Lincoln Electric SVM144-B User Manual
POWER MIG 255
SVM144-B
July, 2006
Safety Depends on You
Lincoln arc welding and cutting
equipment is designed and built
with safety in mind. However,
your overall safety can be
increased by proper installation
. . . and thoughtful operation on
your part. DO NOT INSTALL,
OPERATE OR REPAIR THIS
EQUIPMENT WITHOUT READING THIS MANUAL AND THE
SAFETY PRECAUTIONS CONTAINED THROUGHOUT. And,
most importantly, think before
you act and be careful.
SERVICE MANUAL
For use with machines having Code Number : 10563, 10583,10986, 10990
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• Sales and Service through Subsidiaries and Distributors Worldwide •
Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com
• World's Leader in Welding and Cutting Products •
Copyright © 2006 Lincoln Global Inc.
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i
SAFETY
i
LN-15
FOR ENGINE
powered equipment.
1.a. Turn the engine off before troubleshooting and maintenance
work unless the maintenance work requires it to be running.
____________________________________________________
1.b.Operate engines in open, well-ventilated
areas or vent the engine exhaust fumes
outdoors.
____________________________________________________
1.c. Do not add the fuel near an open flame welding arc or when the engine is running. Stop
the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on
contact with hot engine parts and igniting. Do
not spill fuel when filling tank. If fuel is spilled,
wipe it up and do not start engine until fumes
have been eliminated.
____________________________________________________
1.d. Keep all equipment safety guards, covers and devices in position and in good repair.Keep hands, hair, clothing and tools
away from V-belts, gears, fans and all other moving parts
when starting, operating or repairing equipment.
____________________________________________________
1.e. In some cases it may be necessary to remove safety
guards to perform required maintenance. Remove
guards only when necessary and replace them when the
maintenance requiring their removal is complete.
Always use the greatest care when working near moving
parts.
___________________________________________________
1.f. Do not put your hands near the engine fan.
Do not attempt to override the governor or
idler by pushing on the throttle control rods
while the engine is running.
___________________________________________________
1.g. To prevent accidentally starting gasoline engines while
turning the engine or welding generator during maintenance
work, disconnect the spark plug wires, distributor cap or
magneto wire as appropriate.
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. AFree 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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ii
SAFETY
ii
LN-15
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
POWER MIG 255
SAFETY
iii iii
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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.
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.
POWER MIG 255
SAFETY
iv iv
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PRÉCAUTIONS DE SÛRETÉ
Pour votre propre protection lire et observer toutes les instructions
et les précautions de sûreté specifiques qui parraissent dans ce
manuel aussi bien que les précautions de sûreté générales suivantes:
Sûreté Pour Soudage A L’Arc
1. Protegez-vous contre la secousse électrique:
a. Les circuits à l’électrode et à la piéce sont sous tension
quand la machine à souder est en marche. Eviter toujours
tout contact entre les parties sous tension et la peau nue
ou les vétements mouillés. Porter des gants secs et sans
trous pour isoler les mains.
b. Faire trés attention de bien s’isoler de la masse quand on
soude dans des endroits humides, ou sur un plancher metallique ou des grilles metalliques, principalement dans
les positions assis ou couché pour lesquelles une grande
partie du corps peut être en contact avec la masse.
c. Maintenir le porte-électrode, la pince de masse, le câble de
soudage et la machine à souder en bon et sûr état defonctionnement.
d.Ne jamais plonger le porte-électrode dans l’eau pour le
refroidir.
e. Ne jamais toucher simultanément les parties sous tension
des porte-électrodes connectés à deux machines à souder
parce que la tension entre les deux pinces peut être le total
de la tension à vide des deux machines.
f. Si on utilise la machine à souder comme une source de
courant pour soudage semi-automatique, ces precautions
pour le porte-électrode s’applicuent aussi au pistolet de
soudage.
2. Dans le cas de travail au dessus du niveau du sol, se protéger
contre les chutes dans le cas ou on recoit un choc. Ne jamais
enrouler le câble-électrode autour de n’importe quelle partie du
corps.
3. Un coup d’arc peut être plus sévère qu’un coup de soliel, donc:
a. Utiliser un bon masque avec un verre filtrant approprié ainsi
qu’un verre blanc afin de se protéger les yeux du rayonnement de l’arc et des projections quand on soude ou
quand on regarde l’arc.
b. Porter des vêtements convenables afin de protéger la peau
de soudeur et des aides contre le rayonnement de l‘arc.
c. Protéger l’autre personnel travaillant à proximité au
soudage à l’aide d’écrans appropriés et non-inflammables.
4. Des gouttes de laitier en fusion sont émises de l’arc de
soudage. Se protéger avec des vêtements de protection libres
de l’huile, tels que les gants en cuir, chemise épaisse, pantalons sans revers, et chaussures montantes.
5. Toujours porter des lunettes de sécurité dans la zone de
soudage. Utiliser des lunettes avec écrans lateraux dans les
zones où l’on pique le laitier.
6. Eloigner les matériaux inflammables ou les recouvrir afin de
prévenir tout risque d’incendie dû aux étincelles.
7. Quand on ne soude pas, poser la pince à une endroit isolé de
la masse. Un court-circuit accidental peut provoquer un
échauffement et un risque d’incendie.
8. S’assurer que la masse est connectée le plus prés possible de
la zone de travail qu’il est pratique de le faire. Si on place la
masse sur la charpente de la construction ou d’autres endroits
éloignés de la zone de travail, on augmente le risque de voir
passer le courant de soudage par les chaines de levage,
câbles de grue, ou autres circuits. Cela peut provoquer des
risques d’incendie ou d’echauffement des chaines et des
câbles jusqu’à ce qu’ils se rompent.
9. Assurer une ventilation suffisante dans la zone de soudage.
Ceci est particuliérement important pour le soudage de tôles
galvanisées plombées, ou cadmiées ou tout autre métal qui
produit des fumeés toxiques.
10. Ne pas souder en présence de vapeurs de chlore provenant
d’opérations de dégraissage, nettoyage ou pistolage. La
chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs
du solvant pour produire du phosgéne (gas fortement toxique)
ou autres produits irritants.
11. Pour obtenir de plus amples renseignements sur la sûreté, voir
le code “Code for safety in welding and cutting” CSA Standard
W 117.2-1974.
PRÉCAUTIONS DE SÛRETÉ POUR
LES MACHINES À SOUDER À
TRANSFORMATEUR ET À
REDRESSEUR
1. Relier à la terre le chassis du poste conformement au code de
l’électricité et aux recommendations du fabricant. Le dispositif
de montage ou la piece à souder doit être branché à une
bonne mise à la terre.
2. Autant que possible, I’installation et l’entretien du poste seront
effectués par un électricien qualifié.
3. Avant de faires des travaux à l’interieur de poste, la debrancher à l’interrupteur à la boite de fusibles.
4. Garder tous les couvercles et dispositifs de sûreté à leur place.
POWER MIG 255
vv
MASTER TABLE OF CONTENTS FOR ALL
SECTIONS
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-iv
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section A
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section B
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section C
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section D
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section E
Troubleshooting and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F
Electrical Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section G
Parts Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P344 Series
RETURN TO MAIN MENU
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X
Section A-1 Section A-1
TABLE OF CONTENTS
- INSTALLATION SECTION -
Installation ..............................................................................................................Section A
Technical Specifications...............................................................................................A-2
Safety Precautions .......................................................................................................A-3
Uncrating the POWER MIG 255 ...................................................................................A-3
Location........................................................................................................................A-3
Input Power, Grounding and Connection Diagrams ....................................................A-3
Output Polarity Connections........................................................................................A-5
Gun and Cable Installation...........................................................................................A-6
Shielding Gas ...............................................................................................................A-6
POWER MIG 255
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A-2
INSTALLATION
A-2
75°C Copper Wire 75°C Copper Wire
in Conduit in Conduit
Input Ampere AWG (IEC) Sizes AWG (IEC) Sizes
Input Voltage/ Fuse or Breaker Rating On (For lengths (For lengths
Frequency (Hz) Size (Super Lag) Nameplate up to 100 ft) exceeding 100 ft)
208/60 60 50 8 (10 mm2)6 (16 mm2)
230/60 60 46 10 (6 mm2)8 (10 mm2)
460/60 30 24 14 (2.5 mm2) 12 (4 mm2)
575/60 25 19 14 (2.5 mm2) 12 (4 mm2)
NOTE: Use #10 AWG Grounding Wire
TECHNICAL SPECIFICATIONS – POWER MIG 255
INPUT – SINGLE PHASE ONLY
RATED OUTPUT
OUTPUT
RECOMMENDED INPUT WIRE AND FUSE SIZES
Height Width Depth Weight
31.79 in. 18.88 in. 38.78 in. 220 Ibs
808 mm 480 mm 985 mm 100 kg
PHYSICAL DIMENSIONS
Wire Speed 50 – 700 IPM (1.27 – 17.8 m/minute)
WIRE SPEED RANGE
Standard Voltage/Frequency
Input Current @ 200 Amp Rated Output Input Current @ 250 Amp Rated Output
208/230/60 Hz 41/37 Amps 50/46
230/460/575/60 Hz 41/20/16 Amps 50/24/19
Duty Cycle
Amps V
olts at Rated Amperes
40% 250 Amps 26 Volts
60% 200 Amps 28 Volts
100% 145 Amps 26 Volts
Welding Current Range Maximum Open Circuit V
oltage Welding Voltage Range
(Continuous)
30 – 300 Amps 40 Volts 10-28 Volts
POWER MIG 255
INSTALLATION
A-3 A-3
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INPUT POWER, GROUNDING AND
CONNECTION DIAGRAMS
------------------------------------------------------------------------
1. Before starting the installation, check with the
local power company if there is any question
about whether your power supply is adequate for
the voltage, amperes, phase, and frequency specified on the welder nameplate. Also be sure the
planned installation will meet the U.S. National
Electrical Code and local code requirements. This
welder may be operated from a single phase line
or from one phase of a two or three phase line.
2. Models that have multiple input voltages specified
on the nameplate (e.g. 208/230) are shipped connected for the highest voltage. If the welder is to
be operated on lower voltage, it must be reconnected according to the instructions in Figure A.1
for dual voltage machines and Figure A.2 for
triple voltage machines.
Make certain that the input power is electrically
disconnected before removing the screw on the
reconnect panel access cover.
------------------------------------------------------------------------
Read entire installation section before starting
installation.
SAFETY PRECAUTIONS
ELECTRIC SHOCK can kill.
• Only qualified personnel should perform this
installation.
• Only personnel that have read and understood the POWER MIG 255 Operating
Manual should install and operate this equipment.
• Machine must be grounded per any national,
local or other applicable electrical codes.
• The POWER MIG power switch is to be in the
OFF position when installing work cable and
gun and when connecting other equipment.
WARNING
------------------------------------------------------------------------
UNCRATING THE POWER MIG 255
Cut banding and lift off cardboard carton. Cut banding
holding the machine to the skid. Remove foam and corrugated packing material. Untape accessories from
Gas Bottle Platform. Unscrew the two wood screws (at
the Gas Bottle Platform) holding the machine to the
skid. Roll the machine off the skid assembly.
LOCATION
Locate the welder in a dry location where there is free
circulation of clean air into the louvers in the back and
out the front. A location that minimizes the amount of
smoke and dirt drawn into the rear louvers reduces the
chance of dirt accumulation that can block air passages and cause overheating.
ELECTRIC SHOCK can kill.
• Do not touch electrically live parts such as
output terminals or internal wiring.
• All input power must be electrically disconnected before proceeding.
WARNING
WARNING
POWER MIG 255
INSTALLATION
A-4 A-4
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4. Using the instructions in Figure A.3, have a qualified electrician connect the receptacle or cable to
the input power lines and the system ground per
the U.S. National Electrical Code and any applicable local codes. See Technical Specifications
at the beginning of this chapter for proper wire
sizes. For long runs over 100 feet, larger copper
wires should be used. Fuse the two hot lines with
super lag type fuses as shown in the following diagram. The center contact in the receptacle is for
the grounding connection. A green wire in the
input cable connects this contact to the frame of
the welder. This ensures proper grounding of the
welder frame when the welder plug is inserted into
the receptacle.
3. The 208/230 volt 60 Hz model POWER MIG is
shipped with a 10 ft. input cable and plug connected to the welder. A matching receptacle is
supplied with the machine. Mount the receptacle
in a suitable location using the screws provided.
Be sure it can be reached by the plug on the input
cable attached to the welder. Mount with the
grounding terminal at the top to allow the power
cable to hang down without bending.
The 230/460/575 volt 60 Hz model is not
equipped with a plug, an input cable, or a
receptacle.
FIGURE A.1 — DUAL VOLTAGE MACHINE INPUT CONNECTIONS.
POWER MIG 255
INSTALLATION
A-5 A-5
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FIGURE A.3 — RECEPTACLE DIAGRAM.
CONNECT TO ASYSTEM
GROUNDING WIRE. SEE
THE UNITED STATES
NATIONALELECTRICAL
CODE AND/OR LOCAL
CODES FOR OTHER
DETAILS AND MEANS FOR
PROPER GROUNDING.
CONNECT TO HOT WIRES
OF A THREE-WIRE, SINGLE
PHASE SYSTEM OR TO ONE
PHASE OF ATWO OR
THREE PHASE SYSTEM.
OUTPUT POLARITY CONNECTIONS
The welder, as shipped from the factory, is connected
for electrode positive (+) polarity. This is the normal
polarity for GMA welding.
If negative (–) polarity is required, interchange the connection of the two cables located in the wire drive compartment near the front panel. The electrode cable,
which is attached to the wire drive, is to be connected
to the negative (–) labeled terminal. The work lead,
which is attached to the work clamp, is to be connected to the positive (+) labeled terminal.
FIGURE A.2 — TRIPLE VOLTAGE MACHINE INPUT CONNECTIONS.
POWER MIG 255
INSTALLATION
A-6 A-6
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GUN AND CABLE INSTALLATION
The Magnum 250L gun and cable provided with the
POWER MIG 255 is factory installed with a liner for
0.035-0.045 in. (0.9-1.2 mm) electrode and an 0.035
in. (0.9 mm) contact tip. Install the 0.045 tip (also provided) if this wire size is being used.
Turn the welder power switch off before installing
gun and cable.
------------------------------------------------------------------------
1. Lay the cable out straight.
2. Unscrew knurled screw on the drive unit front end
(inside wire feed compartment) until tip of screw
no longer protrudes into gun opening as seen
from front of machine.
3. Insert the male end of gun cable into the female
casting through opening in front panel. Make sure
connector is fully inserted and tighten knurled
screw.
4. Connect the gun trigger connector from the gun
and cable to the mating receptacle inside the
compartment located above the gun connection
made in item 3 above. Make sure that the keyways are aligned, insert and tighten retaining ring.
SHIELDING GAS
(For Gas Metal Arc Welding Processes)
Customer must provide cylinder of appropriate type
shielding gas for the process being used.
A gas flow regulator, for CO2or Argon blend gas, and
an inlet gas hose are factory provided with the POWER
MIG 255. Install the shielding gas supply as follows:
1. Set gas cylinder on rear platform of POWER MIG
255. Hook chain in place to secure cylinder to rear
of welder.
2. Remove the cylinder cap. Inspect the cylinder
valves and regulator for damaged threads, dirt,
dust, oil or grease. Remove dust and dirt with a
clean cloth.
DO NOT ATTACH THE REGULATOR IF OIL,
GREASE OR DAMAGE IS PRESENT! Inform
your gas supplier of this condition. Oil or grease
in the presence of high pressure oxygen is
explosive.
------------------------------------------------------------------------
3. Stand to one side away from the outlet and open
the cylinder valve for an instant. This blows away
any dust or dirt which may have accumulated in
the valve outlet.
Be sure to keep your face away from the valve outlet when “cracking” the valve.
------------------------------------------------------------------------
4. Attach the flow regulator to the cylinder valve and
tighten the union nut(s) securely with a wrench.
NOTE: If connecting to 100% CO2cylinder, insert
regulator adapter between regulator and cylinder
valve. If adapter is equipped with a plastic washer, be
sure it is seated for connection to the CO2cylinder.
5. Attach one end of the inlet gas hose to the outlet
fitting of the flow regulator, the other end to the
POWER MIG 255 rear fitting, and tighten the
union nuts securely with a wrench.
6. Before opening the cylinder valve, turn the regulator adjusting knob counterclockwise until the
adjusting spring pressure is released.
7. Standing to one side, open the cylinder valve
slowly a fraction of a turn. When the cylinder pressure gauge pointer stops moving, open the valve
fully.
Never stand directly in front of or behind the flow
regulator when opening the cylinder valve. Always
stand to one side.
------------------------------------------------------------------------
8. The flow regulator is adjustable. Adjust it to the
flow rate recommended for the procedure and
process being used before making the weld.
WARNING
WARNING
CYLINDER may explode if
damaged.
• Gas under pressure is explosive. Always keep
gas cylinders in an upright position and always
keep chained to undercarriage or stationary
support. See American National Standard Z-
49.1, “Safety in Welding and Cutting” published by the American Welding Society.
WARNING
WARNING
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POWER MIG 255
Section B-1 Section B-1
TABLE OF CONTENTS
- OPERATION SECTION -
Operation ................................................................................................................Section B
Product Description......................................................................................................B-3
Recommended Processes and Equipment..................................................................B-3
Welding Capability........................................................................................................B-3
Limitations ....................................................................................................................B-3
Description of Controls ................................................................................................B-4
Wire Drive Roll..............................................................................................................B-4
Wire Size Conversion Parts..........................................................................................B-4
Procedure for Changing Drive and Idle Roll Sets ........................................................B-5
Wire Reel Loading - Readi-Reels, Spools, or Coils .....................................................B-5
To Mount a 30 lb (14 kg) Readi-Reel Package
(Using the Molded Plastic K363-P Readi-Reel Adapter).......................................B-5
To Mount 10 to 44 lb (4.5-20 kg) Spools (12 in./300 mm Diameter)
or 14 lb (6 kg) Innershield Coils .............................................................................B-5
To Start the Welder.......................................................................................................B-6
Feeding Wire Electrode................................................................................................B-6
Idle Roll Pressure Setting.............................................................................................B-6
Setting Run-In Speed on Standard Power MIG Feeder ..............................................B-6
Fast or Slow Run-In Mode Selection (When Timer Option is not Installed)..........B-6
Instructions to Enter Slow Run-In..........................................................................B-6
Instructions to Enter Fast Run-In...........................................................................B-6
Making a Weld..............................................................................................................B-7
Avoiding Wire Feeding Problems.................................................................................B-7
Fan Control...................................................................................................................B-8
Input Line Voltage Protection .......................................................................................B-8
Wire Feed Overload Protection....................................................................................B-8
Welding Thermal Overload Protection .........................................................................B-8
Overcurrent Protection .................................................................................................B-8
POWER MIG 255
OPERATION
B-2 B-2
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Read entire Operation section before
operating the POWER MIG 255.
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.
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 closed containers.
ARC RAYS can burn eyes and
skin.
• Wear eye, ear and body protection.
Observe all safety information throughout
this manual.
WARNING
POWER MIG 255
OPERATION
B-3 B-3
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PRODUCT DESCRIPTION
The POWER MIG™ 255 is a complete semiautomatic
constant voltage DC arc welding machine built to meet
NEMA specifications. It combines a constant voltage
power source and a constant speed wire feeder with a
microcomputer-based controller to form a reliable highperformance welding system. Asimple control scheme,
consisting of continuous full range voltage and wire
feed speed controls, provides versatility with ease of
use and accuracy.
Other features include a 2 in. (51 mm) O.D. wire reel
spindle with adjustable brake, an integral gas cylinder
mounting undercarriage, an adjustable CO2or Argon
blend flow regulator with cylinder pressure gauge and
inlet hose, a 12 ft (3.6 m) Magnum 250L GMAW gun
and cable with fixed (flush) nozzle, a 10 ft (3.0 m)
power cable with plug and mating receptacle, and a 10
ft (3.0 m) work cable with clamp.
An Optional Timer kit provides variable burnback control, a spot function, a selectable 4-step trigger interlock and adjustable “Run In” for wire starting optimization. Also optional are a Spool Gun Adapter kit, a Dual
Cylinder Mounting Kit and an Aluminum Feeding Kit for
push feeding with standard built in feeder.
RECOMMENDED PROCESSES
AND EQUIPMENT
The POWER MIG 255 is recommended for GMA
welding processes using 10 to 44 lb (4.5 to 20 kg)
2 in. (51 mm) I.D. spools or Readi-Reel®coils (with
optional adapter) of 0.025 in. through 0.045 in.
(0.6 to 1.2 mm) solid steel, 0.035 in. (0.9 mm)
stainless, 3/64 in. (1.2 mm) aluminum and 0.045 in.
(1.2 mm) Outershield®; as well as 0.035 in. (0.9 mm)
and 0.045 in. (1.2 mm) Innershield®self-shielding
electrodes.
The POWER MIG is factory equipped to feed
0.035 in. (0.9 mm) electrodes and provides tip, guide,
and drive rolls for 0.045 in. (1.2 mm) electrode. It also
includes a 200A, 60% duty cycle (or 250A, 40% duty
cycle) rated, 12 ft (3.6 m) GMAW gun and cable
assembly equipped for these wire sizes. Use of GMAW
processes requires a supply of shielding gas.
WELDING CAPABILITY
The POWER MIG 255 is rated at 250 amps @ 26 volts,
at a 40% duty cycle based on a ten minute cycle time.
It is capable of higher duty cycles at lower output currents and capable of up to 300 Amps at lower duty
cycles.
LIMITATIONS
The POWER MIG 255 MAY NOT operate
satisfactorily if powered with a portable or in-plant
generating system.
POWER MIG 255
OPERATION
B-4 B-4
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DESCRIPTION OF CONTROLS
Power ON/OFF Switch — Place the lever in the “ON”
position to energize the POWER MIG 255. When the
power is on, the red LED display lights illuminate.
Voltage Control — This is a continuous control that
gives full range adjustment of power source output voltage. It can be adjusted while welding over its 10 to 28
volt range.
Wire Speed Control — This controls the wire feed
speed from 50 to 700 inches per minute (1.2 to
17.8 m/min). The wire speed control can be preset on
the dial to the setting specified on the Procedure Decal
located inside the wire compartment door. Wire speed
is not affected when changes are made in the voltage
control.
WIRE DRIVE ROLL
The drive rolls installed with the POWER MIG each
have two grooves, both for 0.030-0.0035 in.
(0.8-0.9 mm) solid steel electrode. Drive roll size is indicated by the stencilling on the exposed side of the drive
roll. If feeding problems occur, then the drive roll may
be reversed or changed. See Procedure for
Changing Drive Roll in this section. This information
also appears on the Procedure Decal on the door
inside the wire compartment. An additional drive roll set
is provided for 0.045 in. (1.2 mm) solid steel electrode,
packaged standard with each machine.
WIRE SIZE CONVERSION PARTS
The POWER MIG 255 is rated to feed 0.025 through
0.045 in. (0.6 to 1.2 mm) solid or cored electrode sizes.
The drive roll kits and Magnum 250L gun and cable
parts are available to feed different sizes and types of
electrodes. See Accessories section.
FIGURE B.1 — OPERATOR CONTROLS
POWER
POWER MIG 255
WIRE SPEED
ON
OFF
VOLTS
LINCOLN
ELECTRIC
POWER MIG 255
OPERATION
B-5 B-5
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PROCEDURE FOR CHANGING
DRIVE AND IDLE ROLL SETS
1. Turn off the power source.
2. Release the pressure on the idle roll by swinging
the adjustable pressure arm down toward the
back of the machine. Lift the cast idle roll assembly and allow it to sit in an upright position.
3. Remove the outside wire guide retaining plate by
loosening the two large knurled screws.
4. Twist the drive roll retaining mechanism to the
unlocked position.
5. Wiggle both the metal idle and drive rolls off of
their plastic hubs.
6. Remove the inside wire guide plate.
7. Replace the drive and idle rolls and inside wire
guide with a set marked for the new wire size.
NOTE: Be sure that the gun liner and contact tip are
also sized to match the selected wire size.
8. Manually feed the wire from the wire reel, over the
drive roll groove and through the wire guide and
then into the brass bushing of the gun and cable
assembly.
9. Replace the outside wire guide retaining plate by
tightening the two large knurled screws.
Reposition the adjustable pressure arm to its original position to apply pressure. Adjust pressure as
necessary.
WIRE REEL LOADING READI-REELS, SPOOLS, OR COILS
To Mount a 30 lb (14 kg) Readi-Reel
Package (Using the Molded Plastic K363-P
Readi-Reel Adapter:)
1. Open the wire drive compartment door.
2. Depress the release bar on the retaining collar
and remove it from the spindle. See Figure B.2.
3. Place the optional adapter on the spindle.
4. Re-install the retaining collar. Make sure that the
release bar “pops up” and that the collar retainers
fully engage the retaining ring groove on the
spindle.
5. Rotate the spindle and adapter so the retaining
spring is at the 12 o'clock position.
6. Position the Readi-Reel so that it will rotate in a
direction when feeding so as to be de-reeled from
top of the coil.
7. Set one of the Readi-Reel inside cage wires on
the slot in the retaining spring tab.
FIGURE B.2 — READI-REEL INSTALLATION.
8. Lower the Readi-Reel to depress the retaining
spring and align the other inside cage wires with
the grooves in the molded adapter.
9. Slide cage all the way onto the adapter until the
retaining spring “pops up” fully.
Check to be sure the retaining spring has fully returned
to the locking position and has securely locked the
Readi-Reel cage in place. The retaining spring must
rest on the cage, not on the welding
electrode.
------------------------------------------------------------------------
10. To remove Readi-Reel from adapter, depress
retaining spring tab with thumb while pulling the
Readi-Reel cage from the molded adapter with
both hands. Do not remove adapter from spindle.
To Mount 10 to 44 lb (4.5-20 kg) Spools
(12 in./300 mm Diameter) or 14 lb
(6 kg) Innershield Coils:
(For 13-14 lb (6 kg) innershield coils, a K435 coil
adapter must be used).
1. Open the wire drive compartment door.
2. Depress the release bar on the retaining collar
and remove it from the spindle.
3. Place the spool on the spindle making certain the
spindle brake pin enters one of the holes in the
back side of the spool (Note: an arrow mark on the
spindle lines up with the brake holding pin to
assist in lining up a hole). Be certain the wire
comes off the reel in a direction that it can de-reel
from the top of the coil.
4. Re-install the retaining collar. Make sure that the
release bar “pops up” and that the collar retainers
fully engage the retaining ring groove on the
spindle.
2 IN. O.D.
SPINDLE
ADAPTER
RETAINING
SPRING
BRAKE
HOLDING
PIN
GROOVES
READI-REEL
INSIDE
CAGE
WIRES
RELEASE
BAR
RETAINING
COLLAR
CAUTION
POWER MIG 255
OPERATION
B-6 B-6
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TO START THE WELDER
Turn the Power Switch switch to ON. This lights the red
LED display lights. With the desired voltage and wire
speed selected, operate the gun trigger for welder output and to energize the wire feed motor.
FEEDING WIRE ELECTRODE
When triggering, the electrode and drive mechanism are electrically “hot” relative to work and
ground and remain “hot” several seconds after the
gun trigger is released.
------------------------------------------------------------------------
NOTE: Check that drive rolls, guide plates, and gun
parts are proper for the wire size and type being used.
Refer to Table C.1 in Accessories section.
1. Turn the Readi-Reel or spool until the free end of
the electrode is accessible.
2. While securely holding the electrode, cut off the
bent end and straighten the first six inches. (If the
electrode is not properly straightened, it may not
feed properly through the wire drive system.)
3. Release the pressure on the idle roll by swinging
the adjustable pressure arm down toward the
back of the machine. Lift the cast idle roll assembly and allow it to sit in an upright position. Leave
the outer wire guide plate installed. Manually feed
the wire through the incoming guide bushing and
through the guide plates (over the drive roll
groove). Push a sufficient wire length to assure
that the wire has fed into the gun and cable
assembly without restriction. Reposition the
adjustable pressure arm to its original position to
apply pressure to the wire.
4. Press gun trigger to feed the electrode wire
through the gun.
IDLE ROLL PRESSURE SETTING
The idle roll pressure adjustment knob is set at the factory at the #2 hash mark. This is an approximate setting. The optimum idle roll pressure varies with type of
wire, wire diameter, surface conditions, lubrication, and
hardness. As a general rule, hard wires may require
greater pressure, and soft, or aluminum wire, may
require less pressure than the factory setting. The optimum idle roll setting can be determined as follows:
1. Press end of gun against a solid object that is
electrically isolated from the welder output and
press the gun trigger for several seconds.
2. If the wire “birdnests”, jams, or breaks at the drive
roll, the idle roll pressure is too great. Back the
adjustment knob out 1/2 turn, run new wire
through gun, and repeat above steps.
3. If the only result was drive roll slippage, loosen the
adjustment knob on the conductor plate and pull
the gun cable forward about 6 in. (15 cm). There
should be a slight waviness in the exposed wire. If
there is not waviness, the pressure is too low.
Tighten the adjustment knob 1/4 turn, reinstall the
gun cable and repeat the above steps.
SETTING RUN-IN SPEED ON STANDARD POWER MIG FEEDER
FAST OR SLOW RUN-IN MODE SELECTION
(When Timer Option is not installed)
The POWER MIG 255 is factory set for fast run-in
mode where the wire feed will accelerate directly to the
preset wire feed speed when the gun trigger is closed.
Slow run-in mode may also be selected, where it will
initially feed wire at 50 IPM until output current is
sensed or for 1.0 second, whichever occurs first. It will
then accelerate to the preset wire feed speed.
NOTE: See operating instructions for Timer Option Kit
if it is installed, as it provides its own run-in operation.
INSTRUCTIONS TO ENTER SLOW RUN-IN
1. Turn power OFF on front panel of POWER MIG
255.
2. Turn the wire feed speed dial fully counterclockwise to minimum.
3. With the gun trigger closed, turn the power ON at
the front panel of the POWER MIG 255.
4. The display will read “SLO run”.
INSTRUCTIONS TO ENTER FAST RUN-IN
1. Turn power OFF on front panel of POWER MIG
255.
2. Turn the wire feed speed dial fully clockwise to
maximum.
3. With the gun trigger closed, turn the power ON at
the front panel of the POWER MIG 255.
4. The display will read “FAS run”.
WARNING
POWER MIG 255
OPERATION
B-7 B-7
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NOTE: Arc starting characteristics may be effected
when using the fast run-in mode since optimum starting processes are being overridden.
On the initial trigger closure at power up, no output
power or wire feed will be available until the trigger is
opened and reclosed, regardless of wire feed speed
dial setting.
It is not necessary to repeat either of the above procedures each time the unit is powered up. The unit will
remember the run-in mode from the previous power
down and return you to that same state upon your next
power up. Therefore, you need only perform one of the
above procedures when you want to change the run-in
mode.
MAKING A WELD
1. Check that the electrode polarity is correct for the
process being used, then turn the power switch
ON.
2. Set desired arc voltage and wire speed for the
particular electrode wire, material type and thickness, and gas (for GMAW) being used. Use the
Application Chart on the door inside the wire compartment as a quick reference for some common
welding procedures.
3. If T imer Kit is installed, select the desired mode as
described in Operating Instructions for Timer
Kit in the Accessories section. Refer to the
Accessories section for additional welding information pertaining to Spot mode.
4. Press the trigger to feed the wire electrode
through the gun and cable and then cut the electrode within approximately 3/8 in. (10 mm) of the
end of the contact tip [3/4 in. (20 mm)
Outershield®].
NOTE: If set for slow run-in when the trigger is pulled,
the wire feeder feeds wire at low speed regardless of
the set wire feed speed until the welding arc starts or 1
second has elapsed. This feature enhances starting
and makes it easier to set the stickout. The 1 second
limit permits high speed loading of the gun and cable.
To change run-in mode, see Setting Run-In Speed in
this section, if the Timer Kit is not installed, or Timer Kit
Operation section if installed.
5. If welding gas is to be used, turn on the gas supply and set the required flow rate (typically 25-35
CFH; 12-16 liters/min).
6. When using innershield electrode, the gas nozzle
may be removed from the insulation on the end of
the gun and replaced with the gasless nozzle.
This will give improved visibility and eliminate the
possibility of the gas nozzle overheating.
7. Connect work cable to metal to be welded. Work
clamp must make good electrical contact to the
work. The work must also be grounded as stated
in Arc Welding Safety Precautions.
When using an open arc process, it is necessary
to use correct eye, head, and body protection.
------------------------------------------------------------------------
8. Position electrode over joint. End of electrode
may be lightly touching the work.
9. Lower welding helmet, close gun trigger, and
begin welding. Hold the gun so the contact tip to
work distance is about 3/8 in. (10 mm) [3/4 in.
(20 mm) for Outershield].
10. To stop welding, release the gun trigger and then
pull gun away from the work after arc goes out.
11. When no more welding is to be done, close valve
on gas cylinder (if used), momentarily operate gun
trigger to release gas pressure, and turn off
POWER MIG 255.
AVOIDING WIRE FEEDING
PROBLEMS
Wire feeding problems can be avoided by observing
the following gun handling procedures:
1. Do not kink or pull cable around sharp corners.
2. Keep the gun cable as straight as possible when
welding or loading electrode through cable.
3. Do not allow dolly wheels or trucks to run over
cables.
4. Keep cable clean by following the maintenance
instructions.
WARNING
POWER MIG 255
OPERATION
B-8 B-8
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5. Use only clean, rust-free electrode. The Lincoln
electrodes have proper surface lubrication.
6. Replace contact tip when the arc starts to become
unstable or the contact tip end is fused or
deformed.
7. Keep wire reel spindle brake tension to minimum
required to prevent excess reel over-travel which
may cause wire “loop-offs” from coil.
8. Use proper drive rolls and wire drive idle roll pressure for wire size and type being used.
FAN CONTROL
The fan is designed to come on automatically when a
weld arc is established. The fan will stay on for a minimum of 6 minutes after the weld arc is terminated. The
fan will also stay on when the machine’s welding and
feeding are disabled during thermostatic over temperature protection. (See Welding Thermal Overload
Protection.)
INPUT LINE VOLTAGE
PROTECTION
High Line V oltage — If the line voltage exceeds 125%
of rated input voltage, the output will be reduced to the
lower level to protect voltage rating of the capacitor
bank.
Low Line Voltage — You may not be able to get maximum output from the machine if the line voltage is less
than rated input. The unit will continue to weld, but the
output may be less than what is set.
WIRE FEED OVERLOAD
PROTECTION
The POWER MIG has solid state overload protection
of the wire drive motor. If the motor becomes
overloaded, the protection circuitry turns off the wire
feed speed and gas solenoid. Check for proper size
tip, liner, and drive rolls, for any obstructions or bends
in the gun cable, and any other factors that would
impede the wire feeding. To resume welding, simply
pull the trigger. There is no circuit breaker to reset as
the protection is done with reliable solid state
electronics.
WELDING THERMAL
OVERLOAD PROTECTION
The POWER MIG 255 has built-in protective thermostats that respond to excessive temperature. They
open the wire feed and welder output circuits if the
machine exceeds the maximum safe operating temperature because of a frequent overload, or high ambient temperature plus overload. The thermostats automatically reset when the temperature reaches a safe
operating level and welding and feeding are allowed
again, when gun is retriggered.
OVERCURRENT PROTECTION
The machine will automatically reduce the output if the
load on the machine exceeds 300 to 320 amperes.
This protects the welding power SCR’s from excessive
short circuit currents and from exceeding their temperature rating before the thermostats can react.
Welding Procedure Information
Note: See inside cover of machine for additional, commonly used welding procedure information.
70
80
90
100 110 120
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POWER MIG 255
Section C-1 Section C-1
TABLE OF CONTENTS
- ACCESSORIES SECTION -
Accessories ............................................................................................................Section C
Drive Roll Kits ...............................................................................................................C-2
3/64 in. (1.2 mm) Aluminum Feeding Kit (K1703-1) .....................................................C-2
K363P Readi-Reel Adapter ..........................................................................................C-2
Dual Cylinder Mounting Kit (K1702-1)..........................................................................C-2
Alternative Magnum GMAW Gun and Cable Assemblies............................................C-2
Magnum Gun Connection Kit (Optional K466-6) .........................................................C-2
Timer Kit Installation (Optional K1701-1) .....................................................................C-2
Operating Instructions for Timer Kit.......................................................................C-3
Spool Gun Adapter Kit (K1700-1) (Included in the K1692-1).......................................C-4
Making a Weld with the Spool Gun, Spool Gun (K1692-1) Installed.....................C-4
POWER MIG 255
ACCESSORIES
C-2 C-2
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DRIVE ROLL KITS
Refer to Table C.1 for various drive roll kits that are
available for the POWER MIG. All items in Bold are
supplied standard with the POWER MIG.
TABLE C.1 — AVAILABLE DRIVE ROLL KITS.
3/64 in. (1.2 mm) ALUMINUM
FEEDING KIT (K1703-1)
This kit helps push feeding aluminum through standard
machine feeder and gun. It provides gun and wire drive
conversion parts to weld with 3/64 in.
(1.2 mm) aluminum wire. 5356 alloy aluminum wire is
recommended for best push feeding performance.
Kit includes drive rolls and wire guide plate for the wire
drive, liner and two contact tips for the gun, along with
installation instructions.
K363P READI-REEL ADAPTER
The K363P Readi-Reel adapter mounts to the
2 in. spindle. It is needed to mount the 22-30 lb ReadiReels.
DUAL CYLINDER
MOUNTING KIT (K1702-1)
Permits stable side-by-side mounting of two full size (9
in. dia. x 5 ft. high) gas cylinders with “no lift” loading.
Simple installation and easy instructions provided.
Includes upper and lower cylinder supports, wheel
axles and mounting hardware.
ALTERNATIVE MAGNUM GMAW
GUN AND CABLE ASSEMBLIES
The following Magnum 250Lgun and cable assemblies
are separately available for use with the POWER MIG
255. Each is rated 200 amps 60% duty cycle (or 250
amps 40% duty) and is equipped with the integrated
connector, twist-lock trigger connector, fixed nozzle
and insulator, and includes a liner, diffuser, and contact
tips for the wire sizes specified:
*Fixed Nozzle
MAGNUM GUN CONNECTION KIT
(Optional K466-6)
Using the optional K466-6 Magnum Connection Kit for
the POWER MIG permits use of standard Magnum
200, 300 or 400 gun and cable assemblies.
TIMER KIT INSTALLATION
(Optional K1701-1)
The timer kit adds selectable 4-step trigger interlock,
spot and Run-In functions and manual adjustment of
burnback time. Install as follows, or per the instructions
included with the kit:
Remove all input power to the POWER MIG 255
before proceeding.
------------------------------------------------------------------------
1. Verify that the following items have been included
in the kit:
a. Timer board with harness and panel
assembly.
b. Two screws.
2. Turn the power switch off and disconnect power
from the machine to prepare for kit installation.
Wire Size Drive Roll Kit
0
.023-0.030 in. (0.6-0.8 mm)
KP1696-030S
Solid
0.035 in. (0.9 mm) KP1696-035S
Steel
0.045 in. (1.2 mm) KP1696-045S
Cored
0.035 in. (0.9 mm) KP1697-035C
0.045 in. (1.2 mm) KP1697-045C
Aluminum
3/64 in. (1.2 mm) KP1695-3/64A
WARNING
English Wire Metric Wire
Length Part No. Size Size
10 ft (3.0 m) K533-1
*12 ft (3.6 m) K533-7 0.035 – 0.045 in. 0.9 – 1.2 mm
15 ft (4.5 m) K533-3
POWER MIG 255
ACCESSORIES
C-3 C-3
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3. Using a screwdriver, remove the two screws
securing the lower cover panel to the front of the
machine. Remove the lower cover panel.
4. Attach the rectangular 10-pin plug connector on
the timer kit wiring harness to the mating receptacle connector located directly behind the removed
cover panel. Be sure that the latch on the connector is aligned with the one on the board and insert
it until the latch engages.
5. Align the timer panel for installation and carefully
insert the printed circuit board and wiring harness
through the opening. Make sure the wiring harness is not pinched between panels or between
printed circuit board and front panel cover.
6. Secure the timer assembly with either the two
supplied screws or with the original screws. The
installation is now complete. Refer to the following
section for operating instructions.
OPERATING INSTRUCTIONS
FOR TIMER KIT
If the optional Timer Kit (K1701-1) is installed, select
the desired mode with the selector switch:
1. Normal Welding mode provides weld power only
while the trigger switch is depressed. This is the
same operation as when the Timer Kit is not
installed.
2. 4-Step Trigger interlock mode eliminates the
need to hold the gun trigger while welding. It operates in 4 steps:
a. Close trigger and establish welding arc.
b. Release trigger and continue welding.
c. Reclose trigger near end of weld.
d. Release trigger again to stop welding.
If the arc is broken while using this feature, the
machine will reset to the “trigger off” condition
automatically.
3. Spot Weld Mode is used for tack welding parts
into position or for spot plug welds to hold thin
sheet metal together prior to manual stitch or continuous welding. To use this feature, adjust the
On-Time (0-5 seconds) as appropriate to obtain
the desired results. Closing the trigger initiates a
single timed spot weld cycle. Plug welds are made
by using a punch to make a 3/16 in. (5 mm) diameter hole in the top sheet and arc welding through
the hole into the back sheet.
To make spot plug welds, punch 3/16 in. (5 mm)
holes in the top sheet. Set the Spot Time control
to approximately 1.2 seconds and set the procedure for the metal thickness to be welded. Install
spot weld nozzle (if available) on gun and press it
against the top sheet so the top and bottom
sheets are tight together. Close trigger and hold it
closed until the arc goes out. If a spot weld nozzle
is not used, smoother welds will result by moving
the welding wire in a small circle during the weld.
4. Burnback Time control provides manual adjustment of the burnback time (0-250 milliseconds) for
any selected welding mode. This control should
be set as low as possible without the wire “sticking” in the puddle after each weld. Too long of a
burnback time may form a “ball” on the end of the
wire, or may “flash back” to the gun tip.
5. Run-In Mode is used to adjust the starting wire
feed speed. Starting conditions for certain welding
applications can be improved with adjustment to
the Run-In speed. The control allows for initial
starting speeds from 50 to 150 IPM. After the arc
is started, the set point on the wire feed speed
control will dominate. Note that the Run-in is not
functional with the spool gun. Also note that if
Run-in is set fully counterclockwise to OFF, Runin speed will equal the preset WFS on the
machine.
POWER MIG 255
ACCESSORIES
C-4 C-4
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SPOOL GUN ADAPTER KIT
Remove all input power to the POWER MIG 255
before proceeding.
------------------------------------------------------------------------
The Spool Gun Adapter Kit provides direct connection
and use of the Spool Gun (with remote speed control)
with the POWER MIG 255 wire feed welder.
It also provides gun trigger switch transfer between the
machine’s use with its feeder gun or the spool gun for
same polarity welding with different wire and gas
processes.
The kit includes a spool gun adapter module assembly
with a single connecting plug, a rear gas inlet setting
with hose and mounting hardware with installation and
operation instructions.
*This kit can only be configured to run a Magnum® SG
Spool Gun OR a Prince® XL Spool Gun at a time; kit is
shipped configured for the Magnum® SG Spool Gun.
MAKING A WELD WITH THE SPOOL GUN,
SPOOL GUN INSTALLED
The POWER MIG control circuitry is designed to
sense either the spool gun (built in) wire feeder trigger
circuitry. After the spool gun adapter kit has been
installed, the spool gun can easily be plugged in and
will be ready to use.
Closing either gun trigger will cause the electrode of
both guns to be electrically “HOT”. Be sure unused gun
is positioned so electrode or tip will not contact metal
case or other metal common to work.
1.Pulling the trigger for the built-in feeder gun:
a. Disables spool gun operation.
b. Closing feeder gun trigger starts feeder gun
welding and makes both
electrodes electri-
cally “HOT”.
2. Pulling SPOOL GUN Trigger:
a. Disables built-in feeder gun operation.
b. Closing spool gun trigger starts spool gun
welding and makes both electrodes electrically “HOT”.
3. Operation with POWER MIG 255:
a. Turn the POWER MIG-255 input power
ON.
b. Adjust the voltage control to increase or
decrease your welding voltage.
c. Adjust the wire speed control on the spool
gun to increase or decrease the spool gun
wire feed speed.
4. The following procedure settings for Aluminum
4043 can be used as initial settings for making
test welds to determine final settings:
5. To return to normal POWER MIG 255 welding
release the spool gun trigger and reset feeder
gun voltage procedure setting if necessary.
6. Operation with Timer Option Kit (K1701-1)
installed in Power MIG 255:
All Timer Option Kit functions, except Run-in,
are functional with the spool gun. (See operating instructions for Timer Option Kit.
WARNING
CAUTION
Wire Dia. WFS Setting Arc Voltage
In. (mm) Spool Gun Setting
0.030 in. (0.8 mm) 270 15V
0.035 in. (0.9 mm) 250 16V
3/64 in. (1.2 mm) 240 20V
K2297-1
K2310-1*
Prince®XL Spool Gun with Adaptor Included
Power MIG 255 Spool Gun Adaptor Kit
(connects Magnum®SG Spool Gun OR
Prince®XL Spool Gun
K487-25
Magnum®SG Spool Gun (requires K23101 Adaptor Kit
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POWER MIG 255
Section D-1 Section D-1
TABLE OF CONTENTS
- MAINTENANCE SECTION -
Maintenance ...........................................................................................................Section D
Safety Precautions ........................................................................................................D-2
Routine and Periodic Maintenance ...............................................................................D-2
Drive Rolls and Guide Tubes.........................................................................................D-2
Cable Cleaning ..............................................................................................................D-2
Gun Tubes and Nozzles ................................................................................................D-2
Contact Tip and Gas Nozzle Installation.......................................................................D-4
Liner Removal and Replacement ..................................................................................D-4
Liner Removal, Installation, and Trimming Instructions for Magnum 250L ..................D-4
Gun Handle Disassembly ..............................................................................................D-5
Accessories and Expendable Replacement Parts for Magnum 250L Gun and Cable Assemblies
............D-6
POWER MIG 255
MAINTENANCE
D-2 D-2
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SAFETY PRECAUTIONS
• Have a qualified electrician do the maintenance
and troubleshooting work.
• Disconnect the input power off using the disconnect switch at the main input supply before
working inside machine.
• Unplug the power cable if it is connected to a
receptacle.
------------------------------------------------------------------------
Read the Safety Precautions in the front of this manual before working on this machine.
ROUTINE AND PERIODIC
MAINTENANCE
1. Disconnect input AC power supply lines to the
machine before performing periodic maintenance,
tightening, cleaning, or replacing parts.
Perform the following daily:
1. Check that no combustible materials are in the
welding or cutting area or around the machine.
2. Remove any debris, dust, dirt, or materials that
could block the air flow to the machine.
3. Inspect the electrode cables for any slits, punctures in the cable jacket, or any condition that
would affect the proper operation of the machine.
Perform Periodically:
Clean the inside of the machine with low pressure air
stream. Clean the following parts. Refer to Figure D.1.
Main transformer and output choke.
Power enhancement choke.
Wire drive assembly.
Capacitor bank.
SCR rectifier bridge and heat sink fins.
Fan motor assembly.
Control printed circuit board.
Snubber printed circuit board.
NOTE: The fan motor has sealed bearings which
require no maintenance.
WARNING
DRIVE ROLLS AND GUIDE TUBES
After every coil of wire, inspect the wire drive mechanism. Clean it as necessary by blowing with low pressure compressed air. Do not use solvents for cleaning
the idle roll because it may wash the lubricant out of
the bearing. All drive rolls are stamped with the wire
sizes they will feed. If a wire size other than that
stamped on the roll is used, the drive roll must be
changed.
CABLE CLEANING
Clean the cable liner after using approximately 300
pounds (136 kg) of electrode.
1. Remove the cable from the wire feeder and lay it
out straight on the floor.
2. Remove the contact tip from the gun.
3. With an air hose at the gas diffuser end, use low
pressure to gently blow out the cable liner.
Excessive pressure at the start may cause the dirt to
form a plug.
------------------------------------------------------------------------
4. Flex the cable over its entire length and again blow
out the cable.
5. Repeat this procedure until no more dirt comes
out.
GUN TUBES AND NOZZLES
1. Replace worn contact tips as required.
2. Remove spatter from the inside of the gas nozzle
and tip every 10 minutes of arc time or as required.
CAUTION
POWER MIG 255
MAINTENANCE
D-3 D-3
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FIGURE D.1 — COMPONENT LOCATIONS.
CONTROL PC
BOARD
POWER
ENHANCEMENT
CHOKE
OUTPUT
CHOKE
MAIN
TRANSFORMER
SCR
RECTIFIER
BRIDGE
CAPACITOR
BANK
SNUBBER
PC BOARD
WIRE DRIVE
ASSEMBLY
FAN
MOTOR
ASSEMBLY
POWER MIG 255
MAINTENANCE
D-4 D-4
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CONTACT TIP AND GAS
NOZZLE INSTALLATION
1. Choose the correct size contact tip for the electrode being used (wire size is stenciled on the side
of the contact tip) and screw it snugly into the gas
diffuser.
a. Be sure the nozzle insulator is fully screwed
onto the gun tube and does not block the gas
holes in the diffuser.
2. Slip or screw the appropriate gas nozzle onto the
nozzle insulator.
NOTE: Either a standard 0.50 in. (12.7 mm) or optional 0.62 in. (15.9 mm) I.D. slip-on gas nozzle may be
used and should be selected based on the welding
application.
3. Adjust the gas nozzle as appropriate for the
GMAW process to be used.
a. Typically, the contact tip end should be flush
to extended 0.12 in. (3.2 mm) for the shortcircuiting transfer process and recessed 0.12
in. (3.2 mm) for spray transfer.
LINER REMOVAL AND
REPLACEMENT
NOTE: When you change wire size, a replacement
gas diffuser is required. Use the table below to select
the proper diffuser so the liner is held securely in place.
LINER REMOVAL, INSTALLATION,
AND TRIMMING INSTRUCTIONS
FOR MAGNUM 250L
NOTE: The variation in cable lengths prevents the
interchangeability of liners between guns. Once a liner
has been cut for a particular gun, it should not be
installed in another gun unless it can meet the liner cut
off length requirement. Liners are shipped with the
jacket of the liner extended the proper amount.
1. Remove the gas nozzle and nozzle insulator. See
Figure D.2.
2. Locate the set screw in the gas diffuser which is
used to hold the old liner in place.
3. Loosen the set screw with a 5/64 in. (2.0 mm) Allen
wrench.
4. Remove the gas diffuser from the gun tube.
5. Lay the gun and cable out straight on a flat surface.
6. Loosen the set screw located in the brass cable
connector at the feeder end of the cable and pull
the liner out of the cable.
7. Insert a new untrimmed liner into the connector
end of the cable.
a. Check the liner bushing stencil to make sure
it is the appropriate one for the wire size being
used.
8. Fully seat the liner bushing into the connector.
Diameter of
Electrodes Used
0.025-0.030 in. Steel
(0.6-0.8 mm)
0.035-0.045 in. Steel
(0.9-1.2 mm)
3/64 in. Aluminum
(1.2 mm)
Replacement
Liner
Part Number
KP1934-2
KP1934-1
KP1955-1
Size Stenciled on
End of Liner
Bushing
0.030 in. (0.8 mm)
0.045 in. (1.2 mm)
3/64 in. (1.2 mm)
Fixed Nozzle Gas
Diffuser Part No.
(and Stencil)
KP2026-3
KP2026-3
KP2026-3
Adjustable Nozzle
Gas Diffuser Part
No. (and Stencil)
KP2026-2
KP2026-1B1
KP2026-1B1
POWER MIG 255
MAINTENANCE
D-5 D-5
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GUN HANDLE DISASSEMBLY
The internal parts of the gun handle may be inspected
or serviced if necessary.
The gun handle consists of two halves that are held
together with a collar on each end.
To open up the handle:
1. Turn the collars approximately 60 degrees counterclockwise (the same direction as removing a
right hand thread) until the collar reaches a stop.
2. Pull the collar off the gun handle.
NOTE: If the collars are difficult to turn, position the
gun handle against a corner, place a screwdriver
against the tab on the collar and give the screwdriver a
sharp blow to turn the collar past an internal locking rib.
See Figure D.3.
FIGURE D.3 — GUN HANDLE DISASSEMBLY.
9. Tighten the setscrew on the brass cable
connector.
NOTE: Do not install the gas diffuser onto the end of
the gun tube at this time.
10. Straighten the cable with the gas nozzle and nozzle insulator removed from the gun tube.
11.Trim the liner to the length shown in Figure D.2.
FIGURE D.2 — LINER MAINTENANCE.
12. Remove any burrs from the end of the liner.
13. Screw the gas diffuser onto the end of the gun tube
and tighten.
NOTE: Be sure the gas diffuser is correct for the liner
being used. (See table and diffuser stencil.)
14. Slightly tighten the set screw in the side of the gas
diffuser against the cable liner using 5/64 in.
(2.0 mm) Allen wrench.
This screw should only be gently tightened. Over tightening will split or collapse the liner and cause poor wire
feeding.
------------------------------------------------------------------------
BRASS CABLE
CONNECTOR
SET
SCREW
GAS DIFFUSER
NOZZLE INSULATOR
GAS NOZZLE
1-1/4" (1.25)
(31.8MM)
LINER TRIM
LENGTH
CAUTION
POWER MIG 255
MAINTENANCE
D-6 D-6
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ACCESSORIES AND EXPENDABLE REPLACEMENT PARTS FOR
MAGNUM 250L GUN AND CABLE ASSEMBLIES
*Included with Power MIG 255.
**Requires S19418-1 Gas Diffuser Assembly.
METRIC SIZE
0.6 - 0.8 mm
0.9 - 1.2 mm
1.2 mm (Alum. Wire)
0.6 mm
0.8 mm
0.9 mm
1.2 mm
0.9 mm
1.2 mm
0.6 mm
0.8 mm
0.9 mm
1.2 mm
1.2 mm (Alum. Wire)
9.5 mm
12.1 mm
15.9 mm
9.5 mm
15.9 mm
15.9 mm
0.6-1.2 mm
12.7 mm
15.9 mm
0.6-0.8 mm
0.9-1.2 mm
ENGLISH SIZE
0.025-0.030 in.
0.035-0.045 in.
3/64 in. (Alum. Wire)
0.025 in.
0.030 in.
0.035 in.
0.045 in.
0.035 in.
0.045 in.
0.025 in.
0.030 in.
0.035 in.
0.045 in.
3/64 in. (Alum. wire)
3/8 in.
1/2 in.
5/8 in.
3/8 in.
5/8 in.
5/8 in.
0.025-0.045 in.
1/2 in.
5/8 in.
0.25-0.030 in.
0.35-0.045 in.
PART NO.
KP1934-2
KP1934-1
KP1955-1
KP2020-6B1
KP2020-7B1
KP2020-1B1*
KP2020-2B1*
KP2021-1B1
KP2021-2B1
KP2021-5B1
KP2021-6B1
KP2022-1B1
KP2022-2B1
KP2010-5B1
KP1931-1
KP1931-2*
KP1931-3
KP1930-1
KP1930-2
KP1930-3
KP2026-3*
KP1935-2
KP1935-1
KP2025-1
KP2026-2
KP2026-1
KP1947-1**
KP2015-1*
KP2041-1
DESCRIPTION
Cable Liner
For 15 ft (4.5 m) or Shorter Cable
Contact Tips
Standard Duty
Heavy Duty
Tapered
Tab (For Aluminum)
Gas Nozzles
Fixed
(Flush)
(Recessed)
(Requires: Gas Diffuser Assembly)
Adjustable Slip-On
(Requires: Nozzle Insulator Assembly)
(Requires: Gas Diffuser Assembly)
Gasless Nozzle
(for Innershield®)
Gun Tube Assembly
Standard (60 Degrees)
45 Degrees
TABLE D.2
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