Lincoln Electric pmn User Manual

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LN-25 PORTABLE CV/CC

SEMIAUTOMATIC WIRE FEEDER

OPERATING MANUAL

IM359-G

February, 1998

For use with machines having Code Number 10231

10232 10233

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.

• Sales and Service through Subsidiaries and Distributors Worldwide •

Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com

World's Leader in Welding and Cutting Products Premier Manufacturer of Industrial Motors

RETURN TO MAIN MENU

FOR ENGINE powered equipment.

1.a. Turn the engine off before troubleshooting and maintenance work unless the maintenance work requires it to be running.

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1.b. Operate engines in open, well-ventilated areas or vent the engine exhaust fumes outdoors.

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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.

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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.

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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.

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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.

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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.

SAFETY

ARC WELDING CAN BE HAZARDOUS. PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.

Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you purchase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1” from the American Welding Society, P.O. Box 351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety” booklet E205 is available from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.

BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE PERFORMED ONLY BY QUALIFIED INDIVIDUALS.

WARNING

Mar ‘95

ELECTRIC AND MAGNETIC FIELDS may be dangerous

2.a. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF). Welding current creates EMF fields around welding cables and welding machines

2.b. EMF fields may interfere with some pacemakers, and welders having a pacemaker should consult their physician before welding.

2.c. Exposure to EMF fields in welding may have other health effects which are now not known.

2.d. All welders should use the following procedures in order to minimize exposure to EMF fields from the welding circuit:

2.d.1. Route the electrode and work cables together - Secure

them with tape when possible.

2.d.2. Never coil the electrode lead around your body.

2.d.3. Do not place your body between the electrode and

work cables. If the electrode cable is on your right

side, the work cable should also be on your right side.

2.d.4. Connect the work cable to the workpiece as close as

possible to the area being welded.

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

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

CALIFORNIA PROPOSITION 65 WARNINGS

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

The engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.

The Above For Diesel Engines

The Above For Gasoline Engines

SAFETY

ARC RAYS can burn.

4.a. Use a shield with the proper filter and cover plates to protect your eyes from sparks and the rays of the arc when welding or observing open arc welding. Headshield and filter lens should conform to ANSI Z87. I standards.

4.b. Use suitable clothing made from durable flame-resistant material to protect your skin and that of your helpers from the arc rays.

4.c. Protect other nearby personnel with suitable, non-flammable screening and/or warn them not to watch the arc nor expose themselves to the arc rays or to hot spatter or metal.

ELECTRIC SHOCK can kill.

3.a. The electrode and work (or ground) circuits are electrically “hot” when the welder is on. Do not touch these “hot” parts with your bare skin or wet clothing. Wear dry, hole-freegloves to insulate hands.

3.b. Insulate yourself from work and ground using dry insulation. Make certain the insulation is large enough to cover your full area of physical contact with work and ground.

In addition to the normal safety precautions, if welding must be performed under electrically hazardous conditions (in damp locations or while wearing wet clothing; on metal structures such as floors, gratings or scaffolds; when in cramped positions such as sitting, kneeling or lying, if there is a high risk of unavoidable or accidental contact with the workpiece or ground) use the following equipment:

• Semiautomatic DC Constant Voltage (Wire)

Welder.

• DC Manual (Stick) Welder.

• AC Welder with Reduced Voltage Control.

3.c. In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or semiautomatic welding gun are also electrically “hot”.

3.d. Always be sure the work cable makes a good electrical connection with the metal being welded. The connection should be as close as possible to the area being welded.

3.e. Ground the work or metal to be welded to a good electrical (earth) ground.

3.f. Maintain the electrode holder, work clamp, welding cable and welding machine in good, safe operating condition. Replace damaged insulation.

3.g. Never dip the electrode in water for cooling.

3.h. Never simultaneously touch electrically “hot” parts of electrode holders connected to two welders because voltage between the two can be the total of the open circuit voltage of both welders.

3.i. When working above floor level, use a safety belt to protect yourself from a fall should you get a shock.

3.j. Also see Items 6.c. and 8.

FUMES AND GASES can be dangerous.

5.a. Welding may produce fumes and gases hazardous to health. Avoid breathing these fumes and gases.When welding, keep your head out of the fume. Use enough ventilation and/or exhaust at the arc to keep

fumes and gases away from the breathing zone. When

welding with electrodes which require special ventilation such as stainless or hard facing (see instructions on container or MSDS) or on lead or cadmium plated steel and other metals or coatings which produce highly toxic fumes, keep exposure as low as possible and below Threshold Limit Values (TLV) using local exhaust or mechanical ventilation. In confined spaces or in some circumstances, outdoors, a respirator may be required. Additional precautions are also required when welding on galvanized steel.

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

FOR ELECTRICALLY powered equipment.

8.a. Turn off input power using the disconnect switch at the fuse box before working on the equipment.

8.b. Install equipment in accordance with the U.S. National Electrical Code, all local codes and the manufacturer’s recommendations.

8.c. Ground the equipment in accordance with the U.S. National Electrical Code and the manufacturer’s recommendations.

CYLINDER may explode if damaged.

7.a. Use only compressed gas cylinders containing the correct shielding gas for the process used and properly operating regulators designed for the gas and

pressure used. All hoses, fittings, etc. should be suitable for the application and maintained in good condition.

7.b. Always keep cylinders in an upright position securely chained to an undercarriage or fixed support.

7.c. Cylinders should be located:

• Away from areas where they may be struck or subjected to

physical damage.

• A safe distance from arc welding or cutting operations and

any other source of heat, sparks, or flame.

7.d. Never allow the electrode, electrode holder or any other electrically “hot” parts to touch a cylinder.

7.e. Keep your head and face away from the cylinder valve outlet when opening the cylinder valve.

7.f. Valve protection caps should always be in place and hand tight except when the cylinder is in use or connected for use.

7.g. Read and follow the instructions on compressed gas cylinders, associated equipment, and CGA publication P-l, “Precautions for Safe Handling of Compressed Gases in Cylinders,” available from the Compressed Gas Association 1235 Jefferson Davis Highway, Arlington, VA 22202.

iii

SAFETY

iii

Mar ‘95

WELDING SPARKS can cause fire or explosion.

6.a. Remove fire hazards from the welding area. If this is not possible, cover them to prevent

the welding sparks from starting a fire.

Remember that welding sparks and hot materials from welding can easily go through small cracks and openings to adjacent areas. Avoid welding near hydraulic lines. Have a fire extinguisher readily available.

6.b. Where compressed gases are to be used at the job site, special precautions should be used to prevent hazardous situations. Refer to “Safety in Welding and Cutting” (ANSI Standard Z49.1) and the operating information for the equipment being used.

6.c. When not welding, make certain no part of the electrode circuit is touching the work or ground. Accidental contact can cause overheating and create a fire hazard.

6.d. Do not heat, cut or weld tanks, drums or containers until the proper steps have been taken to insure that such procedures will not cause flammable or toxic vapors from substances inside. They can cause an explosion even though they have been “cleaned”. For information, purchase “Recommended Safe Practices for the Preparation for Welding and Cutting of Containers and Piping That Have Held Hazardous Substances”, AWS F4.1 from the American Welding Society

(see address above).

6.e. Vent hollow castings or containers before heating, cutting or welding. They may explode.

6.f. Sparks and spatter are thrown from the welding arc. Wear oil free protective garments such as leather gloves, heavy shirt, cuffless trousers, high shoes and a cap over your hair. Wear ear plugs when welding out of position or in confined places. Always wear safety glasses with side shields when in a welding area.

6.g. Connect the work cable to the work as close to the welding area as practical. Work cables connected to the building framework or other locations away from the welding area increase the possibility of the welding current passing through lifting chains, crane cables or other alternate circuits. This can create fire hazards or overheat lifting chains or cables until they fail.

6.h. Also see item 1.c.

SAFETY

PRÉCAUTIONS DE SÛRETÉ

Pour

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

Sûreté Pour Soudage A L’Arc

1. Protegez-vous contre la secousse électrique:

a. Les circuits à l’électrode et à la piéce sont sous tension

quand la machine à souder est en marche. Eviter toujours tout contact entre les parties sous tension et la peau nue ou les vétements mouillés. Porter des gants secs et sans trous pour isoler les mains.

b. Faire trés attention de bien s’isoler de la masse quand on

soude dans des endroits humides, ou sur un plancher metallique ou des grilles metalliques, principalement dans les positions assis ou couché pour lesquelles une grande partie du corps peut être en contact avec la masse.

c. Maintenir le porte-électrode, la pince de masse, le câble de

soudage et la machine à souder en bon et sûr état defonctionnement.

d.Ne jamais plonger le porte-électrode dans l’eau pour le

refroidir.

e. Ne jamais toucher simultanément les parties sous tension

des porte-électrodes connectés à deux machines à souder parce que la tension entre les deux pinces peut être le total de la tension à vide des deux machines.

f. Si on utilise la machine à souder comme une source de

courant pour soudage semi-automatique, ces precautions pour le porte-électrode s’applicuent aussi au pistolet de soudage.

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.

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.

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.

Mar. ‘93

LN-25

Thank You

for selecting a QUALITY product by Lincoln Electric. We want you to take pride in operating this Lincoln Electric Company product ••• as much pride as we have in bringing this product to you!

Read this Operators Manual completely before attempting to use this equipment. Save this manual and keep it handy for quick reference. Pay particular attention to the safety instructions we have provided for your protection. The level of seriousness to be applied to each is explained below:

WARNING

This statement appears where the information must be followed exactly to avoid serious personal injury or loss of life.

This statement appears where the information must be followed to avoid minor personal injury or dam-

age to this equipment.

CAUTION

Please Examine Carton and Equipment For Damage Immediately

When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims for material damaged in shipment must be made by the purchaser against the transportation company at the time the shipment is received.

Please record your equipment identification information below for future reference. This information can be found on your machine nameplate.

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.

LN-25

SAFETY ...............................................................................................................................................i-iv

INSTALLATION .......................................................................................................................SECTION A

Technical Specifications .....................................................................................................................A-1

Safety Precautions.............................................................................................................................A-2

Power Source Connections ................................................................................................................A-2

Gun Cable Connection to Feeder ......................................................................................................A-3

Weld Cable Connection......................................................................................................................A-4

Electrode Cable Connection ..........................................................................................................A-4

Work Cable Connection.................................................................................................................A-4

Wire Feed Drive Roll and Guide Tube Kits........................................................................................A-4

OPERATION ............................................................................................................................SECTION B

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

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

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

Welding Capability .............................................................................................................................B-1

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

Sequence of Operation ...................................................................................................................... B-4

Loading Electrode..........................................................................................................................B-4

Loading Wire Drive ........................................................................................................................B-5

Idle Roll Pressure Setting ..............................................................................................................B-5

Presetting Wire Feed Speed..........................................................................................................B-6

Making a Weld...............................................................................................................................B-7

Procedure at End of Coil ....................................................................................................................B-8

Automatic Protection Shutdown ......................................................................................................... B-8

ACCESSORIES........................................................................................................................ SECTION C

LN-25 Option Chart ............................................................................................................................C-1

Options and Accessories ........................................................................................................ ...........C-2

K430-1 Gas Solenoid Kit ...............................................................................................................C-2

K434-1 Gas Flow Timer Kit............................................................................................................C-2

K460-1 Pulse Power Adapter Kit ................................................................................................... C-3

K461 Pulse Power Control Cable Assembly ..................................................................................C-3

K443-1 LN-25 Contactor Kit........................................................................................................... C-3

Remote Output Control Options and Control Cable Assemblies........................................................C-3

K431-1 Remote Output Control Kit................................................................................................C-3

K433 Power Source Remote Box..................................................................................................C-3

K432 Remote Control Cable Assembly..........................................................................................C-4

K439 Remote Extension Cable Assembly .....................................................................................C-4

K624-1 42V Remote Output Control Module .................................................................................C-4

K625, K626, K626 Remote Control Cable Assembly .....................................................................C-4

K444, K444-1 or K444-2 Remote Voltage Control Kit....................................................................C-5

K557-1 Rear Handle Kit .................................................................................................................C-5

MAINTENANCE ....................................................................................................................... SECTION D

Safety Precautions ............................................................................................................. ................D-1

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

Circuit Protection and Automatic Shutdown ....................................................................................... D-1

Adjusting Speed Sensor Module ........................................................................................................D-1

Calibration of the LN-25 Wire Speed Dial .......................................................................................... D-2

TROUBLESHOOTING GUIDE .................................................................................................SECTION E

How to Use the Troubleshooting Guide .............................................................................................E-1

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

WIRING DIAGRAM...................................................................................................................SECTION F

PHYSICAL DIMENSIONS ........................................................................................................SECTION F

PARTS MANUAL..................................................................................................................P 175 SERIES

TABLE OF CONTENTS

TEMPERATURE RANGE

OPERATION: - 40oC to +40oC (- 40oF to +104oF) STORAGE: - 40oC to +85oC (- 40oF to +185oF)

LN-25

A-1

OPERATING ARC VOLTAGE

Constant Voltage (CV)

or 15-40 VDC (110VDC Maximum OCV)

Constant Current (CC)

RATED CURRENT

Rated current without contactor 500 Amps 60% Duty Cycle

Rated current with contactor 300 Amps 60% Duty Cycle

WIRE SPEED RANGE

50 – 700 Inches Per Minute (IPM)

RECOMMENDED ELECTRODE WIRE SIZES

.023” to

⁄16” SOLID STEEL WIRE

.045” to

⁄64” CORED WIRE

.035” to 1⁄16” ALUMINUM WIRE

PHYSICAL DIMENSIONS

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)

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PPHHYYSSIICCAALL DDIIMMEENNSSIIOONNSS

EENNVVIIRROONNMMEENNTTAALL RRAATTIINNGG

WWIIRREE DDIIAAMMEETTEERRSS

VVOOLLTTAAGGEE

INSTALLATION

TECHNICAL SPECIFICATIONS – LN-25

IP23 (IEC529)

MAR97

LN-25

A-2

INSTALLATION

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

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.

b.Connect the electrode cable to the output

terminal of polarity required by electrode. Connect work lead to other output terminal.

SAFETY PRECAUTIONS

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.

The LN-25 should be positioned upright on a horizontal surface.

ELECTRIC SHOCK can kill.

• Do not touch metal portions of the LN-25 lead clip when welding power source is on.

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.

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.

See the power source instruction manual for proper power source connections and setting required.

WARNING

CAUTION

MAR97

LN-25

A-3

c. Set ELECTRODE POLARITY switch to constant

voltage polarity required by electrode.

d. Set toggle switch to “Constant Voltage” and set

the Constant Voltage Control on welder and the portable field control on #5 for initial start.

SA-200, —250 OR SAE-300, —400 (WITH CV ADAPTER)

a. For electrode negative welding, connect the

electrode lead from the LN-25 to the output terminal on the CV Adapter, and the work lead to the power source output terminal labeled “POSITIVE”. For electrode positive welding, interchange the above lead connections so the LN-25 electrode lead is then connected to the positive power source terminal.

b. Place both switches on the CV Adapter to the CV

INNERSHIELD position and make appropriate power source settings per the CV Adapter instructions provided for the power source being used.

c. The output voltage is set with the voltage control

on the CV Adapter.

NOTE: Refer to the Instruction Manual provided with the machine for details on connection and operation of the LN-25 with the power source.

INVERTEC, CV300 AND OTHER NEWER LINCOLN POWER SOURCES

Refer to the instruction manual provided with the power source for details on connection and operation of the LN-25 with these newer machines.

GUN CABLE CONNECTION TO FEEDER

Lay the cable out straight. Insert the connector on the welding conductor cable into the brass conductor block on the front of the wire drive unit. Make sure it is all the way in and tighten the hand wheel clamp. Keep this connection clean and bright. Connect the control cable polarized amphenol plug into the mating 5-cavity receptacle on the front panel of the wire feeder case.

FOR GMA GUN AND CABLES:

Requires installation of K430-1 Gas Solenoid Kit (factory installed on K446 and K449 models).

See K430-1 Gas Solenoid Kit Section (in Accessories Section) for gas solenoid operation and gas supply connection.

c. Place “Set to Same Polarity As Electrode Cable

Connection” switch at appropriate position.

d. Place power source toggle switch in “Output

Control at DC(CV) -400” position, unless a remote control is connected to 75, 76 and 77 on the power source terminal strip.

e. If power source has a mode switch, set switch to

Constant Voltage Innershield. Initially set the output control on “6”.

DC-600

a. Connect a jumper from 2 to 4 on the power

source terminal strip so the output will be energized when the DC-600 is turned on. (For DC-600 below Code 8200, also jumper N to S.)

b.Connect the electrode cable to the output

terminal of polarity required by electrode. Connect work lead to other output terminal.

c. Place “Set to Same Polarity As Electrode Cable

Connection” switch at appropriate position.

d. Place power source toggle switch in “Output

Control at DC-600” position, unless a remote control is connected to 75, 76 and 77 on the DC600 terminal strip.

e. Set mode switch to Constant Voltage Innershield.

Initially set output control on “4”.

R3S-325

a. Connect a jumper from 4 to 32 on the power

source terminal strip so that the output will be energized when the R3S-325 is turned on.

b. Connect the electrode cable to the output

terminal of polarity required by electrode.

Connect work lead to other output terminal. c. Set power source per its instruction manual. NOTE: Use of the optional Line Voltage

Compensator available for the R3S-325 is

recommended if input line voltage variation

exceeds ±3%.

SAM-400, —650

a. Connect a jumper from 2 to C4 on the power

source terminal strip so the output will be

engergized when the SAM power source is on. b. Connect work lead to WORK stud. Connect

electrode to AUTO EQUIPMENT stud. Connect

SAM-650 “Tap” lead to the Innershield stud

desired.

INSTALLATION

LN-25

A-4

INSTALLATION

Install the barbed fitting and union nut to the 5⁄8-18

female inert gas fitting on the front panel of the

LN-25 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

Total Cable Length

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

⁄2” bolt on the front of the wire drive.

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.

WIRE FEED DRIVE ROLL AND GUIDE TUBE KITS

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

(1)

on each part. Check the kit 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.

TABLE A.2

Kit Instructions

Steel Wire Sizes:

.068-5⁄64 Cored KP653-3⁄32 L9932

⁄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 .035 Solid Steel -.035S .035 Cored -.035C .030 Solid Steel -.030S .025 Solid Steel -.025S

Aluminum Wire Sizes:

⁄16 KP654-

⁄16A L9932

⁄64 -3⁄64A .035 -.035A

(1)

Drive rolls for only cored electrode sizes are stencilled with a “C” suffix to the wire sizes.

Drive rolls for only solid electrode sizes are stencilled with an

“S” suffix to the wire sizes.

Drive rolls for aluminum wire sizes are stencilled with an “A” suffix

to the wire sizes.

WARNING

4/96

LN-25

B-1

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.

ARC RAYS can burn.

• Wear eye, ear and body protection.

FUMES AND GASSES can be dangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust to remove fumes trom breathing zone.

WELDING SPARKS can cause fire or explosion.

• Keep flammable material away.

OPERATION

WARNING

GENERAL DESCRIPTION

The LN-25 is a lightweight portable semiautomatic wire feeder designed for “across-the-arc” operation without a control cable on most any DC welding power source. Simply connect the LN-25 to the electrode cable, clip it to Work 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 “on-the-go” 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. Wire speed is presettable on a dual-range calibrated dial.

The power sources recommended for use with the LN-25 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 SAE-300, -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.

SAFETY PRECAUTIONS

READ AND UNDERSTAND ENTIRE SECTION BEFORE OPERATING MACHINE

LN-25

B-2

OPERATION

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.

NOTE:

1. The Voltmeter will read zero if the LN-25 work clip lead is not connected to work, even if the electrode is electrically “hot” 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.

“ELECTRODE POLARITY” 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 “CV” position provides constant wire feed speed mode for use with constant voltage (CV) welding power sources.

The backward “VV (CC)” 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 7 00 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

LN-25 INSTRUMENTS AND CONTROLS

Refer to Figure B.1 for control locations.

REMOTE

ARC VOLTAGE

CONTROL

(OPTIONAL)

WIRE SPEED

DIAL RANGE

SWITCH

WIRE

SPEED

DIAL

VOLT

METER

WORK CLIP

LEAD

GUN

CONNECTION

BLOCK

GUN

TRIGGER

AMPHENOL

CONNECTOR

GAS

FITTING

(OPTIONAL)

ELECTRODE

POLARITY

SWITCH

GAS POST/

PRE FLOW

TIMERS

(OPTIONAL)

ELECTRODE CABLE

OPTIONAL

GAS INPUT

FITTING

GAS PURGE BUTTON

FIGURE B.1 CONTROL LOCATIONS

LN-25

B-3

wire speed is set to 400 in/min., a welding procedure arc voltage of at least 17V would be required to obtain the 400 in/min. wire feed speed.

WORK CLIP LEAD

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.

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 K624-1 (42V) Remote Output Control Option, or Internal Contactor (K443-1), is not used.

When used with a K460-1 Pulse Power Adapter Kit, the LN-25 does not need a clip lead.

NOTE: The clip lead also serves as a work sensing lead for the LN-25 Voltmeter (if installed). 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:

OPERATION

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, K4441 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 & post-flow at the start and end of the weld. Refer to K434-1 Gas Flow Timer Kit in Accessories Section.

WARNING

ELECTRIC SHOCK can kill.

•Do not touch metal portions of the LN-25 lead clip when welding power source is on.

LN-25

B-4

OPERATION

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. 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.

LOADING ELECTRODE

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.

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.

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.

SEQUENCE OF OPERATION

LN-25

B-5

LOADING WIRE DRIVE

a. Turn the reel or spool until the free end of the

electrode is accessible.

b. While tightly holding the electrode, cut off the

bent end and straighten the first six inches. Cut off 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 “birdnest”.)

c. Insert the free end through the incoming guide

tube to the drive roll.

d. Turn on the welding power source.

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.

e. Press the gun trigger and push the electrode

until it just enters the drive roll.

When inching with gun trigger, the electrode and drive mechanism are always “hot” to work and ground. Use the “cold” inch switch on models with internal contactor.

f. Inch the electrode through the gun. 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.

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 “birdnests,” jams or breaks at the drive roll, the idle roll pressure is too great. Back the pressure setting out 1⁄2 turn, run new wire through gun, and repeat above steps.

WARNING

CAUTION

OPERATION

2" O.D. SPINDLE

MOLDED ADAPTER

RETAINING SPRING

INSIDE CAGE WIRES

READI-REEL

GROOVES

BRAKE HOLDING PIN (MUST ENGAGE HOLE IN ADAPTER RIB)

THREAD LOCKING COLLAR

FIGURE B.2 READI-REEL INSTALLATION

LN-25

B-6

OPERATION

3. If the only result is drive roll slippage, shut off the power source, then loosen the gun cable clamping 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 1⁄4 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 (VV [CC] MODE)

When using a constant current (formerly variable voltage) power source, welding performance is improved using arc sensing wire feed speed (VV [CC] 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 VV (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:

a. Set Wire Feed Mode switch to VV (CC) position.

FIGURE B.3 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 VV (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:

LN-25

B-7

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

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

MAKING A WELD

SETUP

a. Connect work cable to metal to be welded. Work

cable must make good electrical contact to the work. The work must also be grounded as stated in “Arc Welding Safety Precautions.”

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 K432 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.

NOTE: If the K460-1 Pulse Power Adapter Kit is installed but the LN-25 is to be used without the K461 Pulse Power Control Cable Assembly, then the instructions for returning the unit to across the arc operation included with the Installation Instructions (L9636) must be followed.

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.

e. Set WIRE FEED MODE switch to CV or 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.

VV (CC) Speed Setting =

Desired IPM

X 35

Arc Volts

OPERATION

FIGURE B.4 VV(CC) WIRESPEED SETTING

LN-25

B-8

ARC RAYS can burn.

• Do not touch metal portions of the LN-25 lead Clip when welding power source is on.

OPERATION

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.

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.)

h. Turn on the welding power source, as well as the

shielding gas supply (if used).

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.

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.

WARNING

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.

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.

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.

WELDING

LN-25

B-9

OPERATION

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.

To aid in stabilizing the arc voltage when welding on CC power sources the LN-25 is provided with a VV (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.

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.

CAUTION

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 102110 volts.

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

C-1

LN-25 OPTION CHART

O=CANNOT BE USED WITH X = REQUIRED ➀ = REQUIRES ONE OF THESE + = INCLUDED WITH

Solenoid

K430-1

Kit

Remote Output

K431-1

Control Module

➀➀ OXXOOOOOO

Remote

K432

Control Cable

115VAC

K433

Power Source

Remote Box

Gas Flow

K434-1

Timer Kit

➀➀ ➀ ➀ ➀

50 Ft.

K439

Ext. Cable

Contactor

K443-1

Kit

+ OOO

Remote for Power

K444

Source w/Terminal Strip

➀➀ ➀OOO

Remote for Power

K444-1

Source w/6 Pin Amphenol

➀➀ ➀OOO

Remote for Power

K444-2

Source w/14 Pin Amphenol

➀➀ ➀OOO

42VAC Remote

K-624-1

Output Control Module

➀➀ OO OOOOO ➀➀➀

500 Amp Cable /w Stud-

K625

Type Output Terminals

350 Amp Cable /w Stud-

K626

Type Output Terminals

400 Amp Cable /w Twist-

K627

Mate Type Terminals

Pulse Power

K460-1

Adapter Kit

➀➀ OO OOOO X O

Pulse Power

K461

Control Cable

IMPORTANT SAFETY NOTE: This wire feeder provides “COLD” electrode when gun trigger is released if equipped with K431-1, K432 or K433 remote output control system, or K443-1 internal contactor kit. This feature and the use of a DC Constant Voltage 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.

ACCESSORIES

K428

LN-25

K446

LN-25

K449

LN-25

K431-1

K432

K433

K443-1

K444

K444-1

K444-2

K460-1

K461

K624-1

K625

K626

K627

KIT NO.

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 MODELS LN-25 KITS

SEE TEXT

LN-25

C-2

OPTIONAL ACCESSORIES

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.

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.

The LN-25 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 gases such as Argon, Helium, Nitrogen and blended gasses such as Ar-He, Ar-N2, Ar-O2, ArCO2, CO2, Ar-CO2-O2.

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 American National Standard Z-49.1, “Safety in Welding

and Cutting” published by the American Welding Society.

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, K460-1 Pulse Power Adapter 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.

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.

WARNING

ACCESSORIES

WARNING

MAR97

LN-25

C-3

Installation instructions (M17590) are included with this kit.

K460-1 PULSE POWER ADAPTER KIT

(For use with K461 Pulse Power Control Cable.) This kit enables the LN-25 to pulse weld with a Pulse

Power 500 power source above Code 9300 (or lower Codes updated with S18506 Kit).

The kit includes a Remote PC board with output voltage control, and control cable receptacle which mount and connect inside the LN-25 control box per the Installation Instructions (L9636) included with the kit.

K461 PULSE POWER CONTROL CABLE ASSEMBLY

(Requires K460-1 Pulse Power Adapter Kit installed in LN-25.)

The K461 control cable assemblies include an electrode cable, rated for up to 500 amps 60% duty cycle, and a 9-conductor control cable. The control cable pin connector connects to the LN-25 and the lugged leads connect to the Pulse Power. Available in 25, 50, 75 and 100 ft. lengths.

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.

ACCESSORIES

NOTE: The K443-1 cannot be used with K431-1 or

K624-1 Remote Output Control Kit or K460-1 Pulse Power Adapter 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.)

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 12-pin 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.

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.

LN-25

C-4

ACCESSORIES

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.

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.

K439 REMOTE EXTENSION CABLE ASSEMBLY

The 50 ft. Extension cable assemblies are used to extend the K432 Remote Control Cable Assembly when longer cable lengths are required.

Multiple K439 Extensions may be used, however, to prevent excessive weld cable voltage drops, the 500 amp max. rating of the K432 should be reduced by at least 50 amps for each K439 Extension used. For example, if three K439 Extensions are used (150 ft total extension), the maximum welding current used should be less than 350 amps.

The K439 Extension cable end with the male pin connector connects to the K433 Remote Box and power source per the Instructions included with the K433 kit.

The K439 Extension cable end with the socket pin connector connects to the mating K432 cable end (or next K439 Extension cable end). The electrode cables are connected using the bolt and nut provided with the K439 Extension. Properly insulate the bolted connection with electrical tape.

K624-1 42V REMOTE OUTPUT CONTROL MODULE

(For use with K625, K626, K627 Remote Control Cable)

The Module includes a 42V Remote PC board and control cable receptacle which mount and connect inside the LN-25 control box per the Installation Instructions (M17253) included with the kit.

NOTE: If the K624-1 42V Remote Output Control Module is installed but the LN-25 is to be used without the K625, K626 or K627 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.

K625, K626, K627 REMOTE CONTROL CABLE ASSEMBLY

(Requires K624-1 Remote Output Control Module installed in LN-25.)

The K625, K626, K627 control cable assemblies include an electrode cable and a 8-conductor control cable:

The cable assembly end with the socket pin connector connects to the LN-25 per the Instructions (M17253) included with the K624-1 Kit.

The cable assembly end with the male pin connector connects to the power source per the Instructions (M17253) included with the K624-1 kit.

CABLE 60% DUTY POWER SOURCE

TYPE RATING ELECTRODE

CONNECTION

K625 500 Amps Stud Terminal K626 350 Amps Stud Terminal K627 400 Amps Twist-Mate™

LN-25

C-5

ACCESSORIES

K444, K444-1 OR K444-2 REMOTE VOLTAGE CONTROL KIT

(Not required if using K431-1 or K624-1 Remote Output Control Kit or K460-1 Pulse Power Adapter Kit.)

The Remote Voltage Control Kit provides remote (10K ohm rheostat) control of power source output arc voltage level.

K444 connects to power sources with control terminal strip connections for lead numbers 75, 76 and 77.

K444-1 connects to power sources with a 6-pin control receptacle.

NOTE: To use a K444-1 with power sources with only a 14-pin control receptacle, a K864 Adapter is required to connect to K444-1 and if using a power source without an output control switch, a K484 Jumper Plug will also be required to jumper the output pilot circuit (2-4).

K444-2 connects to power sources with a 14-pin control receptacle and provides a 2-4 jumper to activate power source output.

Installation Instructions are included with the kit.

K577-1 REAR HANDLE KIT

(For LN-25 model codes above 9383) The fold-down handle mounts to the rear of the LN-

25 case per the Installation Instructions (M16567) shipped with the kit.

This handle provides a means to also carry the LN25 in the vertical position, especially convenient for passing the unit through a manhole.

LN-25

C-6

ACCESSORIES

“A Dia. Hole”

To be Concentric to .749/.747

Wire Size Dia. Within .008 F.I.M.

.068 thru 5⁄64 .125 (1⁄8 Drill)

⁄16 (.062) .078 (5⁄64 Drill)

.045 & .052 .062 (1⁄16 Drill)

.023 thru .035 .055 (#54 Drill)

Drive Roll & Guide Tube Wire Sizes Used

Kit No.

T-13355-

⁄32

⁄64, .072 & .068

T-13355-1⁄16

(1)

⁄16, .062 T-13355-.052C .045, .052 Cored T-13355-.052 .045, .052 Solid T-15010.-.035S .023 thru .035 Solid

(1)

Can also be used for .052” wire

NOTE: Connector part with .749/.747 diameter should be made from brass if it is to be part of the welding current carrying circuit.

S12024-1 (L.E. Part No.)

Amphenol AN3057-10 (or equiv.)

S12020-6 (L.E. Part No.)

Amphenol MS-3106A-18-11P (or equiv.)

SWITCH REQUIREMENTS

⁄2 Amp AC 24 Volts – Inductive

⁄2 Amp DC 24 Volts – Inductive

GUN CABLE CONNECTOR REQUIREMENTS TO PERMIT PROPER CONNECTION TO LINCOLN LN-25 WIRE FEEDER.

LN-25 Cable Connector for .023 through .052 Wire (For all other dimensions, see above)

The following Figures C.1 and C.2 should serve as a guide to determine if a particular gun or switch can be connected to the LN-25.

FIGURE C.1

FIGURE C.2 SWITCH REQUIREMENTS

LN-25

D-1

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.

CIRCUIT PROTECTION AND AUTOMATIC SHUTDOWN

CONTROL PC BOARD FUSE

On G1757-6 (or higher part no.) P.C. Boards the 1⁄8 amp fuse was replaced with electronic protection for trigger circuit faults to electrode circuit.

On G1757-2 through -5 part no. PC boards, the 1⁄8 amp fuse interrupts the 500A lead to the trigger switch. On G1757- 1 PC boards a 5 amp fuse was used to interrupt the 667 lead. The LN-25 will not operate if the fuse is blown.

AUTOMATIC PROTECTION SHUTDOWN

(See Automatic Protection Shutdown Section.)

ADJUSTING SPEED SENSOR MODULE

The LN-25 Speed Sensor Module is a three lead Hall Effect switch device encased in an externally threaded housing which is screwed into a mounting plate on the motor side of the wire drive gearbox.

Proper positioning of this module is critical to proper operation of the LN-25 wire feed speed control. If the

ROUTINE MAINTENANCE

DRIVE ROLLS AND GUIDE TUBES

After feeding every coil of wire, inspect the drive roll section. Clean it as necessary. Do not use a solvent for cleaning the idle roll because it may wash the lubricant out of the bearing. The drive roll, idle roll and guide tubes are stamped with the wire sizes they will feed. If a wire size other than that stamped on the rolls is to be used, the rolls and guide tubes must be changed.

The drive rolls for .035 through .052 cored electrode and 1⁄16 through 5⁄64 electrode have a double set of teeth so they can be reversed for additional life. Drive rolls for .023 through .052 solid electrode and aluminum sizes have no teeth but use two grooves so they also can be reversed for additional life.

See Wire Feed Drive Roll and Guide Tube Kits Section for roll changing instructions.

WIRE REEL SPINDLE

No routine maintenance required. Do not lubricate spindle.

WARNING

SAFETY PRECAUTIONS

CONTROL BOX

Every six months open and inspect the control section. The accumulated dirt should be gently blown off all of the electrical components. Be sure the air that is being used is dry. Check that lead plugs are secure in their receptacles.

WIRE DRIVE MOTOR AND GEAR BOX

Every year examine the gear box. Paint the gear teeth with molydisulfide filled grease. Lincoln specification E2322. Do not use a graphite grease.

Check the motor brushes. Replace if they are worn down to 1⁄4’’ or less. When ordering feed motor brushes, give all information from the motor nameplate.

GUN AND CABLE MAINTENANCE

See IM manual provided with the gun and cable assembly.

MAINTENANCE

4/96

LN-25

D-2

device is not screwed in far enough, the LN-25 motor speed could be unstable or run at full speed with no control. If screwed in too far, it will rub a moving part inside the gearbox.

The module is properly mounted to the gearbox as shipped from the factory. If the device is ever removed or replaced, proper mounting technique is as follows:

1. Be sure all power to the LN-25 is shut off at the power source.

2. Check that the module mounting plate is screwed securely to the side of the gearbox.

3. Gently screw the module into the mounting plate until it just touches and stops against the rotating part inside the gearbox.

4. Back the module out 1⁄2 turn, then snug the module locknut without rotating the module position. Do not overtighten locknut.

CALIBRATION OF LN-25 WIRE SPEED DIAL

Calibration of the LN-25 Wire Speed dial is achieved by proper mounting of the dial knob to the speed potentiometer shaft. Whenever the knob is removed, the dial is recalibrated as follows:

NOTE: Knob set screw does not seat on shaft flat.

1. Be sure the Wire Speed potentiometer mounting nut is securely tightened, then rotate the potentiometer shaft so its flat faces about to the 100 mark on the LO range calibrated dial.

2. Set DIAL RANGE switch to LO and WIRE FEED MODE switch to CV position.

3.Press gun trigger to feed wire and measure the wire feed speed (IN/MIN) using a Portable Digital Wire Feed Speed Meter (Lincoln K283). Take at least two readings to assure repeatable accuracy.

Feed Speed Meter (Lincoln K283). Take at least two readings to assure repeatable accuracy.

Electrode will be electrically “hot”. Do not allow fed wire to contact any metal common with welding work.

An alternate means to measure wire feed speed is as follows:

a.Cut wire off at the end of the gun tip. b. Press trigger to feed wire for exactly 30 seconds. c. Cut fed wire off at the end of the gun tip and

accurately measure its length.

d. Multiply the measured length by 2 to obtain

the wire speed (IN/MIN).

e. Repeat above steps to assure repeatable

accuracy.

4. Carefully slip speed knob onto potentiometer shaft so it points precisely to the wire speed measured in step 3, then secure the knob set screw without disturbing the position. Recheck by repeating step 3.

WARNING

MAINTENANCE

LN-25

E-1

HOW TO USE TROUBLESHOOTING GUIDE

Service and Repair should only be performed by Lincoln Electric Factory Trained Personnel. Unauthorized repairs performed on this equipment may result in danger to the technician and machine operator and will invalidate your factory warranty. For your safety and to avoid Electrical Shock, please observe all safety notes and precautions detailed throughout this manual.

TROUBLESHOOTING

WARNING

This Troubleshooting Guide is provided to help you locate and correct possible machine malfunctions or misadjustments. Simply follow the three-step procedure listed below.

Step 1. LOCATE PROBLEM (SYMPTOM).

Look under the column labeled “PROBLEM (SYMPTOMS)”. This column describes possible symptoms that the machine may exhibit. Find the listing that best describes the symptom that the machine is exhibiting.

Symptoms are grouped into the following categories: Output Problems, Feeding Problems and Welding Problems.

Step 2. PERFORM EXTERNAL TESTS.

The second column labeled “POSSIBLE AREAS OF MISADJUSTMENT(S)” lists the obvious external possibilities that may contribute to the machine symptom. Perform these tests/checks in the order listed. In general, these tests can be conducted without removing the case wrap-around cover.

Step 3. CONSULT LOCAL AUTHORIZED FIELD SERVICE FACILITY.

If you have exhausted all of the recommended tests in Step 2, Consult your Local Authorized Field Service Facility.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your LOCAL AUTHORIZED LINCOLN ELECTRIC FIELD SERVICE FACILITY for assistance before you proceed.

LN-25

E-2

TROUBLESHOOTING

PROBLEMS (SYMPTOMS)

No wire feed when gun trigger is pulled

POSSIBLE AREAS OF MISADJUSTMENT(S)

1. Power source must be on and open circuit voltage (OCV) present at weld terminals.

2. LN-25 work clip may not be connected.

3. LN-25 polarity switch must match electrode polarity.

4. Jumper plug on control or option board may be loose or missing.

5. The power source O.C.V. must be above 15 VDC. But not more than 110 VDC.

6. The gun trigger may be faulty.- Replace gun.

Wire feeds for a short time but stops feeding. When gun trigger is released and retriggered wire feeding starts but stops again.

1. The drive motor may be overloaded. Check the wire feeding system. EX. Drive roll tension, reel brake and gun cable liner.

Wire feeds OK, but stubs or stops while welding.

1. If the power source is a constant current type supply the arc voltage may be “dipping” below 15 VDC causing the LN-25 to stop or hesitate.

2. Connect a constant voltage type power supply to the LN-25.

3. Make sure wire-feed mode switch (S3) is in the proper position.

RECOMMENDED COURSE OF ACTION

FEEDING PROBLEMS

Contact your local Lincoln Authorized Field Service Facility

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your local authorized field service facility for technical troubleshooting assistance before you proceed.

CAUTION

LN-25

E-3

TROUBLESHOOTING

Rough wire feeding or wire not feeding but drive rolls turning.

1. Gun cable kinked and/or twisted.

2. Wire jammed in gun and cable.

3. Incorrect size or installation

of drive roll and guide tubes.

4. Drive roll loose.

5. Gun cable dirty.

6. Worn drive roll.

7. Electrode rusty and/or dirty.

8. Worn nozzle or cable liner.

9. Partially flashed or melted contact tip.

10. Incorrect idle roll pressure.

11. Wire reel brake tension set too high.

RECOMMENDED COURSE OF ACTION

FEEDING PROBLEMS

POSSIBLE AREAS OF MISADJUSTMENT(S)

PROBLEMS (SYMPTOMS)

Contact your local Lincoln Authorized Field Service Facility

CAUTION

LN-25

E-4

TROUBLESHOOTING

Solenoid does not close when trigger is pulled or purge button is pressed. Wire feeds properly.

1. Make certain that plugs J2 and J3 are connected to the control board securely.

RECOMMENDED COURSE OF ACTION

OUTPUT PROBLEMS

WELD PROBLEMS

POSSIBLE AREAS OF MISADJUSTMENT(S)

PROBLEMS (SYMPTOMS)

Contact your local Lincoln Authorized Field Service Facility

Variable or “hunting” arc.

1. Worn and/or melted contact tip -Replace.

2. Worn work cable or poor work connection.

3. Loose electrode connections. -Check for loose or faulty connections.

4. Wrong electrode polarity for process being used.

Weld porosity, narrow and ropey bead, or electrode stubbing into plate when welding.

1. Contaminated weld joint or improper procedures. Clean joint and check procedure (wire speed and all voltage).

Motor feeds but there is no wire feed speed control.

1. Make sure all molex plugs and leads are securely connected to the control board.

2. Check speed sensor - see maintenance section.

CAUTION

LN-25

F-1

WIRING DIAGRAM

530C

530

530B

500

530A

512

606

607

530

500

523

522

667

500

530

621

607

606

512

530A

ARC

VOLTMETER

667

621

632

633

631

10K

WIRE SPEED

CONTROL RHEOSTAT

N.B.

CONTACTOR

P C BOARD

OPTIONAL

TIMER

PLUG

TO WORK CLIP

BLACK

POS

667

621

N.B.

NEG

ABCDE

622A

500A

TRIGGER

CONNECTOR

621

500A

667

622A

606

512

624A

N.D.

509

632

523

522

633

523

524

631

BLACK

BLUE

RED

524

523

509

N.B.

WHITE

539

BLACK

541

530B

500

530

530C

530B

BLACK

RED

BLUE

HALL

EFFECT

SWITCH

GUN CABLE

N.F.

N.G.

N.D.,N.E.

N.A.

N.F.

N.B.

WIRE FEED

MODE SWITCH

POLARITY

SWITCH

WIRE SPEED DIAL

RANGE SWITCH

COLD INCH

SWITCH

PUSHBUTTON

,N.H.

624

932

86574

131412

667

621

4123

1 2

BLACK

WHITE

J13

121014

324

539

541

BLACK WHITE

OPTIONAL REMOTE

KIT PLUG

CONTROL

P.C. BOARD

LEGEND

S1 POLARITY SWITCH

S2 WIRE SPEED DIAL RANGE SWITCH

S3 WIRE FEED MODE SWITCH

S4 COLD INCH SWITCH

622A

621

500A

530A

530

624

606

622

607

512

432

500

J13

234

56789

101112

ARC VOLTS

TO CONTROL BOARD

TO TIMER P.C. BOARD

34334

6-14-96D

L9644

WIRING DIAGRAM - LN-25

702

622A

621

500A

530A

530

624

606

622

607

512

7002701

500

J13

234

56789

ABCDE

757677

ARC VOLTS

TO CONTROL BOARD

REMOTE

P.C. BOARD

POLARITY

SWITCH

4333421757677

667

621

ABCDEFGHI

667

621

REMOTE

P.C. BOARD

N.E.

N.F.

CONTACTOR CAN BE INSTALLED IN UNITS WITH A G1757-3 (OR HIGHER

PART NO.) CONTROL PC BOARD.

WHEN A CONTACTOR IS NOT USED, THE '67' LEAD TO THE POLARITY

SWITCH COMES FROM THE CONDUCTOR BLOCK AND THE INPUT CABLE

CONNECTS DIRECTLY TO THE CONDUCTOR BLOCK.

N.H.

TOGGLE SWITCH USED ON EARLIER UNITS.

N.G.

JUMPER PLUG MUST BE INSTALLED UNLESS OPTIONAL TIMER IS USED.

N.A.

N.B.

WHEN A CONTACTOR IS NOT USED THE JUMPER PLUG MUST BE

INSTALLED UNLESS OPTIONAL REMOTE KIT IS BEING USED.

CONNECTIONS AS VIEWED FROM BACK OF RHEOSTAT AND SWITCHES.

N.D.

ITEM FACTORY INSTALLED ON SOME MODELS AND OPTIONAL EQUIPMENT

ON SOME MODELS.

NOTES

UBR

OPTIONAL PULSE POWER ADAPTOR KIT

OPTIONAL REMOTE OUTPUT CONTROL

TO TIMER P.C. BOARD

500

555

512

606

500

512

607

530A

530

J10

TIMER P.C.

BOARD

TO REMOTE

OR CONTACTOR

P.C. BOARD

12345

GAS

SOLENOID

VALVE

N.D.

PURGE

608

621

512

624A

606

N.D.

621

3 7 6 8 42

GAS SOLENOID

P C BOARD

J11

CONTACTOR

COIL

N.F.

N.D.,N.E.

INPUT

CABLE

N.F.

CONNECTOR CAVITY NUMBER

500A

607

622A

512

530A

667

624

500A

530

606

621

622A

500

121014

532

N.G.

530

530A

607

512

500

606

N.G.

530

530A

607

512

500

606

700

701

702

500

607

622

512

530A

624

500A

530

606

621

622A

621

500A

530A

530

624

606

622

607

512

765

500

J12

234

56789

ABCDE

41422

ARC VOLTS

TO CONTROL BOARD

REMOTE

P.C. BOARD

TO TIMER P.C. BOARD

N.G.

530

530A

607

512

500

606

432

24142

47576

OPTIONAL 42 VOLT REMOTE OUTPUT CONTROL

757677

OPTIONAL REMOTE VOLTAGE CONTROL

ARC VOLTS

ABCDE

OPTIONAL TIMER KIT

SOLENOID P.C.

BOARD PLUG

OPTIONAL

CONTACTOR

P.C. BOARD PLUG

PUSHBUTTON

N.L.

N.B.,N.D.,

N.L.

N.J. PROVIDES AN ESD PATHWAY FROM EXPOSED METAL SURFACES TO THE WORK.

N.K. PRESENT ON EUROPEAN MODELS ONLY.

N.L. CONNECTS TO THE BUSHING OF THE COMPONENT.

ESD SNUBBER

N.J.,N.K

S5 PURGE PUSHBUTTON

NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The specific diagram for a particular code is pasted inside the

machine on one of the enclosure panels. If the diagram is illegible, write to the Service Department for a replacement. Give the equipment code number..

MAR97

LN-25

F-2

LN-25 PHYSICAL DIMENSIONS

16.60

14.00

21.00

7.40

.25

DIMENSIONS

4/96

Lincoln Electric pmn User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual