Lincoln Electric SVM150-A User Manual

SVM150-A

September, 2002

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
CONT AINED THROUGHOUT .

And, most importantly, think
before you act and be careful.

SERVICE MANUAL

For use with machines having Code Numbers: 10654

Ranger 250

TM

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• Sales and Service through Subsidiaries and Distributors Worldwide •

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

• World's Leader in Welding and Cutting Products •

Copyright © 2002 Lincoln Global Inc.

SAFETY

i i

RANGER 250

FOR ENGINE
powered equipment.

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

____________________________________________________

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

____________________________________________________

1.c. Do not add the fuel near an open flame weld-

ing arc or when the engine is running. Stop
the engine and allow it to cool before refuel­ing to prevent spilled fuel from vaporizing on
contact with hot engine parts and igniting. Do
not spill fuel when filling tank. If fuel is spilled,
wipe it up and do not start engine until fumes
have been eliminated.

____________________________________________________

1.d. Keep all equipment safety guards, covers

and devices in position and in good
repair.Keep hands, hair, clothing and tools
away from V-belts, gears, fans and all other
moving parts when starting, operating or
repairing equipment.

____________________________________________________

1.e. In some cases it may be necessary to remove safety
guards to perform required maintenance. Remove
guards only when necessary and replace them when the
maintenance requiring their removal is complete.
Always use the greatest care when working near moving
parts.

___________________________________________________

1.f. Do not put your hands near the engine fan. Do not attempt to
override the governor or idler by pushing on the throttle con­trol rods while the engine is running.

___________________________________________________

1.g. To prevent accidentally starting gasoline engines while
turning the engine or welding generator during maintenance
work, disconnect the spark plug wires, distributor cap or
magneto wire as appropriate.

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

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SAFETY

ii ii

RANGER 250

ARC RAYS can burn.

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

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

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

ELECTRIC SHOCK can kill.

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

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

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

• Semiautomatic DC Constant Voltage (Wire) Welder.

• DC Manual (Stick) Welder.

• AC Welder with Reduced Voltage Control.

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

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

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

3.f.

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

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

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

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

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

FUMES AND GASES
can be dangerous.

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

fumes and gases away from the breathing zone. When

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

5.b.

Do not weld in locations near chlorinated hydrocarbon

vapors
coming from degreasing, cleaning or spraying operations.
The heat and rays of the arc can react with solvent vapors

to
form phosgene, a highly toxic gas, and other irritating
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

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RANGER 250

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.

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SAFETY

iv iv

RANGER 250

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 soud

e 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.

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

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MASTER TABLE OF CONTENTS FOR ALL SECTIONS

v v

RANGER 250

Page

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

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

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

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

Location and Ventilation..............................................................................................................A-3

Pre-Operation Engine Service ....................................................................................................A-4

Electrical Output Connections.....................................................................................................A-5

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

Safety Instructions.......................................................................................................................B-2

General Description ....................................................................................................................B-2

Design Features ..........................................................................................................................B-3

Controls and Settings..................................................................................................................B-3

Engine Operation........................................................................................................................B-5

Welder Operation........................................................................................................................B-7

Auxiliary Power ...........................................................................................................................B-9

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

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

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

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

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

Parts Manual ................................................................................................................................P-358

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TABLE OF CONTENTS

- INSTALLATION SECTION -

Section A-1 Section A-1

RANGER 250

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

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

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

Location and Ventilation..............................................................................................................A-3

Storing ..................................................................................................................................A-3

Stacking................................................................................................................................A-3

Angle of Operation................................................................................................................A-3

Lifting....................................................................................................................................A-3

Additional Safety Precautions.....................................................................................................A-4

High Altitude Operation.........................................................................................................A-4

High Temperature Operation ................................................................................................A-4

Towing...................................................................................................................................A-4

Pre-Operation Engine Service ....................................................................................................A-4

Oil .........................................................................................................................................A-4

Fuel.......................................................................................................................................A-4

Engine Cooling System........................................................................................................A-4

Battery Connections .............................................................................................................A-5

Muffler Outlet Pipe ............................................................................................................ ....A-5

Spark Arrester.......................................................................................................................A-5

High Frequency Generators for TIG Applications.................................................................A-5

Remote Control.....................................................................................................................A-5

Welding Terminals ................................................................................................................A-5

Electrical Output Connections.....................................................................................................A-5

Machine Grounding ..............................................................................................................A-5

Welding Output Cables.........................................................................................................A-6

Cable Installation ............................................................................................................A-7

Auxiliary Power Receptacles................................................................................................A-7

Standby Power Connections................................................................................................A-7

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INSTALLATION

A-2 A-2

RANGER 250

Onan P216
(K1725-1)

Kohler CH20
(K1725-2)

2 cylinder

16 HP @

3600 RPM

(Onan)

20 HP @

3600 RPM

(Kohler)

High Idle 3700

Full Load 3500

Low Idle 2400

44 (714) - Onan

38 (624) - Kohler

Bore x Stroke inch

(mm)

3.25 x 2.625

(83 x 67) (Onan)

3.03 x 2.64

(77 x 67) (Kohler)

12 VDC Battery &
Starter

(Group 58; 435 cold
crank amps)

Battery Charger

20 A. regulated (K1725-1)
15 A. regulated (K1725-2)

(Push Button Start)

Fuel: 12 gal.

45.4 L
Oil: 1.8 Qts.

1.7 L (Onan)
Oil: 2.0 Qts.

1.9 L (Kohler)
Cooling System:

Air-Cooled

TECHNICAL SPECIFICATIONS - RANGER 250 (K1725-1/K1725-2)

INPUT - GASOLINE ENGINE

Make/Model Description Speed (RPM) Displacement Starting Capacities

cu. in. (cu. cm.) System

RATED OUTPUT - WELDER

Welding Output Volts at Rated Amps Duty Cycle Max. OCV @ 3700 RPM

CC STICK & PIPE DC Output 25 Volts at 250 Amps 100%
STICK / PIPE Output Range 20 to 250 Amps
TIG Output Range 20 to 250 Amps 80 Volts
CV WIRE DC Output 25 Volts at 250 Amps 100%
CV WIRE Output Range 14 to 28 Volts

OUTPUT - GENERATOR

Auxiliary Power

1

8,000 Watts, 60 Hz

120/240 Volts

100% Duty Cycle

PHYSICAL DIMENSIONS

Height Width Depth Weight

30.00* in. 21.50 in. 42.25 in. 452 lbs. (205 kg.) K1725-1

762.0 mm 546.0 mm 1073.0 mm 434 lbs. (197 kg.) K1725-2

* Top of enclosure, add 6.0” (152 mm) for exhaust

ENGINE COMPONENTS

Lubrication Valve Lifters Fuel System Governor

Full Pressure Solid (Onan) Vacuum Pulse Pump (Onan) Mechanical Governor
with Full Flow Filter Hydraulic (Kohler) Mechanical Fuel Pump (Kohler) 5% Regulation

Air Cleaner Engine Idler Muffler Engine Protection

Duel Element Automatic Idler Low noise muffler: Top outlet Shutdown on low oil

can be rotated. Made from pressure.
long life, aluminized steel.

Receptacles Auxiliary Power Circuit Breaker Other Circuit Breakers

Two 120 VAC Duplex Two 20 Amp for Two Duplex 25 Amp for Battery Charging
(5-20R) Receptacle Circuit

One 120/240 VAC Dual Two 35 Amp for Dual Voltage 150 Amp for 42 Volt Wire Feeder
Voltage Power

Full KVA (14-50R)

1. Output rating in watts is equivalent to volt-amperes at unity power factor. Output voltage is within ±10% at all loads up to rated capacity. When welding,
available auxiliary power will be reduced.

Read this entire installation section before you
start installation.

SAFETY PRECAUTIONS

Do not attempt to use this equipment until you have
thoroughly read the engine manufacturer’s manual
supplied with your welder. It includes important safety
precautions, detailed engine starting, operating and
maintenance instructions and parts lists.

ELECTRIC SHOCK can kill.

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

• Insulate yourself from work and
ground.

• Always wear dry insulating
gloves.

ENGINE EXHAUST can kill.

• Use in open, well ventilated
areas or vent exhaust outside.

• Do not stack anything near the
engine.

MOVING PARTS can injure.

• Do not operate with doors open
or guards off.

• Stop engine before servicing.

• Keep away from moving parts.

See additional safety information at the front of this
manual.

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

LOCATION AND VENTILATION

The welder should be located to provide an unrestrict­ed flow of clean, cool air to the cooling air inlets and to
avoid restricting the cooling air outlets. Also, locate the
welder so that the engine exhaust fumes are properly
vented to an outside area.

STORING

1. Store the machine in a cool, dry place when it is
not in use. Protect it from dust and dirt. Keep it
where it can’t be accidentally damaged from con­struction activities, moving vehicles, and other haz­ards.

2. If you will be storing the machine for over 30 days,
you should drain the fuel to protect fuel system and
carburetor parts from gum deposits. Empty all fuel
from the tank and run the engine until it stops from
lack of fuel. If you prefer, you can treat the gaso­line with a stabilizer to prevent deterioration rather
than drain the system. Follow the stabilizer manu­facturer’s instructions. Add the correct amount of
stabilizer for the size of the fuel tank. Fill the tank
with clean, fresh gasoline. Run the engine for two
to three minutes to circulate the stabilizer through
the carburetor.

3. While the engine is still warm, drain the oil and refill
with fresh 10W30 oil. Change the oil filter.

4. Remove the spark plugs and add one to two table­spoons of engine oil or rust inhibitor into each cylin­der. Replace the spark plugs but do not connect
the plug leads. Crank the engine two or three
times to distribute the oil.

5. Clean any dirt or debris from the cylinder and cylin­der head fins and other exterior surfaces.

STACKING

Ranger 250 machines CANNOT be stacked.

ANGLE OF OPERATION

Engines are designed to run in the level condition,
which is where the optimum performance is achieved.
The maximum angle of continuous operation is 15
degrees in any direction. If the engine is to be operat­ed at an angle, provisions must be made for checking
and maintaining the oil level at the normal (FULL) oil
capacity in the crankcase.

When operating the welder at an angle, the effective
fuel capacity will be slightly less than the specified 12
gallons (45.4 liters).

LIFTING

The Ranger 250 weighs approximately 452 lbs./205 kg.
with a full tank of gasoline. A lift bail is mounted to the
machine and should always be used when lifting it.

INSTALLATION

A-3 A-3

RANGER 250

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WARNING

ADDITIONAL SAFETY PRECAUTIONS

FALLING EQUIPMENT can cause
injury.

• Do not lift this machine using lift bail if
it is equipped with a heavy accessory
such as trailer or gas cylinder.

• Lift only with equipment of adequate lifting capacity.

• Be sure machine is stable when lifting.

HIGH ALTITUDE OPERATION

At higher altitudes, output de-rating may be necessary.
For maximum rating, de-rate the welder output 3.5%
for every 1000 ft. (305m). Contact an authorized
engine service shop for modifications to operate above
5,000 ft. (1525m).

HIGH TEMPERATURE OPERATION

At temperatures above 30°C, output de-rating is nec­essary. For maximum output ratings, de-rate the
welder output 5% for every 10°C above 30°C.

TOWING

The recommended trailer for use with this equipment
for road, in-plant and yard towing by a vehicle1is
Lincoln’s K957-1. If the user adapts a non-Lincoln trail­er, he must assume responsibility that the method of
attachment and usage does not result in a safety haz­ard nor damage the welding equipment. Some of the
factors to be considered are as follows:

1. Design capacity of trailer vs. weight of Lincoln
equipment and likely additional attachments.

2. Proper support of, and attachment to, the base of
the welding equipment so there will be no undue
stress to the framework.

3. Proper placement of the equipment on the trailer to
insure stability side to side and front to back when
being moved and when standing by itself while
being operated or serviced.

4. Typical conditions of use such as travel speed,
roughness of surface on which the trailer will be
operated, environmental conditions, and likely
maintenance.

5. Conformance with federal, state and local laws.

1

1

Consult applicable federal, state and local laws regarding specific
requirements for use on public highways.

PRE-OPERATION ENGINE SERVICE

Read and understand the information about the gaso­line engine in the Operation and Maintenance sec­tions of this manual before you operate the Ranger

250.

• Keep hands away from the engine muffler or HOT
engine parts.

• Stop the engine and allow it to cool before fueling.

• Do not smoke when fueling.

• Fill the fuel tank at a moderate rate and do not over­fill.

• Wipe up spilled fuel and allow the fumes to clear
before starting the engine.

• Keep sparks and flame away from the fuel tank.

• Remove the fuel cap slowly to release pressure.

OIL

The Ranger 250 is shipped with the engine

crankcase filled with high quality SAE 10W­30 oil (API class CD or better). CHECK THE OIL
LEVEL BEFORE YOU START THE ENGINE. If it is
not up to the FULL mark on the dipstick, add oil as
required. Check the oil every four hours of running
time during the first 25 running hours. Refer to the
engine operator’s manual for specific oil recommenda­tions and break-in information. The oil change interval
is dependent on the quality of the oil and the operating
environment. Refer to the engine operator’s manual
for the proper service and maintenance intervals.

FUEL

Use gasoline fuel only.

Fill the fuel tank with clean, fresh fuel. The
capacity of the fuel tank is 12 gallons (45.4
liters).

NOTE: The fuel tank is mounted below the engine, so
a fuel shutoff valve is not required.

ENGINE COOLING SYSTEM

Air to cool the engine is drawn in through the lower set
of louvers on the case back. It is important that the
intake air is not restricted. Allow a minimum clearance
of 2 feet (0.6m) from the case back to a vertical sur­face.

INSTALLATION

A-4 A-4

RANGER 250

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WARNING

WARNING

BATTERY CONNECTIONS

BATTERY ACID CAN BURN EYES AND
SKIN.

• Wear gloves and eye protection and be
careful when working near a battery.
Follow the instructions printed on the
battery.

Use caution as the electrolyte is a strong acid that can
burn skin and damage eyes.

The Ranger 250 is shipped with the negative battery
cable disconnected. Make certain that the RUN-STOP
switch is in the STOP position. Remove the screws
from the rear battery tray using a screwdriver or a 3/8"
socket. Attach the negative battery cable to the nega­tive battery terminal and tighten using a socket or
wrench.

NOTE: This machine is furnished with a wet charged
battery; if unused for several months, the battery may
require a booster charge. Be careful to charge the bat­tery with the correct polarity. See the battery charging
instructions in the Maintenance section.

MUFFLER OUTLET PIPE

Using the clamp provided, secure the outlet pipe to the
outlet tube with the pipe positioned to direct the ex­haust in the desired direction. Tighten using a socket or
wrench.

SPARK ARRESTER

Some federal, state or local laws may require spark
arresters in locations where unarrested sparks may
present a fire hazard. The standard muffler included
with this welder does not qualify as a spark arrester.
When required by local regulations, a suitable spark
arrester, such as the S24647, must be installed and
properly maintained. See the Accessories section for
more information.

An incorrect spark arrester may lead to engine damage
or may adversely affect performance.

HIGH FREQUENCY GENERATORS FOR
TIG APPLICATIONS

The K930-2 TIG Module is suitable for use with the
Ranger 250. The Ranger 250 and any high frequency
generating equipment must be properly grounded.
See the K930-2 operating manual for complete instruc­tions on installation, operation, and maintenance.

REMOTE CONTROL

The Ranger 250 is equipped with a 6-pin and a 14-pin
Amphenol connector. The 6-pin connector is for con­necting the K857 or K857-1 Remote Control (optional)
or for TIG welding, the K870 foot Amptrol or the K963­2 hand Amptrol.

When in the CC-STICK, PIPE, and CV-WIRE modes
and when a remote control is connected to the
Amphenol, the auto-sensing circuit in the Ranger 250
automatically switches the OUTPUT control from con­trol at the welder to remote control.

The 14-pin connector is used to directly connect a wire
feeder. In the CV-WIRE mode, the Ranger 250 auto­sensing circuit automatically makes the Ranger 250
OUTPUT control inactive and the wire feeder voltage
control active when the control cable is connected to
the 14-pin connector.

NOTE: When a wire feeder with a built in welding volt­age control is connected to the 14-pin connector, do
NOT connect anything to the 6-pin connector.

WELDING TERMINALS

The Ranger 250 is equipped with a toggle switch for
selecting “hot” welding terminals when in the “WELD
TERMINALS ON” position or “cold” welding terminals
when in the “REMOTELY CONTROLLED” position.

ELECTRICAL OUTPUT
CONNECTIONS

See Figure A.1 for the location of the 120 and 240 volt
receptacles, weld output terminals, and ground stud.

MACHINE GROUNDING

Because this portable engine driven welder
creates its own power, it is not necessary to connect its
frame to an earth ground, unless the machine is con­nected to premises wiring (home, shop, etc.)

INSTALLATION

A-5 A-5

RANGER 250

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WARNING

CAUTION

To prevent dangerous electric shock, other equipment
to which this engine driven welder supplies power
must:

a) Be grounded to the frame of the welder using a

grounded type plug.

b) Be double insulated.

Do not ground the machine to a pipe that carries explo­sive or combustible material.

When this welder is mounted on a truck or trailer, its
frame must be securely connected to the metal frame
of the vehicle. When connected to premises wiring
such as that in a home or shop, the welder frame must
be connected to the system earth ground. See further
connection instructions in the section entitled Standby
Power Connections as well as the article on ground­ing in the latest U.S. National Electrical Code and the
local code.

In general, if the machine is to be grounded, it should
be connected with a #8 or larger copper wire to a solid
earth ground such as a metal water pipe going into the
ground for at least ten feet and having no insulated
joints, or to the metal framework of a building which
has been effectively grounded. The U.S. National
Electrical Code lists a number of alternate means of
grounding electrical equipment. A machine grounding
stud marked with the ground symbol is provided
on the front of the welder.

WELDING OUTPUT CABLES

With the engine off, connect the electrode and work
cables to the output terminals. The welding process
dictates the polarity of the electrode cable. These con­nections should be checked periodically and tightened
with a wrench.

Table A.1 lists recommended cable sizes and lengths
for rated current and duty cycle. Length refers to the
distance from the welder to the work and back to the
welder. Cable diameters are increased for long cable
lengths to reduce voltage drops. Avoid coiling long
cables on the machine when welding.

INSTALLATION

A-6 A-6

RANGER 250

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FIGURE A.1 – RANGER 250 OUTPUT CONNECTIONS

CHOKE

RUN

START HIGH

IDLER

AUTO

G3668 VM

STOP

K NO.- CODE - SERIAL NO.

OUTPUT

20 CV

120 CC

22 CV

155 CC

24 CV

190 CC

17 CV
85 CC

26 CV

220 CC

28 CV

250 CC

14 CV
50 CC

12 CV
20 CC

THE LINCOLN ELECTRIC COMPANY CLEVELAND, OHIO USA

CV-WIRE

ARC CONTROL

WELD MODE

PIPE

CC-STICK

TOUCH START TIG

SOFT CRISP

+8

+6

+4

+2

0

-2

-4

-6

-8

-10

+10

WELD

TERMINALS ON

WIRE FEEDER

VOLTMETER

REMOTELY

CONTROLLED

NRTL/C

CIRCUIT

BREAKERS

120/240 V

120 V

WELDER OUTPUT RATING

VOLTS

DUTY CYCLE

250 DC 100% 25

80V MAX OCV AT RATED 3700 RPM

AMPS

AUXILIARY POWER RATING

VOLTS

DUTY CYCLE

WATTS

8,000

100% 120/240

AVAILABLE POWER IS REDUCED WHILE WELDING

SINGLE PHASE 60 HZ

SIMULTANEOUS WELDING AND POWER

WELD CURRENT

AMPS

AUX. POWER

WATTS

240V.RECEPTACLE

AMPS

0
100
150
200
250

8000
5000
3000
1500

0

33
21
13
6
0

NEUTRAL GROUND TO FRAME

Hobbs

QUARTZ

HOURS

0 0 0 0 0 0

1

2

4

3

1. 120 VAC
RECEPTACLES

2. 120/240 VAC
RECEPTACLES

3. WELD OUTPUT
TERMINALS

4. GROUND STUD

WARNING

TABLE A.1 – TOTAL COMBINED LENGTH

OF ELECTRODE AND WORK CABLES

Cable

Cable Size for

Length

250 Amps

100% Duty Cycle

0-100 ft. (0-30 meters) 1 AWG
100-200 ft. (30-46 meters) 1 AWG
150-200 ft. (46-61 meters) 1/0 AWG

CABLE INSTALLATION

Install the welding cables to your Ranger 250 as fol­lows.

1. The engine must be OFF to install welding cables.

2. Remove the flanged nuts from the output terminals.

3. Connect the electrode holder and work cables to
the weld output terminals. The terminals are iden­tified on the case front.

4. Tighten the flanged nuts securely.

5. Be certain that the metal piece you are welding (the
“work”) is properly connected to the work clamp
and cable.

6. Check and tighten the connections periodically.

• Loose connections will cause the output terminals to

overheat. The terminals may eventually melt.

• Do not cross the welding cables at the output termi-

nal connection. Keep the cables isolated and sepa­rate from one another.

AUXILIARY POWER RECEPTACLES

The auxiliary power of the Ranger 250 consists of two
20 amp-120 VAC (5-20R) duplex receptacles and one
50 amp 120/240 VAC (14-50R) receptacle. The 240
VAC receptacle can be split for single-phase 120 VAC
operation.

The auxiliary power capacity is 8,000 watts of 60 Hz,
single-phase power. The auxiliary power capacity rat­ing in watts is equivalent to volt-amperes at unity power
factor. The maximum permissible current of the 240
VAC output is 33 amps. The 240 VAC output can be
split to provide two separate 120 VAC outputs with a
maximum permissible current of 33 amps per output to

two separate 120 VAC branch circuits (these circuits
cannot be paralleled). Output voltage is within ±10% at
all loads up to rated capacity.

The 120 VAC auxiliary power receptacles should only
be used with three-wire grounded type plugs or
approved double insulated tools with two-wire plugs.
The current rating of any plug used with the system
must be at least equal to the current capacity of the
associated receptacle.

NOTE: The 240 VAC receptacle has two 120 VAC cir­cuits, but they are of opposite polarities and cannot be
paralleled.

STANDBY POWER CONNECTIONS

The Ranger 250 is suitable for temporary, standby or
emergency power using the engine manufacturer’s rec­ommended maintenance schedule.

The Ranger 250 can be permanently installed as a
standby power unit for 240 VAC, three-wire, single­phase, 35 amp service. Connections must be made by
a licensed electrician who can determine how the
120/240 VAC power can be adapted to the particular
installation and comply with all applicable electrical
codes. The following information can be used as a
guide by the electrician for most applications. Refer to
the connection diagram in Figure A-2.

1. Install the double-pole, double-throw switch
between the power company meter and the
premises disconnect. Switch rating must be the
same or greater than the customer’s premises dis­connect and service over current protection.

2. Take necessary steps to assure load is limited to
the capacity of the Ranger 250 by installing a 35
amp, 240 VAC double-pole circuit breaker.

Maximum rated load for each leg of the 240 VAC
auxiliary is 33 amperes. Loading above the rated
output will reduce output voltage below the allow­able ±10% of rated voltage, which may damage
appliances or other motor-driven equipment and
may result in overheating of the Ranger 250 engine
and/or alternator windings.

3. Install a 50 amp, 120/240 VAC plug (NEMA Type
14-50) to the double-pole circuit breaker using No.
6, 4-conductor cable of the desired length. (The 50
amp, 120/240 VAC plug is available in the optional
K802R plug kit or as part number T12153-9.)

4. Plug this cable into the 50 amp, 120/240 VAC
receptacle on the Ranger 250 case front.

INSTALLATION

A-7 A-7

RANGER 250

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CAUTION

INSTALLATION

A-8 A-8

RANGER 250

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FIGURE A.2 – CONNECTION OF THE RANGER 250 TO PREMISES WIRING

240 Volt

60 Hz.
3-Wire

Service

POWER

COMPANY

METER

240 VOLT

120 VOLT

120 VOLT

LOAD

N

NEUTRAL
BUS

GROUND

PREMISES

DISCONNECT AND

SERVICE

OVERCURRENT

PROTECTION

GND

N

NOTE: No. 8 COPPER CONDUCTOR CABLE SEE

NATIONAL ELECTRICAL CODE FOR ALTERNATE WIRE

SIZE RECOMMENDATIONS.

240 VOLT

GROUNDED CONDUCTOR

35AMP

240 VOLT

DOUBLE

POLE

CIRCUIT

BREAKER

DOUBLE POLE DOUBLE THROW
SWITCH RATING TO BE THE SAME
AS OR GREATER THAN PREMISES
SERVICE OVERCURRENT
PROTECTION.

50 AMP, 120/240

VOLT PLUG

NEMA TYPE 14-50

50 AMP, 120/240 VOLT

RECEPTACLE

• Only a licensed, certified, trained electrician should install the machine to a premises or residential elec­trical system. Be certain that:

• The installation complies with the National Electrical Code and all other applicable electrical codes.

• The premises is isolated and no feedback into the utility system can occur. Certain state and local laws

require the premises to be isolated before the generator is linked to the premises. Check your state and
local requirements.

• A double-pole, double-throw transfer switch in conjunction with the properly rated double-throw circuit
breaker is connected between the generator power and the utility meter.

WARNING

Section B-1 Section B-1

RANGER 250

TABLE OF CONTENTS

- OPERATION SECTION -

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

Operating Instructions.................................................................................................................B-2

Safety Instructions.......................................................................................................................B-2

General Description ....................................................................................................................B-2

Design Features ..........................................................................................................................B-3

Controls and Settings..................................................................................................................B-3

Engine Controls....................................................................................................................B-4

Welding Controls ..................................................................................................................B-5

Engine Operation........................................................................................................................B-5

Before Starting the Engine ...................................................................................................B-5

Starting the Engine...............................................................................................................B-6

Stopping the Engine.............................................................................................................B-6

Welder Operation........................................................................................................................B-7

General Operation................................................................................................................B-7

Stick Welding........................................................................................................................B-8

Constant Current (CC-Stick) Welding .............................................................................B-8

Pipe Welding ...................................................................................................................B-8

TIG Welding.................................................................................................................... ......B-9

Wire Welding-CV..................................................................................................................B-9

Arc Gouging.................................................................................................................... ......B-9

Auxiliary Power ...........................................................................................................................B-9

Simultaneous Welding and Auxiliary Power Loads............................................................B-10

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OPERATING INSTRUCTIONS

Read and understand this entire section before operat­ing your Ranger 250.

SAFETY INSTRUCTIONS

Do not attempt to use this equipment until you have
thoroughly read all the operating and maintenance
manuals supplied with your machine. They include
important safety precautions; detailed engine starting,
operating and maintenance instructions and parts lists.

ELECTRIC SHOCK can kill.

• Do not touch electrically live parts such
as output terminals or internal wiring.

• Insulate yourself from the work and
ground.

• Always wear dry insulating gloves.

FUMES AND GASES can be dan­gerous.

• Keep your head out of fumes.

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

WELDING SPARKS can cause
fire or explosion.

• Keep flammable material away.

• Do not weld on containers that have held
combustibles.

ARC RAYS can burn.

• Wear eye, ear, and body protection.

ENGINE EXHAUST can kill.

• Use in open, well ventilated areas or
vent exhaust to the outside.

• Do not stack anything on or near the
engine.

MOVING PARTS can injure.

• Do not operate this equipment with any
of its doors open or guards off.

• Stop the engine before servicing it.

• Keep away from moving parts.

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

ADDITIONAL SAFETY PRECAUTIONS

Always operate the welder with the hinged door closed
and the side panels in place. These provide maximum
protection from moving parts and insure proper cooling
air flow.

GENERAL DESCRIPTION

The Ranger 250 is a gasoline-engine-powered DC
multi-process welding power source and 120 / 240
VAC power generator. The engine drives a generator
that supplies three-phase power for the DC welding cir­cuit and single-phase power for the AC auxiliary out­lets. The DC welding control system uses state of the
art Chopper Technology (CT™) for superior welding
performance.

OPERATION

B-2 B-2

RANGER 250

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WARNING

WARNING

DESIGN FEATURES

• Single, full-range output control dial.

• 4 welding modes: CC-stick, downhill stick welding on
pipe, CV wire welding and Touch-Start TIG™ (elimi­nates high frequency and tungsten contamination).

• Output at welding terminals controlled by electronic
contactor. Can be switched to “On”, or to “Remotely
Controlled”. Contactor auto-activated when con­nected. 6-pin connector for remote output.

• Many wire feeder combinations: 14-pin connector for
Lincoln wire feeders LN-25, LN-23P, LN-7, LN-8
operates when using a Lincoln wire feeder with the
appropriate control cable.

• Smart machine! Remote operation and Magnum®
spool gun; 42VAC for LN-742 and Cobramatic® wire
feeders.

• Wire feed voltmeter switch matches polarity of wire
feeder voltmeter to polarity of electrode.

• 12 gallon fuel capacity allows you to run an extend­ed day.

• Easily check fuel level during operation and refu­elling with highly visible fuel gauge located next to
the fuel cap on case top side.

• Longer engine life, reduced noise emissions and
greater fuel economy with the automatic engine idler.

• Conveniently located engine maintenance label
under top engine door.

• Engine hour meter for scheduled maintenance.

• Automatic engine shutdown protection for low oil
pressure.

• Electric start. Reduce abnormal charging thanks to
a backlit battery charger system light indicator.

• Oil drain valve (no tools required).

• 8,000 watts of continuous duty AC generator power.

• Up to 33 amps at 240V from the 120V/240V recep­tacle. Circuit breaker protection.

• Two 120V 20A duplex receptacles. Circuit breaker
protection. Will operate up to a 9” grinder.

CONTROLS AND SETTINGS

The gasoline engine stop/start and idler controls are
located on the case front panel. The welder controls are
also located here. See Figure B.1.

OPERATION

B-3 B-3

RANGER 250

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OPERATION

B-4 B-4

RANGER 250

ENGINE CONTROLS

1. RUN/STOP SWITCH: RUN position energizes the
engine prior to starting. STOP position stops the
engine. The oil pressure interlock switch prevents
battery drain if the switch is left in the RUN position
and the engine is not operating.

2. CHOKE: When pulled out, it closes the choke valve
on the engine carburetor for quick starting.

3. START PUSHBUTTON: Energizes the starter
motor to crank the engine.

4. IDLER SWITCH: Has two positions as follows:
A) In the HIGH position, the engine runs at the high

idle speed controlled by the engine governor.

B) In the AUTO position, the idler operates as fol-

lows:

a. When switched from HIGH to AUTO or after

starting the engine, the engine will operate
at high speed for approximately 12 seconds
and then go to low idle speed.

b. When the electrode touches the work or

power is drawn from the auxiliary power

receptacles (approximately 100 watts mini­mum), the engine accelerates and operates
at high speed.

c. When welding ceases or the AC power load

is turned off, a fixed time delay of approxi­mately 12 seconds starts. If the welding or
AC power load is not restarted before the
end of the time delay, the idler reduces the
engine speed to low idle speed.

d. The engine will automatically return to high

idle speed when the welding load or AC
power load is reapplied.

5. ENGINE ALTERNATOR TROUBLE LIGHT: The
yellow engine alternator light is off when the battery
charging system is functioning normally. If the light
turns on, the alternator or the voltage regulator may
not be operating correctly. The light may also come
on if the battery is not holding a charge. It is normal
for the light to come on while starting the engine.

6. ENGINE HOUR METER: Displays the total time

that the engine has been running. This meter is
useful for scheduling prescribed maintenance.

FIGURE B.1 – CASE FRONT PANEL CONTROLS

1

K NO.- CODE - SERIAL NO.

Hobbs

6

7

QUARTZ

0 0 0 0 0 0

HOURS

THE LINCOLN ELECTRIC COMPANY CLEVELAND, OHIO USA

WELD MODE

CV-WIRE

PIPE

CC-STICK

TOUCH START TIG

8

RUN

STOP

OUTPUT

20 CV

120 CC

17 CV
85 CC

14 CV
50 CC

12 CV
20 CC

ARC CONTROL

SOFT CRISP

-2

-4

-6

-8

-10

START HIGH

CHOKE

22 CV

155 CC

24 CV

190 CC

220 CC

28 CV

250 CC

0

+2

+4

+6

+8

+10

26 CV

TERMINALS ON

CONTROLLED

NEUTRAL GROUND TO FRAME

WELD

REMOTELY

9

CIRCUIT

BREAKERS

120 V

SIMULTANEOUS WELDING AND POWER

WELD CURRENT

AMPS

0
100
150
200
250

WELDER OUTPUT RATING

DUTY CYCLE

AMPS

250 DC 100% 25

80V MAX OCV AT RATED 3700 RPM

AUX. POWER

VOLTS

120/240 V

240V.RECEPTACLE

AMPS

WATTS

33

8000

21

5000

13

3000

6

1500

0

0

AUXILIARY POWER RATING

DUTY CYCLE

WATTS

100% 120/240

8,000

AVAILABLE POWER IS REDUCED WHILE WELDING

SINGLE PHASE 60 HZ

VOLTS

IDLER

WIRE FEEDER

VOLTMETER

G3668 VM

AUTO

4

3

NRTL/C

2

5

13

12

11

10

OPERATION

B-5 B-5

RANGER 250

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WELDING CONTROLS

7. OUTPUT CONTROL: The OUTPUT dial provides
continuous control of the welding current or weld­ing voltage depending on the selected welding
mode. This control is not active in the CC-STICK,
PIPE, and CV-WIRE modes when a remote con­trol or wire feeder with remote control is connect­ed to either the 6-pin or 14-pin Amphenol.

8. WELD MODE SELECTOR SWITCH: This switch
provides four selectable welding modes:

• CV-WIRE

• PIPE

• CC-STICK

• TOUCH START TIG

9. ARC CONTROL: The ARC CONTROL WIRE/
STICK dial is active in the CV-WIRE and CC­STICK modes, and has different functions in
these modes. This control is not active in the TIG
and PIPE modes.

CC-STICK mode: In this mode, the ARC CON­TROL sets the short circuit current during stick
welding (arc-force). Increasing the number from

-10 to +10 increases the short circuit current and
prevents sticking of the electrode to the plate
while welding. This can also increase spatter. It
is recommended that the ARC CONTROL be set
to the minimum number without electrode stick­ing. Start with a setting at 0.

CV-WIRE mode: In this mode, turning the ARC
CONTROL clockwise from -10 (soft) to +10 (crisp)
changes the arc from soft and washed-in to crisp
and narrow. It acts as an inductance control. The
proper setting depends on the procedure and
operator preference. Start with a setting at 0.

10. 14-PIN AMPHENOL: For attaching wire feeder
control cables to the Ranger 250. Includes con­tactor closure circuit, auto-sensing remote control
circuit, and 120V and 42V power. The remote
control circuit operates the same as the 6-pin
Amphenol. See below.

11. 6-PIN AMPHENOL: For attaching optional
remote control equipment. When in the CC­STICK, PIPE, and CV-WIRE modes and when a
remote control is connected to the Amphenol, the
auto-sensing circuit in the Ranger 250 automati­cally switches the OUTPUT control from control at
the welder to remote control.

When using the TOUCH START TIG mode, the
OUTPUT control on the front of the Ranger 250
sets the maximum current range.

12. WELD TERMINALS CONTROL SWITCH: In the
WELD TERMINALS ON position, the weld output
is electrically hot all the time. In the REMOTELY
CONTROLLED position, the weld output is con­trolled by a wire feeder or amptrol device, and is
electrically off until a remote switch is depressed.

13. WIRE FEEDER VOLTMETER SWITCH: Matches
the polarity of the wire feeder voltmeter to the
polarity of the electrode.

ENGINE OPERATION

DO NOT RUN THE ENGINE AT EXCESSIVE
SPEEDS. The maximum allowable high idle speed for
the Ranger 250 is 3750 RPM, no load. Do NOT adjust
the governor screw on the engine. Severe personal
injury and damage to the machine can result if it is
operated at speeds above the maximum rated speed.

Read and understand all safety instructions included in
the engine operator’s manual that is shipped with your
Ranger 250.

BEFORE STARTING THE ENGINE

Check and fill the engine oil level:

1. Be sure the machine is on a level surface.

2. Open top engine door and remove the engine oil

dipstick and wipe it with a clean cloth. Reinsert the
dipstick and check the level on the dipstick.

3. Add oil (if necessary) to bring the level up to the full

mark. Do not overfill. Close engine door.

4. See the Maintenance section for specific oil rec-

ommendations.

Check and fill the engine fuel tank:

GASOLINE can cause fire or
explosion.

• Stop engine when fueling.

• Do not smoke when fueling.

• Do not overfill tank.

• Avoid contact with skin or breathing of vapor.

• Keep sparks and flame away from tank.

WARNING

WARNING

1. Remove the fuel tank cap.

2. Fill the tank approximately 4 inches (100mm) from
the top of the filler neck to allow for fuel expansion.
(Observe the fuel gauge while filling.) DO NOT
FILL THE TANK TO THE POINT OF OVERFLOW.

3. Replace the fuel cap and tighten securely.

4. See the Maintenance section for specific fuel rec­ommendations.

STARTING THE ENGINE

1. Remove all plugs connected to the AC power
receptacles.

2. Set the IDLER switch to AUTO.

3. Set the RUN/STOP switch to RUN.

4. Pull the choke to the full out position.

5. Press and hold the engine START button until the
engine starts.

6. Release the engine START button when the
engine starts.

7. Push the choke back in.

8. The engine will run at high idle speed for approx­imately 12 seconds and then go to low idle speed.
Allow the engine to warm up at low idle for sever­al minutes before applying a load and/or switch­ing to high idle. Allow a longer warm up time in
cold weather.

Operating the starter motor for more than 5 seconds
can damage the motor. If the engine fails to start,
release the START button and wait 10 seconds before
activating the starter again. Do NOT push the START
button while the engine is running because this can
damage the ring gear and/or the starter motor.

NOTE: Starting a Ranger 250 for the first time, or after
an extended period of time of not operating, will take
longer than normal. The fuel pump has to fill the fuel
line and carburetor. If the engine will not start, see the
Troubleshooting section of this manual.

STOPPING THE ENGINE

1. Remove all welding and auxiliary power loads and
allow the engine to run at low idle speed for a few
minutes to cool the engine.

2. Stop the engine by placing the RUN-STOP switch in
the STOP position.

NOTE: A fuel shut off valve is not required on the
Ranger 250 because the fuel tank is mounted below
the engine.

BREAK-IN PERIOD

Any engine will use a small amount of oil during its
“break-in” period. For the gasoline engine on the
Ranger 250, break-in is about 50 running hours.

Check the oil at least twice a day during break-in.
Change the oil after the first 25 hours of operation.
Change the oil filter at the second oil change. For more
details, see the Maintenance section of this manual.

During break-in, subject the Ranger 250 to moderate
loads. Avoid long periods running at idle. Before stop­ping the engine, remove all loads and allow the engine
to cool several minutes.

OPERATION

B-6 B-6

RANGER 250

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/

CAUTION

CAUTION

WELDER OPERATION

GENERAL INFORMATION

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

• Do not breathe welding fumes or gases.

• Use ventilation or exhaust to remove weld­ing from the breathing area.

• Keep flammable material away.

• Wear eye, ear, and body protection.

The Ranger 250 can deliver from 40 to 250 amps of
constant current for DC stick welding or from 20 to 250
amps of constant voltage current for DC semiautomat­ic wire feed welding. DC TIG welding is possible
across the entire range from 20 to maximum rated out­put. Output can be adjusted by setting the OUTPUT
control dial and the ARC control dial on the output con­trol panel to the settings that are best for your selected
welding process.

NOTE: An unstable or unsatisfactory welding arc can
result if welding cables are too long or are coiled on the
machine when welding. See Table A.1 in the

Installation section. Straighten out coiled cables
before welding.

OPERATION

B-7 B-7

RANGER 250

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WARNING

Onan P216 Kohler CH20 Running Time for

16 hp @ 3600 rpm 12 gallons-hours 12 gallons-hours

gal./hr (liters/hr) gal./hr (liters/hr) Onan/Kohler

Low Idle - No Load
2400 R.P.M. 0.6 (2.3) 0.6 (2.3) 20/20

High Idle - No Load
3700 R.P.M. 0.8 (3.0) 0.8 (3.0) 15/15

DC Weld Output
250 Amps @ 25 Volts 1.7 (6.4) 1.4 (5.3) 7.0/8.6

Auxiliary Power
8,000 Watts 1.8 (6.8) 1.4 (5.3) 6.4/8.6

TABLE B.1 – TYPICAL RANGER 250 FUEL CONSUMPTION

STICK WELDING

The Ranger 250 can be used with a broad range of DC
stick electrodes.

The MODE switch provides two stick welding settings
as follows:

CONSTANT CURRENT (CC-STICK) WELDING

The CC-STICK position of the MODE switch is
designed for horizontal and vertical-up welding with all
types of electrodes, especially low hydrogen. The
OUTPUT control adjusts the full output range for stick
welding.

The ARC control sets the short circuit current during
stick welding (arc-force). Increasing the number from

-10 to +10 increases the short circuit current and pre­vents sticking of the electrode to the plate while weld­ing. This can also increase spatter. It is recommended
that the ARC control be set to the minimum number
without electrode sticking. Start with the dial set at 0.

PIPE WELDING

This slope-controlled setting is intended for “out-of­position” and “downhill” pipe welding where the opera­tor would like to control the current level by changing
the arc length. The OUTPUTcontrol dial adjusts the full
output range for pipe welding. The ARC control is not
active in the PIPE mode.

OPERATION

B-8 B-8

RANGER 250

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Tungsten
Electrode
Diameter

in. (mm)

2-15
5-20

15-80

70-150

150-250
250-400

400-500
500-750

750-1000

3
3
3

10-20
15-30

25-40
40-55

55-80

180-125

3-8 (2-4)
5-10 (3-5)
5-10 (3-5)

5-10 (3-5)
13-17 (6-8)

15-23 (7-11)
21-25 (10-12)

23-27 (11-13)
28-32 (13-15)

3-8 (2-4)
5-10 (3-5)
5-10 (3-5)

9-13 (4-6)
11-15 (5-7)

11-15 (5-7)
13-17 (6-8)

18-22 (8-10)
23-27 (11-13)

TIG TORCH

Nozzle
Size

4, 5

Approximate Argon Gas Flow Rate

C.F.H. (l/min.)

DCEN (-) DCEP (+)

#4, #5, #6

#5, #6
#6, #7, #8

#8, #10

0 .010 (.25)

0.020 (.50)

0.040 (1.0)
1/16 (1.6)
3/32 (2.4)

1/8 (3.2)
5/32 (4.0)

3/16 (4.8)
1/4 (6.4)

1%, 2%
Thoriated
Tungsten

1%, 2%

Thoriated

Tungsten

Aluminum Stainless Steel

TABLE B.2 – TYPICAL CURRENT RANGES1FOR TUNGSTEN ELECTRODES

2

1

When used with argon gas. The current ranges shown must be reduced when using argon/helium or pure helium shield­ing gases.

2

Tungsten electrodes are classified as follows by the American Welding Society (AWS):

Pure EWP
1% Thoriated EWTh-1

2% Thoriated EWTh-2
Though not yet recognized by the AWS, Ceriated Tungsten is now widely accepted as a substitute for 2% Thoriated
Tungsten in AC and DC applications.

3

DCEP is not commonly used in these sizes.

4

TIG torch nozzle “sizes” are in multiples of 1/16ths of an inch:

# 4 = 1/4 in. (6 mm)
# 5 = 5/16 in. (8 mm)
# 6 = 3/8 in. (10 mm)
# 7 = 7/16 in. (11 mm)
# 8 = 1/2 in. (12.5 mm)
#10 = 5/8 in. (16 mm)

5

TIG torch nozzles are typically made from alumina ceramic. Special applications may require lava nozzles, which are
less prone to breakage, but cannot withstand high temperatures and high duty cycles.

TIG WELDING

The TOUCH START TIG setting of the MODE switch is
for DC TIG (Tungsten Inert Gas) welding. To initiate a
weld, the OUTPUT control is first set to the desired cur­rent and the tungsten is touched to the work. During
the time the tungsten is touching the work there is very
little voltage or current and, in general, no tungsten
contamination. Then the tungsten is gently lifted off the
work in a rocking motion, which establishes the arc.

The ARC CONTROL is not active in the TIG mode.
The Ranger 250 can be used in a wide variety of DC

TIG welding applications. In general the “Touch Start”
feature allows contamination-free starting without the
use of a Hi-frequency unit. If desired, the K930-2 TIG
Module can be used with the Ranger 250. The follow­ing settings are for reference.

Ranger 250 settings when using the K930-2 TIG
Module with an Amptrol or Arc Start Switch:

a. Set the MODE Switch to the TOUCH START TIG

setting.
b. Set the “IDLER” Switch to the “AUTO” position.
c. Set the "WELD TERMINALS” switch to the

“REMOTELY CONTROLLED” position. This will

keep the solid state contactor open and provide a

“cold” electrode until the Amptrol or Arc Start switch

is pressed.
When using the TIG Module, the OUTPUT control on

the Ranger 250 is used to set the maximum range of
the CURRENT.

WIRE WELDING-CV

Connect a wire feeder to the Ranger 250 according to
the instructions in the Accessories section.

In the CV-WIRE mode, the Ranger 250 can be used
with a broad range of flux cored wire (Innershield and
Outershield) electrodes and solid wires for MIG weld­ing (gas metal arc welding). Welding can be finely
tuned using the ARC CONTROL. Turning the ARC
CONTROL clockwise from -10 (soft) to +10 (crisp)
changes the arc from soft and washed-in to crisp and
narrow. It acts as an inductance control. The proper
setting depends on the procedure and operator prefer­ence. Start with the dial set at 0.

Some recommended Innershield electrodes are:
NR-311, NS-3M, NR-207, NR-203 Ni 1%, NR-204-H.
Recommended Outershield electrodes are: 0S-70,
0S-71M.

Some recommended solid wires for MIG welding are:
.035 (0.9 mm), and .045 (1.1 mm), L-50 and L-56, .035
(0.9 mm) and .045 (1.1 mm) Blue Max MIG 308 LS.

For any electrodes, including those above, the proce­dures should be kept within the rating of the machine.

ARC GOUGING

The Ranger 250 can be used for limited arc gouging.
For optimal performance, set the MODE switch to CC­STICK and the ARC CONTROL to +10.

Set the OUTPUT CONTROL to adjust output current to
the desired level for the gouging electrode being used
according to the ratings in Table B.3.

TABLE B.3 – CURRENT RANGE

PER ELECTRODE DIAMETER

Electrode Current Range

Diameter (DC, Electrode Positive)

1/8" 30-60 Amps
5/32" 90-150 Amps
3/16" 150-200 Amps

AUXILIARY POWER

Be sure that any electrical equipment plugged into the
generator AC power receptacles can withstand a ±10%
voltage and a ±3% frequency variation.

Start the engine and set the IDLER control switch to
the desired operating mode. Full power is available
regardless of the welding control settings as long as no
welding current is being drawn.

The auxiliary power of the Ranger 250 consists of two
20 amp-120 VAC (5-20R) duplex receptacles and one
50 amp 120/240 VAC (14-50R) receptacle. The 240
VAC receptacle can be split for single-phase 120 VAC
operation.

The auxiliary power capacity is 8,000 watts of 60 Hz,
single-phase power. The auxiliary power capacity rat­ing in watts is equivalent to volt-amperes at unity power
factor. The maximum permissible current of the 240
VAC output is 33 amps.

OPERATION

B-9 B-9

RANGER 250

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WARNING

The 240 VAC output can be split to provide two sepa­rate 120 V AC outputs with a maximum permissible cur­rent of 33 amps per output to two separate 20 amp
branch circuits. (These circuits cannot be paralleled.)
Output voltage is within ±10% at all loads up to rated
capacity.

The 120 VAC auxiliary power receptacles should only
be used with three-wire, grounded type plugs or
approved double-insulated tools with two-wire plugs.
The current rating of any plug used with the system
must be at least equal to the current capacity of the
associated receptacle. For extension cord lengths, see
Table B.5.

NOTE: The 240 VAC receptacle has two circuits, each
of which measures 120 VAC to neutral. However, they
are of opposite polarity and cannot be paralleled.

SIMULTANEOUS WELDING AND
AUXILIARY POWER LOADS

The auxiliary power ratings are with no welding load.
Simultaneous welding and power loads are specified in
Table B.4. The permissible currents shown assume
that current is being drawn from either the 120 VAC or
240 VAC supply (not both at the same time).

OPERATION

B-10 B-10

RANGER 250

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* Each duplex receptacle is limited to 20 amps.
** Not to exceed 25 amps per 120 VAC branch circuit when splitting the 240 VAC output.

TABLE B.4 – RANGER 250 SIMULTANEOUS WELDING AND POWER LOADS

Welding Permissible Power-Watts

Permissible Auxiliary

Output- Amps (Unity Power Factor)

Current in Amps

@ 120 VAC* @ 240 VAC**

0 8000 40* 33
100 5000 40* 21
150 3000 25 12.5
200 1500 12.5 6.3
250 0 0 0

TABLE B.5 – RANGER 250 EXTENSION CORD LENGTH RECOMMENDATIONS

(Use the shortest length extension cord possible sized per the following table)

Current Voltage

Load

Maximum Allowable Cord Length in Ft. (m) for Conductor Size

(Amps) (Volts)

(Watts)

14 AWG 12 AWG 10 AWG 8 AWG 6 AWG 4 AWG
15 120 1800 30 (9) 40 (12) 75 (23) 125 (38) 175 (53) 300 (91)
20 120 2400 30 (9) 50 (15) 88 (27) 138 (42) 225 (69)
15 240 3600 60 (18) 75 (23) 150 (46) 225 (69) 350 (107) 600 (183)
20 240 4800 60 (18) 100 (30) 175 (53) 275 (84) 450 (137)
33 240 8000 60 (18) 100 (30) 175 (53) 250 (76)

Conductor size is based on maximum 2.0% voltage drop.

TABLE OF CONTENTS

- ACCESSORIES -

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

Options/Accessories ...................................................................................................................C-2

Field Installed Options ....................................................................................................... ..C-2

TIG Welding Accessories .....................................................................................................C-2

Semiautomatic FCAW and MIG Welding Accessories.........................................................C-2

Connection of Lincoln Electric Wire Feeders.......................................................................C-3

Connection of the K867 Universal Adapter ....................................................................C-3

Connection of the LN-25 “Across the Arc”.....................................................................C-4

Connection of the LN-25 with 42V Remote Output Control Module..............................C-5

Connection of the LN-25 with K857 Remote Control .....................................................C-6

Connection of the LN-7 Using the K584 Control Cable.................................................C-7

Connection of the LN-8 Using the K595 Control Cable.................................................C-8

Connection of the LN-742..............................................................................................C-9

Section C-1 Section C-1

RANGER 250

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OPTIONS/ACCESSORIES

FIELD INSTALLED OPTIONS

The following options/accessories are available for
your Ranger 250 from your local Lincoln distributor.

K957-1 HEAVY DUTY, TWO-WHEEL TRAILER FOR
SMALL WELDERS - For road, off-road and in-plant

and yard towing. (For highway use, consult applicable
federal, state and local laws regarding requirements for
brakes, lights, fenders, etc.)

K1737-1 FOUR-WHEEL ALL-TERRAIN UNDERCAR­RIAGE - For moving by hand.

K1770-1 UNDERCARRIAGE (FACTORY) - For mov-

ing by hand on a smooth surface. One or two gas
cylinders can be mounted on the rear of the undercar­riage with the installation of K1745-1 Cylinder
Holder(s).

K1739-1 CABLE CARRIER KIT - For use on K1737-1
and K1770-1 Undercarriages.

K1745-1 SINGLE GAS CYLINDER HOLDER - For use
on K1770-1 Undercarriage. One or two may be
installed on an undercarriage.

K1788-1 ROLL CAGE - Gives added damage protec­tion.

K886-2 CANVAS COVER - Protects machine when
not in use.

S24647 SPARK ARRESTER - Mounts inside exhaust
pipe.

K702 ACCESSORY KIT - Accessory set includes 35 ft.
(10.7 meters) 2 AWG electrode cable, 30 ft. (9.1
meters) 2 AWG work cable, headshield with No. 12 fil­ter, GC300 work clamp and Cooltong 300 electrode
holder. Cables are rated at 250 amps, 40% duty cycle.

K857 28 ft. (8.5m) or K857-1 100 ft. (30.4m)
REMOTE CONTROL - Portable control provides same

dial range as the output control on the welder. Has a
convenient 6-pin plug for easy connection to the
welder.

K1690-1 GFCI RECEPTACLE KIT - Includes one UL
approved 120 volt ground fault circuit interrupter duplex
type receptacle with cover and installation instructions.
Replaces the factory installed 120V duplex receptacle.
Each receptacle of the GFCI Duplex is rated at 20
amps. The maximum total current from the GFCI
Duplex is limited to 20 amps. Two kits are required.

K802-N POWER PLUG KIT - Provides four 120 volt
plugs rated at 20 amps each and one dual voltage, full
KVA plug rated at 120/240 volts, 50 amps.

K802-R POWER PLUG KIT - Provides four 120 volt

plugs rated at 15 amps each and one dual voltage, full
KVA plug rated at 120/240 volts, 50 amps.

T12153-9 50 AMP, 120/240V POWER PLUG -

Provides one dual voltage plug for full KVA power.

TIG WELDING ACCESSORIES

K1783-9 TIG TORCH - For TIG welding with shielding

gas. Includes 25 feet of cable.

K963-2 - Hand Amptrol.
K870 - Foot Amptrol.
NOTE: TIG welding requires a Magnum™ TIG Gun,

appropriate Magnum Parts Kit and argon gas.

SEMIAUTOMATIC FCAW AND MIG
WELDING ACCESSORIES

LN-25 WIRE FEEDER K449 - This portable unit pro-

vides CC/CV for flux-cored arc welding (FCAW) and
metal inert gas welding (MIG). Includes a gas solenoid
and an internal contactor that allows across-the-arc
operation with no control cable. The LN-25 provides a
“cold” electrode until the gun trigger is pressed. For
voltage control at the feeder, a K444-1 Remote Voltage
Control Kit or K857 Remote Control is required. Refer
to connection instructions later in this section.

LN-7 OR LN-8 WIRE FEEDER - Semiautomatic, con­stant speed wire feeders.

NOTE: Gas-shielded welding requires a Magnum Gun.
Gasless welding requires an Innershield Gun.

LN-742 WIRE FEEDER - A semiautomatic wire feeder
with “cold” electrode. Refer to connection instructions
later in this section.

MAGNUM SPOOL GUN (K487-25) - A lightweight,
semiautomatic wire feeder for aluminum welding with
argon gas. Has built-in remote wire speed control in
the handle. Requires the K488 SG Control Module.
Refer to connection instructions later in this section.

SG CONTROL MODULE (K488) - Controls wire speed
and gas flow. Provides the required control interface
between the Ranger 250 and the K487-25 Magnum
Spool Gun. Requires the K691-10 Input Cable.

K444-1 REMOTE VOLTAGE CONTROL - Provides
voltage adjustment control at the feeder. Includes 25
feet of cable.

K126-2 INNERSHIELD GUN - For gasless welding.
Includes 15 feet of cable.

K470-2 MAGNUM GUN CONNECTOR KIT - For gas­shielded welding.

K466-1 MAGNUM GUN CONNECTOR KIT - For con­necting the Magnum 300 MIG Gun to the feeder for
gas-shielded welding.

ACCESSORIES

C-2 C-2

RANGER 250

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CONNECTION OF LINCOLN
ELECTRIC WIRE FEEDERS

ELECTRIC SHOCK can kill.

• Do not operate with panels open.

• Disconnect NEGATIVE (-) BATTERY
LEAD before servicing.

• Do not touch electrically live parts.

MOVING PARTS can injure.

• Keep guards in place.

• Keep away from moving parts.

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

CONNECTION OF THE RANGER 250 TO
WIRE FEEDERS USING K867 UNIVERSAL
ADAPTER (SEE FIGURE C.1)

NOTE: When you use the Ranger 250 with non-Lincoln

Electric wire feeders or with certain earlier models of
Lincoln wire feeders, you will require the K867
Universal Adapter. The following discussion and con­nection diagram explain in general how to make the
proper connections.

1. Shut the welder off.

2. Connect the electrode cable from the wire feeder to
the “+” terminal of the welder. Connect the work
cable to the “-” terminal of the welder.

NOTE: Welding cable must be sized for current and
duty cycle of application.

3. Connect the K867 Universal Adapter to the 14-pin
amphenol of the Ranger 250 as shown in Figure
C.1. Make the proper connections for local or
remote control according to Figure C.1 and the fol­lowing NOTES, indicated on the figure:

A. These leads are not used for the Ranger 250.

Insulate each unused lead individually.

B. For wire feeders that return a signal for welding

output, use an isolation relay to close leads 2
and 4.

C. Refer to the Operation section of this manual

for maximum wire feeder auxiliary current draw.

4. Set the “MODE” switch to the “CV-WIRE” position.

5. Place the “IDLER” switch in the “AUTO” position.

Any increase of the high idle engine RPM by changing
the governor setting or overriding the throttle linkage
will cause an increase in the AC auxiliary voltage. If
this voltage goes over 140 volts, wire feeder control cir­cuits may be damaged. The engine governor setting is
preset at the factory – do not adjust above RPM spec­ifications listed in this manual.

6. Set the “VOLTMETER” switch to “+” or “-” depend­ing on the polarity chosen.

7. Set the ARC control to “0” initially and adjust to suit.

8. Adjust wire feed speed at the wire feeder.

ACCESSORIES

C-3 C-3

RANGER 250

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WARNING

FIGURE C.1 – RANGER 250/K867 UNIVERSAL ADAPTER CONNECTION DIAGRAM

ELECTRODE CABLE
TO WIRE FEED UNIT

TO WORK

14-PIN
AMPHENOL

A

B

C

K867 UNIVERSAL
ADAPTER PLUG

+–

CAUTION

CONNECTION OF THE LN-25 TO THE
RANGER 250 “ACROSS THE ARC”
(SEE FIGURE C.2.)

1. Shut the welder off.

2. Connect the electrode cable from the LN-25 to the
“-” terminal of the welder. Connect the work cable
to the “+” terminal of the welder.

NOTE: Figure C.2 shows the electrode connected for
negative polarity. To change polarity, shut the welder
off and reverse the electrode and work cables at the
Ranger 250 output terminals.

NOTE: Welding cable must be sized for current and
duty cycle of application.

3. Set the “VOLTMETER” switch to “+” or “-” depend­ing on the polarity chosen.

4. Set the “MODE” switch to the “CV-WIRE” position.

5. Attach the single lead from the LN-25 control box
to the work using the spring clip on the end of the
lead. This is only a control lead – it carries no
welding current.

6. Place the “IDLER” switch in the “AUTO” or “HIGH”
position as desired.

If you are using an LN-25 without an internal contactor,
the electrode will be “HOT” when the Ranger 250 is
started.

7. Place the “WELD TERMINALS” switch in the
“WELD TERMINALS ON” position.

8. Adjust wire feed speed at the LN-25 and adjust the
welding voltage with the output “CONTROL” at the
LN-25 if optional remote control kit is used.

9. Set the ARC control to “0” initially and adjust to suit.

ACCESSORIES

C-4 C-4

RANGER 250

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CAUTION

FIGURE C.2 – RANGER 250/LN-25 ACROSS THE ARC CONNECTION DIAGRAM

-

-

+ –

ACCESSORIES

C-5 C-5

RANGER 250

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CONNECTION OF THE LN-25 TO THE
RANGER 250 WITH 42 VOLT REMOTE
OUTPUT CONTROL MODULE
(SEE FIGURE C.3.)

1. Shut the welder off.

2. Connect the electrode cable from the K626-XX
Input Cable Assembly to the “-” terminal of the
welder and to the LN-25 Wire Feeder. Connect the
work cable to the “+” terminal of the welder.

NOTE: Figure C.3 shows the electrode connected for
negative polarity. To change polarity, shut the welder
off and reverse the electrode and work cables at the
Ranger 250 output terminals.

NOTE: Welding cable must be sized for current and
duty cycle of application.

3. Connect the input cable from the K626-XX Input
Cable Assembly to the 14-pin amphenol on the
Ranger 250 and the input cable plug on the LN-25.

4. Set the “VOLTMETER” switch to “+” or “-” depend­ing on the polarity chosen.

5. Set the “MODE” switch to the “CV-WIRE” position.

6. Place the “IDLER” switch to the “AUTO” or “HIGH”
position as desired.

Any increase of the high idle engine RPM by changing
the governor setting or overriding the throttle linkage
will cause an increase in the AC auxiliary voltage. If
this voltage goes over 140 volts, wire feeder control cir­cuits may be damaged. The engine governor setting is
preset at the factory – do not adjust above RPM spec­ifications listed in this manual.

7. Place the “WELD TERMINALS” switch in the
“REMOTELY CONTROLLED” position.

8. Adjust wire feed speed and voltage at the LN-25.

9. Set the ARC control to “0” initially and adjust to suit.

FIGURE C.3 – RANGER 250/LN-25 WITH

42 VOLT REMOTE OUTPUT CONTROL MODULE CONNECTION DIAGRAM

CAUTION

-

+–

CONNECTION OF THE LN-25 TO THE
RANGER 250 “ACROSS THE ARC”
WITH K857 REMOTE CONTROL
(SEE FIGURE C.4.)

1. Shut the welder off.

2. Connect the electrode cable from the LN-25 to the
“-” terminal of the welder. Connect the work cable
to the “+” terminal of the welder.

NOTE: Welding cable must be sized for current and
duty cycle of application.

NOTE: Figure C.4 shows the electrode connected for
negative polarity. To change polarity, shut the welder
off and reverse the electrode and work cables at the
Ranger 250 output terminals.

3. Connect the K857 Remote Control to the 6-pin
amphenol on the Ranger 250.

4. Attach the single lead from the LN-25 to the work
using the spring clip on the end of the lead. This is
only a sense lead – it carries no welding current.

5. Place the “IDLER” switch in the “AUTO” or “HIGH”
position, as desired.

If you are using an LN-25 without an internal contactor,
the electrode will be “HOT” when the Ranger 250 is
started.

6. Set the “MODE” switch to “CV-WIRE.”

7. Set the “WELD TERMINALS” switch to “WELD
TERMINALS ON.”

8. Set the “VOLTMETER” switch to “+” or “-”
depending on the polarity chosen.

9. Adjust wire feed speed at the LN-25 and adjust
the welding voltage with the K857 if optional
remote control is used.

10. Adjust the “ARC” control to “0” initially and adjust
to suit.

ACCESSORIES

C-6 C-6

RANGER 250

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FIGURE C.4 – RANGER 250/LN-25 ACROSS THE ARC

CONNECTION DIAGRAM WITH K857 REMOTE CONTROL

(RANGER 300 DLX
ONLY)

6 PIN

AMPHENOL

TO WORK

14 PIN
AMPHENOL

LN-25

ELECTRODE CABLE

WIRE FEEDER

TO WORK

WORK CLIP LEAD

OPTIONAL K857

REMOTE CONTROL

ELECTRODE

TO WORK

-

-

CAUTION

+

–

CONNECTION OF THE LN-7 TO THE
RANGER 250 USING K584 CONTROL
CABLE (SEE FIGURE C.5.)

NOTE: If your LN-7 comes equipped with a K291 or

K404 input cable, refer to CONNECTION OF THE LN­7 Using K867 UNIVERSALADAPTER, rather than this
discussion, to connect your Ranger 250 for wire feed
welding.

1. Shut the welder off.

2. Connect the electrode cable from the K584-XX
Control Cable to the “+” terminal of the welder and
to the LN-7 wire feeder. Connect the work cable to
the “-” terminal of the welder.

NOTE: Figure C.5 shows the electrode connected for
positive polarity . To change polarity , shut the welder of f
and reverse the electrode and work cables at the out­put terminals.

NOTE: Welding cable must be sized for current and
duty cycle of application.

3. Connect the input cable from the K584-XX Control
Cable to the 14-pin amphenol on the Ranger 250
and the input cable plug on the LN-7.

4. Set the “VOLTMETER” switch to “+” or “-” depend­ing on the polarity chosen.

5. Set the “MODE” switch to the “CV-WIRE” position.

6. Place the “IDLER” switch in the “HIGH” position.

Any increase of the high idle engine RPM by changing
the governor setting or overriding the throttle linkage
will cause an increase in the AC auxiliary voltage. If
this voltage goes over 140 volts, wire feeder control cir­cuits may be damaged. The engine governor setting is
preset at the factory – do not adjust above RPM spec­ifications listed in this manual.

7. Place the “WELD TERMINALS” switch in the
“REMOTELY CONTROLLED” position.

8. Adjust wire feed speed at the LN-7 and adjust the
welding voltage with the optional remote control if
used.

9. Set the “ARC” control at “0” initially and adjust to
suit.

ACCESSORIES

C-7 C-7

RANGER 250

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FIGURE C.5 – RANGER 250/LN-7 WITH 584 CONTROL CABLE CONNECTION DIAGRAM

-

-

CAUTION

CONNECTION OF THE LN-8 TO THE
RANGER 250 USING K595 CONTROL
CABLE (SEE FIGURE C.6.)

NOTE: If your LN-8 comes equipped with a K291 or

K404 input cable, refer to CONNECTION OF THE LN­7 Using K867 UNIVERSALADAPTER, rather than this
discussion, to connect your Ranger 250 for wire feed
welding.

1. Shut the welder off.

2. Connect the electrode cable from the LN-8 to the
“+” terminal of the welder. Connect the work cable
to the “-” terminal of the welder.

NOTE: Welding cable must be sized for current and
duty cycle of application.

NOTE: Figure C.6 shows the electrode connected for
positive polarity . To change polarity , shut the welder of f
and reverse the electrode and work cables at the
Ranger 250 output terminals.

3. Connect the K595-XX Control Cable to the LN-8.

4. Connect the K595-XX to the 14-pin amphenol on
the Ranger 250.

5. Place the IDLER switch in the “HIGH” position.

An increase of the high idle engine RPM by changing
the governor setting or overriding the throttle linkage
will cause an increase in the AC auxiliary voltage. If
this voltage goes over 140 volts, wire feeder control cir­cuits may be damaged. The engine governor setting is
preset at the factory – do not adjust above RPM spec­ifications listed in this manual.

6. Set the “VOLTMETER” switch to “+” or “-” depend­ing on the polarity chosen.

7. Set the “MODE” switch to “CV-WIRE.”

8. Set the “WELD TERMINALS” switch to “WELD
TERMINALS REMOTELY CONTROLLED.”

9. Adjust wire feed speed and voltage at the LN-8.

10. Adjust the “ARC” control to “0” initially and adjust
to suit.

ACCESSORIES

C-8 C-8

RANGER 250

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FIGURE C.6 – RANGER 250/LN-8 WITH K595 CONTROL CABLE CONNECTION DIAGRAM

–

TO LN-8 INPUT
CABLE PLUG

AMPHENOL

ELECTRODE CABLE

TO WORK

14 PIN

K595 CONTROL CABLE

TO WIRE FEED UNIT

+

-

CAUTION

ACCESSORIES

C-9 C-9

RANGER 250

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CONNECTION OF THE LN-742 TO THE
RANGER 250 (SEE FIGURE C.7.)

1. Shut the welder off.

2. Connect the electrode cable from the LN-742 to
the “+” terminal of the welder. Connect the work
cable to the “-” terminal of the welder.

NOTE: Figure C.7 shows the electrode connected for
positive polarity . To change polarity , shut the welder of f
and reverse the electrode and work cables at the out­put terminals.

NOTE: Welding cable must be sized for current and
duty cycle of application.

3. Connect the K619 Control Cable to the 14-pin
amphenol on the Ranger 250 and the input cable
plug on the LN-742.

4. Set the VOLTMETER” switch to “+” or “-” depend­ing on the polarity chosen.

5. Set the “MODE” switch to the “CV-WIRE” position.

6. Place the “IDLER” switch in the “AUTO” or “HIGH”
position as desired.

An increase of the high idle engine RPM by changing
the governor setting or overriding the throttle linkage
will cause an increase in the AC auxiliary voltage. If
this voltage goes over 140 volts, wire feeder control cir­cuits may be damaged. The engine governor setting is
preset at the factory – do not adjust above RPM spec­ifications listed in this manual.

7. Place the “WELD TERMINALS” switch in the
“REMOTELY CONTROLLED” position.

8. Adjust wire feed speed and voltage at the LN-742.

9. Set the “ARC” control to “0” initially and adjust to
suit.

FIGURE C.7 – RANGER 250/LN-742 CONNECTION DIAGRAM

-

+

–

CAUTION

C-10

NOTES

RANGER 250

C-10

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Section D-1 Section D-1

RANGER 250

TABLE OF CONTENTS

-MAINTENANCE-

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

Safety Precautions ......................................................................................................................D-2

Routine and Periodic Maintenance .............................................................................................D-2

Engine Maintenance............................................................................................................. D-2

Engine Oil Change ........................................................................................................D-4

Oil Filter Change ............................................................................................................D-4

Air Cleaner Service ........................................................................................................D-4

Spark Plug Service.........................................................................................................D-5

Fuel Filter Service ..........................................................................................................D-5

Engine Adjustment .........................................................................................................D-5

Battery Maintenance.............................................................................................................D-6

Optional Spark Arrestor ........................................................................................................ D-6

Welder/Generator Maintenance ..................................................................................................D-7

Storage.................................................................................................................................D-7

Cleaning ...............................................................................................................................D-7

Receptacles..........................................................................................................................D-7

Cable Connections...............................................................................................................D-7

Brush Removal and Replacement........................................................................................D-7

SAFETY PRECAUTIONS

• Have qualified personnel do all maintenance and
troubleshooting work.

• Turn the engine off before working inside the
machine.

• Remove guards only when necessary to perform
maintenance and replace them when the mainte­nance requiring their removal is complete. If guards
are missing from the machine, obtain replacements
from a Lincoln Distributor. (See Operating Manual
Parts List.)

Read the Safety Precautions in the front of this manu­al and in the Engine Owner’s Manual before working
on this machine.

Keep all equipment safety guards, covers, and devices
in position and in good repair. Keep your hands, hair,
clothing, and tools away from the fans, and all other
moving parts when starting, operating, or repairing the
equipment.

ROUTINE AND PERIODIC
MAINTENANCE

ENGINE MAINTENANCE

To prevent the engine from accidentally starting, dis­connect the spark plug leads before servicing the
engine.

See Table D.1 (Kohler engine) or D.2 (Onan Engine)
for a summary of maintenance intervals for the items
listed in Table D.3. Follow either the hourly or the cal­endar intervals, whichever comes first. More frequent
servicing may be required, depending on your specific
application and operating conditions. See Figure D.1
for major component locations.

At the end of each day’s use, refill the fuel tank to min­imize moisture condensation in the tank. Running out
of fuel tends to draw dirt into the fuel system. Also,
check the crankcase oil level and add oil if indicated.

MAINTENANCE

D-2 D-2

RANGER 250

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WARNING

FREQUENCY MAINTENANCE REQUIRED

Daily or Before • Fill fuel tank
Starting Engine • Check oil level

• Check air cleaner for dirty, loose, or damaged parts

• Check air intake and cooling areas, clean as necessary
5 Hours • First Oil Change
Every 25 Hours • Service air pre-cleaner
Every 100 Hours • Change engine oil

1

• Replace fuel filter element

• Clean or replace air filter element

1

• Clean spark arrestor
Every 200 Hours • Replace oil filter

1

• Check spark plug and gap
Every 2 Years • Check fuel lines and clamps

1

Service more frequently when used in dusty areas and/or at high ambient temperatures.

TABLE D.1 – KOHLER ENGINE MAINTENANCE SCHEDULE

CAUTION

MAINTENANCE

D-3 D-3

RANGER 250

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ITEM MAKE AND PART NUMBER

ONAN P216 ENGINE KOHLER CH20 ENGINE

Oil Filter Onan 122-0645, Fram PH3614 Kohler 1205001, Fram PH3614
Air Filter Element Onan 140-2628-01, Fram CA140PL Kohler 4708303, Fram CA79
Air Filter Pre-Cleaner Onan 140-1496 Kohler 2408302
Fuel Filter Onan 149-2005, Fram G1 Kohler 2505002, Fram G1
Spark Plug Onan 167-0263, Champion RS14YC Champion RC12YC (.030" Gap)

(.025" Gap)

Battery BCI Group 58 (435 CCA) BCI Group 58 (435 CCA)

FREQUENCY MAINTENANCE REQUIRED

Daily or Before • Fill fuel tank
Starting Engine • Check oil level

• Check air cleaner for dirty, loose, or damaged parts

• Check air intake and cooling areas, clean as necessary
5 Hours • First Oil Change
Every 50 Hours • Service air pre-cleaner

• Change engine oil

1

Every 100 Hours • Replace oil filter

1

• Clean spark arrestor
Every 200 Hours • Clean or replace air filter element

1

• Replace fuel filter element
Every 500 Hours • Check spark plug and gap
Every 2 Years • Check fuel lines and clamps

1

Service more frequently when used in dusty areas and/or at high ambient temperatures.

TABLE D.2 – ONAN ENGINE MAINTENANCE SCHEDULE

TABLE D.3 – ENGINE MAINTENANCE COMPONENTS

ENGINE OIL CHANGE

Drain the oil while the engine is warm to assure rapid
and complete draining.

1. Remove the oil filler cap and dipstick. Remove the
yellow cap from the oil drain valve and attach the
flexible drain tube supplied with the machine.
Push in and twist the drain valve counterclockwise.
Pull the valve out and drain the oil into a suitable
container.

2. Close the drain valve by pushing in and twisting
clockwise. Replace the yellow cap.

3.

Refill to the upper limit mark on the dipstick with the
recommended oil. Tighten the oil filler cap securely.

Engine Oil Refill Capacities

Without oil filter replacement:

• 1.7 US qt. (1.4 Imp qt., 1.6 liter) - Kohler

• 1.6 US qt. (1.3 Imp qt., 1.5 liter) - Onan

With oil filter replacement:

• 2.0 US qt. (1.7 Imp qt., 1.9 liter) - Kohler

• 1.8 US qt. (1.5 Imp qt., 1.7 liter) - Onan

Use 4-cycle motor oil that meets or exceeds the
requirements for API service classification SG or SH.
Always check the API SERVICE label on the oil con­tainer to be sure it includes the letters SG or SH.

SAE 10W-30 is recommended for general, all-temper­ature use, -5°F to 104°F (-20°C to 40°C). For the Onan
engine, it is recommended that SAE 30 oil be used
above 82°F (27°C). See the engine Owner’s Manual
for more specific information on oil viscosity recom­mendations.

Wash your hands with soap and water after handling
used oil.

Please dispose of used motor oil in a manner that is
compatible with the environment. We suggest you
take it in a sealed container to your local service sta­tion or recycling center for reclamation. Do not throw it
in the trash, pour it on the ground or down a drain.

OIL FILTER CHANGE

1. Drain the engine oil.

2. Remove the oil filter, and drain the oil into a suit­able container. Discard the used oil filter.

3. Clean the filter mounting base and coat the gasket
of the new oil filter with clean engine oil.

4. Screw on the new oil filter by hand, until the gasket
contacts the filter mounting base. Then use an oil
filter socket tool to tighten the filter an additional
1/2 to 7/8 turn.

5. Refill the crankcase with the specified amount of
the recommended oil. Reinstall the oil filler cap.

6. Start the engine and check for oil filter leaks.

7. Stop the engine and check the oil level. If neces­sary , add oil to the upper limit mark on the dipstick.

AIR CLEANER SERVICE

A dirty air cleaner will restrict air flow to the carburetor.
To prevent carburetor malfunction, service the air
cleaner regularly. Service more frequently when oper­ating the engine in extremely dusty areas.

Never use gasoline or low flash point solvents for
cleaning the air cleaner element. A fire or explosion
could result.

Never run the engine without the air cleaner. Rapid
engine wear will result from contaminants, such as
dust and dirt being drawn into the engine.

Air Pre-Cleaner Service

1. Loosen the cover retaining knob and remove the
cover.

2. Remove the pre-cleaner from the paper element.

3. Wash the pre-cleaner in warm water with deter­gent. Rinse the pre-cleaner thoroughly until all
traces of detergent are eliminated. Squeeze out
excess water (do not wring). Allow the pre-cleaner
to air dry.

4. Saturate the pre-cleaner with new engine oil.
Squeeze out all excess oil.

5. Reinstall the pre-cleaner over the paper element.

6. Reinstall the air cleaner cover. Secure the cover
with the cover retaining knob.

MAINTENANCE

D-4 D-4

RANGER 250

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WARNING

CAUTION

Air Filter Paper Element Service

1. Loosen the cover retaining knob and remove the
cover.

2. Remove the pre-cleaner from the paper element.

3. Remove the element cover nut, element cover, and
paper element.

4. Do not wash the paper element or use pressurized
air, as this will damage the element. Replace a
dirty, bent, or damaged element with a new ele­ment. Handle new elements carefully; do not use
if the sealing surfaces are bent or damaged.

5. When servicing the air cleaner, check the air
cleaner base. Make sure it is secured and not bent
or damaged. Also check the element cover for
damaged or improper fit. Replace all damaged air
cleaner components.

NOTE: Before the air cleaner is reassembled, make
sure rubber seal is in position around the stud. Inspect,
making sure it is not damaged and seals with the ele­ment cover.

6. Reinstall the paper element, pre-cleaner, element
cover, element cover nut, and air cleaner cover.
Secure the cover with the cover retaining knob.

SPARK PLUG SERVICE

To ensure proper engine operation, the spark plugs
must be properly gapped and free of deposits.

The muffler becomes very hot during operation and
remains hot for a while after stopping the engine. Be
careful not to touch the muffler while it is hot.

1. Remove the spark plug cap.

2. Clean any dirt from around the spark plug base.

3. Use a plug wrench to remove the spark plugs.

4. Visually inspect the spark plugs. Discard them if
the insulator is cracked or chipped. Clean the
spark plug with a wire brush if it is to be reused.

5. Measure the plug gap with a feeler gauge. Correct
as necessary by bending the side electrode.

6. Check that the spark plug washer is in good condi­tion and thread the spark plug in by hand to pre­vent cross-threading.

7. After the spark plug is seated, tighten with a spark
plug wrench to compress the washer.

• If installing a new spark plug, tighten 1/2 turn after

the spark plug seats to compress the washer.

• If reinstalling a used spark plug, tighten 1/8 - 1/4

turn after the spark plug seats to compress the
washer.

Spark Plug Gap: .030 in. (0.76 mm)-Kohler

.025 in. (0.64 mm)-Onan

Spark Plug Torque: 20 ft. Lb. (27 N-m)-Kohler

11 ft. Lb. (14 N-m)-Onan

The spark plug must be securely tightened. An improp­erly tightened spark plug can become very hot and
may cause engine damage.

Use only the recommended spark plug or equivalent.
A spark plug which has an improper heat range may
cause engine damage.

FUEL FILTER SERVICE

1. Check the fuel filter for water accumulation or sed­iment.

2. Replace the fuel filter if it is found with excessive
water accumulation or sediment.

ENGINE ADJUSTMENT

OVERSPEED IS HAZARDOUS.

The maximum allowable high idle speed for this
machine is 3750 RPM, no load. Do NOT tamper with
governor components or setting or make any other
adjustments to increase the maximum speed. Severe
personal injury and damage to the machine can result
if operated at speeds above maximum.

Adjustments to the engine are to be made only by a
Lincoln Service Center or an authorized Field Service
Shop.

MAINTENANCE

D-5 D-5

RANGER 250

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WARNING

WARNING

CAUTION

BATTERY MAINTENANCE

To access the battery, remove the screws from the rear
battery tray using a screwdriver or a 3/8" socket. Slide
the battery tray out only far enough to access the bat­tery terminals.

GASES FROM BATTERY can explode.

• Keep sparks, flame, and cigarettes
away from battery.

To prevent EXPLOSION when:

• INSTALLING A NEW BATTERY - Disconnect the
negative cable from the old battery first and connect
to the new battery last.

• CONNECTING A BATTERY CHARGER - Remove
the battery from the welder by disconnecting the
negative cable first, then the positive cable and bat­tery clamp. When reinstalling, connect the negative
cable last. Keep the area well ventilated.

• USING A BOOSTER - Connect the positive lead to
the battery first, then connect the negative lead to the
engine foot.

BATTERY ACID can burn eyes and
skin.

• Wear gloves and eye protection and be
careful when working near a battery.

• Follow the instructions printed on the
battery.

CLEANING THE BATTERY

Keep the battery clean by wiping it with a damp cloth
when dirty. If the terminals appear corroded, discon­nect the battery cables and wash the terminals with an
ammonia solution or a solution of 1/4 pound (0.113 kg)
of baking soda and 1 quart (0.946 l) of water. Be sure
the battery vent plugs (if equipped) are tight so that
none of the solution enters the cells.

After cleaning, flush the outside of the battery, the bat­tery compartment, and surrounding areas with clear
water. Coat the battery terminals lightly with petroleum
jelly or a non-conductive grease to retard corrosion.

Keep the battery clean and dry . Moisture accumulation
on the battery can lead to more rapid discharge and
early battery failure.

CHECKING ELECTROLYTE LEVEL

If battery cells are low, fill them to the neck of the filler
hole with distilled water and recharge. If one cell is low,
check for leaks.

CHARGING THE BATTERY

When you charge, jump, replace, or otherwise connect
battery cables to the battery , be sure the polarity is cor­rect. Improper polarity can damage the charging cir­cuit. The Ranger 250 positive (+) battery terminal has
a red terminal cover.

If you need to charge the battery with an external
charger, disconnect the negative cable first, then the
positive cable before you attach the charger leads.
After the battery is charged, reconnect the positive bat­tery cable first and the negative cable last. Failure to
do so can result in damage to the internal charger com­ponents.

Follow the instructions of the battery charger manufac­turer for proper charger settings and charging time.

OPTIONAL SPARK ARRESTOR

MUFFLER MAY BE HOT.
Allow the engine to cool before installing the spark

arrestor!
Do not operate the engine while installing the spark

arrestor!

Clean the spark arrestor after every 100 hours of use.

MAINTENANCE

D-6 D-6

RANGER 250

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WARNING

WARNING

WELDER/GENERATOR
MAINTENANCE

STORAGE

Store the Ranger 250 in clean, dry, protected areas.

CLEANING

Blow out the generator and controls periodically with
low pressure air. Do this at least once a week in par­ticularly dirty areas.

RECEPTACLES

Keep the electrical receptacles in good condition.
Remove any dirt, oil, or other debris from their surfaces
and holes.

CABLE CONNECTIONS

Check the welding cable connections at the weld out­put terminals often. Be sure that the connections are
always firm.

BRUSH REMOVAL AND REPLACEMENT

It’s normal for the brushes and slip rings to wear and
darken slightly. Inspect the brushes when a generator
overhaul is necessary.

Do not attempt to polish slip rings while the engine is
running.

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.

MAINTENANCE

D-7 D-7

RANGER 250

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CAUTION

WARNING

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MAINTENANCE

D-8 D-8

RANGER 250

FIGURE D.1 – MAJOR COMPONENT LOCATIONS

1

2

3

4

5

6

7

8

9

14

13

12

11

10

1. CASE COVER AND DOOR ASSEMBLY/CASE BACK

2. ENGINE

3. IDLER SOLENOID

4. ROTOR/STATOR

5. POWER MODULE ASSEMBLY

6. POWER CAPACITORS

7. PC BOARDS

8. FRONT PANEL (OUTPUT) ASSEMBLY

9. CONTROL PANEL

10. OUTPUT CHOKE

11. OUTPUT RECTIFIER BRIDGE

12. FUEL TANK

13. MACHINE BASE

14. BATTERY

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Section E-1 Section E-1

RANGER 250

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

General Description ..............................................................................................................E-2

Battery, Engine, Rotor, Stator and Engine Protection...........................................................E-2

Weld Windings, Rectifier, Power Module and Feedback.......................................................E-3

Analog Power Board and Control Board...............................................................................E-4

Insulated Gate Bipolar Transistor (IGBT) Operation.............................................................E-5

Pulse Width Modulation.........................................................................................................E-6

Chopper Technology Fundamentals......................................................................................E-7

TABLE OF CONTENTS

-THEORY OF OPERATION SECTION-

FIGURE E.1 – RANGER 250 BLOCK LOGIC DIAGRAM

ENGINE

CONTROL

BOARD

ROTOR

STATOR

BATTERY

BOARD

BATTERY

CHOKE

IGBT

MECHANICAL

ROTATION

STARTER

I
D
L
E
R

ARC

CONTROL

OUTPUT

CONTROL

MODE

SELECTOR

POWER MODULE

THREE-PHASE

RECTIFIER

WORK

TERMINAL

ELECTRODE

TERMINAL

+

120VAC

RECEPTACLE

240VAC

RECEPTACLE

SLIP

RINGS

TO

CONTROL

BOARD

GAS

OIL

PRESSURE

SWITCH

RUN/STOP
SWITCH

FLYWHEEL

ALTERNATOR

TO CONTROL

BOARD

AMPHENOL

4
2

V
A
C

FIELD

WINDING

AUXILIARY

WINDINGS

WIRE FEED

PWR WNDG

4
2

V
A
C

2
4
0

V
A
C

1
2
0

V
A
C

W

E

L

D W

I

N

D

I

N

G

+

ANALOG

POWER

BOARD

2
0

V
D
C

4
0

TO
1

0
0

V
D
C

FROM
TOROID
CURRENT
SENSOR

SHUNT

F
E
E
D
B
A
C
K

SOL

____

REGULATED VOLTAGES

P
W
M

S
I
G
N
A
L
S

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GENERAL DESCRIPTION

The Ranger 250 is a gasoline engine-driven welding
power source capable of producing 250 amps at
25VDC at a 100% duty cycle. The engine is coupled to
a brush-type alternating current generator. This AC
output is rectified and controlled by Chopper
Technology to produce DC current for multi-purpose
welding applications. The Ranger 250 is also capable
of producing 8,000 watts of AC auxiliary power at 100%
duty cycle.

BATTERY, ENGINE, ROTOR, STA­TOR AND ENGINE PROTECTION

The 12VDC battery powers the engine starter motor
and also supplies power to the battery PC board and
associated circuitry. When the engine, which is
mechanically coupled to the rotor, is started and run­ning, the 12 VDC battery voltage is fed through the bat­tery board to the rotor field coil via a brush and slip ring
configuration. This excitation or “flashing” voltage mag-

netizes the rotor lamination. This rotating magnet
induces a voltage in the stationary windings of the main
alternator stator. The stator houses a three-phase weld
winding, a 120/240VAC single-phase auxiliary winding,
a 42VAC wire feeder power winding, and a separate
42VAC field feedback winding that is rectified and
serves as a feedback supply for the rotor field winding.

The engine flywheel alternator supplies charging cur­rent for the battery circuit. The oil pressure switch mon­itors engine oil pressure. If a low oil pressure condition
should develop, the engine will shut down and the bat­tery PC board will disable the rotor flashing current.
The idler solenoid is mechanically connected to the
engine’s throttle linkage. If no welding or auxiliary cur­rent is being drawn from the Ranger 250, the control
board activates the idler solenoid, which then brings
the engine to a low idle state. When either welding or
auxiliary current is detected at the toroid current sen­sor, the control board deactivates the idler solenoid and
the engine returns to high RPM.

THEORY OF OPERATION

E-2 E-2

RANGER 250

FIGURE E.2 – BATTERY, STARTER, ENGINE, ROTOR, STATOR AND ENGINE PROTECTION

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

__

WORK

THREE-PHASE

RECTIFIER

TO

CONTROL

BOARD

TERMINAL

__

BATTERY

STARTER

RUN/STOP
SWITCH

GAS

ENGINE

FLYWHEEL

ALTERNATOR

OIL

PRESSURE

SWITCH

TO CONTROL

BOARD

BATTERY

BOARD

S
I
G
N
A
L
S

MODE

SELECTOR

ELECTRODE

TERMINAL

SHUNT

F
E
E
D
B
A
C
K

+

MECHANICAL

ROTATION

SLIP

RINGS

D W

L

E

W

ROTOR

+

4
0

I

N

D

I

N

G

TO
1

0
0

V
D
C

POWER MODULE

ANALOG

POWER

BOARD

REGULATED VOLTAGES

IGBT

CHOKE

2
0

V
D
C

FROM
TOROID
CURRENT
SENSOR

P
W
M

CONTROL

BOARD

OUTPUT

ARC

CONTROL

CONTROL

STATOR

FIELD

AUXILIARY

WINDING

WINDINGS

SOL

I
D
L
E
R

4
2

V
A
C

WIRE FEED
PWR WNDG

2
4
0

V
A
C

240VAC

RECEPTACLE

1
2
0

V
A
C

120VAC
RECEPTACLE

4
2

V
A
C

AMPHENOL

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WELD WINDINGS, RECTIFIER,
POWER MODULE AND FEEDBACK

The three-phase stator weld windings are connected to
a three-phase rectifier bridge. The resultant DC volt­age is applied to parallel capacitors incorporated with­in the power module. These capacitors function as fil­ters and also as power supplies for the IGBT. See
IGBT Operation in this section. The IGBT acts as a
high-speed switch operating at 20KHZ. This device is
switched on and off by the control board through
pulsewidth modulation circuitry. See Pulse Width
Modulation in this section. This “chopped” DC output

is applied through a choke coil and shunt to the weld­ing output terminals. The choke functions as a current
filter. Free-wheeling diodes are incorporated in the
power module to provide a current path for the stored
energy in the chokes when the IGBT is turned off. See
Chopper Technology in this section.

Output voltage and current feedback information is fed
to the control board. This information is sensed from
the output terminal circuits and the shunt.

THEORY OF OPERATION

E-3 E-3

RANGER 250

FIGURE E.3 – WELD WINDINGS, RECTIFIER, POWER MODULE AND FEEDBACK

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

ENGINE

CONTROL

BOARD

ROTOR

STATOR

BATTERY

BOARD

BATTERY

CHOKE

IGBT

MECHANICAL

ROTATION

STARTER

I
D
L
E
R

ARC

CONTROL

OUTPUT

CONTROL

MODE

SELECTOR

POWER MODULE

THREE-PHASE

RECTIFIER

WORK

TERMINAL

ELECTRODE

TERMINAL

+

120VAC

RECEPTACLE

240VAC

RECEPTACLE

SLIP

RINGS

TO

CONTROL

BOARD

GAS

OIL

PRESSURE

SWITCH

RUN/STOP
SWITCH

FLYWHEEL

ALTERNATOR

TO CONTROL

BOARD

AMPHENOL

4
2

V
A
C

FIELD

WINDING

AUXILIARY

WINDINGS

WIRE FEED
PWR WNDG

4
2

V
A
C

2
4
0

V
A
C

1
2
0

V
A
C

W

E

L

D W

I

N

D

I

N

G

+

ANALOG

POWER
BOARD

2
0

V
D
C

4
0

TO
1

0
0

V
D
C

FROM
TOROID
CURRENT
SENSOR

SHUNT

F
E
E
D
B
A
C
K

SOL

____

REGULATED VOLTAGES

P
W
M

S
I
G
N
A
L
S

THEORY OF OPERATION

E-4 E-4

RANGER 250

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ANALOG POWER BOARD AND
CONTROL BOARD

The analog power board, which is powered by the two
filter capacitors on the power module, supplies various
regulated DC voltages to operate the control board cir­cuitry. It also supplies a regulated DC voltage to oper­ate the chopper board.

The control board monitors the operator controls (arc

control, output, and mode selector). It compares these
commands to the current and voltage feedback infor­mation it receives from the shunt and output terminal
circuits. The circuitry on the control board determines
how the output should be controlled to optimize weld­ing results, and it sends the correct PWM signals to the
IGBT driver circuit.

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

FIGURE E.4 – ANALOG POWER BOARD AND CONTROL BOARD

__

WORK

THREE-PHASE

RECTIFIER

TO

CONTROL

BOARD

TERMINAL

__

BATTERY

STARTER

RUN/STOP
SWITCH

GAS

ENGINE

FLYWHEEL

ALTERNATOR

OIL

PRESSURE

SWITCH

TO CONTROL

BOARD

BATTERY

BOARD

S
I
G
N
A
L
S

MODE

SELECTOR

ELECTRODE

TERMINAL

+

SHUNT

F
E
E
D
B
A
C
K

MECHANICAL

ROTATION

SLIP

RINGS

D W

L

E

W

ROTOR

+

4
0

I

N

D

I

N

G

TO
1

0
0

V
D
C

ANALOG

POWER MODULE

POWER

BOARD

REGULATED VOLTAGES

IGBT

CHOKE

2
0

V
D
C

FROM
TOROID
CURRENT
SENSOR

P
W
M

CONTROL

BOARD

OUTPUT

ARC

CONTROL

CONTROL

STATOR

FIELD

AUXILIARY

WINDING

WINDINGS

SOL

I
D
L
E
R

4
2

V
A
C

WIRE FEED
PWR WNDG

2
4
0

V
A
C

240VAC

RECEPTACLE

1
2
0

V
A
C

120VAC
RECEPTACLE

4
2

V
A
C

AMPHENOL

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THEORY OF OPERATION

E-5 E-5

RANGER 250

FIGURE E.5 – IGBT OPERATION

DRAIN

SOURCE

GATE

INJECTING LAYER

BUFFER LAYER

DRAIN DRIFT REGION

BODY REGION

p +

n +

n -

p

n + n +

DRAIN

SOURCE

GATE

INJECTING LAYER

BUFFER LAYER

DRAIN DRIFT REGION

BODY REGION

p +

n +

n -

p

n + n +

POSITIVE
VOLTAGE
APPLIED

B. ACTIVE

A. PASSIVE

INSULATED GATE BIPOLAR
TRANSISTOR (IGBT) OPERATION

An IGBT is a type of transistor. IGBTs are semiconduc­tors well suited for high frequency switching and high
current applications.

Drawing Ashows an IGBT in a passive mode. There is
no gate signal, zero volts relative to the source, and
therefore, no current flow. The drain terminal of the
IGBT may be connected to a voltage supply; but since
there is no conduction the circuit will not supply current
to components connected to the source. The circuit is
turned off like a light switch in the OFF position.

Drawing B shows the IGBT in an active mode. When
the gate signal, a positive DC voltage relative to the
source, is applied to the gate terminal of the IGBT, it is
capable of conducting current. A voltage supply con­nected to the drain terminal will allow the IGBT to con­duct and supply current to circuit components coupled
to the source. Current will flow through the conducting
IGBT to downstream components as long as the posi­tive gate signal is present. This is similar to turning ON
a light switch.

RANGER 250

PULSE WIDTH MODULA TION

The term PULSE WIDTH MODULATION is used to
describe how much time is devoted to conduction in the
cycle. Changing the pulse width is known as MODU­LA TION. Pulse Width Modulation (PWM) is the varying
of the pulse width over the allowed range of a cycle to
affect the output of the machine.

MINIMUM OUTPUT

By controlling the duration of the gate signal, the IGBT
is turned on and off for different durations during a
cycle. The top drawing shows the minimum output sig­nal possible over a 50-microsecond time period.

The positive portion of the signal represents one IGBT
group conducting for 2 microsecond. The dwell time (off
time) is 48 microseconds. Since only 2 microseconds of
the 50-microsecond time period is devoted to conduct­ing, the output power is minimized.

MAXIMUM OUTPUT

By holding the gate signals on for 48 microseconds and
allowing only 2 microseconds of dwell time (off time)
during the 50-microsecond cycle, the output is maxi­mized. The darkened area under the top curve can be
compared to the area under the bottom curve. The
more darkened area under the curve, the more power
is present.

E-6 E-6

THEORY OF OPERATION

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FIGURE E.6 – TYPICAL IGBT OUTPUTS

MINIMUM OUTPUT

(Dwell or Off Time)

sec

2

MAXIMUM OUTPUT

48
50

sec

sec

(Dwell or Off Time)

sec

48

sec

50

CHOPPER TECHNOLOGY
FUNDAMENTALS

The new era of welding machines such as the Ranger
250 employ a technology whereby a DC source is
turned on and off (chopped up) at high speed,
thensmoothed through an inductor to control an arc.

Hence the name “Chopper.” The biggest advantage of
chopper technology is the high-speed control of the
arc, similar to the inverter machines. A block diagram
for this is as follows:

In this system, the engine drives a three-phase alter­nator, which generates power that is rectified and fil­tered to produce about 85VDC. The current is applied
through a solid state switch to an inductor. By turning

the switch on and off, current in the inductor and the
arc can be controlled. The following diagram depicts
the current flow in the system when the switch is open
and closed:

When the switch is closed, current is applied through
the inductor to the arc. When the switch opens, current
stored in the inductor sustains flow in the arc and
through the diode. The repetition rate of switch closure
is 20Khz, which allows ultra-fast control of the arc. By

varying the ratio of on time versus off time of the switch
(Duty Cycle), the current applied to the arc is con­trolled. This is the basis for Chopper Technology:
Controlling the switch in such a way as to produce
superior welding.

THEORY OF OPERATION

E-7 E-7

RANGER 250

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3 PHASE

ALTERNATOR

DC RECTIFIER

AND FILTER

INDUCTOR

AND DIODE

ARC

ARC

CONTROL

SOLID STATE

SWITCH

INDUCTOR

SWITCH

DIODE

ARC

CURRENT WITH SWITCH OPEN

CURRENT WITH SWITCH CLOSED

85VDC

E-8

NOTES

RANGER 250

E-8

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Section F-1 Section F-1

RANGER 250

Troubleshooting & Repair Section................................................................................Section F

How to Use Troubleshooting Guide.......................................................................................F-2

PC Board Troubleshooting Procedures.................................................................................F-3

Troubleshooting Guide ................................................................................................F-4 - F-12

Test Procedures...................................................................................................................F-13

Case Cover Removal and Replacement Procedure ....................................................F-13

Power Module Capacitor Discharge Procedure ...........................................................F-15

Idler Solenoid Test ........................................................................................................F-17

Engine Throttle Adjustment Test ...................................................................................F-19

Rotor Resistance Test ..................................................................................................F-23

Flashing and Rotor Voltage Test ..................................................................................F-25

Stator Voltage Tests .....................................................................................................F-28

Analog Power PC Board Voltage Test .........................................................................F-33

Output Rectifier Bridge Test .........................................................................................F-36

Power Module Test .......................................................................................................F-39

Flywheel Alternator T est................................................................................................F-43

Oscilloscope Waveforms......................................................................................................F-45

Normal Open Circuit Voltage Waveform (120 VAC Supply)..........................................F-45

Normal Open Circuit Voltage Waveform (Stick) ............................................................F-46

Normal Weld Voltage Waveform (Stick CC)..................................................................F-47

Normal Open Circuit Voltage Waveform (Wire CV Tap)................................................F-48

Normal Weld Voltage Waveform (Wire CV)..................................................................F-49

Replacement Procedures ....................................................................................................F-50

Power Module Assembly/Power Module PC Board/

Diode Module Removal and Replacement....................................................................F-50

Power Capacitor Removal and Replacement...............................................................F-55

Output Rectifier Bridge and Choke Removal and Replacement...................................F-57

Engine/Stator/Rotor Removal and Replacement ..........................................................F-60

Retest After Repair...............................................................................................................F-68

TABLE OF CONTENTS

TROUBLESHOOTING & REPAIR SECTION

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HOW TO USE TROUBLESHOOTING GUIDE

Service and repair should be performed by only 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 & REPAIR

F-2 F-2

RANGER 250

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

Step 1. LOCA TE 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 four main categories: Output Problems,
Function Problems, Engine 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 cover.

Step 3. PERFORM COMPONENT TESTS. The
last column, labeled “Recommended Course of
Action” lists the most likely components that may
have failed in your machine. It also specifies the
appropriate test procedure to verify that the sub­ject component is either good or bad. If there are
a number of possible components, check the
components in the order listed to eliminate one
possibility at a time until you locate the cause of
your problem.

All of the referenced test procedures referred to in
the Troubleshooting Guide are described in detail
at the end of this section. Refer to the
Troubleshooting and Repair Table of Contents to
locate each specific Test Procedure. All of the
referred to test points, components, terminal
strips, etc., can be found on the referenced elec­trical wiring diagrams and schematics. Refer to
the Electrical Diagrams Section Table of Contents
to locate the appropriate diagram.

WARNING

If for any reason you do not understand the test procedures or are unable to perform the test/repairs
safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before
you proceed. Call 1-800-833-9353.

CAUTION

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ELECTRIC SHOCK can kill.

Have an electrician install and service
this equipment. Turn the machine OFF
before working on equipment. Do not
touch electrically hot parts.

Sometimes machine failures appear to be due to PC
board failures. These problems can sometimes be
traced to poor electrical connections. To avoid prob­lems when troubleshooting and replacing PC boards,
please use the following procedure:

1. Determine to the best of your technical ability that
the PC board is the most likely component causing
the failure symptom.

2. Check for loose connections at the PC board to
assure that the PC board is properly connected.

3. If the problem persists, replace the suspect PC
board using standard practices to avoid static elec­trical damage and electrical shock. Read the warn­ing inside the static resistant bag and perform the
following procedures:

PC Board can be damaged by static electricity.

• Remove your body’s static charge
before opening the static-shield­ing bag. Wear an anti-static wrist
strap. For safety, use a 1 Meg
ohm resistive cord connected to a
grounded part of the equipment
frame.

• If you don’t have a wrist strap,
touch an unpainted, grounded,
part of the equipment frame.
Keep touching the frame to pre­vent static build-up. Be sure not
to touch any electrically live parts
at the same time.

• Tools which come in contact with
the PC Board must be either con­ductive, anti-static or static-dissi­pative.

• Remove the PC Board from the static-shielding bag
and place it directly into the equipment. Don’t set the
PC Board on or near paper, plastic or cloth which
could have a static charge. If the PC Board can’t be
installed immediately , put it back in the static-shielding
bag.

• If the PC Board uses protective shorting jumpers,
don’t remove them until installation is complete.

• If you return a PC Board to The Lincoln Electric
Company for credit, it must be in the static-shielding
bag. This will prevent further damage and allow prop­er failure analysis.

4. Test the machine to determine if the failure symp-

tom has been corrected by the replacement PC
board.

NOTE: Allow the machine to heat up so that all elec­trical components can reach their operating tempera­ture.

5. Remove the replacement PC board and substitute

it with the original PC board to recreate the original
problem.

a. If the original problem does not reappear

by substituting the original board, then the
PC board was not the problem. Continue
to look for bad connections in the control
wiring harness, junction blocks, and termi­nal strips.

b. If the original problem is recreated by the

substitution of the original board, then the
PC board was the problem. Reinstall the
replacement PC board and test the
machine.

6. Always indicate that this procedure was followed

when warranty reports are to be submitted.

NOTE: Following this procedure and writing on the
warranty report, “INSTALLED AND SWITCHED PC
BOARDS TO VERIFY PROBLEM,” will help avoid
denial of legitimate PC board warranty claims.

TROUBLESHOOTING & REPAIR

F-3 F-3

RANGER 250

PC BOARD TROUBLESHOOTING PROCEDURES

WARNING

ATTENTION
Static-Sensitive
Devices
Handle only at
Static-Safe
Workstations

Reusable
Container
Do Not Destroy

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TROUBLESHOOTING & REPAIR

F-4 F-4

RANGER 250

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

OUTPUT PROBLEMS

Major physical or electrical damage is evident.

1. Contact your local Lincoln
Authorized Field Service
Facility.

1. Contact the Lincoln Electric
Service Department at 1-800­833-9353 (WELD).

No welding output in all modes. The engine operates normally . The auxiliary output is normal.

1. Place the Welding Terminals
switch in the “WELD TERMI­NALS ON” position. If the prob­lem is solved, the fault may be
in the external control cable (if
used), leads #2 and #4. See
the Wiring Diagram.

2. With the engine at high idle
(3700RPM), the machine in the
Stick mode and the OUTPUT
CONTROL at maximum, check
for the presence of approxi­mately 80VDC (open circuit
voltage) at the output terminals.

3. If the correct OCV is present at
the welding output terminals,
check the welding cables,
clamps and electrode holder for
loose or faulty connections.

4. Air flow may be blocked or
restricted.

1. Check for loose or faulty con­nections on the heavy current
carrying leads between the
output bridge, the power mod­ule, the choke, the shunt and
the output terminals. Check
thermostat TS1 and associated
wiring. See the Wiring
Diagram.

2. Check the Welding Terminals
switch and associated leads (2
and 4). See the Wiring
Diagram.

3. If the correct OCV is present
when the Welding Terminals
switch is in the “WELD TERMI­NALS ON” position, the By­pass Board may be faulty . Also
check associated wiring. See
the Wiring Diagram.

4. Check gate leads (#23 and
#25) for loose or faulty connec­tions. See the Wiring Diagram.

CAUTION

Observe Safety Guidelines
detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

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TROUBLESHOOTING & REPAIR

F-5 F-5

RANGER 250

TROUBLESHOOTING GUIDE Observe Safety Guidelines

detailed in the beginning of this manual.

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

OUTPUT PROBLEMS

No welding output in all modes.
The engine operates normally . The
auxiliary output is normal.

(continued)

5.

Perform the Stator Voltage

Test.

6. Perform the Output Rectifier

Bridge Test.

7.

Perform the Power Module

Test.

8. Perform the Analog Power
Board Test.

9. Check the output control
potentiometer and associated
wiring.

10. The Control Board may be
faulty.

No welding output in all modes. Also no auxiliary power. The engine operates normally at approximately 3700 RPM.

1. Check the brushes for wear and
proper contact to the rotor slip
rings.

2. Make sure the engine is operat­ing at the correct high idle
speed (3700 RPM).

3. Check for loose or faulty con­nections or leads at the auxiliary
output receptacles and/or the
welder output terminals. See
the Wiring Diagram.

1. Perform the Rotor Resistance

Test.

2. Perform the Flashing and
Rotor Voltage Test. If the

“flashing” voltage is not present,
the battery board or leads #201
or #200 may be faulty. See the
Wiring Diagram. Also, make
sure that lead #5H has continu­ity (zero ohms) to ground.

3. Check the field diode and
capacitor. Replace if neces­sary.

4. Perform the Stator Voltage

Test.

CAUTION

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TROUBLESHOOTING & REPAIR

F-6 F-6

RANGER 250

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

OUTPUT PROBLEMS

No auxiliary power at the recepta­cles. The welding output is normal
and the engine operates normally.

1. The circuit breakers may be
tripped. Reset if necessary.

2. Check for loose or faulty con­nections at the auxiliary recep­tacles.

1. Check the wiring between the
auxiliary receptacles, the con­nection studs, and the main sta­tor. See the Wiring Diagram.

2. Perform the Stator Voltage

Test.

The machine has welding output but no control of output in some or all modes. The auxiliary power is normal.

1. If a remote control unit is con­nected, check the remote control
and related cable.

2. Check the welding and work
cables for loose or faulty con­nections.

1. Check the OUTPUT control
potentiometer and related
leads. See the Wiring Diagram.

2. Check the shunt and associated
feedback leads. See the Wiring
Diagram.

3. Check the voltage feedback
leads for loose or faulty connec­tions. See the Wiring Diagram.

4. Perform the Power Module

Test.

5. The Control Board may be
faulty.

CAUTION

Observe Safety Guidelines
detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

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TROUBLESHOOTING & REPAIR

F-7 F-7

RANGER 250

TROUBLESHOOTING GUIDE Observe Safety Guidelines

detailed in the beginning of this manual.

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

OUTPUT PROBLEMS

The machine has low welding out­put and low auxiliary output.

1. The engine RPM may be low.

2. Check the brushes for wear and
proper contact to the slip rings.

1. If the engine high idle speed is
low, perform the Engine

Throttle Adjustment Test.

2. Perform the Rotor Resistance
Test.

3. Perform the Flashing and
Rotor Voltage T est. If the rotor

voltage is low, the field capaci­tor or field bridge may be faulty.
Test and replace if necessary.
See the Wiring Diagram.

4. If the engine high idle RPM is
OK but slows down excessively
under load, then the engine
may have lost horsepower and
be in need of major repair.

CAUTION

The machine control is still active when the remote control unit is connected.

1. This is normal in TIG mode.

2. The remote control unit may be
defective.

3. Check the amphenol connec­tions and associated wiring.

1. Check Plug J10 on the Control
Board for loose or faulty con­nections.

2. The bypass board may be
faulty.

3. The Control Board may be
faulty.

Machine seems to be locked into the CC mode of operation (stick mode.)

1. Check the position of the Mode
Selector switch. It must be in
the correct position for the
process being used.

2. Check that jumper plug J3 is
properly installed in the Control
Board. (J3 has a jumper wire
from pin 1 to pin 5.)

3. Make sure plug J2 is properly
connected to the Control Board.

1. Check the Mode Selector switch
and associated wiring. See the
Wiring Diagram.

2. The Control Board may be
faulty.

F-8 F-8

RANGER 250

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TROUBLESHOOTING & REPAIR

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

FUNCTION PROBLEMS

The wire feeder does not work when connected to the welder amphenol.

1. Check the appropriate circuit
breaker (CB1 or CB8). Reset if
tripped.

2. The wire feeder control cable
may be faulty.

3. The wire feeder may be faulty.

1. Check for the presence of
appropriate source voltage at
the 14-pin amphenol.

2. If the appropriate voltage (42
VAC or 115 VAC) is NOT pre­sent at the 14-pin amphenol,
check for loose or faulty con­nections. See the Wiring
Diagram.

3. Perform the Stator Voltage

Test.

The battery does not stay charged. 1. Check for loose or faulty con-

nections at the battery and
engine charging system.

2. The battery may be faulty.
Check or replace.

1. If the yellow engine alternator
light is on, perform the

Flywheel Alternator Test.

2. If the battery is not charging and
the yellow engine alternator
light is not lit. The battery board
may be faulty.

CAUTION

Observe Safety Guidelines
detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

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TROUBLESHOOTING & REPAIR

F-9 F-9

RANGER 250

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

ENGINE PROBLEMS

The engine cranks but will not start. 1. Check for adequate fuel supply.

2. Check for adequate oil level.

3. The battery voltage may be too
low.

4. The fuel filter may be clogged or
the fuel contaminated. Replace
the fuel filter if necessary.

1. The oil pressure switch may be
faulty. See the Wiring Diagram.

2. The engine may be in need of
mechanical repair. Check for
spark and fuel.

The engine will not develop full power.

1. The fuel filter may be clogged or
the fuel contaminated. Replace
the fuel filter if necessary.

2. The air filter may be clogged.
Replace if necessary.

3. The spark plug(s) may be faulty.
Replace if necessary.

1. Due to wear, the engine may
need major repair.

The engine will not crank when the start button is pushed.

1. Check the circuit breaker (CB7).
Reset if tripped.

2. Make sure the Run/Stop switch
is in the “RUN” position.

3. Check for loose or faulty battery
cable connections.

4. The battery may be low or faulty .

5. The Start button may be faulty.

1. If the battery is replaced or tests
good, then the charging circuit
may be faulty. Perform the

Flywheel Alternator Test.

2. The starter motor or starter
solenoid may be faulty.

3. The engine may be hard to
crank due to a mechanical fail­ure in the engine.

CAUTION

TROUBLESHOOTING GUIDE Observe Safety Guidelines

detailed in the beginning of this manual.

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TROUBLESHOOTING & REPAIR

F-10 F-10

RANGER 250

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

ENGINE PROBLEMS

The engine shuts down shortly after starting.

1. Check for adequate fuel supply
and a clean fuel filter.

2. Low oil level. Fill to proper
level. Start engine and look for
leaks.

3. Check the battery cables for
loose or faulty connections.

1. Check the RUN/STOP switch
and associated leads for loose
or faulty connections.

2. The oil pressure switch may be
faulty. Replace if necessary.

The engine will not idle down to low speed. The machine has normal weld output and auxiliary power.

1. Make sure the IDLER switch is
in the "AUTO" position.

2. Make sure there is NOT an
external load on the weld termi­nals or the auxiliary power
receptacles.

3. Check for mechanical restric­tions in the idler solenoid link­age.

1. Check leads #210C and 215 for
loose or faulty connections.
See the Wiring Diagram.

2. Perform the Idler Solenoid

Test.

3. The Control Board may be
faulty.

CAUTION

The engine will not go to high idle
when using the auxiliary power.
Auxiliary power is normal when the
IDLER switch is in the "HIGH" posi­tion. Automatic idle function works
properly when the welding termi­nals are loaded.

1. Make sure the auxiliary power
leads are tight.

2. The automatic idler may not
function if the auxiliary power is
loaded to less than 100 watts.

1. Make sure leads #3 and #6
pass through the toroid twice in
opposite directions. See the
Wiring Diagram.

Observe Safety Guidelines
detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

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F-11 F-11

RANGER 250

TROUBLESHOOTING & REPAIR

TROUBLESHOOTING GUIDE Observe Safety Guidelines

detailed in the beginning of this manual.

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

ENGINE PROBLEMS

The engine will not go to high idle
when attempting to weld or when
the auxiliary power is loaded.
Welding output and auxiliary power
outputs are normal when IDLER
switch is in the " HIGH" position.

1. Make sure the welding cables
and auxiliary power lead con­nections are tight.

1. Check the Current Sensing
Toroid leads for loose or faulty
connections. See the Wiring
Diagram.

2. The Current Sensing Toroid
may be faulty.

3. The Control Board may be
faulty.

The machine goes to low idle but does not stay at low idle.

1. Make sure there is NOT an
external load (auxiliary or weld)
connected to the Ranger 250.

1. The idler solenoid linkage may
be misadjusted or damaged.

2. The idler solenoid lead connec­tions (#210C and #215) may be
loose or damaged.

3. Perform the Idler Solenoid

Test.

4. The Control Board may be
faulty.

CAUTION

TROUBLESHOOTING & REPAIR

F-12 F-12

RANGER 250

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If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.

PROBLEMS
(SYMPTOMS)

POSSIBLE AREAS OF
MISADJUSTMENT(S)

RECOMMENDED
COURSE OF ACTION

WELDING PROBLEMS

The welding arc is “cold.” The engine runs normally . The auxiliary power is normal.

1. Check for loose or faulty con­nections at the weld output ter­minals and welding cable con­nections.

2. The welding cables may be too
long or coiled, causing an
excessive voltage drop.

3. Make sure the electrode (wire,

gas, voltage, current etc.) is
correct for the process being
used.

1. Check for the correct OCV at
the welding output terminals. If
the correct voltage is present at
the output terminals, check for
loose connections on the heavy
current carrying leads inside the
Ranger 250. See the Wiring
Diagram.

2. If the OCV is low at the welder
output terminals, perform the

Engine Throttle Adjustment
Test.

3. Perform the Output Rectifier
Bridge Test.

4. Perform the Stator Voltage
Test.

5. Perform the Power Module
Test.

6. The Control Board may be
faulty.

CAUTION

Observe Safety Guidelines
detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

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TROUBLESHOOTING & REPAIR

F-13 F-13

RANGER 250

CASE COVER REMOVAL AND REPLACEMENT PROCEDURE

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This procedure will aid the technician in the removal and replacement of the case sheet
metal cover and engine access doors.

MATERIALS NEEDED

3/8" Wrench or socket wrench
9/16" Wrench

This procedure should take approximately 15 minutes to perform.

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TROUBLESHOOTING & REPAIR

F-14 F-14

RANGER 250

FIGURE F.1 – DOOR REMOVAL

CASE COVER REMOVAL AND REPLACEMENT PROCEDURE (continued)

REMOVAL PROCEDURE

1. Turn the engine off.

2. Unlatch and open the engine service
access doors.

3. For each door, lift up on the stop pin and
slide the door off the hinge. It may be nec­essary to lightly tap the door with a rubber
mallet to free it from the hinge. See Figure
F.1.

4. Using the 9/16" wrench, remove the
exhaust pipe extension.

5. Remove the cover seal from around the lift
bail.

6. Using the 3/8" wrench, remove the sheet
metal and machine screws holding the case
cover in place.

7. Using the 3/8" wrench, remove the sheet
metal screws from the right and left case
sides. Tilt each side back and lift up to free
the bottom tabs from their slots.

8. Lift the case cover off the machine.
NOTE: It is not necessary to remove the gas

cap in order to take the case cover off the
machine. Leave the gas cap on when working
on the Ranger 250.

REPLACEMENT PROCEDURE

1. Install the right and left case sides and
screw them in place.

2. Carefully set the case cover in place.
Replace the lift bail cover seal.

3. Install the exhaust pipe extension.

4. Install the screws that hold the case cover
in place.

5. Install the doors by lifting the stop pins and
sliding each door onto its hinges.

6. Close and latch the doors.

ENGINE
ACCESS
DOOR

HINGES

TROUBLESHOOTING & REPAIR

F-15 F-15

RANGER 250

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WARNING

POWER MODULE CAPACITOR DISCHARGE PROCEDURE

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This procedure will insure that the large capacitors in the power module have been dis­charged. This procedure should be performed whenever work is to be attempted on or
near the power module.

MATERIALS NEEDED

3/8" Wrench or socket wrench
9/16" Wrench
Volt/Ohmmeter
Resistor (25-1000 ohms and 25 watts minimum)
Jumper leads

This procedure should take approximately 20 minutes to perform.

TROUBLESHOOTING & REPAIR

F-16 F-16

RANGER 250

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POWER MODULE CAPACITOR DISCHARGE PROCEDURE (continued)

FIGURE F.2 – POWER MODULE CAPACITOR TERMINAL DISCHARGE

SHORT ACROSS
TERMINALS
WITH RESISTOR

POWER
MODULE
CAPACITORS

{

{

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

NOTE: It is not necessary to remove the gas
cap in order to take the case cover off the
machine. Be sure the gas cap is ON when dis­charging the power module capacitors.

3. Locate the power module capacitors on the
left side of the inner machine baffle. See
Figure F.2.

4. Using the resistor and jumper leads,
CAREFULLY discharge the capacitor ter­minals. NEVER USE A SHORTING
STRAP FOR THIS PURPOSE. DO NOT
TOUCH THE TERMINALS WITH YOUR
BARE HANDS. Repeat the procedure for
the second capacitor.

5. Using the volt/ohmmeter, check the voltage
across the capacitor terminals. It should
be zero volts.

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TROUBLESHOOTING & REPAIR

F-17 F-17

RANGER 250

WARNING

IDLER SOLENOID TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This test will determine if the idler solenoid is capable of functioning when it is energized
with 12VDC.

MATERIALS NEEDED

3/8" Wrench or socket wrench
9/16" Wrench
External 12VDC supply (30 amps)
Diagonal cutters
Wiring Diagram
Volt/Ohmmeter

This procedure should take approximately 30 minutes to perform.

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TROUBLESHOOTING & REPAIR

F-18 F-18

RANGER 250

IDLER SOLENOID TEST (continued)

FIGURE F.3 – IDLER SOLENOID LEADS

SOLENOID

HOUSING

STATOR

LEADS #210C
AND #215 TO

CONNECTORS

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

3. Locate the idler solenoid mounted on the
stator beside the fuel tank filler neck.

4. Locate and remove the two in-line connec­tors that attach the idler solenoid leads to
the wiring harness leads (#210C and
#215). Cut any necessary cable ties. See
Figure F.3 and the Wiring Diagram.

5. Check the coil resistance. The normal
resistance is approximately 15 ohms. If the
coil resistance is not correct, the solenoid
may be faulty. Replace.

6. Using the external 12VDC supply, apply
12VDC to the solenoid leads. Push the
solenoid plunger in (this simulates the
action that takes place when the engine is

running and there is less resistance to
solenoid movement) and check that it
holds by itself. The solenoid should deac­tivate when the 12VDC is removed.

7. If the solenoid does not operate properly,
check for a mechanical restriction in the
linkage. Also check for proper operation
of the governor. See the Engine Owner's
Manual.

8. If the linkage is intact and the solenoid
does not operate correctly when the
12VDC is applied, the solenoid may be
faulty. Replace.

9. Replace leads #210C and #215 to the
correct in-line connectors. See Figure F.3
and the Wiring Diagram. Replace any
previously removed cable ties.

10. If finished testing, perform the Case
Cover Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-19 F-19

RANGER 250

WARNING

ENGINE THROTTLE ADJUSTMENT TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

If the machine output is low or high, this test will determine whether the engine is operat­ing at the correct speed (RPM) during both HIGH and LOW idle conditions. You can check
RPM using a strobe-tach, a frequency counter, an oscilloscope or a vibratach. Directions
for adjusting the throttle to the correct RPM are given.

MATERIALS NEEDED

3/8" Wrench or socket wrench
9/16" Wrench
White or red marking pencil
Stobe-tach, frequency counter, oscilloscope, or vibratach

This procedure should take approximately 35 minutes to perform.

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TROUBLESHOOTING & REPAIR

F-20 F-20

RANGER 250

ENGINE THROTTLE ADJUSTMENT TEST (continued)

FIGURE F.4 – STROBE MARK LOCATION

MARK BLOWER
PADDLE

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

Strobe-Tach Method

1. With a white or red marking pencil, place a
mark on one of the blower paddles. See
Figure F.4 for location.

2. Connect the strobe-tach according to the
manufacturer's instructions.

3. Start the engine and direct the strobe-tach
light on the blower paddle. Synchronize it to
the rotating mark.

With the machine at HIGH IDLE the tach should
read between 3700 and 3750 RPM.

With the machine at LOW IDLE the tach should
read between 2350 and 2450 RPM.

4. If either of the readings is incorrect, adjust
the throttle as follows:

Adjust HIGH IDLE: Use the 3/8" wrench to
loosen the spring-loaded adjustment nut. See
Figure F.5 for location of the adjustment nut.
Turn the nut clockwise to increase the HIGH
IDLE speed. Adjust the speed until the tach
reads between 3700 and 3750 RPM.

Adjust LOW IDLE: First make sure there is no
load on the machine. Set the IDLER switch to
AUTO and wait for the engine to change to low
idle speed. Use the 7/16" wrench to adjust the
solenoid nut, which changes the amount of throw
in the throttle lever arm. See Figure F.6 for the
location of the adjustment nut. Adjust the nut
until the tach reads between 2350 and 2450
RPM.

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TROUBLESHOOTING & REPAIR

F-21 F-21

RANGER 250

ENGINE THROTTLE ADJUSTMENT TEST (continued)

FIGURE F.5 – HIGH IDLE ADJUSTMENT

CHOKE CABLE

FIGURE F.6 – LOW IDLE ADJUSTMENT

SOLENOID

HOUSING

7/16" LOW IDLE
ADJUSTMENT NUT

ROD

MUFFLER

Frequency Counter Method

1. Plug the frequency counter into one of the
120 VAC auxiliary receptacles.

2. Start the engine and check the frequency
counter. At HIGH IDLE (3700 RPM), the
counter should read between 61 and 63
Hz. At LOW IDLE (2400 RPM), the counter
should read between 39 and 40 Hz. Note
that these are median measurements;
hertz readings may vary slightly above or
below.

3. If either of the readings is incorrect, adjust
the throttle as follows:

Adjust HIGH IDLE: Use the 3/8" wrench to
loosen the spring-loaded adjustment nut. See
Figure F.5 for location of the adjustment nut.
Turn the nut clockwise to increase the HIGH
IDLE speed. Adjust the speed until the fre­quency reads between 61 and 63 Hz.

Adjust LOW IDLE: First make sure there is no
load on the machine. Set the IDLER switch to
AUTO and wait for the engine to change to low
idle speed. Use the 7/16" wrench to adjust the
solenoid nut, which changes the amount of
throw in the throttle lever arm. See Figure F.6
for the location of the adjustment nut. Adjust
the nut until the frequency reads between 39
and 40 Hz.

THROTTLE LINKAGE

3/8" HIGH IDLE
ADJUSTMENT NUT

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TROUBLESHOOTING & REPAIR

F-22 F-22

RANGER 250

ENGINE THROTTLE ADJUSTMENT TEST (continued)

Oscilloscope Method

1. Connect the oscilloscope to the 120 VAC
receptacle, according to the manufacturer's
instructions. At HIGH IDLE (3700 RPM),
the waveform should exhibit a period of

16.2 milliseconds. At LOW IDLE (2400
RPM), the waveform should exhibit a peri­od of 25.0 milliseconds. Refer to the NOR-

MAL OPEN CIRCUIT VOLTAGE WAVE­FORM (120 VAC SUPPLY) HIGH IDLE ­NO LOAD in this section of the manual.

2. If either of these waveform periods is incor­rect, adjust the throttle as follows:

Adjust HIGH IDLE: Use the 3/8" wrench to
loosen the spring-loaded adjustment nut. See
Figure F.5 for location of the adjustment nut.
Turn the nut clockwise to increase the HIGH
IDLE speed. Adjust the speed until the period
is 16.2 milliseconds.

Adjust LOW IDLE: First make sure there is no
load on the machine. Set the IDLER switch to
AUTO and wait for the engine to change to low
idle speed. Use the 7/16" wrench to adjust the
solenoid nut, which changes the amount of
throw in the throttle lever arm. See Figure F.6
for the location of the adjustment nut. Adjust
the nut until the period is 25.0 milliseconds.

Vibratach Method

1. Place the vibratach as close to the engine
as possible. With the machine case top
removed, the top of the air cleaner is the
best location.

2. Start the engine and observe the whip han­dle of the vibratach. At HIGH IDLE (3700
RPM), the whip handle should exhibit max­imum oscillation. At LOW IDLE (2400
RPM), the whip handle should exhibit mini­mum oscillation. Note that these are medi­an measurements; vibratach readings may
vary slightly above or below.

3. If either of the vibratach indications is incor-

rect, adjust the throttle as follows:

Adjust HIGH IDLE: Use the 3/8" wrench to turn
the spring-loaded adjustment nut. See Figure
F.5 for location of the adjustment nut. Turn the
nut clockwise to increase HIGH IDLE speed.
Adjust the speed until the vibratach whip han­dle exhibits maximum oscillation at 3650 to
3750 RPM.

Adjust LOW IDLE: First make sure there is no
load on the machine. Set the IDLER switch to
AUTO and wait for the engine to change to low
idle speed. Use the 7/16" wrench to adjust the
solenoid nut, which changes the amount of
throw in the throttle lever arm. See Figure F.6
for location of the adjustment nut. Adjust the
speed until the vibratach whip handle exhibits
minimum oscillation at 2350 to 2450 RPM.

When finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-23 F-23

RANGER 250

WARNING

ROTOR RESISTANCE TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This test will determine if there is an open winding in the rotor or if the rotor is grounded.

MATERIALS NEEDED

Ohmmeter
3/8" Wrench or socket wrench
7/16" wrench
9/16" Wrench
Needle nose pliers
Wiring Diagram

This procedure should take approximately 30 minutes to perform.

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TROUBLESHOOTING & REPAIR

F-24 F-24

RANGER 250

ROTOR RESISTANCE TEST (continued)

FIGURE F.7 – ROTOR BRUSH LEADS

SLIP RINGS

BRUSHES

LEADS
201
5H

+

-

LEADS
200A
200

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

3. Locate and label the four leads from the rotor
brush holder assembly. See Figure F.7.
Using the needle nose pliers, remove the
leads. See Figure F.7. This will electrically
isolate the rotor windings.

4. Using the ohmmeter, check the rotor winding
resistance across the slip rings. See Figure
F.7. Normal resistance is approximately 4.7
ohms.

5. Measure the resistance to ground. Place
one meter probe on either of the slip rings.
Place the other probe on any good unpaint­ed ground. The resistance should be very
high, at least 500,000 ohms.

6. If the test does not meet the resistance spec­ifications, then the rotor may be faulty.
Replace.

7. Connect the leads previously removed from
the brush assembly. Make sure the leads
are connected to the proper brushes. See
the Wiring Diagram.

8. If finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-25 F-25

RANGER 250

WARNING

FLASHING AND ROTOR VOLTAGE TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This test will determine if the correct DC voltage is being applied to the rotor at the maxi­mum engine speed (3700 RPM). This information will aid the technician in determining if
the generator field is operating properly. Tests can be conducted with the engine stopped
(static test) and running (dynamic test). These procedures also allow you to test the oil
pressure switch for proper functioning.

MATERIALS NEEDED

3/8" Wrench or socket wrench
9/16" Wrench
Test pins
Jumper lead
Volt/Ohmmeter
Wiring Diagram

This procedure should take approximately 35 minutes to perform.

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TROUBLESHOOTING & REPAIR

F-26 F-26

RANGER 250

FLASHING AND ROTOR VOLTAGE TEST (continued)

FIGURE F.8 – ROTOR BRUSH LEADS

SLIP RINGS

BRUSHES

LEADS
201
5H

+

-

LEADS
200A
200

TEST PROCEDURE

1. Perform the Case Cover Removal proce-
dure.

2. Set the volt/ohmmeter to the DC volts posi­tion.

3. Test rotor voltage - static (engine stopped
but running condition simulated):

a. Connect a jumper between P51 leads

#210 and #224. See the Wiring
Diagram. This bypasses the oil pressure
switch and simulates the test with the
engine running.

b. Remove the spark plug wires, then set

the RUN/STOP switch to RUN.

c. Connect the positive meter probe to the

brush nearest the rotor lamination (leads
#200A and #200). See Figure F.8 for
location.

d. Connect the negative meter probe to the

other brush (leads #201 and #5H).

e. Measure the voltage. It should read

between 3.0 and 4.0 VDC.

f. Set the RUN/STOP switch to STOP.

Oil Pressure Switch Test

The oil pressure switch is designed to open if it
detects low or no oil pressure. If you can con­duct the test described here in Step 3 and
obtain the 3.0 to 4.0 VDC voltage reading,
WITHOUT THE JUMPER, then the oil pressure
switch or the Battery PC board may be faulty.

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TROUBLESHOOTING & REPAIR

F-27 F-27

RANGER 250

FIGURE F.9 – FIELD DIODE RECTIFIER BRIDGE AND FILTER CAPACITOR

FIELD

RECTIFIER

BRIDGE

RETAINING

TAB

7

9

CAPACITOR

201

201A

200A
200B

CABLE

FLASHING AND ROTOR VOLTAGE TEST (continued)

4. Test rotor voltage - dynamic (engine run­ning)

a. Remove the jumper used in the previous

step. Replace the spark plug wires, set
the RUN/STOP switch to RUN, start the
engine and run it at high idle speed
(3700 RPM).

b. Connect the positive meter probe to the

brush nearest the rotor lamination (leads
#200A and #200). See Figure F.8 for
location.

c. Connect the negative meter probe to the

other brush (leads #201 and #5H).

d. Carefully measure the voltage. It should

read approximately 46 - 52 VDC.

5. If the voltage reading is low or not present,
the generator field is not functioning prop­erly. Perform the Rotor Resistance Test.
Also check the field diode rectifier bridge,
filter capacitor, and associated leads and
connections. See Figure F.9 for location.
See the Wiring Diagram.

6. Check the rotor ground wire #5H for good
connection. See the Wiring Diagram.

7. If the rotor voltage readings are normal, the
field circuit is functioning properly.

8. If finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-28 F-28

RANGER 250

WARNING

STATOR VOLTAGE TESTS

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This test will determine if the correct AC voltages are being generated from the stator
windings.

MATERIALS NEEDED

3/8" Wrench or socket wrench
9/16" Wrench
3/4" Wrench
Test pins
Volt/Ohmmeter
Wiring Diagram

This procedure should take approximately 40 minutes to perform.

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TROUBLESHOOTING & REPAIR

F-29 F-29

RANGER 250

STATOR VOLTAGE TESTS (continued)

FIGURE F.10 – RECEPTACLE LEAD LOCATIONS

CASE FRONT - REAR VIEW

AMPHENOL 2

AMPHENOL 1

B

B

A

A

C

C

D

D

E

E

F

F

KEY

KEY

G

H

I

J

K

L

M

N

GND C

3E

6F

J100
120/240 V AC

5C

3D

GOLD

J102

SILVER

SILVER

5A

GND G

6E

GOLD

J101

5B

GND D

CB5

3A

3A

3

3E

50 AMP 25 AMP

20 AMP

209

CB7

CB1

212A

212

3D, 32

6

6B

6B

CB6

6F

50 AMP

42

CB8

42A

CB2

6E

15 AMP

20 AMP

GND M

GND L

GND J

GND G

GND D

GND C

GND B

GND A

31

5

5A
5B
5C

5F

5G

5H

5K

5L

GND E

SHUNT

204S

206S

POSITIVE PUTPUT STID

206A
206B

208

208A
208B

NEGATIVE PUTPUT STUD

TEST PROCEDURE

For all tests: Perform the Case Cover Removal
procedure.

To test the 120 VAC winding:

1. Connect the volt/ohmmeter probes to either
120 VAC receptacle as follows. See Figure
F.10 and the Wiring Diagram.

Upper receptacle, to leads #3D and #5A.
Lower receptacle, to leads #6E and 5B.

NOTE: It is easier to insert the probes directly
into the receptacle to perform this test. However,
the probes may not reach in far enough to make
or keep a good connection. In this case, before
you start the engine, insert two test pins into the
receptacle. Hold the test probes against these
inserts to measure voltage (Step 3).

2. Start the engine and run it at high idle (3700
RPM).

3. Check the AC voltage reading. It should read
between 118 and 126 VAC.

To test the 240 VAC winding:

1. Connect the volt/ohmmeter probes to leads
#6F and #3E where they connect to the
240VAC receptacle.

NOTE: It is easier to insert the probes directly
into the receptacle to perform this test. However,
the probes may not reach in far enough to make
or keep a good connection. In this case, before
you start the engine, insert two test pins into the
receptacle. Hold the test probes against these
inserts to measure voltage (Step 3).

2. Start the engine and run it at high idle (3700
RPM).

3. Check the AC voltage reading. It should read
between 236 and 252 VAC.

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TROUBLESHOOTING & REPAIR

F-30 F-30

RANGER 250

STATOR VOLTAGE TESTS (continued)

FIGURE F.11 – LOCATION OF LEADS #7 AND #9 AT FIELD DIODE RECTIFIER BRIDGE

FIELD

RECTIFIER

BRIDGE

RETAINING

TAB

7

9

CAPACITOR

201

201A

200A
200B

CABLE

201

201A

200A
200B

7

9

+

_

AC

AC

To test the field winding:

1. Connect the volt/ohmmeter probes to leads
#7 and #9 where they connect to the field
diode rectifier bridge. See Figure F.11.

2. Start the engine and run it at high idle (3700
RPM).

3. Check the AC voltage reading. It should be
between 40 and 50 VAC.

If any one or more of the readings are missing or
not within specifications, check for loose or bro-

ken wires between the test points and the stator
windings. See the Wiring Diagram. Make sure
that the windings are NOT grounded internally to
the stator iron. If the leads are intact, then the
stator may be faulty. Replace the stator.

If the voltage readings are within specifications,
then the windings are good and functioning prop­erly.

4. If finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-31 F-31

RANGER 250

STATOR VOLTAGE TESTS (continued)

FIGURE F.12 – 14-PIN AMPHENOL PIN ASSIGNMENTS

Z

W

Y

X

K

B

I

H

N

L

C

D

M

G

E

F

A

J

To test the feeder winding:

1. Connect the volt/ohmmeter probes to leads
#31 and #32 where they connect to circuit
breaker CB1 and the 14-pin amphenol. See
the Wiring Diagram.

NOTE: It is possible to check this voltage reading
at the amphenol by inserting the test probe pins
at pin A (for lead #32) and pin J (for lead #31).
See Figure F.12. However, if you use this method
and you get no voltage reading, it could mean
there is a break or loose connection in the leads
between the circuit breaker and the amphenol.
Check the reading again with one probe at the
circuit breaker connection for lead #32 and the
other probe at amphenol pin J.

2. Start the engine and run it at high idle (3700

RPM).

3. Check the AC voltage reading. It should be

between 118 and 126 VAC.

4. Connect the volt/ohmmeter probes to leads
#41A and #42A where they connect to circuit
breaker CB8 and the 14-pin amphenol. See
the Wiring Diagram.

NOTE: It is possible to check this voltage reading
at the amphenol by inserting the test probe pins
at pin K (for lead #42A) and pin I (for lead #41A).
See Figure F.12. However, if you use this method
and you get no voltage reading, it could mean
there is a break or loose connection in the leads
between the circuit breaker and the amphenol.
Check the reading again with one probe at the
circuit breaker connection for lead #42A and the
other probe at amphenol pin I.

5. Start the engine and run it at high idle (3700
RPM).

6. Check the AC voltage reading. It should be
between 40 and 46 VAC.

TROUBLESHOOTING & REPAIR

F-32 F-32

RANGER 250

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STATOR VOLTAGE TESTS (continued)

FIGURE F.13 – OUTPUT RECTIFIER BRIDGE CONNECTIONS

W1
W2
W3

W4
W5

W10

W8
W9

W6
W7
W11

OUTPUT
RECTIFIER
BRIDGE

TOP
CENTER
BOTTOM

CHOKE

If any one or more of the readings are missing or
not within specifications, then check for loose or
broken wires between the test points and the sta­tor windings. See the Wiring Diagram. Make
sure that the windings are NOT grounded inter­nally to the stator iron. If the leads are intact,
then the stator may be faulty. Replace the stator.

If the voltage readings are within specifications,
then the windings are good and functioning prop­erly.

7. If finished testing, perform the Case Cover
Replacement procedure.

To test the stator weld windings:

1. Locate the weld winding leads connected to
the three-phase output rectifier bridge. See
Figure F.13.

2. Check for approximately 58 - 65 VAC from
W1 to W2. Also check for the same voltage
from W2 to W3 and from W1 to W3.

3. If any of these voltages are low or missing,
perform the Flashing and Rotor Voltage
Test and also the Rotor Resistance Test.

4. If the tests in Step 2 are OK and the stator
voltages are low or missing, the stator may
be faulty.

5. If finished testing, perform the Case Cover
Replacement procedure.

TROUBLESHOOTING & REPAIR

F-33 F-33

RANGER 250

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WARNING

ANALOG POWER PC BOARD VOLTAGE TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This test will determine if the Analog Power PC board is receiving and passing the prop­er signal voltages.

MATERIALS NEEDED

Analog Volt/Ohmmeter
3/8" Wrench or Socket Wrench
9/16" Wrench
Wiring Diagram

This procedure should take approximately 30 minutes to perform.

TROUBLESHOOTING & REPAIR

F-34 F-34

RANGER 250

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ANALOG POWER PC BOARD VOLTAGE TEST (continued)

FIGURE F.14 – ANALOG POWER PC BOARD

K

L

C1

C2

RESISTOR R3
(0N BLOWER
SIDE OF
BAFFLER)

BLOWER BAFFLE - SIDE OPPOSITE BLOWER

3

2

4

1

10

9

8

7

6

1
2
3
4
5

J41

J42

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

3. Locate plugs J41 and J42 from the Analog
Power PC board. See Figure F.14.

4. Start the engine and run it at high idle (3700
RPM) with no load.

5. Check for the correct Analog Power PC
board input voltage:

a. Set the volt/ohmmeter to the Volts DC

position.

b. Place the negative probe on J41 pin 2 and

the positive probe on J41 pin 1.

c. The reading should be between 75 and 85

VDC.

If the reading is not correct, the stator output may
be incorrect, the rectifier output may be incorrect,
the capacitors may be faulty or the Power Module
PC board may be faulty. Perform the Stator
Voltage Test, the Output Rectifier Bridge Test,
and the Power Module PC Board Test. The
capacitors C1 and C2 may be faulty. Test and
replace if necessary.

6. Check for the correct output voltage readings
per Table F.1. If any of the readings are not
correct, the Analog Power PC board may be
faulty.

PCB5
BY-PASS
PC BOARD

J60

1

J61

1

J62

1

CONTROL CIRCUIT
INPUT POWER

13 1J41 to POS TERMINAL ON C2 - 85V SUPPLY

14 2J41 to NEG TERMINAL ON C2 - 85V SUPPLY

PCB2
ANALOG POWER

1

PC BOARD

J41

1

J42

GND

GND

TABLE F.1. – ANALOG PC BOARD OUTPUT VOLTAGE TABLE

TEST POINTS COMPONENT TESTED VOLTAGE READING

1J42 to 6J42 Chopper Power Supply +20 VDC
2J42 to 7J42 Weld Control PC Board Power Supply +5 VDC
5J42 to 7J42 Weld Control PC Board Power Supply +15 VDC
9J42 to 7J42 Weld Control PC Board Power Supply -15 VDC

10J42 to 4J42 Weld Control PC Board Power Supply +15 VDC

TROUBLESHOOTING & REPAIR

F-35 F-35

RANGER 250

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ANALOG POWER PC BOARD VOLTAGE TEST (continued)

7. If finished testing, perform the Case Cover
Replacement procedure.

NOTE ON THE BYPASS PC BOARD

The purpose of the Bypass PC board circuitry is
to provide a more attractive path to ground for
transient spikes and high frequency signals that
could damage sensitive circuit components. The
Ranger 250 Bypass PC board cannot be tested.
However, a faulty Bypass PC may show visible
physical damage. As a general rule of practice, if
you have catastrophic damage to any other PC
board on the machine, the Bypass PC board
should be replaced as well.

TROUBLESHOOTING & REPAIR

F-36 F-36

RANGER 250

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WARNING

OUTPUT RECTIFIER BRIDGE TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

TEST DESCRIPTION

This test will determine if there are faulty diodes in the output rectifier bridge.

MATERIALS NEEDED

Volt/Ohmmeter (Analog)
11/32" Nut driver
1/2" Wrench
3/8" Wrench or socket wrench
9/16" Wrench
Wiring Diagram

This procedure should take approximately 45 minutes to perform.

TROUBLESHOOTING & REPAIR

F-37 F-37

RANGER 250

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OUTPUT RECTIFIER BRIDGE TEST (continued)

FIGURE F.15 – PLUG J41 AND RESISTOR R3 LOCATIONS

K

L

C1

C2

RESISTOR R3
(0N BLOWER
SIDE OF
BAFFLER)

BLOWER BAFFLE - SIDE OPPOSITE BLOWER

3

2

4

1

10

9

8

7

6

1
2
3
4
5

J41

J42

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

3. Perform the Power Module Capacitor
Discharge procedure.

4. Disconnect plug J41 (with leads #13 and
#14) from the Analog Power PC board. See
Figure F.15.

5. If your machine has resistor R3, with the
11/32" nut driver, disconnect one end of
resistor R3, either lead #252 or #253. See
Figure F.15.

PCB5
BY-PASS
PC BOARD

J60

1

CONTROL CIRCUIT
INPUT POWER

13 1J41 to POS TERMINAL ON C2 - 85V SUPPLY
14 2J41 to NEG TERMINAL ON C2 - 85V SUPPLY

PCB2
ANALOG POWER

1

PC BOARD

J41

11 1J42 toPIN 3 of P50
105A 2J42 to3J13
5L 4J42 to GND. SCREW

115A 5J42 to 1J13
12 6J42 to PIN 1 of P50
101A 7J42 to 2J13
116A 9J42 to 4J13
118A 10J42 to 5J13

CHOPPER POWER SUPPLY, 20V

WELD BOARD POWER SUPPLY, +5V TO CIRCUIT GROUND

WELD BOARD POWER SUPPLY, +5V TO CIRCUIT GROUNDWELD BOARD POWER SUPPLY, +5V TO CIRCUIT GROUNDWELD BOARD POWER SUPPLY, +5V TO CIRCUIT GROUND
FRAME GROUND
WELD BOARD POWER SUPPLY, +15V TO CIRCUIT GROUND

CHOPPER POWER SUPPLY, 20V

CIRCUIT GROUND
WELD BOARD POWER SUPPLY, -15V TO CIRCUIT GROUND
WELD BOARD POWER SUPPLY, +15V TO CASE GROUND

J61

1

J42

1

J62

1

GND

GND

TROUBLESHOOTING & REPAIR

F-38 F-38

RANGER 250

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OUTPUT RECTIFIER BRIDGE TEST (continued)

FIGURE F.16 – OUTPUT RECTIFIER BRIDGE LEAD REMOVAL AND TEST POINTS

W1
W2
W3

OUTPUT
RECTIFIER
BRIDGE

TOP
CENTER

BOTTOM

CHOKE

6. Electrically isolate the output rectifier bridge:
Using the 1/2" wrench, remove stator leads
W1, W2, and W3 from their bolted connec­tions on the left side of the bridge. Note lead
placement for reassembly. Bend the leads
out into "free air" so that they do not touch
anything. See Figure F.16.

7. Remove any load that may be connected to
the weld output terminals.

8. Check all diode assemblies individually for
opens or shorts. If any of the checks are not
correct, the output rectifier bridge may be
faulty. See the Output Rectifier Bridge
Removal and Replacement procedure.

When all tests are complete:

1. Replace stator leads W1, W2, and W3 to
their respective terminals. Replace lead(s)
#252 or #253 previously removed. See
Figure F.16.

2. If finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-39

F-39

RANGER 250

WARNING

POWER MODULE TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician or
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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshoot­ing assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).

DESCRIPTION

This test will help determine if the power module is shorted. This is a resistance test, not a
voltage test. This test will only help diagnose a problem in the "power" section of the module.

Other PC board components could be faulty.

MATERIALS NEEDED

Volt/Ohmmeter (Analog)
3/8" Wrench or socket wrench
9/16" Wrench
1/2" Wrench
7/16" Wrench

This procedure should take approximately 45 minutes to perform.

TROUBLESHOOTING & REPAIR

F-40 F-40

RANGER 250

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POWER MODULE TEST (continued)

FIGURE F.17 – POWER MODULE CONNECTIONS

POSITIVE (+)
STRAP

W6

W9

POWER
MODULE
PC BOARD

TEMPERATURE
SWITCH

POSITIVE (+)
STRAP

W8

TEST PROCEDURE

1. Turn the engine off.

2. Perform the Case Cover Removal proce-
dure.

3. Perform the Power Module Capacitor
Discharge procedure.

4. Using the 7/16" wrench, loosen the nuts on
the positive terminals of the power capaci­tors. Then remove the nuts, lock washers,
and flat washers from the terminals where
the positive straps connect to the Power
Module PC board. Flip the straps out of the
way. See Figure F.17.

5. Using the 7/16" wrench, remove the flex
leads W8 and W9 from the Power Module PC
board terminals.

6. Using the 7/16" wrench, remove the two pos­itive jumper straps attaching the capacitors to
the Power Module PC board. Note all lead
placements for reassembly. Note lead #253,
#13, W4 and W5 do not have to be removed
from the circuit. See the Wiring Diagram.
The small flex lead connected to D4 should
be removed and electrically isolated.

7. Using the 7/16" wrench, remove the W6 lead
strap from the power module (two bolted con­nections). Suggestion: First loosen the
straps at the capacitor terminals and remove
the nuts on the power module. Then fold the
straps back out of the way.

NOTE: Make sure the bolts do not fall back
against the heat sink.

TROUBLESHOOTING & REPAIR

F-41 F-41

RANGER 250

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POWER MODULE TEST (continued)

FIGURE F.18 – IGBT TEST

HEAT SINK

POSITIVE (+)
CAPACITOR
TERMINAL
CONNECTIONS

Check IGBT for “Shorts”

8. Using the analog ohmmeter, connect the
positive meter probe to the heat sink and the
negative meter probe to the positive capaci­tor terminal on the power module chopper
PC board. See Figure F.18. The resistance
reading should be high (over 20,000 ohms).

9. Reverse the meter probe leads. The resis­tance should be very high (over 20,000
ohms). It the resistance is low in either Step
8 or 9, the IGBT may be shorted or leaky.

TROUBLESHOOTING & REPAIR

F-42 F-42

RANGER 250

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POWER MODULE TEST (continued)

FIGURE F.19 – DIODE MODULE TEST

HEAT SINK

DIODE
MODULE
TERMINALS

Check Diode Module

10. Using the analog ohmmeter, connect the
negative meter probe to the terminal on the
diode module. See Figure F.19. Connect the
positive meter probe to the heat sink. The
resistance should be very high (over 20,000
ohms).

11. Using the analog ohmmeter, connect the
positive meter probe to the terminal on the
diode module. Connect the negative meter
probe to the heat sink. The resistance should
be lower (approximately 300 ohms). Also
check diode D4 for shorted or open condition.
See the Wiring Diagram.

When all tests are complete:

1. Reconnect all leads previously removed.

2. Torque the capacitor nuts to 50-60 inch­pounds.

3. If finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-43

F-43

RANGER 250

WARNING

FLYWHEEL ALTERNATOR TEST

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician or
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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical troubleshoot­ing assistance before you proceed. Call 216-383-2531 or 1-800-833-9353 (WELD).

DESCRIPTION

This test will help determine if the flywheel alternator is properly charging the battery.

MATERIALS NEEDED

Volt/Ohmmeter
3/8" Wrench or socket wrench

This procedure should take approximately 15 minutes to perform.

TROUBLESHOOTING & REPAIR

F-44 F-44

RANGER 250

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FLYWHEEL ALTERNATOR TEST (continued)

FIGURE F.20 – PLUG J51 PIN LOCATION

ENGINE CONNECTOR BLOCK J51

ONAN P216 ENGINE

210 (TO
RUN-STOP
SWITCH)

224 (TO HOUR
METER POS.)

212A (TO BATTERY
CHARGER CIRCUIT
BREAKER)

WELDER HARNESS SIDE
LEAD ENTRY VIEW

224A

1

133

224

4

1

3

24

13
2

4

BATTERY
CHARGER

IGNITION
CIRCUIT +12V

TO OIL
PRESSURE
SWITCH

ENGINE SIDE
LEAD ENTRY VIEW

ENGINE CONNECTOR BLOCK J51

KOHLER CH20 ENGINE

221 (TO
RUN-STOP
SWITCH)

212A (TO BATTERY
CHARGER CIRCUIT
BREAKER)

WELDER HARNESS SIDE
LEAD ENTRY VIEW

211A (TO START

BUTTON SWITCH)
225 (TO BATTERY
PC BOARD)

TO FUEL
SHUTOFF
SOLENOID

IGNITION GROUND
TO STOP ENGINE
BATTERY
CHARGER

ENGINE SIDE
LEAD ENTRY VIEW

TEST PROCEDURE

1. Turn the engine off.

2. Using the 3/8" wrench, remove the three
screws holding the battery access cover in
place and slide the battery tray out enough to
access the terminals. Using the volt/ohmme­ter measure the voltage at the battery termi­nals. It should be approximately 12 volts DC.

3. Start the engine and run it at high idle for
approximately 30 seconds. Measure the
voltage at the battery terminals. It should be

13.7 to 14.2 volts DC. If correct, the test is
over. If not correct, proceed to the next step.

4. Check circuit breaker CB7 on the front panel.
Reset if tripped. Repeat Step 3. If circuit
breaker is functioning properly, proceed to
Step 5.

5. Perform the Case Cover Removal proce-
dure.

6. Perform the Power Module Capacitor
Discharge procedure.

7. Locate plug J51 leads 212A (pin 3 or 2) or
engine alternator lead pin 3 (C1). See Figure
F.20. Check from pin 3 to the negative bat­tery terminal with the engine running at high
idle speed (3700 RPM). Normal voltage is

13.7 to 14.2 volts DC. If not correct, the fly­wheel alternator may be faulty. If correct,
check the wiring between the flywheel alter­nator and the positive battery terminal. See
the Wiring Diagram.

8. If finished testing, perform the Case Cover
Replacement procedure.

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TROUBLESHOOTING & REPAIR

F-45 F-45

RANGER 250

This is the typical auxiliary output
voltage generated from a properly
operating machine. Note that each
vertical division represents 50 volts
and that each horizontal division rep­resents 5 milliseconds in time.

NOTE: Scope probes are connected
at machine 120 VAC receptacle.

SCOPE SETTINGS

Volts/Div.....................50V/Div.

Horizontal Sweep.....5 ms/Div.

Coupling.............................DC

Trigger.........................Internal

NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM (120VAC SUPPLY)

HIGH IDLE – NO LOAD

0 volts

16.2 ms

50V 5ms

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TROUBLESHOOTING & REPAIR

F-46 F-46

RANGER 250

This is the typical DC open circuit out­put voltage generated from a properly
operating machine. Note that each
vertical division represents 50 volts
and that each horizontal division rep­resents 5 milliseconds in time.

NOTE: Scope probes are connected
at weld output terminals.

SCOPE SETTINGS

Volts/Div.....................50V/Div.

Horizontal Sweep.....5 ms/Div.

Coupling.............................DC

Trigger.........................Internal

NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM (STICK)

MAX CONTROL POT - HIGH IDLE - NO LOAD

0 volts

50V 5ms

CH1

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TROUBLESHOOTING & REPAIR

F-47 F-47

RANGER 250

This is the typical DC open circuit out­put voltage generated from a properly
operating machine. Note that each
vertical division represents 20 volts
and that each horizontal division rep­resents 1 millisecond in time.

The machine was loaded with a resis­tance grid bank to 250 amps at 25
volts.

NOTE: Scope probes are connected
at weld output terminals.

SCOPE SETTINGS

Volts/Div .....................20V/Div

Horizontal Sweep.....1 ms/Div.

Coupling.............................DC

Trigger.........................Internal

NORMAL WELD VOLTAGE WAVEFORM (STICK CC)

MACHINE LOADED TO 250 AMPS AT 25 VOLTS

0 volts

20V 1ms

Trig +15V CH1

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TROUBLESHOOTING & REPAIR

F-48 F-48

RANGER 250

This is the typical DC open circuit out­put voltage generated from a properly
operating machine. Note that each
vertical division represents 50 volts
and that each horizontal division rep­resents 5 milliseconds in time.

NOTE: Scope probes are connected
at weld output terminals.

SCOPE SETTINGS

Volts/Div.....................50V/Div.

Horizontal Sweep.....5 ms/Div.

Coupling.............................DC

Trigger.........................Internal

NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM (WIRE CV TAP)

MAX CONTROL POT - HIGH IDLE - NO LOAD

0 volts

50V 5ms

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TROUBLESHOOTING & REPAIR

F-49 F-49

RANGER 250

This is the typical DC voltage gener­ated from a properly operating
machine. Note that each vertical divi­sion represents 20 volts and that
each horizontal division represents 1
millisecond in time.

The machine was loaded with a resis­tance grid bank to 250 amps at 28
volts.

NOTE: Scope probes are connected
at weld output terminals.

SCOPE SETTINGS

Volts/Div.....................20V/Div.

Horizontal Sweep.....1 ms/Div.

Coupling.............................DC

Trigger.........................Internal

NORMAL WELD VOLTAGE WAVEFORM (WIRE CV)

MACHINE LOADED TO 250 AMPS AT 28 VOLTS

0 volts

20V 1ms

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TROUBLESHOOTING & REPAIR

F-50 F-50

RANGER 250

WARNING

POWER MODULE ASSEMBLY/POWER MODULE PC BOARD/

DIODE MODULE REMOVAL AND REPLACEMENT

Service and repair should be performed by only Lincoln Electric factory trained personnel.
Unauthorized repairs performed on this equipment may result in danger to the technician
or 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.

If for any reason you do not understand the test procedures or are unable to perform the
test/repairs safely, contact the Lincoln Electric Service Department for electrical trou­bleshooting assistance before you proceed. Call 1-800-833-9353 (WELD).

DESCRIPTION

This procedure will aid the technician in the removal and replacement of the Power
Module assembly. Procedures for removal and replacement of the Power Module PC
board and the diode module are included.

MATERIALS NEEDED

3/8" wrench or socket wrench
7/16" wrench
7/16" Socket wrench
1/2" Wrench
9/16" Wrench
3/16" Allen head wrench
9/64" Allen head wrench
Torque wrench with 3/16" and 9/64" allen head sockets
Phillips head screw driver
Diagonal cutters
Electrical thermal joint compound - Penetrox A-13

This procedure should take approximately 1 hour to perform.