Lincoln Electric LN-25, LN-25 PORTABLE CV, LN-25 PORTABLE CC Service Manual
LN-25 PORTABLE CV/CC
SEMIAUTOMATIC WIRE FEEDER
SVM114-A
June 1995
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. DO NOT INSTALL,
OPERATE OR REPAIR THIS
EQUIPMENT WITHOUT READING THIS MANUAL AND THE
SAFETY PRECAUTIONS CONTAINED THROUGHOUT. And,
most importantly, think before you
act and be careful.
9218
9219
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9383
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10148
10149
10150
SERVICE MANUAL
World's Leader in Welding and Cutting Products Premier Manufacturer of Industrial Motors
Sales and Service through Subsidiaries and Distributors Worldwide
22801 St. Clair Ave. Cleveland, Ohio 44117-1199 U.S.A. Tel. (216) 481-8100
SAFETY
ii
WARNING
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 W elding 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 THA T ALLINSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE PERFORMED ONLY BY QUALIFIED INDIVIDUALS.
ELECTRIC SHOCK can kill.
1.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.
1.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 Iying, 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.
1.c. In semiautomatic or automatic wire welding, the electrode,
electrode reel, welding head, nozzle or semiautomatic
welding gun are also electrically “hot”.
1.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.
1.e. Ground the work or metal to be welded to a good electrical
(earth) ground.
1.f.
Maintain the electrode holder, work clamp, welding cable and
welding machine in good, safe operating condition. Replace
damaged insulation.
1.g. Never dip the electrode in water for cooling.
1.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.
1.i. When working above floor level, use a safety belt to protect
yourself from a fall should you get a shock.
1.j. Also see Items 4.c. and 6.
2.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
the arc rays.
2.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 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.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
irritating products.
3.c. Shielding gases used for arc welding can displace air and
cause injury or death. Always use enough ventilation,
especially in confined areas, to ensure breathing air is safe.
3.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.
ARC RAYS can burn.
2.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.
FUMES AND GASES
can be dangerous.
3.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
vapors
to
form phosgene, a highly toxic gas, and other
3.e. Also see item 7b.
LN-25
Apr. ‘93
SAFETY
iiii
WELDING SPARKS can
cause fire or explosion.
4.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.
4.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.
4.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.
4.d. Do not heat, cut or weld tanks, drums or containers until the
proper steps have been taken to ensure 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).
4.e. Vent hollow castings or containers before heating, cutting or
welding. They may explode.
4.f.
Sparks and spatter are thrown from the welding arc. Wear oil
free protective garments such as leather gloves, heavy shirt,
cuffless trousers, high shoes and a cap over your hair. Wear
ear plugs when welding out of position or in confined places.
Always wear safety glasses with side shields when in a
welding area.
4.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.
4.h. Also see item 7c.
Remember that welding sparks and hot
though
they have
Preparation
for Welding and Cutting of
CYLINDER may explode
if damaged.
5.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.
5.b. Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.
5.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.
5.d. Never allow the electrode, electrode holder or any other
electrically “hot” parts to touch a cylinder.
5.e. Keep your head and face away from the cylinder valve outlet
when opening the cylinder valve.
5.f. Valve protection caps should always be in place and hand
tight except when the cylinder is in use or connected for
use.
5.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.
6.a.Turn off input power using the disconnect
switch at the fuse box before working on
the equipment.
6.b. Install equipment in accordance with the U.S. National
Electrical Code, all local codes and the manufacturer’s
recommendations.
6.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
Mar. ‘93
LN-25
SAFETY
iiiiii
FOR ENGINE
powered equipment.
7.a. Turn the engine off before troubleshooting and maintenance
work unless the maintenance work requires it to be running.
____________________________________________________
7.b. Operate engines in open, well-ventilated
areas or vent the engine exhaust fumes
outdoors.
____________________________________________________
7.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.
____________________________________________________
7.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.
ELECTRIC AND MAGNETIC FIELDS
may be dangerous
8.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
8.b. EMF fields may interfere with some pacemakers, and
welders having a pacemaker should consult their physician
before welding.
8.c. Exposure to EMF fields in welding may have other health
effects which are now not known.
8d. All welders should use the following procedures in order to
minimize exposure to EMF fields from the welding circuit:
8.d.1.
Route the electrode and work cables together - Secure
them with tape when possible.
8.d.2. Never coil the electrode lead around your body.
8.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.
8.d.4. Connect the work cable to the workpiece as close as
possible to the area being welded.
8.d.5. Do not work next to welding power source.
____________________________________________________
7.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.
7.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.
7.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. ‘93
LN-25
SAFETY
iviv
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.
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” CSAStandard
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
zones où l’on pique le laitier.
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.
LN-25
MASTER TABLE OF CONTENTS FOR ALL SECTIONS
Page
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-iv
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section A
Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Power Source Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Gun Cable Connection to Feeder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Weld Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Wire Feed Drive Roll and Guide Tube Kits . . . . . . . . . . . . . . . . . . . . . . A-5
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section B
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Recommended Processes and Equipment . . . . . . . . . . . . . . . . . . . . . . B-2
Welding Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
LN-25 Instruments and Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5
Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-9
Procedure at End of Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-9
Open Arc Welding with a Constant Current Power Source . . . . . . . . . . B-9
Automatic Protection Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-10
vv
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section C
LN-25 Option Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
Remote Output Control Options and Control Cable Assemblies . . . . . . C-4
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section D
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
Circuit Protection and Automatic Shutdown . . . . . . . . . . . . . . . . . . . . . . D-2
Adjusting Speed Sensor Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
Calibration of LN-25 Wire Speed Dial . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section E
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2
Control Circuit Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2
Auxiliary Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-4
Troubleshooting and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F
How to Use Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . F-2
PC Board Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . F-3
Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-4
Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-7
Component Replacement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . F-20
Retest After Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-38
Electrical Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section G
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-3
Operating Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-5
Control PC Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-7
Contactor PC Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-11
Parts Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-175
LN-25
NOTES
vi
TABLE OF CONTENTS
- INSTALLATION SECTION -
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section A
Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Power Source Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
DC-250 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
DC-400 and CV-400 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
DC-600 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
R3S-325 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
SAM-400, -650 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
SA-200, -250 or SAE-300, -400 . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Invertec, CV300 and other newer Lincoln Power Sources . . . . . . . . A-4
Gun Cable Connection to Feeder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Weld Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Electrode Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Work Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Wire Feed Drive Roll and Guide Tube Kits . . . . . . . . . . . . . . . . . . . . . . A-5
Section A
LN-25
A-2
RATED CURRENT
WIRE FEED SPEED
PHYSICAL DIMENSIONS
WIRE DIAMETERS
VOLTAGE
INSTALLATION
TECHNICAL SPECIFICATIONS – LN-25
VOLTAGE
Modes Range
Constant Voltage (CV)
or 15-40 VDC (110VDC Maximum OCV)
Constant Current (CC)
RATED CURRENT
Without Contactor With Contactor
500 Amps 60% Duty Cycle 300 Amps 60% Duty Cycle
WIRE SPEED RANGE
50 – 700 Inches Per Minute (IPM)
A-2
RECOMMENDED ELECTRODE WIRE SIZES
Diameter Wire Type
.023" to 1⁄16" SOLID STEEL WIRE
.035" to 5⁄64" CORED WIRE
.035" to 1⁄16" ALUMINUM WIRE
HEIGHT WIDTH DEPTH WEIGHT
(Handle Down) w/o Options
14 Inches 7.4 Inches 21 Inches 28 lbs
(354 mm) (187 mm) (531 mm) (13 kg)
PHYSICAL DIMENSIONS
LN-25
A-3
INSTALLATION
A-3
SAFETY PRECAUTIONS
WARNING
Unless an optional output control or contactor is used
with the LN-25, the electrode circuit (including welding
wire, wire drive and welding gun) is electrically hot
when the welding power source is on. The gun trigger
controls wire feed only.
Disconnect or shut off welding power source before
making connections or installations to the LN-25.
Welding gun should be stored in the insulated
gun holder, located near the rear on the top of the
LN-25 case, to avoid accidental arcing.
WARNING
ELECTRIC SHOCK can kill.
• Do not touch metal portions
of the LN-25 lead clip when
welding power source is on.
WARNING
ELECTRIC SHOCK can kill.
• Do not operate with covers
removed.
• Turn off power source before
installing or servicing.
• Do not touch electrically
hot parts.
• Turn the input power to the
welding power source off at the
fuse box before working in the
terminal strip.
• Only qualified personnel should
install, use or service this
equipment.
DC-250
POWER SOURCE CONNECTION
The LN-25 can be used with any DC welding power
source. A constant voltage power source is
recommended; however, the LN-25 can also be used
with a constant current power source as long as the
open circuit voltage is less than 110V DC.
CAUTION
Do not use LN-25 models below Code 9200 with any
TIG or Square Wave welding power sources. Do not
use LN-25 models equipped with internal contactors
with non- Lincoln TIG or Square Wave welding power
sources. Damage to the LN-25 circuit can occur as a
result of the high output inductance typically
associated with these power sources. TIG high
frequency power should never be applied to the LN-25.
If not using an LN-25 Remote Output Control option
(See Remote Output Control Options and Cable
Assemblies Section), the power source output must
be electrically “hot” at all times when the power
source is turned on.
a. Connect a jumper from 2 to 4 on the power source
terminal strip so the output will be energized when
the DC-250 is turned on.
b. Connect electrode cable to the “Innershield/
GMAW” output terminal of polarity required by
electrode. Connect work lead to other
“Innershield/GMAW” output terminal.
c. Place “Set to CV Electrode Cable Polarity” switch
at appropriate position.
d. Place power source toggle switch in “Output
Control at DC-250” position, unless a Remote
Control is connected to 75, 76 and 77 on the DC250 terminal strip.
e. Place mode switch in “Innershield GMAW (CV)”
position. Set CV arc control to “2” (or “NORMAL”
on some machines). Initially set the output
control on “7”.
DC-400 AND CV-400
a. Connect a jumper from 2 to 4 on the power
source terminal strip so the output will be
energized when the power source is turned on.
NOTE: DC-400 machines above Code 9200 have
an output toggle switch to perform this function.
See the power source instruction manual for proper
power source connections and setting required.
b.Connect the electrode cable to the output
terminal of polarity required by electrode.
Connect work lead to other output terminal.
LN-25
A-5
INSTALLATION
A-5
Install the barbed fitting and union nut to the 5⁄8-18
female inert gas fitting on the front panel of the LN25 case. Connect the 3⁄16" I.D. gas hose from the gun
cable to the barbed fitting.
When the gun is to be removed, this fitting can be
easily detached by loosening the union nut.
WELD CABLE CONNECTION
The size of the electrode cable and work cable must
be sufficient for the maximum weld current and total
cable length to be used. Refer to table A.1.
TABLE A.1
Weld Current
60% Duty Cycle 50'-100' 100'-150' 150'-200' 200'-250'
200Amps 2 AWG 2 AWG 1 AWG 1/0
300Amps 1 AWG 1 AWG 1/0 2/0
400Amps 2/0 2/0 3/0 3/0
500Amps 2/0 3/0 3/0 4/0
ELECTRODE CABLE CONNECTION
On units without an internal contactor route the
electrode cable through the oval hole in the LN-25 rear
panel, then along the case floor behind the reel
support and around the door side of the wire drive.
Connect the electrode cable to the LN-25 using the
1
⁄2" bolt on the front of the wire drive.
Total Cable Length
WIRE FEED DRIVE ROLL AND
GUIDE TUBE KITS
WARNING
Turn off power source before installing or changing
drive roll and/or guide tubes.
NOTE: The maximum wire sizes the LN-25 will
satisfactorily feed are 5⁄64" cored and 1⁄16" solid
electrodes.
The electrode sizes that can be fed with each roll and
guide tube are stencilled
for proper components. See the instructions, included
with the drive roll kit, to install these parts on new
machines or replace them on used machines. Refer
to table A.2.
Steel Wire Sizes:
.068-5⁄64 Cored KP450-3⁄32 S17984
1
⁄16 (.062) Cored or Solid -1⁄16
Steel
(Can also be used for .052)
.045 and .052 Solid Steel -.052
.045 and .052 Cored -.052C
.023-.035 Solid Steel KP451-.035S S17831
(1)
on each part. Check the kit
TABLE A.2
Kit Instructions
On units with an internal contactor connect the
electrode cable to the LN-25 electrode input cable with
the nut and bolt provided. Tape the bolted connection.
WORK 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.
Aluminum Wire Sizes:
1
⁄16 KP452-
3
⁄64 -3⁄64A
.035 -.035A
(1)
Drive rolls for .045-.052 cored electrode sizes are stencilled with
a “C” suffix to the wire sizes. Drive rolls for aluminum wire sizes
are stencilled with an “A” suffix to the wire sizes.
1
⁄16A S17083
LN-25
NOTES
A-6A-6
LN-25
TABLE OF CONTENTS
- OPERATION SECTION -
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section B
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Recommended Processes and Equipment . . . . . . . . . . . . . . . . . . . . . . B-2
Welding Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
LN-25 Instruments and Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5
Loading Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5
Mounting 22 to 30 lb Readi-Reel Coils . . . . . . . . . . . . . . . . . . . B-5
Mounting 10 to 30 lb Spools . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5
Mounting 13 or 14 lb Innershield Coils . . . . . . . . . . . . . . . . . . . B-5
Loading Wire Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Idle Roll Pressure Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Presetting Wire Feed Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7
Setting Constant Wire Feed Speed (CV Mode) . . . . . . . . . . . . . B-7
Setting Arc Sensing Wire Feed Speed (VV [CC] Mode) . . . . . . B-7
Making a Weld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-8
Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-9
Procedure at End of Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-9
Open Arc Welding with a Constant Current Power Source . . . . . . . . . . B-9
Automatic Protection Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-10
Overvoltage Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-10
Motor Overload Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-10
Section B
LN-25
OPERATION
B-2B-2
SAFETY PRECAUTIONS
READ AND UNDERSTAND ENTIRE SECTION
BEFORE OPERATING MACHINE
WARNING
ELECTRIC SHOCK can kill.
¥Do not touch electrically live
part or electrode with skin or
wet clothing.
¥Insulate yourself from work
and ground.
¥Always wear dry insulating
gloves.
FUMES AND GASSES can
be dangerous.
¥Keep your head out of
fumes.
¥Use ventilation or exhaust to
remove fumes from breath-
WELDING SPARKS can
cause fire or explosion.
¥Keep flammable material
away.
ARC RAYS can burn.
¥Wear eye, ear and body pro-
tection.
GENERAL DESCRIPTION
The LN-25 is a lightweight portable semiautomatic
wire feeder designed for Òacross-the-arcÓ operation
without a control cable on most any DC welding power
source. Simply connect the LN-25 to the electrode
cable, clip it to W ork and it is ready to weld, using up
to 30 lb. coils or spools.
The wire drive, controls and wire reel are fully
enclosed in a rugged molded plastic case providing a
compact and versatile welding package ideally suited
to Òon-the-goÓ field welding applications in virtually any
environment.
RECOMMENDED PROCESSES
AND EQUIPMENT
When combined with the quality drive roll kits and
accessories available for use with the LN-25, a
versatile portable welding system can be provided to
meet the specific needs of Innershield, submerged arc
or gas metal arc welding applications within the wire
feed capabilities of the LN-25.
The LN-25 provides constant wire feed speed for use
with constant voltage (CV) power sources, and arcsensing wire feed speed for use with constant current
(CC) (formerly variable voltage) power sources. W ire
speed is presettable on a dual-range calibrated dial.
The power sources recommended for use with the LN25 include the DC-250, -400, -600, CV -400 and R3S
type transformer machines, and the SAM-400, -650
engine welders, as well as the SA-200, -250 or SAE300, -400 with CV Adapter and Pulse Power 500 with
K460-1 LN-25 Kit.
WELDING CAPABILITY
The LN-25 will handle up to 500 Amp 60% duty cycle
welding currents. However , when equipped with a
K443-1 Contactor , the LN-25 will handle up to 300
Amp 60% duty cycle.
LN-25
OPERATION
B-3B-3
LN-25 INSTRUMENTS AND
CONTROLS
Refer to Figure B.1 for control locations.
FIGURE B.1 Ð CONTROL LOCATIONS.
REMOTE
ARC VOLTAGE
CONTROL
(OPTIONAL)
GAS POST/
PRE FLOW
TIMERS
(OPTIONAL)
ELECTRODE
POLARITY
SWITCH
GAS
FITTING
(OPTIONAL)
GUN
TRIGGER
AMPHENOL
CONNECTOR
WIRE SPEED
DIAL RANGE
SWITCH
WIRE
SPEED
DIAL
VOLT
METER
WORK CLIP
LEAD
GUN
CONNECTION
BLOCK
NOTE:
1. The Voltmeter will read zero if the LN-25 work clip
lead is not connected to work, even if the elec trode is electrically ÒhotÓ to work.
2. The Voltmeter will read below zero if the LN-25
polarity switch is not set to the same polarity as
the electrode.
3. The Voltmeter will read power source open circuit
voltage when the gun trigger is open, even if the
LN-25 is equipped with the internal contactor .
ÒELECTRODE POLARITYÓ SWITCH
The polarity switch is located on the front panel of the
LN-25 case.
Set the switch to the same polarity as the electrode
lead connection to the power source. If the switch is
not set for the correct polarity , the wire feeder will not
operate.
WIRE FEED MODE SWITCH
The CV-VV (CC) Wire Feed Mode switch is located
inside the LN-25 case. The toggle switch extends from
beneath the control box just above the wire drive.
The forward ÒCVÓ position provides constant wire feed
speed mode for use with constant voltage (CV)
welding power sources.
OPTIONAL
GAS INPUT
FITTING
GAS PURGE
BUTTON
ELECTRODE
CABLE
VOLTMETER
(Factory installed on model Codes above 9218)
The 40V DC analog voltmeter is mounted to the front
control panel of the LN-25 and is connected to read
the arc voltage between the LN-25 electrode cable
connection and the work clip lead.
The backward ÒVV (CC)Ó position provides arc-sensing
wire feed speed mode for use with constant current
(formerly variable voltage) welding power sources.
WIRE SPEED DIAL AND RANGE SWITCH
The Wire Speed control dial on the front panel of the
LN-25 has two calibrated dial ranges selected by the
HI-LO Dial Range switch.
When switched to the LO range position, the constant
wire feed speed (CV Wire Feed Mode) is set on the
inside (white) dial range calibrated for 50 to
350 in/min.
When switched to the HI range position, the constant
wire feed speed (CV Wire Feed Mode) is set on the
outside (black) dial range calibrated for 50 to
700 in/min.
The volts marks around the HI range calibrated dial
indicate the minimum arc volts required to obtain the
indicated HI range wire feed speeds. For example; if
wire speed is set to 400 in/min., a welding procedure
LN-25
OPERATION
B-4B-4
arc voltage of at least 17V would be required to obtain
the 400 in/min. wire feed speed.
WORK CLIP LEAD
WARNING
ELECTRIC SHOCK can kill.
• Do not touch metal portions
of the LN-25 lead clip when
welding power source is on.
WARNING
IMPORTANT SAFETY NOTE: To avoid possible
electrical shock, do not touch the metal portions of
the LN-25 work lead clip if the power source output is
on. The clip will be electrically “HOT” to work if the
input electrode cable to the LN-25 is electrically “HOT”
even if the gun trigger is off and even if an internal
contactor is used. Care should be taken to only handle
the LN-25 work clip by its non-metal insulated portions
and/or the welding power source should be turned off
before handling the work clip.
AWG Maximum Length
#14 25 Ft
#12 50 Ft
#10 100 Ft
#6 200 Ft
REMOTE ARC VOLTAGE CONTROL (OPTIONAL)
This rheostat control allows you to control the power
source output arc voltage level. Refer to K444, K444-1
and K444-2 Remote Voltage Kits in the Accessories
section.
GAS FITTING (OPTIONAL)
Provides gas output connection to the welding gun for
the GMAW process. Refer to K430-1 Gas Solenoid Kit
in the Accessories Section.
GAS POST PRE-FLOW TIMERS (OPTIONAL)
Allows for variable adjustment of gas pre-flow & postflow at the start and end of the weld. Refer to K4341 Gas Flow Timer Kit in Accessories Section.
The 15 ft work clip lead attached to the front panel of
the LN-25 case must be connected directly to the work
using the spring clip on the end of the lead.
If not connected, the LN-25 will not operate even if a
K431-1 or K624-1 (42V) Remote Output Control
option (refer to Accessories Section) is used.
However, the electrode will still be electrically “HOT”
when the clip lead is disconnected, if K431-1 or K6241 (42V) Remote Output Control Option, or Internal
Contactor (K443-1), is not used.
NOTE: The clip lead also serves as a work sensing
lead for the LN-25 Voltmeter. If the clip lead is
extended by the user beyond the standard 15 ft.
length, the voltmeter reading will be lower than the
actual arc volts due to the LN-25 motor control current flowing through the resistance of the extended
lead. To minimize this voltmeter error, the following
minimum lead size is recommended for the maximum
extended lengths shown:
LN-25
OPERATION
B-5B-5
SEQUENCE OF OPERATION
LOADING ELECTRODE
WARNING
ELECTRIC SHOCK can kill.
•Unless an optional output
control or internal contactor is
used with the LN-25, the
electrode circuit is electrically
“Hot” when the power source
is on.
• Turn off the power source
while mounting electrode
coils.
MOUNTING 22 TO 30 LB READI-REEL®COILS
The LN-25 is factory equipped with a K363-P ReadiReel®Adapter which is required to load Lincoln 22 to
30 lb Readi-Reel coils.
a. Make certain that the threaded locking collar is
tight and securely locks the adapter on the
spindle (see figure B.2).
b. Rotate the spindle and adapter so the retaining
spring is at the 12 o’clock position.
c. Position the Readi-Reel so that it will rotate in a
clockwise direction when feeding (wire is to be
dereeled from bottom of the coil).
d. Set one of the Readi-Reel inside cage wires on
the slot in the retaining spring tab.
e. Lower the Readi-Reel to depress the retaining
spring and align the other inside cage wires with
the grooves in the molded adapter.
f. Slide cage all the way onto the adapter until the
retaining spring “pops up” fully.
g. To remove Readi-Reel from Adapter, depress re-
taining spring tab with thumb while pulling the
Readi-Reel cage from the molded adapter with
both hands. It is not necessary to remove adapter
from spindle.
h. Load wire into wire drive per Loading Wire Drive
Section.
MOUNTING 10 TO 30 LB SPOOLS
For 12" Diameter Spools:
a. Remove the locking collar and the Readi-Reel
adapter shipped on the 2" diameter spindle
(adapter is not required).
b. Place the spool on the spindle so the brake
holding pin enters one of the holes in the back
side of the spool. Be sure the wire comes off the
spool in a clockwise direction when dereeled from
the bottom of the coil.
c. Replace and tighten the locking collar.
d. See Loading Wire Drive section for loading
instructions.
For 8" Diameter Spools (Requires optional K468
Spindle Adapter for 8" Spools):
a. Remove the locking collar and the Readi-Reel
adapter shipped on the 2" diameter spindle
(adapter is not required).
b. Slide S18221 Spindle Adapter onto the 2" spindle
so the brake holding pin enters the adapter pin
hole.
c. Place the spool on the spindle so the adapter tab
enters one of the holes in the back side of the
spool. Be sure the wire comes off the spool in a
clockwise direction when dereeled from the
bottom of the coil.
d. Replace and tighten the Locking Collar.
WARNING
Check to be sure the retaining spring has fully
returned to the locking position and has securely
locked the Readi-Reel cage in place. Retaining spring
must rest on the cage, not the welding electrode.
e. Load wire into wire drive per Loading Wire Drive
Section.
MOUNTING 13 OR 14 LB INNERSHIELD COILS
(Requires Optional K435 Spindle Adapter for 14 lb
Coils.)
a. Remove the locking collar and the Readi-Reel
adapter shipped on the 2" diameter spindle
(adapter is not required).
b. Mount K435 Spindle Adapter and Innershield coil
per the Instructions (S18256) included with the
K435.
LN-25
OPERATION
FIGURE B.2 Ð READI-REEL INSTALLATION.
B-6B-6
2" O.D.
SPINDLE
BRAKE HOLDING PIN
(MUST ENGAGE HOLE
IN ADAPTER RIB)
LOADING WIRE DRIVE
MOLDED ADAPTER
RETAINING
SPRING
THREAD LOCKING
COLLAR
GROOVES
READI-REEL
INSIDE CAGE
WIRES
f. Inch the electrode through the gun.
a. Turn the reel or spool until the free end of the
electrode is accessible.
b. While tightly holding the electrode, cut of f the bent
end and straighten the first six inches. Cut of f the
first inch. (If the electrode is not properly
straightened, it may not feed or may not go into
the outgoing guide tube causing a ÒbirdnestÓ.)
c. Insert the free end through the incoming guide
tube to the drive roll.
d. Turn on the welding power source.
WARNING
Unless an optional output control or internal contactor
is used with the LN-25, the electrode circuit is
electrically ÒhotÓ when the power source is on.
e. Press the gun trigger and push the electrode until
it just enters the drive roll.
WARNING
When inching with gun trigger , the electrode and drive
mechanism are always ÒhotÓ to work and ground. Use
the ÒcoldÓ inch switch on models with internal
contactor .
g. Adjust the brake tension with the thumbscrew on
the spindle hub until the reel turns freely , but with
little or no overrun when wire feeding is stopped.
Do not overtighten.
CAUTION
Keep gun in LN-25 gun holder when not feeding wire
to prevent accidental arcing.
IDLE ROLL PRESSURE SETTING
The idle roll pressure is set at the factory backed out
two turns from full pressure. This is an approximate
setting. For small wire sizes and aluminum wire, the
optimum idle roll pressure varies with type of wire,
surface condition, lubrication and hardness. The optimum idle roll setting can be determined as follows:
1. Press end of gun against a solid object that is
electrically isolated from the welder output. Press
the gun trigger for several seconds.
2. If the wire Òbirdnests,Ó jams or breaks at the drive
roll, the idle roll pressure is too great. Back the
pressure setting out 1Ú2 turn, run new wire through
gun, and repeat above steps.
3. If the only result is drive roll slippage, shut of f the
power source, then loosen the gun cable clamping
LN-25
OPERATION
B-7B-7
screw in the gearbox conductor block and pull the
gun cable forward about six inches. There should
be a slight waviness in the exposed wire. If there
is no waviness, the pressure is too low . Increase
the pressure setting 1Ú4 turn, lock the gun cable in
place and repeat the above steps.
PRESETTING WIRE FEED SPEED
The LN-25 permits accurate presetting of the desired
wire feed speed, before welding, in both CV and CC
wire feed modes.
SETTING CONSTANT WIRE FEED SPEED (CV
MODE)
a. Set Wire Feed Mode switch to CV position.
b. Set Dial Range switch to LO position for wire feed
speeds up to 350 in/min., or HI position for wire
feed speeds over 350 in/min.
c. Set Wire Feed dial to the desired wire feed speed
on the selected calibrated dial range.
The wire speed will remain constant at the value set,
independent of arc voltage changes, as long as the
arc voltage does not drop below the value per the
chart below for the max. wire feed speed shown:
Maximum Speed Minimum Arc Volts
350 IPM 15V
400 IPM 17V
500 IPM 21V
600 IPM 24V
700 IPM 27V
SETTING ARC SENSING WIRE FEED SPEED
(CC MODE)
When using a constant current (formerly variable
voltage) power source, welding performance is im proved using arc sensing wire feed speed (CC [VV]
mode). In this wire feed mode the wire speed
increases if arc voltage increases, and decreases if
arc voltage decreases, but remains constant at any
specific voltage level.
The LN-25 permits accurate CC mode presetting of
the desired wire feed speed, for the desired arc
voltage to be used, by setting the Wire Speed dial in
the following manner before welding:
FIGURE B.3 Ð CC WIRE SPEED SETTING.
DESIRED IN/MIN ARC VOLTS USED
700
650
600
550
500
450
400
350
300
250
200
150
100
50
50 100 150 200 250 300 350 400 450 500 550 600 650 700
35
31
29
27
25
23
21
19
17
15
CC Wire Speed Setting
(Hl or LO Range)
b. Referring to the graph located above the Mode
switch (also shown in Figure B.3):
1. Select the horizontal line representing the DESIRED IN/MIN. for the welding procedure. (See
example arrow line for 375 in/min.)
2. Select the diagonal line representing the ARC
VOLTS to be used for the welding procedure.
(See example arrow line for 29 volts.)
3. Determine the vertical line representing the CC
WIRE SPEED SETTING where the above two
lines cross. (See example arrow line for 450.)
c. Set the Wire Speed dial to the value determined
in Step (3) above (450 for example used). Use HI
Dial Range if value to be set is over 350.
The wire will feed at the DESIRED IN/MIN speed
when the welding power source is set to the arc
voltage to be used for the weld procedure (375 in/min.
at 29V for example used).
A chart representation of the CC wire speed setting
graph is shown in Figure B.4, giving the Wire Speed
dial setting required for the DESIRED IN/MIN and ARC
VOLTS used for the welding procedures:
a. Set Wire Feed Mode switch to CC position.
LN-25
OPERATION
B-8B-8
FIGURE B.4 Ð CC WIRESPEED SETTING.
Arc Volts Used
Desired
In/Min 16 18 20 22 24 26 28 30 32 34
50 109 97 88 80 73 67 63 58 55 51
60 131 117 105 95 88 81 75 70 66 62
70 153 136 123 111 102 94 88 82 77 72
80 175 156 140 127 117 108 100 93 88 82
90 197 175 158 143 131 121 113 105 98 93
100 219 194 175 159 146 135 125 117 109 103
110 241 214 193 175 160 148 138 128 120 113
120 263 233 210 191 175 162 150 140 131 124
130 284 253 228 207 190 175 163 152 142 134
140 306 272 245 223 204 188 175 163 153 144
150 328 292 263 239 219 202 188 175 164 154
160 350 311 280 255 233 215 200 187 175 165
170 372 331 298 270 248 229 213 198 186 175
180 394 350 315 286 263 242 225 210 197 185
190 416 369 333 302 277 256 238 222 208 196
200 438 389 350 318 292 269 250 233 219 206
210 459 408 368 334 306 283 263 245 230 216
220 481 428 385 350 321 296 275 257 241 226
230 503 447 403 366 335 310 288 268 252 237
240 525 467 420 382 350 323 300 280 263 247
250 547 486 438 398 365 337 313 292 273 257
260 569 506 455 414 379 350 325 303 284 268
270 591 525 473 430 394 365 338 315 295 278
280 613 544 490 445 408 377 350 327 306 288
290 634 564 508 461 423 390 363 338 317 299
MAKING A WELD
SETUP
a. Connect work cable to metal to be welded. W ork
cable must make good electrical contact to the
work. The work must also be grounded as stated
in ÒArc Welding Safety Precautions.Ó
b. Check that the LN-25 is properly connected to the
power source for the polarity and process to be
used, and appropriate power source settings are
made for the procedure to be used. (Refer to
power source operating and connection
instructions.)
NOTE
: If the K431-1 Remote Output Control Kit or
K624-1 42V Remote Control Module is installed but
the LN-25 is to be used without the Remote Control
Cable Assembly , then the Remote Board harness plug
must be removed from the 16-pin receptacle on the
Control Board and the jumper plug (T13498-21)
reinstalled.
c. Place the LN-25 conveniently near the work area
in a location to minimize exposure to weld spatter
and to avoid sharp bends in the gun cable.
d. Connect the LN-25 Clip Lead to work and set Po -
larity Switch to same polarity as electrode.
300 656 583 525 477 438 404 375 350 328 309
310 678 603 543 493 452 417 388 362 339 319
320 700 622 560 509 467 431 400 373 350 329
330 642 578 525 481 444 413 385 361 340
340 661 595 541 496 458 425 397 372 350
350 681 613 557 510 471 438 408 383 360
360 700 630 572 526 484 450 420 394 370
380 666 604 554 512 472 444 416 392
400 700 636 584 538 500 466 438 412
420 668 612 566 526 490 460 432
440 700 642 592 550 514 482 452
460 670 620 576 536 504 472
480 700 646 600 560 526 494
500 674 626 584 546 514
520 700 650 606 568 536
540 676 630 590 556
560 700 654 612 576
580 676 634 598
600 700 656 618
620 678 638
640 700 658
660 680
680 700
700
CC Speed Setting =
Desired IPM
X 35
Arc Volts
e. Set WIRE FEED MODE switch to CV or VV (CC),
as appropriate for the power source, then set the
proper DIAL RANGE and WIRE SPEED dial setting for the proper wire feed speed per the
welding procedure:
For CV: Set dial to the calibrated IN/MIN desired.
(Refer to Setting Constant Wire Feed Speed
Section.)
For CC: Set dial to value determined from the CC
Wire Speed Graph for the DESIRED IN/ MIN
and ARC VOLTS to be used. (Refer to Setting
Arc Sensing Wire Feed Speed Section.)
NOTE: If procedure permits a range of acceptable
arc voltage, use the middle of the range to
determine proper WIRE SPEED setting.
f. If using the optional Gas Flow Timer, set the de-
sired PREFLOW TIME and POSTFLOW TIME.
g. Be sure the proper contact tip for the wire size
being used is in the gun, and the gun is safe
from work contact. (Use the LN-25 insulated
gun holder .)
LN-25
OPERATION
B-9B-9
h. Turn on the welding power source, as well as the
shielding gas supply (if used).
WARNING
Unless an optional output control or internal contactor
is used, the electrode is electrically “hot” when the
power source is on. The gun trigger controls wire
feed only.
WARNING
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.
WELDING
WARNING
ARC RAYS can burn.
c. Lower welding helmet, close gun trigger, and
begin welding. Hold the gun so the contact tip to
work distance gives the correct electrical stickout
as required for the procedure being used.
NOTE: If the arc voltage is not within the proper
procedure range adjust the power source output
control. (The CC mode WIRE SPEED setting should
not be changed from the preset procedure value for
the proper arc voltage.)
d. To stop welding, release the gun trigger and
then pull the gun away from the work. Store the
gun in the LN-25 insulated gun holder when
not welding.
PROCEDURE AT END OF COIL
When the wire on the reel is used up, the following
procedure is to be followed for removing the old wire
from the gun cable and loading a new reel.
a. Shut off power source if a Remote Output Control
Option or internal contactor is not used.
b. Cut the end of the electrode off at the gun end.
Do not break it off by hand since this puts a slight
bend in the wire and makes it difficult or
impossible to pull it back through the nozzle.
c. Uncouple the gun conductor cable from
the LN-25.
d. Lay the cable out straight.
e. Using pliers to grip the wire, pull it out of the
cable from the connector end. Do not pull it from
the gun end.
f. Put the conductor cable back on wire drive unit
after the electrode has been removed.
g. Load a new coil of wire and feed it through the
cable as described in Loading Electrode Section.
•Do not touch metal portions
of the LN-25 lead Clip when
welding power source is on.
a. Cut the electrode within approximately 3⁄8" of the
end of the contact tip for solid wire and within
approximately 3⁄4" of the extension guide for cored
wire.
b. Position electrode over joint. End of electrode
should be slightly off the work.
OPEN ARC WELDING WITH A
CONSTANT CURRENT (formerly
variable voltage) POWER
SOURCE
Although a constant voltage (CV) power source
is recommended for Innershield®and gas metal
arc (GMAW) open arc welding, satisfactory general
purpose welding may be obtained using the
LN-25 with a constant current (CC) power source
for noncritical commercial quality mild steel
welding applications.
LN-25
OPERATION
CAUTION
Do not use LN-25 models below Code 9200 with any
TIG or Square Wave welding power sources. Do not
use LN-25 models equipped with internal contactors
with non-Lincoln TIG or Square Wave welding power
sources. Damage to the LN-25 circuit can occur as
a result of the high output inductance typically
associated with these power sources. TIG high
frequency power should never be applied to the
LN-25.
While welding with a continuously fed electrode, weld
current variations are continuously taking place. There
are many causes for these variations, but
predominantly they occur due to changes in electrical
stickout (operator hand movements, nozzle tip contact
variations, etc.) and the dynamic metal transfer
characteristics of the process or procedure being
used (short arc, globular transfer, etc.).
When using a CV power source, these current
variations have essentially no effect on the welding
arc stability since CV power sources can provide a
wide range of weld current levels with virtually no
change in average arc voltage. These “flat slope” CV
power sources, therefore, provide the arc power
required to produce the best welding characteristics
and ease of operation for most open arc, constant
wire feed speed, welding processes.
CC (formerly VV) power sources, on the other hand,
permit the arc voltage to decrease with increases in
welding current. The output characteristics of these
power sources can range from a “drooping slope,”
which provide minor arc voltage changes with weld
current variations, to “steep slope” which provide
broad voltage changes with only minor current
variations. The steeper the slope the more difficult it
becomes to maintain arc voltage stability with a
constant wire speed open arc process.
B-10B-10
Arc shorting is more difficult to avoid when using
a CC power source, and requires a more refined
operator technique than when using a CV power
source. Improved performance can be obtained
on CC power source applications within the
following guidelines:
1. Flatter slope power sources with higher arc force
(short circuit current) will improve performance
over steep slope machines. The steeper the
slope, the more critical it is to hold proper
electrode stickout to maintain arc stability.
Welding techniques, such as weaving, will be
more difficult to control. Use the highest output
current tap or setting capable of providing the
voltage adjustment required for the procedure.
2. Use spray or non-shorting small ball type transfer
processes at higher procedure voltage levels.
Generally, open arc processes with procedure
voltage levels over 22 volts perform satisfactorily.
Arc stability at procedure voltage levels below 22
volts may be more difficult to control, with the
general exception of fine (.023–.035) solid steel
electrodes with Argon-rich shielding gas or NR-152
and NR-211 Innershield.
AUTOMATIC PROTECTION
SHUTDOWN
The LN-25 control provides automatic electronic
protection circuits which shut down the LN-25 for
excessively high power source open circuit voltage or
excessive motor overload.
OVERVOLTAGE SHUTDOWN
If the power source open circuit voltage exceeds about
110-120 volts, the LN-25 will not operate until the
power source voltage drops below about 102-110
volts.
To aid in stabilizing the arc voltage when welding on
CC power sources the LN-25 is provided with a CC
wire feed mode. This arc voltage sensing feed mode
decreases (or increases) the wire speed when the arc
voltage decreases (or increases). However, if the
electrode shorts to the work, the arc voltage will
essentially drop to zero and the short circuit current
supplied by the CC power source may not provide
enough power to re-establish the arc (especially with
steeper slope machines). Under this condition the
LN-25 feeder will stop, as if the trigger was released,
and not restart until the short has been opened.
MOTOR OVERLOAD SHUTDOWN
If excessive motor overload occurs (due to prolonged
excessive feeding force, jammed drive rolls or shorted
motor leads), the LN-25 will shut down within a few
seconds after the overload occurs.
The shutdown will reset automatically when the gun
trigger is released, but will reoccur if the overload
situation is not remedied.
LN-25
TABLE OF CONTENTS
- ACCESSORIES SECTION -
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section C
LN-25 Option Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
K430-1 Gas Solenoid Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
K434-1 Gas Flow Timer Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
K443-1 LN-25 Contactor Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4
Remote Output Control Options and Control Cable Assemblies . . . . . . C-4
K431-1 Remote Output Control Kit . . . . . . . . . . . . . . . . . . . . . . . . . C-4
K433 Power Source Remote Box . . . . . . . . . . . . . . . . . . . . . . . . . . C-4
K432 Remote Control Cable Assembly . . . . . . . . . . . . . . . . . . . . . . C-4
K439 Remote Extension Cable Assembly . . . . . . . . . . . . . . . . . . . . C-5
K624-1 42V Remote Output Control Module . . . . . . . . . . . . . . . . . . C-5
K625, K626, K627 Remote Control Cable Assembly . . . . . . . . . . . . C-5
K444, K444-1 or K444-2 Remote V oltage Control Kit . . . . . . . . . . . C-5
K557-1 Rear Handle Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5
Section CSection C
LN-25
ACCESSORIES
C-2C-2
How to use Table C.1.
Determine which Kit No. is to be used. Locate that Kit No. in the left hand vertical column.
Scan horizontally to determine which LN-25 model is required and what additional kits may be required.
TABLE C.1
LN-25 OPTION CHART
O=CANNOT BE USED WITH X = REQUIRED ➀ = REQUIRES ONE OF THESE + = INCLUDED WITH
LN-25 MODELS LN-25 KITS
SEE TEXT
KIT NO.
K430-1
K431-1
K432
K433
K434-1
K439
K443-1
K444
K444-1
K444-2
K-624-1
K625
K626
K627
Solenoid
Kit
Remote Output
Control Module
Remote
Control Cable
115VAC
Power Source
Remote Box
Gas Flow
Timer Kit
50 Ft.
Ext. Cable
Contactor
Kit
Remote for Power
Source w/T erminal Strip
Remote for Power
Source w/6 Pin Amphenol
Remote for Power
Source w/14 Pin Amphenol
42VAC Remote
Output Control Module
500 Amp Cable /w Stud-
Type Output Terminals
350 Amp Cable /w Stud-
Type Output Terminals
400 Amp Cable /w Twist-
Mate Type Terminals
K428
LN-25
K446
LN-25
++
X
➀➀ OXXOOOOO
K431-1
K432
K433
K443-1
K444
K444-1
K449
LN-25
XX
XX
➀➀ ➀ ➀
X
K444-2
K624-1
K626
K625
+ OO
➀➀➀ OO
➀➀➀ OO
➀➀➀ OO
➀➀ OO OOOO ➀➀➀
X
X
X
K627
IMPORTANT SAFETY NOTE: This wire feeder provides ÒCOLDÓ electrode when gun trigger is released if
equipped with K431-1 or K624-1 remote output control system, or K443-1 internal contactor kit. This feature
and the use of a DC Constant V oltage welder provide an added margin of safety when welding must be
performed under electrically hazardous conditions such as:
¥ Damp locations ¥ While wearing wet clothing ¥ On metal structures, or , ¥ In cramped positions (sitting, kneeling
or lying) if there is a high risk of unavoidable or accidental contact with the workpiece or ground.
LN-25
OPTIONAL ACCESSORIES
ACCESSORIES
C-3C-3
WARNING
ELECTRIC SHOCK can kill.
•Do not operate with covers
removed.
• Turn off power source before
installing or servicing.
• Do not touch electrically hot
parts.
•Turn the input power to the
welding power source off at
the fuse box before working in
the terminal strip.
•Only qualified personnel
should install, use or service
this equipment.
K430-1 GAS SOLENOID KIT
(Factory Installed on K446 and K449 Models)
The kit permits the LN-25 to be used for Gas Metal
Arc Welding (GMAW) processes with a GMA gun
cable.
The kit can be used with or without a Remote Output
Control option installed in the LN-25 and provides flow
of shielding gas:
1. With wire feed, when the gun trigger is closed.
2. Without wire feed, when the kit’s Purge button
(located beneath the gas inlet fitting) is pressed.
WARNING
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 trom
welding or other live electrical
circuits.
See GMA Gun Cable Gas Connection.
Installation instructions (M17587) are included with the
kit.
K434-1 GAS FLOW TIMER KIT
(Requires either a K431-1 Remote Output Control Kit,
K624-1 42V Remote Output Control Kit, or internal
contactor K443-1 installed in LN-25).
The K434-1 Gas Flow Timer Kit is used with the
LN-25 Gas Solenoid when the LN-25 is equipped
with any of the Remote Output Control Options or
internal contactor.
NOTE: Always shut off the valve at the gas cylinder
before making any gas connections to the LN-25.
User must provide a supply 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-25.
Install by connecting a supply hose from the gas flow
valve outlet to the 5⁄8-18 female inert gas fitting on the
back panel of the LN-25 case.
WARNING
See American National Standard Z-49.1, “Safety in
Welding and Cutting” published by the American
Welding Society.
This kit provides the following gas flow
timer functions:
1. Preflow Control - Provides flow of shielding
gas to the work before the arc is established.
The solenoid valve is energized immediately
when the gun trigger is closed, but the time
delay before the wire feeder and welding output
are energized is adjustable between at least
0 to 1 second.
2. Postflow Control - Provides flow of shielding gas
to the work after welding is stopped. Delay of the
shut off of the solenoid valve after the gun trigger
is released is adjustable between at least 0.5 to
5 seconds.
Installation instructions (M17590) are included with
this kit.
LN-25
ACCESSORIES
C-4C-4
K443-1 LN-25 CONTACTOR KIT
(Factory installed in K449 Model.)
The internal contactor provides “cold” electrode until
the gun trigger is pressed, and a fixed burnback time
delay to prevent electrode from sticking in the weld
crater when the trigger is released. The contactor is
rated for use up to 300 amps. A cold inch switch
allows the wire to be loaded into the system without
being electrically “hot”.
Installation Instructions (L9676) are included with
the kit.
CAUTION
This kit can only be used with LN-25’s above Code
9200 or with LN-25’s equipped with a G1757-3 (or
higher part number) Control PC board. To prevent
possible damage to the LN-25 with internal contactor,
do not connect to non-Lincoln TIG or Square Wave
power sources. TIG high frequency power should
never be applied to the LN-25.
The Kit includes a Remote PC board and control
cable receptacle which mount and connect inside the
LN-25 control box per the Installation Instructions
(M17584) included with the kit.
NOTE: If the K431-1 Remote Output Control Kit is
installed but the LN-25 is to be used without the K432
Remote Control Cable Assembly, then the Remote
Board harness plug must be removed from the 12pin receptacle on the Control Board and the jumper
plug (T13498-21) reinstalled.
K433 POWER SOURCE REMOTE BOX
(Requires K431-1 Remote Output Control Kit installed
in LN-25 using K432 Remote Control Cable.)
The Remote Box is designed to mount and connect
to Lincoln Idealarc®semiautomatic power sources per
the Installation Instructions (M15324) and power
source connection diagrams included with the kit.
The Remote Box provides the proper welding power
source control interface and isolated 24V AC input
supply for the LN-25 equipped with the K431-1
Remote Output Control Kit.
NOTE: The K443-1 cannot be used with K431-1 or
K624-1 Remote Output Control Kit. If remote voltage
control is desired along with the internal contactor,
obtain a K444, K444-1 or K444-2 Remote Voltage
Control Kit.
REMOTE OUTPUT CONTROL
OPTIONS AND CONTROL CABLE
ASSEMBLIES
Remote Output Control Options are available to provide the LN-25 with the following additional features:
1. “Cold” electrode until the gun trigger is pressed,
and a fixed burnback time delay to prevent electrode from sticking in the weld crater when the
gun trigger is released.
2. Remote (10K ohm rheostat) control of power
source output arc voltage level.
K431-1 REMOTE OUTPUT CONTROL
KIT
(For use with K432 Remote Control Cable and K433
Power Source Remote Box.)
Remote Box requires 115V AC, 50/60 Hz input and a
welding power source using a contact closure output
pilot circuit, as available on appropriate Lincoln welding power sources.
K432 REMOTE CONTROL CABLE
ASSEMBLY
(Requires K431-1 Remote Output Control Kit installed
in LN-25 and K433 Remote Box mounted to power
source with 115V AC auxiliary power.)
The K432 control cable assemblies include an electrode cable, rated for up to 500 amps 60% duty cycle,
and a 6-conductor control cable with pin connectors
on both ends. Available in 25, 50, 75 and 100 ft.
lengths.
The cable assembly end with the socket pin connector
connects to the LN-25 per the Instructions (M17584)
included with the K431-1 kit.
The cable assembly end with the male pin connector
connects to the K433 and power source per the Instructions included with the K433 kit.
LN-25
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