power source
output terminal of the desired polarity.

3. Referring to Figure A.1, route the other end of the
electrode cable through the large oval hole in the
rear panel of the LN-742 case. Connect the
electrode to the copper strap on the side of the
gearbox using the stud and nut provided.

FIGURE A.1 – INPUT CONTROL CABLE AND

ELECTRODE CABLE CONNECTIONS.

CONTROL

CABLE

NUT

COPPER

LN-742 & LN-742H

STRAP

ELECTRODE

STUD

A-3

INSTALLATION

A-3

4. Connect the remaining end of the control cable
with the eight-socket cable plug to the mating
receptacle on the LN-742.

5. Referring to Figure A.2, install the input cable
under the wire reel mounting stand strain relief
clamp. Remove the screws holding the clamp to
the base of wire reel mounting assembly. Put the
input cable under the clamp and reinstall the
screws.

The connection diagram, Figure A.3, shows the
electrode as positive. To change polarity, turn the
power source off. Reverse the electrode and work
cables at the power source, and set the wire feeder
voltmeter polarity switch on the power source to the
proper polarity.

Pins not listed in the table in Figure A.3 are not
connected on the cable.

If using the K589-1 remote control kit, set the power
source control switch to the “Remote” position.

FIGURE A.2 – STRAIN RELIEF CLAMP.

CONTROL

CABLE

WIRE REEL
MOUNTING
ASSEMBLY

ELECTRODE

CABLE

STRAIN

RELIEF
CLAMP

LN-742 & LN-742H

A-4

INSTALLATION

FIGURE A.3 – LN-742 WIRE FEEDER TO LINCOLN POWER SOURCE – CONNECTION DIAGRAM.

A-4

POWER SOURCE

+

-

LINCOLN

WARNING

ELECTRIC

SHOCK

CAN KILL

TO WORK

ELECTRODE CABLE

K=42

I=41 I=41

TURN INPUT POWER OFF
BEFORE CONNECTING THE
LN-742 WIRE FEEDER.

14 PIN

AMPHENOL

LN-742

WIRE FEEDER

LN-742

INPUT CABLE

ASSEMBLY

K=42

F=76

14-SOCKET BOX RECEPTACLE, FRONT VIEW
AND 14-PIN CABLE PLUG, REAR VIEW

LEAD FUNCTION

PIN

2 TRIGGER CIRCUIT

C

4

D

E

F

G

H

I

K

FUNCTIONS ARE LISTED FOR REFERENCE
ONLY AND EACH MAY OR MAY NOT BE
PRESENT IN YOUR EQUIPMENT.

TRIGGER CIRCUIT

77

OUTPUT CONTROL

76

OUTPUT CONTROL

75

OUTPUT CONTROL

21

WORK

41

42V AC

42

42V AC

H=21 H=21C=2 C=2

G=75 G=75D=4 D=4

F=76E=77 E=77

14-SOCKET BOX RECEPTACLE, REAR VIEW
AND 14-PIN CABLE PLUG, FRONT VIEW

LN-742 & LN-742H

CLEVELAND, OHIO U.S.A

A-5

INSTALLATION

WORK CABLE

Connect a work lead of sufficient size and length
(Table A.1) 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.

TABLE A.1 – WORK LEAD SPECIFICATIONS

Copper Work Cable Size, AWG

Current 60% Up To 50 Ft 50 Ft-100 Ft

Duty Cycle (15.2 m) (15.2-30.4 m)

2

300 Amps 0 (53 mm
400 Amps 00 (67 mm
500 Amps 00 (67 mm
600 Amps 000 (85 mm2) 0000 (107 mm2)

) 00 (67 mm2)

2

) 000 (85 mm2)

2

) 000 (85 mm2)

GUN AND CABLE ASSEMBLIES

A-5

An expanding line of Magnum Fast-Mate gun and
cable assemblies are available to allow welding with
solid and cored electrodes using the GMAW process.
See the appropriate Magnum literature for descriptions
of the 200 to 400 ampere air cooled gun and cables
that are available. Gun cable lengths range from 10 ft.
(3.0m) to 25 ft. (7.6m) and feed electrode sizes .025”
(0.6mm) to 5/64” (2.0mm).

An expanding line of Magnum X-Tractor gun and cable
assemblies provides fume extraction capability for
welding with solid and cored electrodes using the
GMAW process. See the appropriate Magnum
literature for descriptions of the 250 to 400 ampere air
cooled gun and cables that are available. Gun cable
lengths range from 10 ft. (3.0 m) to 15 ft. (4.5 m) and
feed electrode sizes .035” (0.9 mm) to 1/16” (1.6 mm).
These guns require the use of either the K173-1 or
K184* vacuum units.

* Requires S14927-8 connector hose and an S20591 hose adapter.

LN-742 & LN-742H

A-6

t

INSTALLATION

A-6

WATER CONNECTIONS
(FOR WATER COOLED GUNS)

The LN-7 GMA must have a K590-1 Water Solenoid
Kit installed (see Section C, Accessories). Refer to
Figure A.4 and perform the following steps:

The maximum water pressure permitted for use with
the LN-742 is 55 psi (3.8 bar).

NOTE: If not using a Lincoln water cooler, and if your
water cooling device is not designed for use with a
waterline solenoid valve, you may remove the solenoid
and screw the male fitting (after applying sealant)
directly into the brass manifold block.

FIGURE A.4 – WATER CONNECTIONS.

1. Using male 5/8-18 UNF left-hand thread fittings,
connect appropriate water hoses to the coolant
inlet and outlet on the back of the LN-742.
Connect the other ends of these hoses to the
appropriate ports on your water cooling units.

2. In the event the water line fittings on your water
cooled gun are incompatible with the female quick
connects on the front of the LN-742, male quick
connects are provided for installation on 3/16 in.
I.D. hose (customer to provide appropriate
clamps). The feeder connectors self seal when
disconnected.

t

FRONT

BACK

LN-742 & LN-742H

A-7

INSTALLATION

A-7

GMAW SHIELDING GAS HOOKUP

WARNING

Gas under pressure is explosive.
Always keep gas cylinders in an
upright position and chained to the
undercarriage or a stationary
support. See American National
Standard Z-49.1, “Safety In Welding
And Cutting”, published by the
American Welding Society.

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

Customer must provide a cylinder of shielding gas, a
pressure regulator, a flow control valve, and a hose
from the flow valve to the gas inlet fitting of the LN-742.
Install per Figure A.5 and the following:

1. Connect the supply hose from the gas cylinder
flow valve outlet to the 5/8-18 female inert gas
fitting on the back panel of the LN-742.

The LN-742 can be used with any shielding gas
recommended in the electrode’s product literature at a
maximum pressure of 60 psi (4.1 bar). This may
include gasses such as Argon, Helium and Nitrogen
and blended gases such as Ar-He, Ar-N2, Ar-O2,Ar-

CO2, CO2, AR-CO2,-O2.

FIGURE A.5 – SHIELDING GAS HOOKUP.

GAS

SUPPLY

HOSE

LN-742 & LN-742H

B-1

OPERATION

B-1

OPERATING INSTRUCTIONS

Read and understand the entire Operation Section
prior to operating the machine.

SAFETY PRECAUTIONS

WARNING

ELECTRIC SHOCK
can kill.

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

• Insulate yourself from work or
ground.

• Always wear dry insulating
gloves.

GENERAL DESCRIPTION

The LN-742 semiautomatic constant speed wire feeder
is specifically equipped for gas metal arc welding using
flux-cored Outershield electrodes and solid wire. The
LN-742 is also suitable for self-shielded flux-cored
Innershield electrodes, submerged arc welding (if
constant voltage is satisfactory), and other open arc
welding. It has been factory assembled with the
following features:

• Wire feed control [50 to 770 in./min (1.25 to 19.5
m/min) for the LN-742; 80 to 1200 in./min (2.00 to

30.5 m/min) for the LN-742H].

• Factory installed gas solenoid valve and gas
fittings.

• Wire drive uses a permanent magnet motor and
includes tool-less “quick-release” idle roll pressure
arm, outgoing guide tube and gun cable fastening.

• Optional factory installed water solenoid and fittings
for use with water cooled welding guns.

FUMES AND GASES
can be dangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust to

remove fumes from breathing
zone.

WELDING SPARKS
can cause fire or explosion.

• Keep flammable material away.

• Do not weld on containers that

have held combustibles.

ARC RAYS
can burn.

• Wear eye, ear, and body
protection.

Observe additional Safety Guidelines detailed in
the beginning of this manual.

The LN-742 4-Roll is designed to provide the additional
feeding force required when using gun cables over 15
ft (4.6 m) long or when the wire is pulled long distances
(such as when bulk packages are used). Because the
four-roll feeder has twice the contact surface, it can
also help when feeding softer wires by delivering the
same or more feeding force as the two-roll with less
overall wire deformation.

RECOMMENDED PROCESSES AND
EQUIPMENT

The LN-742 is recommended for use in MIG and
Innershield welding applications with constant voltage
power sources with 42 VAC auxiliary power and a 14­pin connector receptacle, such as the Invertec V300­PRO, DC-650-PRO, or Lincoln CV type power
sources.

The LN-742 is capable of the following wire feed
ranges:

• 0.025 to 1/16 in. (0.6 to 1.6 mm) solid wire for gas­metal-arc or CV submerged arc processes.

• 0.045 to 3/32 in. (1.2 to 2.4 mm) cored wire for
Outershield gas-metal-arc processes.

LN-742 & LN-742H