RETURN TO MAIN INDEX
IM520-B
SQUARE WAVE TIG 255 January, 1997
For use with machines having Code Number 10022 thru 10024 & 10451 thru 10453.
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.
OPERATOR’S MANUAL
World's Leader in Welding and Cutting Products Premier Manufacturer of Industrial Motors
Sales and Service through Subsidiaries and Distributors Worldwide
22801 St. Clair Ave. Cleveland, Ohio 44117-1199 U.S.A. Tel. (216) 481-8100
SAFETY
WARNING
CALIFORNIA PROPOSITION 65 WARNINGS
The engine exhaust from this product contains
Diesel engine exhaust and some of its constituents
chemicals known to the State of California to cause
are known to the State of California to cause
cancer, birth defects, or other reproductive harm.
cancer, birth defects, and other reproductive harm.
The Above For Gasoline Engines
The Above For Diesel Engines
ARC WELDING CAN BE HAZARDOUS. PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH.
KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.
Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you
purchase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1� from the American Welding Society, P.O. Box
351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety� booklet E205 is available
from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.
BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE
PERFORMED ONLY BY QUALIFIED INDIVIDUALS.
FOR ENGINE 1.h. To avoid scalding, do not remove the
radiator pressure cap when the engine is
powered equipment. hot.
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.
ELECTRIC AND
MAGNETIC FIELDS
____________________________________________________
may be dangerous
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 2.a. Electric current flowing through any conductor causes
refueling to prevent spilled fuel from localized Electric and Magnetic Fields (EMF). Welding
vaporizing on contact with hot engine parts current creates EMF fields around welding cables and
and igniting. Do not spill fuel when filling welding machines
tank. If fuel is spilled, wipe it up and do not
start engine until fumes have been 2.b. EMF fields may interfere with some pacemakers, and
eliminated.
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:
____________________________________________________
1.d. Keep all equipment safety guards, covers and devices in
2.d.1. Route the electrode and work cables together - Secure
position and in good repair.Keep hands, hair, clothing and
them with tape when possible.
tools away from V-belts, gears, fans and all other moving
parts when starting, operating or repairing equipment.
2.d.2. Never coil the electrode lead around your body.
____________________________________________________
2.d.3. Do not place your body between the electrode and
1.e. In some cases it may be necessary to remove safety
work cables. If the electrode cable is on your right
guards to perform required maintenance. Remove
side, the work cable should also be on your right side.
guards only when necessary and replace them when the
maintenance requiring their removal is complete.
2.d.4. Connect the work cable to the workpiece as close as
Always use the greatest care when working near moving
possible to the area being welded.
parts.
___________________________________________________
1.f. Do not put your hands near the engine fan. Do not attempt 2.d.5. Do not work next to welding power source.
to override the governor or idler by pushing on the throttle
control rods while the engine is running.
Mar �95
�2�
SAFETY
ARC RAYS can burn.
ELECTRIC SHOCK can
4.a. Use a shield with the proper filter and cover
kill. plates to protect your eyes from sparks and
3.a. The electrode and work (or ground) circuits
the rays of the arc when welding or observing
are electrically “hot� when the welder is on. open arc welding. Headshield and filter lens
Do not touch these “hot� parts with your bare should conform to ANSI Z87. I standards.
skin or wet clothing. Wear dry, hole-free
gloves to insulate hands. 4.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
3.b. Insulate yourself from work and ground using dry insulation. the arc rays.
Make certain the insulation is large enough to cover your full
area of physical contact with work and ground. 4.c. Protect other nearby personnel with suitable, non-flammable
screening and/or warn them not to watch the arc nor expose
In addition to the normal safety precautions, if welding themselves to the arc rays or to hot spatter or metal.
must be performed under electrically hazardous
conditions (in damp locations or while wearing wet
FUMES AND GASES
clothing; on metal structures such as floors, gratings or
scaffolds; when in cramped positions such as sitting,
can be dangerous.
kneeling or lying, if there is a high risk of unavoidable or
accidental contact with the workpiece or ground) use 5.a. Welding may produce fumes and gases
the following equipment: hazardous to health. Avoid breathing these
� Semiautomatic DC Constant Voltage (Wire) Welder. fumes and gases.When welding, keep
� DC Manual (Stick) Welder. your head out of the fume. Use enough
� AC Welder with Reduced Voltage Control. ventilation and/or exhaust at the arc to keep
fumes and gases away from the breathing zone. When
3.c. In semiautomatic or automatic wire welding, the electrode, welding with electrodes which require special
electrode reel, welding head, nozzle or semiautomatic ventilation such as stainless or hard facing (see
welding gun are also electrically “hot�. instructions on container or MSDS) or on lead or
cadmium plated steel and other metals or coatings
3.d. Always be sure the work cable makes a good electrical which produce highly toxic fumes, keep exposure as
connection with the metal being welded. The connection low as possible and below Threshold Limit Values (TLV)
should be as close as possible to the area being welded. using local exhaust or mechanical ventilation. In
confined spaces or in some circumstances, outdoors, a
3.e. Ground the work or metal to be welded to a good electrical respirator may be required. Additional precautions are
(earth) ground. also required when welding on galvanized steel.
5.b. Do not weld in locations near chlorinated hydrocarbon vapors
3.f. Maintain the electrode holder, work clamp, welding cable and
coming from degreasing, cleaning or spraying operations.
welding machine in good, safe operating condition. Replace
The heat and rays of the arc can react with solvent vapors to
damaged insulation.
form phosgene, a highly toxic gas, and other irritating
products.
3.g. Never dip the electrode in water for cooling.
5.c. Shielding gases used for arc welding can displace air and
3.h. Never simultaneously touch electrically “hot� parts of
cause injury or death. Always use enough ventilation,
electrode holders connected to two welders because voltage
especially in confined areas, to insure breathing air is safe.
between the two can be the total of the open circuit voltage
of both welders.
5.d. Read and understand the manufacturer’s instructions for this
equipment and the consumables to be used, including the
3.i. When working above floor level, use a safety belt to protect
material safety data sheet (MSDS) and follow your
yourself from a fall should you get a shock.
employer’s safety practices. MSDS forms are available from
your welding distributor or from the manufacturer.
3.j. Also see Items 6.c. and 8.
5.e. Also see item 1.b.
Mar �95
�3�
SAFETY
WELDING SPARKS can CYLINDER may explode
cause fire or explosion. if damaged.
6.a. Remove fire hazards from the welding area.
7.a. Use only compressed gas cylinders
If this is not possible, cover them to prevent
containing the correct shielding gas for the
the welding sparks from starting a fire.
process used and properly operating
Remember that welding sparks and hot
regulators designed for the gas and
materials from welding can easily go through small cracks
pressure used. All hoses, fittings, etc. should be suitable for
and openings to adjacent areas. Avoid welding near
the application and maintained in good condition.
hydraulic lines. Have a fire extinguisher readily available.
7.b. Always keep cylinders in an upright position securely
6.b. Where compressed gases are to be used at the job site,
chained to an undercarriage or fixed support.
special precautions should be used to prevent hazardous
situations. Refer to “Safety in Welding and Cutting� (ANSI
7.c. Cylinders should be located:
Standard Z49.1) and the operating information for the
� Away from areas where they may be struck or subjected to
equipment being used.
physical damage.
6.c. When not welding, make certain no part of the electrode
� A safe distance from arc welding or cutting operations and
circuit is touching the work or ground. Accidental contact
any other source of heat, sparks, or flame.
can cause overheating and create a fire hazard.
7.d. Never allow the electrode, electrode holder or any other
6.d. Do not heat, cut or weld tanks, drums or containers until the
electrically “hot� parts to touch a cylinder.
proper steps have been taken to insure that such procedures
will not cause flammable or toxic vapors from substances
7.e. Keep your head and face away from the cylinder valve outlet
inside. They can cause an explosion even though they have
when opening the cylinder valve.
been “cleaned�. For information, purchase “Recommended
Safe Practices for the Preparation for Welding and Cutting of
7.f. Valve protection caps should always be in place and hand
Containers and Piping That Have Held Hazardous
tight except when the cylinder is in use or connected for
Substances�, AWS F4.1 from the American Welding Society
use.
(see address above).
7.g. Read and follow the instructions on compressed gas
6.e. Vent hollow castings or containers before heating, cutting or
cylinders, associated equipment, and CGA publication P-l,
welding. They may explode.
“Precautions for Safe Handling of Compressed Gases in
Cylinders,� available from the Compressed Gas Association
6.f. Sparks and spatter are thrown from the welding arc. Wear oil
1235 Jefferson Davis Highway, Arlington, VA 22202.
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.
FOR ELECTRICALLY
Always wear safety glasses with side shields when in a
powered equipment.
welding area.
6.g. Connect the work cable to the work as close to the welding
8.a. Turn off input power using the disconnect
area as practical. Work cables connected to the building
switch at the fuse box before working on
framework or other locations away from the welding area
the equipment.
increase the possibility of the welding current passing
through lifting chains, crane cables or other alternate
8.b. Install equipment in accordance with the U.S. National
circuits. This can create fire hazards or overheat lifting
Electrical Code, all local codes and the manufacturer’s
chains or cables until they fail.
recommendations.
6.h. Also see item 1.c.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
Mar �95
�4�
SAFETY
zones où l’on pique le laitier.
PRÉCAUTIONS DE SÛRETÉ
6. Eloigner les matériaux inflammables ou les recouvrir afin de
Pour votre propre protection lire et observer toutes les instructions
prévenir tout risque d’incendie dû aux étincelles.
et les précautions de sûreté specifiques qui parraissent dans ce
manuel aussi bien que les précautions de sûreté générales
7. Quand on ne soude pas, poser la pince à une endroit isolé de
suivantes:
la masse. Un court-circuit accidental peut provoquer un
échauffement et un risque d’incendie.
Sûreté Pour Soudage A L’Arc
1. Protegez-vous contre la secousse électrique:
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
a. Les circuits à l’électrode et à la piéce sont sous tension
la masse sur la charpente de la construction ou d’autres
quand la machine à souder est en marche. Eviter toujours
endroits éloignés de la zone de travail, on augmente le risque
tout contact entre les parties sous tension et la peau nue
de voir passer le courant de soudage par les chaines de
ou les vétements mouillés. Porter des gants secs et sans
levage, câbles de grue, ou autres circuits. Cela peut
trous pour isoler les mains.
provoquer des risques d’incendie ou d’echauffement des
b. Faire trés attention de bien s’isoler de la masse quand on
chaines et des câbles jusqu’� ce qu’ils se rompent.
soude dans des endroits humides, ou sur un plancher
metallique ou des grilles metalliques, principalement dans
9. Assurer une ventilation suffisante dans la zone de soudage.
les positions assis ou couché pour lesquelles une grande
Ceci est particuliérement important pour le soudage de tôles
partie du corps peut être en contact avec la masse.
galvanisées plombées, ou cadmiées ou tout autre métal qui
c. Maintenir le porte-électrode, la pince de masse, le câble
produit des fumeés toxiques.
de soudage et la machine à souder en bon et sûr état
defonctionnement.
10. Ne pas souder en présence de vapeurs de chlore provenant
d.Ne jamais plonger le porte-électrode dans l’eau pour le
d’opérations de dégraissage, nettoyage ou pistolage. La
refroidir.
chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs
e. Ne jamais toucher simultanément les parties sous tension
du solvant pour produire du phosgéne (gas fortement toxique)
des porte-électrodes connectés à deux machines à souder
ou autres produits irritants.
parce que la tension entre les deux pinces peut être le
total de la tension à vide des deux machines.
11. Pour obtenir de plus amples renseignements sur la sûreté,
f. Si on utilise la machine à souder comme une source de
voir le code “Code for safety in welding and cutting� CSA
courant pour soudage semi-automatique, ces precautions
Standard W 117.2-1974.
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
PRÉCAUTIONS DE SÛRETÉ POUR
enrouler le câble-électrode autour de n’importe quelle partie
LES MACHINES À SOUDER À
du corps.
TRANSFORMATEUR ET À
3. Un coup d’arc peut être plus sévère qu’un coup de soliel,
REDRESSEUR
donc:
a. Utiliser un bon masque avec un verre filtrant approprié
ainsi qu’un verre blanc afin de se protéger les yeux du 1. Relier à la terre le chassis du poste conformement au code de
rayonnement de l’arc et des projections quand on soude l’électricité et aux recommendations du fabricant. Le dispositif
ou quand on regarde l’arc. de montage ou la piece à souder doit être branché à une
b. Porter des vêtements convenables afin de protéger la bonne mise à la terre.
peau de soudeur et des aides contre le rayonnement de
l‘arc. 2. Autant que possible, I’installation et l’entretien du poste seront
c. Protéger l’autre personnel travaillant à proximité au effectués par un électricien qualifié.
soudage à l’aide d’écrans appropriés et non-inflammables.
3. Avant de faires des travaux à l’interieur de poste, la
4. Des gouttes de laitier en fusion sont émises de l’arc de debrancher à l’interrupteur à la boite de fusibles.
soudage. Se protéger avec des vêtements de protection libres
de l’huile, tels que les gants en cuir, chemise épaisse, 4. Garder tous les couvercles et dispositifs de sûreté à leur
pantalons sans revers, et chaussures montantes. place.
5. Toujours porter des lunettes de sécurité dans la zone de
soudage. Utiliser des lunettes avec écrans lateraux dans les
Mar. �93
�5�
for selecting a QUALITY product by Lincoln Electric. We want you
Thank You to take pride in operating this Lincoln Electric Company product
•â?¢â?? as much pride as we have in bringing this product to you!
Please Examine Carton and Equipment For Damage Immediately
When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims
for material damaged in shipment must be made by the purchaser against the transportation company at the
time the shipment is received.
Please record your equipment identification information below for future reference. This information can be
found on your machine nameplate.
Model Name & Number _____________________________________
Code & Serial Number _____________________________________
Date of Purchase _____________________________________
Whenever you request replacement parts for or information on this equipment always supply the information
you have recorded above.
Read this Operators Manual completely before attempting to use this equipment. Save this manual and keep it
handy for quick reference. Pay particular attention to the safety instructions we have provided for your protection.
The level of seriousness to be applied to each is explained below:
WARNING
This statement appears where the information must be followed exactly to avoid serious personal injury or
loss of life.
CAUTION
This statement appears where the information must be followed to avoid minor personal injury or damage to
this equipment.
�6�
TABLE OF CONTENTS
Page
Safety .....................................................................................................................2-6
Installation................................................................................................................8-12
Technical Specifications ............................................................................................8
Input and Output Specifications
Cable and Fuse Sizes
Physical Dimensions
Location .....................................................................................................................9
Machine Grounding....................................................................................................9
Input Connections ....................................................................................................10
Output Connections .................................................................................................11
Operation................................................................................................................13-23
Safety Instructions ...................................................................................................13
Graphic Symbols ................................................................................................14-15
General Description .................................................................................................16
Design Features and Advantages............................................................................16
Welding Capability ...................................................................................................17
Limitations................................................................................................................17
Controls and Settings...............................................................................................18
Hand and Foot Amptrol Operation ...........................................................................20
Welding Operation ..............................................................................................20-23
Tig Welding Guidelines .......................................................................................20
Tig Welding Sequence of Operation (2 Step Mode) ...........................................21
Tig Welding Sequence of Operation (4 Step Mode) ...........................................22
Advanced Tig Welding Features.........................................................................22
Stick Welding ......................................................................................................23
Auxillary Power ........................................................................................................23
Overload Protection .................................................................................................23
Accessories.................................................................................................................24
Maintenance ...........................................................................................................25-26
Safety Precautions...................................................................................................25
Routine and Periodic Maintenance ..........................................................................25
General Assembly Exploded View...........................................................................26
Troubleshooting ....................................................................................................27-34
How To Use Troubleshooting Guide........................................................................27
Troubleshooting Guide .......................................................................................28-34
Wiring Diagrams ....................................................................................................35-36
Parts Manual .................................................................................................APPENDIX
�7�
INSTALLATION
TECHNICAL SPECIFICATIONS - SQUARE WAVE TIG 255
INPUT - SINGLE PHASE ONLY
Code
Standard Input Current at
Number
Voltage Rated Output (1)
10022
208/230/460/1/60 81/74/37
10023
230/460/575/1/60 74/37/30
10024
200/240/400/1/50/60 85/77/44
10452
220/380/440/1/50/60 77/45/39
10453
380/415/500/1/50/60 45/41/33
10451
220/380/415/1/50/60 77/45/41
RATED OUTPUT
Volts at Rated Amperes
Duty Cycle Amps
30
40% Duty Cycle 255
NEMA Class II (40)
28
60% Duty Cycle 200
26
100% Duty Cycle 150
OUTPUT
Auxiliary Power
Welding Current Range Constant Open
(Continuous) Circuit Voltage 115 Volts AC, 10 Amps
5-315 Amps Stick OCV: 76 220Volts AC, 2 Amps
(50/60 Hz. machines only)
AC and DC TIG OCV: 53
RECOMMENDED INPUT WIRE AND FUSE SIZES
For all Stick, DC TIG, and Balanced AC TIG For Unbalanced AC TIG Welding Above 180
Welding at 255A/30V/40% Duty Cycle Amps, 255A/16V/40% Duty Cycle, Auto
Based on the 1993 US. National Balance Based on the 1993 U.S. National
Electrical Code Electrical Code
Type 75°C
Type 75°C
Fuse Input Type 75°C Copper Ground
Copper Ground Type 75°C
(Super Lag) Ampere Copper Wire in Wire in Conduit
Input Wire in Conduit Copper Wire in
or Breaker Rating on Conduit AWG Input AWG (IEC)
Voltage / AWG (IEC) Conduit AWG
Size Nameplate (IEC) Sizes Amperes Sizes
Frequency Sizes (IEC) Sizes
6 (16mm2) 6 (16mm2)
6 (16mm2) 4 (25mm2)
125 81 102
208/60
6 (16mm2) 6 (16mm2)
8 (10mm2) 4 (25mm2)
100 74 92
230/60
10 (6mm2) 10 (6mm2)
10 (6mm2) 8 (10mm2)
50 37 46
460/60
10 (6mm2) 10 (6mm2)
10 (6mm2) 10 (6mm2)
50 30 37
575/60
6 (16mm2) 6 (16mm2)
6 (16mm2) 4 (25mm2)
125 85 105
200/50/60
6 (16mm2) 8 (10mm2)
8 (10mm2) 4 (25mm2)
100 77 96
220/50/60
8 (10mm2) 8 (10mm2)
8 (10mm2) 8 (10mm2)
70 46 55
380/50/60
10 (6mm2) 10 (6mm2)
10 (6mm2) 8 (10mm2)
60 43 53
400/50/60
10 (6mm2) 10 (6mm2)
10 (6mm2) 8 (10mm2)
60 41 51
415/50/60
10 (6mm2) 10 (6mm2)
10 (6mm2) 8 (10mm2)
60 39 48
440/50/60
10 (6mm2) 10 (6mm2)
10 (6mm2) 10 (6mm2)
50 34 42
500/50/60
PHYSICAL DIMENSIONS
Height Width Depth Weight
30.5 in. 19.0 in. 30.0 in.
(Lift bail, add 3.5 in) 300 lbs
(137 kg)
775 mm 485 mm 760 mm
(Lift bail, add 90 mm)
(1) Unbalanced TIG welding above 180 amps will draw higher input currents; see Supply Connections section.
�8�
INSTALLATION
Read entire installation section before starting MACHINE GROUNDING AND HIGH
installation.
FREQUENCY INTERFERENCE
PROTECTION
Safety Precautions
The frame of the welder must be grounded. A ground
terminal marked with the symbol is located at
WARNING the bottom of the input box for this purpose. See your
local and national electrical codes for proper
ELECTRIC SHOCK can kill. grounding methods.
� Only qualified personnel should
perform this installation.
The spark gap oscillator in the high frequency
� Turn the input power OFF at the
generator, being similar to a radio transmitter, can be
disconnect switch or fuse box
blamed for many radio, TV and electronic equipment
before working on this
equipment. interference problems. These problems may be the
result of radiated interference. Proper grounding
� Do not touch electrically hot
parts.
methods can reduce or eliminate radiated
� Always connect the Square Wave interference.
TIG 255 grounding terminal
(located on the bottom of the
Radiated interference can develop in the following
input connection box) to a good
four ways:
electrical earth ground.
1. Direct interference radiated from the welder.
2. Direct interference radiated from the welding leads.
SELECT SUITABLE LOCATION 3. Direct interference radiated from feedback into the
power lines.
Place the welder where clean cooling air can freely
circulate in through the rear louvers and out through 4. Interference from re-radiation of “pickup� by
the side louvers. Dirt, dust or any foreign material that ungrounded metallic objects.
can be drawn into the welder should be kept at a
minimum. Failure to observe these precautions can Keeping these contributing factors in mind, installing
result in excessive operating temperatures and
equipment per the following instructions should
nuisance shut-downs.
minimize problems.
1. Keep the welder power supply lines as short as
STACKING
possible and completely enclose them in rigid
metallic conduit or equivalent shielding for a
Square Wave TIG 255’s cannot be stacked.
minimum distance of 50 feet (15.2m). There
should be good electrical contact between this
TILTING conduit and the welder. Both ends of the conduit
should be connected to a driven ground and the
Each machine must be placed on a secure, level entire length should be continuous.
surface, either directly or on a recommended
undercarriage. The machine may topple over if this
2. Keep the work and electrode leads as short as
procedure is not followed.
possible and as close together as possible.
Lengths should not exceed 25 ft (7.6m). Tape the
leads together when practical.
ENVIRONMENTAL PROTECTION
3. Be sure the torch and work cable rubber coverings
Square Wave TIG 255 power sources carry an IP21
are free of cuts and cracks that allow high
protection rating. They are rated for use in rain-
frequency leakage. Cables with high natural
sheltered environments.
rubber content, such as Lincoln Stable-Arc® better
resist high frequency leakage than neoprene and
other synthetic rubber insulated cables.
�9�
INSTALLATION
See Figure 1 for the location of the rating plate, the
4. Keep the torch in good repair and all connections
entry hole, and the reconnect panel.
tight to reduce high frequency leakage.
FIGURE 1 - REAR PANEL
5. The work terminal must be connected to a ground
within ten feet of the welder, using one of the
following methods:
a) A metal underground water pipe in direct
contact with the earth for ten feet or more.
1
2
b) A 3/4� (19mm) galvanized pipe or a 5/8�
(16mm) solid galvanized iron, steel or copper
rod driven at least eight feet into the ground.
The ground should be securely made and the
grounding cable should be as short as possible
using cable of the same size as the work cable, or
larger. Grounding to the building frame electrical
conduit or a long pipe system can result in re-
radiation, effectively making these members
radiating antennas.
3 4
6. Keep all access panels and covers securely in
place.
7. All electrical conductors within 50 ft (15.2m) of the
welder should be enclosed in grounded rigid
metallic conduit or equivalent shielding. Flexible
metallic conduit is generally not suitable.
1. RATING PLATE 3. 220V RECEPTACLE & BREAKER
2. INPUT ENTRY & (50/60 HZ MACHINE ONLY)
8. When the welder is enclosed in a metal building, RECONNECT PANEL 4. 115V RECEPTACLE & BREAKER
several good earth driven electrical grounds (as in
5 (b) above) around the periphery of the building
are recommended.
Have a qualified electrician connect the input leads to
Failure to observe these recommended installation
L1 and L2 of the input panel in accordance with all
procedures can cause radio or TV interference
local codes and national electrical codes, and the
problems and result in unsatisfactory welding
connection diagram located on the inside of the cover.
performance resulting from lost high frequency
Use a single phase line or one phase of a two or three
power.
phase line.
On multiple input voltage welders, be sure the
INPUT CONNECTIONS
reconnect panel is connected per the following
instructions for the voltage being supplied to the
Be sure the voltage, phase, and frequency of the input
welder.
power is as specified on the rating plate, located on
the rear of the machine.
CAUTION
Welder supply line entry provision is in the case rear
Failure to follow these instructions can cause
panel with a removable cover over the input
immediate failure of components within the welder.
connection panel area. Entry is through a 1.7 in
___________________________________________
(43mm) diameter hole in the case back. European
machines have a plastic bushing good for 3 - 10mm2
conductors. For larger input conductors a customer
supplied plastic bushing should be used if required by
local or national code specifications.
� 10 �
INSTALLATION
Welders are shipped connected for the highest input FIGURE 2 - FRONT PANEL
voltage as listed on the rating Plate. To change this
connection for a different input voltage, reconnect the
power strap (P) to the terminal corresponding to the
input voltage used. Designations on reconnect panel,
LOW, MID and HIGH correspond to the nameplate
input voltages of a triple voltage welder. Dual voltage 1 4
2 3
welders use only LOW and HIGH. Single voltage
welders use only HIGH. L9119-1
DC
I
EXAMPLE: On a 208/230/460 volt welder, LOW is POWER
AC DO NOT SWITCH
WHILE WELDING
208V, MID is 230V, and HIGH is 460V.
O
DC WARNING
Fuse the input circuit with the recommended super lag
L9119-2
GAS ELECTRODE
WORK
WATER REMOTE
OUT
IN IN
OUT
fuses or delay type1 circuit breakers. Choose an input
and grounding wire size according to local or national
codes, refer to Specification page at the beginning of
this chapter. Using fuses or circuit breakers
smaller than recommended may result in “nuisance�
shut-offs from welder inrush currents even if not
welding at high currents.
7
8
6
5
Unbalanced AC TIG welding draws higher input
1. CONTROL AND DISPLAY AREA 5. OPTIONAL WATER SOLENOID
currents than those for stick, DC TIG, or Balanced AC
2. POWER SWITCH 6. GAS SOLENOID
TIG welding. The welder is designed for these higher 3. THERMOSTATIC 7. WORK (LEFT) AND
input currents. However, where unbalanced AC TIG PROTECTION LIGHT ELECTRODE STUDS
4. POLARITY SWITCH 8. REMOTE RECEPTACLE
welding above 180 amps is planned, the higher input
currents require larger input wire sizes and fuses.
Refer to Specification page at the beginning of this TIG TORCH CONNECTION
chapter.
TIG welding torches come with 12.5 ft (3.8m) and 25 ft
(7.6m) cables. Use the shorter length whenever
The Square Wave TIG 255 should be permanently possible to minimize possible radio interference
wired into the power system. No plugs or connectors problems. With power source off, connect the torch
are necessary. cable to the “Electrode� stud on the welder. Connect
a separate work cable to the “Work� stud of the
welder. See Table 1 for recommended work cable
sizes. Both work and electrode cables should be
OUTPUT CONNECTIONS routed through the cable strain relief holes provided in
the base directly below the welding output terminals.
WARNING
To avoid receiving a high frequency shock, keep the
TABLE 1
TIG torch and cables in good condition.
Cable Sizes for Combined Lengths of Copper
___________________________________________
Electrode and Work Cable
See Figure 2 for the location of the work and Lengths up to
Machine Size 100 ft 100 to 200 ft 200 to 250 ft
electrode terminals, the gas and optional water
255 Amp
solenoids, and the Remote Receptacle. #2 (35mm2) #1 (45mm2) 1/0 (55mm2)
40% Duty Cycle
TIG torches include the necessary gas and, when
designed for water cooling, water hoses. Connect the
1 Also called “inverse time� or “thermal/magnetic�
fittings on these hoses to the welder fittings. Any torch
circuit breakers; circuit breakers which have a delay
conforming to Compressed Gas Association (CGA)
in tripping action that decreases as the magnitude
of the current increases.
standards can be connected.
� 11 �
INSTALLATION
The welder fittings have the following threads: Gas
Inlet and Outlet: 5/8�-18 right-hand female; Water inlet
and Outlet: 5/8�-18 left-hand female. The cylinder of
inert shielding gas must be equipped with a pressure
regulator and flow meter. Install a hose between the
flow meter and gas inlet on the welder.
WARNING
Observe the safety precautions necessary for
handling and using compressed gas containers.
Contact your supplier for specific information.
___________________________________________
DO NOT operate a water-cooled torch unless water is
flowing. Water doesn’t flow until solenoid is actuated.
If using a water-cooled torch with a Magnum water
cooler, connect the cooler water outlet to the ‘Water
Valve In� fitting. Connect the TIG torch inlet to the
“Water Valve Out� fitting.
If using a water-cooled torch with a free-running water
supply, install a water line between the welder “Water
Inlet� and the supply. Include a strainer in the water
supply line to prevent dirt particles from obstructing
water flow in the valve and cooling chamber of the
TIG torch. Failure to do so could result in water valve
malfunction and overheating of the water-cooled
torch. Connect the torch water line to the welder
“Water Out� fitting. Use a nonmetallic drain line from
the electrode connection to the drain or water
recirculating pump.
For other conditions, consult the manufacturer’s
instructions for the water cooler or TIG torch being
used.
STICK ELECTRODE CABLE CONNECTION
Turn the Power switch Off. Run the electrode and
work cables through the strain relief holes below the
welding output terminals, and connect the cables to
the proper terminals. This strain relief prevents
damage to the welding output terminals if the cables
are pulled excessively. Select cable size according to
Table 1.
WARNING
Do not connect a TIG torch and stick electrode cable
at the same time. They will both be electrically HOT
whenever the output contactor is energized.
___________________________________________
� 12 �
OPERATION
OPERATING INSTRUCTIONS
General Warnings
SAFETY INSTRUCTIONS
WARNING
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 containers that
have held combustibles.
ARC RAYS
can burn.
� Wear eye, ear and body
protection.
Observe additional Safety Guidelines detailed in
the beginning of this manual.
� 13 �
OPERATION
GRAPHIC SYMBOLS THAT APPEAR ON
THIS MACHINE OR IN THIS MANUAL
AFTERFLOW /
TIG 2-STEP
&
AFTERFLOW
2
TIME
TIG 4-STEP
CONTINUOUS
HIGH
STICK
FREQUENCY
START ONLY
CURRENT
HIGH
CONTROL
FREQUENCY
OUTPUT
OFF
LOCAL
CURRENT
CONTROL
ON
REMOTE
CURRENT
CLEAN
CONTROL
(INCREASE
&
POSITIVE
INCREASE
POLARITY)
PENETRATE
OUTPUT
A
(INCREASE
&
NEGATIVE
POLARITY)
DECREASE
TIG PULSER
HIGH
HF FREQUENCY
� 14 �
OPERATION
GRAPHIC SYMBOLS THAT APPEAR ON
THIS MACHINE OR IN THIS MANUAL (CONT.)
AC WAVE
GAS OUTPUT
BALANCE
PULSED PER
f GAS INPUT
SECOND
OVER ELECTRODE
TEMPERATURE CONNECTION
INPUT
PROTECTIVE
POWER
GROUND
DC+
&
POLARITY SINGLE PHASE
TRANSFORMER
DC- AC & DC
&
POLARITY RECTIFIER
POWER
SOURCE
DO NOT
SWITCH
WHILE TIG (GTAW)
WELDING
WARNING
SINGLE
PHASE
WATER
WORK
(COOLANT)
CONNECTION
OUTPUT
WATER AC POLARITY
(COOLANT)
INPUT
� 15 �
OPERATION
GENERAL DESCRIPTION � Welding current limit can be preset from 5 to 315
amps and is displayed on the Ammeter when not
welding.
The Square Wave TIG 255 is a constant current,
single range square wave AC/DC TIG (GTAW) arc
� Auto Balance circuitry automatically provides the
welding power source with built-in high frequency
proper amount of cleaning and penetration when
stabilization. It also has stick (SMAW) capability. It is
AC TIG welding. Manual AC wave balance adjust-
available from the factory in one model only; there are
ment is also possible.
no factory installed options, only variations in input
voltage and frequency.
� 2-Step/4-Step Arc Start Switch Capability.
The Square Wave TIG 255 includes advanced
� TIG Pulser with On/Off Selection, and Pulses Per
features such as Auto-Balanceâ„?, 2-Step/4-Step Arc
Second adjustment. Background current and duty
Start Switch operation and a TIG pulser. In addition,
cycle are automatically adjusted according to the
fixed preflow and variable afterflow timers are
peak welding current.
included for shielding gas and cooling water control.
� Fixed preflow time of 0.5 seconds. Preflow time is
eliminated if welding restarts during gas afterflow of
previous weld. This avoids unnecessary delays
Recommended Processes And when making repeated welds.
Equipment
� Adjustable afterflow time control.
The Square Wave TIG 255 is recommended for the
� Local/Remote current selection.
TIG (GTAW) and stick (SMAW) welding processes
within its output capacity of 5 to 315 amps, on both
� Stick/TlG selection.
AC and DC polarity. It is compatible with all Magnum
TIG accessories (see Accessory section in this � Continuous/Start/Off High Frequency selection.
manual), as well as many industry standard
� DC+/AC/DC- Polarity Switch.
items, such as TIG torches, hoses, and water coolers.
� Power Factor Correction for lower input currents and
Operational Features and Controls smaller input wire sizes.
The Square Wave 255 has the following controls as � Remote Receptacle for Amptrol or Arc Start Switch.
standard: TIG 2-Step/TlG 4-Step/Stick mode
selection, Local/Remote current control selection, � Low Voltage Arc Start Switch Circuit (24 V AC) for
Continuous/Start Only/Off high frequency selection, maximum operator safety.
Auto/Manual AC wave balance selection with the
manual wave balance adjustment, TIG pulser On/Off � Gas and optional Water Valves: Inlet & outlet fittings
selection with frequency adjustment, afterflow conform to Compressed Gas Association (CGA)
adjustment, and DC+/DC-/AC polarity selection. standards.
� Built-in High Frequency Generator.
Design Features and Advantages � 115 Volt Receptacle with 10 amp Circuit Breaker.
� Designed to NEMA EW-1 & International IEC-974 � 220 Volt European (Schuko) type receptacle with 2
Standards. amp circuit breaker for water coolers (50/60Hz
machines only).
� Single output range of 5-315 amps covers the
majority of all TIG welding applications. � Excellent arc starting and stability up through 315
amps.
� Solid State Output Contactor: no noise, no parts to
wear. � High resistance to AC arc rectification.
� No tungsten spitting within current range of
� Digital Ammeter and Voltmeter for precise readings
electrode.
from 5 to 315 amps welding.
� Compact size, requires only a 19 in x 30 in
(485 mm x 760 mm) footprint.
� 16 �
OPERATION
� Strain relief holes in base for welding cables, gas
and water hoses and control cables.
� Easy access for input connections. Connections
are simple strip and clamp of input wires (no lugs
required).
� Low fan noise at idle.
� Modular construction for easy servicing.
� Simple keypad layout allows even novice users to
operate with minimal instruction.
� Unused controls are automatically locked out to
simplify setup. Examples: the AC wave balance
control has no effect in DC; the High Frequency and
gas and water valves do not operate in Stick mode;
TIG Pulser is locked out in the Stick mode.
� Recessed panels protect controls, output terminals
gas and water fittings.
� Large safety margins and protective circuits protect
rectifiers from transient voltages and high currents.
� Submersion dipping of assembled transformer,
choke, rectifier in special sealing/insulating material
gives added protection against moisture and
corrosive atmospheres.
� Line Voltage Compensated.
� Thermostatically Protected.
� Electronic Over Current Protection.
� Hinged Cover over Output Panel.
Welding Capability
The Square Wave TIG 255 is rated at 255 amps, 30
volts, at 40% duty cycle on a ten minute basis. It is
capable of higher duty cycles at lower output currents.
If the duty cycle(s) are exceeded, a thermal protector
will shut off the output until the machine cools to a
reasonable operating temperature.
Limitations
Arc Gouging cannot be performed with the Square
Wave TIG 255.
The Square Wave TIG 255 is not recommended for
pipe thawing.
� 17 �
OPERATION
CONTROLS AND SETTINGS
All operator controls and adjustments are located on the case front of the Square Wave TIG 255. Refer to Figures
3 and 4 and corresponding explanations.
FIGURE 3 - CONTROL PANEL KEYS
7
G2612
AC/DC OUTPUT CAPACITY: 255 AMPS 30 VOLTS 40% DUTY CYCLE
THE LINCOLN ELECTRIC COMPANY CLEVELAND, OHIO USA
AC WAVE BALANCE
CURRENT CONTROL TIG PULSER
WELD MODE HF HIGH FREQUENCY AFTERFLOW
2
LOCAL REMOTE
TIG 2-STEP CONTINUOUS
SECONDS
ON
OFF
HF MANUAL
AUTO-
BALANCE
BALANCE
AMPS
START ONLY
TIG 4-STEP PULSES PER SECOND
CLEAN
HF 2
f
STICK
A PENETRATE
OFF
LINCOLN R
ELECTRIC
6
2 4
1
5
3
1. WELD MODE KEYS 5. TIG PULSER KEYS
2. CURRENT CONTROL KEYS 6. AFTERFLOW KEYS
3. HIGH FREQUENCY KEYS 7. DISPLAY
4. AC WAVE BALANCE KEYS
CONTROL PANEL KEYS 4. AC WAVE BALANCE: These keys are active in
the AC TIG mode only. They are used to set the
The keys are grouped into six areas, described below amount of cleaning and/or penetration produced
and in Figure 3. Some areas are active in both TIG during an AC TIG weld. Auto Balanceâ„?
and Stick, while others are active in TIG only. The red automatically sets the AC Wave Balance according
LED indicator lights are used to tell which functions to the welding current. If manual adjustment is
are active, and the display (Item 1) is used to check desired, the Manual Balance key can be pressed,
the settings of the up/down keys. and the balance adjusted from +5 (cleaning) to -10
(penetration) with the Cleaning and Penetration
1. WELD MODE KEYS: These keys select the Weld keys. Read the Advanced Features section for a
Mode desired: TIG 2-Step, TIG 4-Step, or Stick. complete explanation of the AC Wave Balance.
Read the complete Operating Instructions section
for more information on TIG 2-Step and 5. TIG PULSER: These keys are active in the TIG
TIG 4-Step. mode only. The On/Off keys turn the TIG Pulser
on and off. The Pulses Per Second keys adjust
2. CURRENT CONTROL: This area contains the the pulsing frequency up and down, from 0.5 to 10
Local/Remote keys, as well as the Amps Up/Amps pulses per second. Read the Advanced Features
Down keys. These keys are used to set the section for more information on the TIG Pulser.
welding current from 5 to 315 amps, as well as to
select Local or Remote control. Local control 6. AFTERFLOW: These keys are active in the TIG
allows the current to be adjusted only with the mode only. They must adjust the afterflow time
Amps Up/Amps Down keys. Remote control from 5 to 50 seconds for shielding gas and cooling
allows the use of a hand or foot operated remote water flow through solenoids located on the case
control. Read the complete Operating Instructions front. As the Afterflow time is adjusted, the
section for more information on Local and Remote. Afterflow time, in seconds, is shown in the
Momentary Display.
3. HIGH FREQUENCY: These keys are active in the
TIG mode only. Select from Continuous, Start
Only, or Off. Read the TIG Welding Section for
information on High Frequency.
� 18 �
OPERATION
7. CONTROL PANEL: The display is divided into five E. BAR GRAPH DISPLAY: This area provides a
sections. See Figures 4A and 4B. graphical display of values shown on the Ammeter
and on the Momentary Display. When the
Momentary Display is blank (as in Figure 4A), the
FIGURE 4A - DISPLAY Bar Graph Display represents values shown on the
ammeter. When a low value is shown on the
ammeter, only a few “bars� will appear on the left
C
D A
B
hand side of the Bar Graph Display. As the
ammeter value increases, more and more “bars�
will appear. Whenever a value increases, more
and more “bars� will appear. Whenever a value
appears in the Momentary Display, the Bar Graph
Display will represent the Momentary Display
value, not the ammeter value.
CASE FRONT CONTROLS
E
Refer to Figure 5 for the location of the following
A. AC/DC INDICATOR D. MOMENTARY DISPLAY
controls:
B. VOLTMETER E. BAR GRAPH
C. AMMETER
1. POWER SWITCH: Controls the input power to the
FIGURE 4B - DISPLAY
Square Wave TIG 255.
2. OVER TEMPERATURE LIGHT: A yellow light
which only lights when an over temperature
situation occurs. See the Maintenance Section for
more information on the thermostatic protection.
3. POLARITY SWITCH: Selects DC+, AC or DC-
welding polarity. Do not switch under load.
FIGURE 5 - CASE FRONT CONTROLS
A. AC/DC INDICATOR: This symbol represents the
output polarity of the 255 . . . either AC or DC. AC
is shown in Figure 4A; DC is shown in Figure 4B.
B. VOLTMETER: This meter displays open circuit
voltage as well as welding voltage, as measured
3
1
on the output studs of the Square Wave TIG 255. 2
L9119-1
DC
C. AMMETER: The ammeter can display preset I
current (for setting the welding current before POWER
AC DO NOT SWITCH
WHILE WELDING
welding) and actual welding current (the value of O
the welding current during a weld). Read the DC WARNING
complete Operating Instructions section for more L9119-2
GAS ELECTRODE
WORK
WATER REMOTE
OUT
IN IN
OUT
information on the ammeter.
D. MOMENTARY DISPLAY: This area is blank under
most conditions; see Figure 4A. Different values
may be displayed here as certain keypad keys are
pressed. See Figure 4B; the TIG Pulser is being
adjusted, so the Pulse Frequency, 2.0 Hz, is being
displayed. Information in the Momentary Display
lasts for five seconds after a key is pressed. Read 1. POWER SWITCH
2. THERMOSTATIC
the complete Operating Instructions section for
PROTECTION LIGHT
more information on the values that appear in the 3. POLARITY SWITCH
Momentary Display.
� 19 �
OPERATION
WELDING OPERATION
HAND AND FOOT AMPTROL ACCESSORY
OPERATION
TIG Welding
Both the Hand and Foot Amptrol work in a similar
Familiarize yourself with the Controls and Display
manner. They are meant to be used for remote current
Section before attempting operation of the Square
control when Remote Current Control is selected.
Wave TIG 255.
The TIG 2-Step mode must be selected when using
an Amptrol for remote current control. As explained
TIG Welding Guidelines
below, Amptrols can also be used as arc start
switches if Local Current Control is selected.
TIG welding can be done in either the TIG 2-Step or
the TIG 4-Step Weld Mode. TIG 2-Step is typically
For simplicity, the following explanation will refer only
used with Hand or Foot Amptrols, with Remote
to “Amptrols�, meaning both Foot and Hand models.
Current control. TIG 4-Step is typically used with Arc
The term “minimum� refers to a Foot pedal in the “up�
Start switches and Local Current Control, because it
position, as it would be with no foot pressure, or a
provides a very brief current upslope, and a 5-second
Hand Amptrol in the relaxed position, with no thumb
current downslope. TIG 4-Step also functions like a
pressure. “Maximum� refers to a fully depressed Foot
trigger interlock, making it unnecessary to hold down
Amptrol, or a fully extended Hand Amptrol.
the Arc Start switch during a weld. Note, on later
versions, TIG 4-Step was made available for use with
The Amptrol is capable of controlling the output
Remote Current Control with the release of ROM
current from 5 amps to the preset current displayed on
version S21228-4 (initiated on Control board G2150-3
the ammeter. For example, if the ammeter is preset
on codes 10022 and higher). This feature requires
for 200 amps and the Current Control switch is in the
that the remote control devise in use must have
REMOTE position, the Amptrol, when depressed just
separate Arc Start and Output Control mechanisms.
past its minimum position, will cause the Square
Read the TIG Welding Sequence of Operation
Wave TIG 255 to weld at 5 amps. At the Amptrols
sections for more details on 2-Step and 4-Step
maximum position, the output would be near 200
Operation.
amps.
It is important to note that, for many applications, the TABLE 2
tungsten will not start an arc at only 5 amps. To start RECOMMENDED POLARITY
an arc reliably, it is important to depress the Amptrol SETTINGS FOR TIG WELDING
far enough so that the machine output current is near
Electrode High Frequency
the tungsten operating range. In the example above, a
Type of Welding Polarity Setting
3/32� tungsten may be used on DC- to weld near 200
Stainless Steel DC- START
amps. To start the weld, the operator may have to
depress the Amptrol approximately 1/4 of the way Aluminum & Magnesium AC CONTINUOUS
down, or to nearly 50 amps, in order to start the arc. Other Metals DC- START
Merely depressing the Amptrol to its 5 amp minimum
position will not start the arc.
If the Current Control switch is set to the LOCAL
position, an Amptrol can be used as an arc start
switch. Depressing the Amptrol just past minimum will
cause the Amptrols built-in arc start switch to close,
and backing off completely causes the built-in start
switch to open. The Amptrol will have no effect on the
welding current when used as an arc start switch.
� 20 �
OPERATION
TABLE 3
(1) (2)
TYPICAL CURRENT RANGES FOR TUNGSTEN ELECTRODES
AC Approximate Argon
Gas Flow Rate
DCEP ( + )
DCEN ( - ) Unbalanced Wave Balanced Wave C.F.H. (1/min.)
1%, 2% 1%, 2%
Tungsten
1%, 2% 1%, 2% Thoriated Thoriated
Electrode TIG Torch
Thoriated Thoriated Pure Tungsten Pure Tungsten Stainless
Diameter Nozzle
Tungsten Tungsten Tungsten Zirconiated Tungsten Zirconiated Aluminum Steel
in. (mm) Size (4), (5)
.010 (.25) 2-15 2-15 2-15 2-15 --- 3-8 (2-4) 3-8 (2-4) #4, #5, #6
(3)
0.020 (.50) 5-20 5-15 5-20 10-20 5-20 5-10 (3-5) 5-10 (3-5)
(3)
0.040 (1.0) 15-80 10-60 15-80 20-30 20-60 5-10 (3-5) 5-10 (3-5)
(3)
1/16 (1.6) 70-150 10-20 50-100 70-150 30-80 60-120 5-10 (3-5) 9-13 (4-6) #5, #6
3/32 (2.4) 150-250 15-30 100-160 140-235 60-130 100-180 13-17 (6-8) 11-15 (5-7) #6, #7, #8
1/8 (3.2) 250-400 25-40 150-210 225-325 100-180 160-250 15-23 (7-11) 11-15 (5-7)
5/32 (4.0) 400-500 40-55 200-275 300-400 100-240 200-320 21-25 (10-12) 13-17 (6-8) #8, #10
23-27 (11-13) 18-22 (8-10)
3/16 (4.8) 500-750 55-80 250-350 400-500 190-300 290-390
1/4 (6.4) 750-1000 80-125 325-450 500-630 250-400 340-525 28-32 (13-15) 23-27(11-13)
(1) When used with argon gas. The current ranges shown must be reduced when using argon/helium or pure helium shielding gasses.
(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 SEQUENCE OF OPERATION
(2-STEP MODE) 7. If welding with AC polarity, select Auto Balanceâ„?.
This gives the optimum ratio between cleaning and
1. Connect an Arc Start Switch or an Amptrol to the penetration, automatically adjusted for the output
Remote Receptacle. current. If manual adjustment of the AC Wave
Balance is desired, select Manual Balance, and
2. Turn on the welder, gas supply and water supply (if adjust the wave balance with the Cleaning and
so equipped). The Control Panel Display and Penetration keys. See the Advanced Features
red LEDS will illuminate when the power is on. section for more information on setting and using
the AC Wave Balance.
3. Select the TIG 2-Step Weld Mode.
8. Select TIG Pulser On or Off. If the TIG Pulser is
4. Select Local (if using an Arc Start Switch) or on, adjust the pulse frequency with the Pulses Per
Remote (if using an Amptrol) current control. Set Second Up/Down keys. See the Advanced
the output current using the Amps Up/Down keys. Features section for more information on setting
The output current setting will be displayed on the and using the TIG Pulser.
Ammeter.
9. Set the Afterflow time with the Seconds Up/Down
5. Select Continuous High Frequency if welding with keys. Afterflow time provides shielding gas flow
AC polarity, or Start Only High Frequency if (and cooling water, if used) after the weld. Use
welding with DC- polarity. High Frequency Off can short Afterflow times with low currents and small
be used for scratch start welding. tungstens, use long afterflow times at high output
currents with large tungstens.
6. Select AC or DC- electrode polarity. See Table 2.
� 21 �
OPERATION
9. Set the Afterflow time with the Seconds Up/Down
10. Press and release the Arc Start Switch, and set
keys. Afterflow time provides shielding gas flow
the gas flow meter. The welder is now ready for
(and cooling water, if used) after the weld. Use
welding.
short Afterflow times with low currents and small
tungstens, long afterflow times at high output
11. Position the tungsten electrode at the start of the
currents with large tungstens.
weld at a 65 to 75 angle with the horizontal so
that the electrode is approximately 1/8� (4mm) 10. Press and release the Arc Start Switch, and set
above the work piece. Press the Arc Start Switch. the gas flow meter. The welder is now ready for
This opens the gas and water valves to welding.
automatically purge air from the hose and torch.
11. Position the tungsten electrode at the start of the
After a 0.5 second preflow time, the high
weld at a 65 to 75 angle with the horizontal so
frequency becomes available to strike the arc.
that the electrode is approximately 1/8� (4mm)
above the work piece. Press the Arc Start Switch.
12. Hold the Arc Start Switch or Amptrol down until an
This opens the gas and water valves to
arc is established. If using an Amptrol, read the
automatically purge air from the hose and torch.
section on Hand and Foot Amptrol Operation.
After a 0.5 second preflow time, the high
Release the Arc Start Switch or Amptrol to stop frequency becomes available to strike the arc.
the arc and start the Afterflow timer. After the
Afterflow time has expired, the gas and water 12. Hold the Arc Start Switch down until an arc is
valves will close. To make another weld, repeat established. The arc will start at a low current
steps 11 and 12. value. Release the Arc Start Switch. At this point,
the Square Wave TIG 255 will quickly ramp up to
TIG WELDING SEQUENCE OF OPERATION the welding current, and the weld will continue
(4-Step Mode) indefinitely. Press the Arc Start Switch a second
time to initiate a 5-second downslope. The current
1. Connect an Arc Start Switch to the Remote will go down to a crater fill current that is equal to
Receptacle.
25% of the welding current. Release the Arc Start
Switch to stop the arc and start the Afterflow timer.
2. Turn the welder, gas supply and water supply (if so
After the Afterflow time has expired, the gas and
equipped), on. The Control Panel Display and red
water valves will close. To make another weld,
LEDS will illuminate when the power is on.
repeat steps 11 and 12.
3. Select the TIG 4-Step Weld Mode.
4. Select the Local current control. Set the output
current using the Amps Up/Down keys. The output
current setting will be displayed on the Ammeter. On later
ADVANCED TIG WELDING FEATURES
version machines, remote control is also available in TIG 4-
Step mode on codes 10022 and higher utilizing ROM
AC Wave Balance and Auto Balanceâ„?
version S21228-4 and higher provided that the remote
control used has separate Arc Start and Output Control
mechanisms. AC Wave Balance is a feature unique to square wave
TIG power sources. It is active only in AC TIG mode.
5. Select Continuous High Frequency if welding with
It controls the amount of positive and negative current
AC polarity, or Start Only High Frequency if
in the AC output.
welding with DC- polarity. High Frequency Off can
be used for scratch start welding.
The Square Wave TIG 255 allows the operator to
6. Select AC or DC- electrode polarity. See Table 2. select Auto Balanceâ„?. This selection provides
automatic adjustment of the AC Wave Balance; it is
7. If welding with AC polarity, select Auto Balanceâ„?. suitable for most welding conditions. Auto Balance
This gives the optimum ratio between cleaning and
gives the ideal amount of cleaning and penetration,
penetration, automatically adjusted for the output
based on the welding current output.
current. If manual adjustment of the AC Wave
Balance is desired, select Manual Balance, and
Manual adjustment of the AC Wave Balance is also
adjust the wave balance with the Cleaning and
Penetration keys. See the Advanced Features possible. Select the Manual Balance key, and the
section for more information on setting and using Balance setting will appear in the Momentary Display.
the AC Wave Balance. Manual Balance settings vary from +5 (maximum
cleaning) to -10 (maximum penetration). A setting of
8. Select TIG Pulser On or Off. If the TIG Pulser is on, adjust
0 yields a balanced output (equal amounts of cleaning
the pulse frequency with the Pulses Per Second Up/Down
and penetration). Use the following as a guide when
keys. See the Advanced Features section for more
setting the Balance manually:
information on setting and using the TIG Pulser.
� 22 �
OPERATION
5. Clamp the electrode in the electrode holder, start
BALANCED (0): The amounts of positive and
the weld by lightly touching the electrode to the
negative are the same.
work. Stop the weld by pulling the electrode away
from the work piece. Note, in Stick Mode the
CLEANING (+1 to +5): Provides more positive
output studs remain electrically “HOT�.
current than negative. Since the positive
current produces the “cleaning� or oxide
removal on aluminum, this setting is used for
welding on heavily oxidized aluminum.
AUXILIARY POWER
PENETRATION (-1 to -10): Provides more negative
ALL MACHINES
current than positive. The arc plasma will be
more concentrated and more easily directed
The Square Wave TIG 255 provides 10 amps of 115
to where the heat is needed. Higher
volt AC power at a standard NEMA 5-15R receptacle,
penetration settings allow a given size of
located on the lower case back of the machine. This
tungsten to carry more current.
circuit is protected from shorts and overloading by a
10 amp circuit breaker, located next to the receptacle.
CAUTION: Use only the amount of cleaning required
The auxiliary circuit is intended for running water
because the greater amount of positive current will
coolers and small power tools, whose current draw is
heat the tungsten more and possibly cause it to melt
within the 10 amp rating. Note that some types of
or “spit�. Also, the arc is usually more flared and less
equipment, especially pumps and large motors, have
stable with more cleaning current.
starting currents which are significantly higher than
their running current. These higher starting currents
In general, use just enough “cleaning� to remove
may cause the circuit breaker to open. If this situation
oxides and to give good wetting to the puddle.
occurs, the user should refrain from using the Square
TIG Pulser Wave TIG 255 auxiliary for that equipment.
The Square Wave TIG 255 contains a unique TIG 50/60Hz MACHINES - (Codes 10024 thru 10026 & 10134)
Pulser circuit. The TIG Pulser has On/Off selections,
as well as adjustments for Pulses Per Second Square Wave TIG 255 machines rated for 50/60Hz
Up/Down. When the Pulser is turned On, or when the operation provide 2 amps of 220 volt AC power at a
Pulses Per Second are adjusted, the pulse frequency is continental European (Schuko) type receptacle,
shown in the Momentary Display. It can be varied located on the lower case back of the machine. This
from 0.5 Hz to 10 Hz in 0.5 Hz increments. (One circuit is protected from shorts and overloading by a 2
Hertz {Hz} is equivalent to one pulse per second.) amp circuit breaker, located above the receptacle.
The background current (the welding current at the The auxiliary circuit is intended for running water
low point of the pulse cycle) is automatically adjusted coolers whose current draw is within the 2 amp rating
from 40% to 60% of the peak current by the Square of the receptacle. Note that some types of equipment,
Wave TIG 255. The duty cycle (the ratio between that especially pumps and motors, have starting currents
time spent at the peak current vs, the time spent at which are significantly higher than their running
the background current) is fixed at 50%. currents. These higher starting currents may cause
the circuit breaker to open. If this situation occurs, the
STICK WELDING user should refrain from using the Square Wave TIG
255 auxiliary for that equipment.
1. Remove the amptrol or Arc Start Switch from the
OVERLOAD PROTECTION
Remote Receptacle.
This welder has thermostatic protection from
2. Turn the welder on. The Control Panel Display
excessive duty cycles, overloads, loss of cooling, and
and red LEDS will illuminate when the power is on.
high ambient temperatures. When the welder is
subjected to an overload or loss of cooling, a
3. Select Stick Mode and Local Current Control. Set
thermostat will open. This condition will be indicated
the output current using the Amps Up/Down keys.
by the illumination of the yellow Thermostatic
The output current setting will be displayed on the
Protection Light on the case front (see Figure 2).
Ammeter. No other functions or adjustments
Also, the Display will be blank, and all of the red
operate in the Stick Mode.
Control Panel LEDS will be out. The fan will continue
to run to cool the power source. No welding is
4. Select DC+, AC or DC- electrode polarity.
possible until the machine is allowed to cool and the
Thermostatic Protection Light goes out.
� 23 �
ACCESSORIES
OPTIONS / ACCESSORIES
� Hand Amptrol (K963)
� Foot Amptrol (K870)
� Arc Start Switch (K814)
� Magnum Cooler Horizontal TIG Mounting Bracket
(K559-2)
� Undercarriage (K932-1)
UNDERCARRIAGE FUNCTION
The Square Wave TIG 255 is designed to be used
with a Lincoln K932-1 Undercarriage. Complete
installation instructions are included with the K932-1
undercarriage. When the undercarriage is properly
installed, the Square Wave TIG 255 lift bail is non-
functional. Do not attempt to lift the power source with
the undercarriage attached. The undercarriage is
designed for hand moving only; mechanized towing
can lead to injury and/or damage to the Square Wave
TIG 255.
INSTALLATION OF FIELD INSTALLED OPTIONS
Instructions for connecting the K932-1 Undercarriage
and the K559-2 Magnum Cooler Horizontal TIG
Mounting Bracket are included with those
accessories.
Installation of the K963 Hand Amptrol, the K814 Arc
Start Switch and K870 Foot Amptrol are as follows:
Lift the Output Cover Door (if so equipped) on the
Square Wave TIG 255. Feed the cable up through the
strain relief holes in the base, and connect the 6-pin
MS-type (Amphenol) connector to the Remote
Receptacle (See Figure 2). Secure with the threaded
collar.
� 24 �
MAINTENANCE
MAINTENANCE
Safety Precautions
WARNING
ELECTRIC SHOCK can kill.
� Only qualified personnel should
perform this maintenance.
� Turn the input power OFF at the
disconnect switch or fuse box
before working on this
equipment.
� Do not touch electrically hot
parts.
Routine and Periodic Maintenance
WARNING
To avoid receiving a high frequency shock, keep the
TIG torch and cables in good condition.
1. Disconnect power supply lines to machine before
performing periodic maintenance.
2. Periodically clean the inside of the machine with a
low pressure air system. Be sure to clean the
following components thoroughly. See Figure 6
for location of those components.
� Main Transformer
� Output Studs
� Polarity Switch
� Rectifier Assembly
� Control Box Assembly
� Spark Gap Assembly
� Protection PC Board - (Mounted to rear of control box assembly)
3. Inspect welder output and control cables for
fraying, cuts, and bare spots.
4. Keep TIG torch and cables in good condition.
5. The fan motor has sealed ball bearings which
require no maintenance.
6. Inspect spark gap spacing at regular intervals to
maintain a 0.015 in (0.4mm) gap. (Smallest
possible air gap consistent with good welding is
desirable to minimize R.F.I. problems.) Dressing
or any refinishing of the spark gap contacts is not
recommended. If the contact surfaces become
irregular or completely eroded, replacement of both
electrodes is recommended.
� 25 �
MAINTENANCE
FIGURE 6 - GENERAL ASSEMBLY EXPLODED VIEW
1
5
22
6
4
11
3
2
28
2
38
1. MAIN TRANSFORMER 5. CONTROL BOX ASSEMBLY
2. OUTPUT STUDS 6. SPARK GAP ASSEMBLY
3. POLARITY SWITCH 7. PROTECTION PC BOARD -
4. RECTIFIER ASSEMBLY (Mounted to rear of control box assembly)
� 26 �
TROUBLESHOOTING
How To Use Troubleshooting Guide
WARNING
This Troubleshooting Guide is designed to be used by the machine Owner/Operator. 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, please observe all safety notes and precautions detailed in the Safety Section of
this manual to avoid electrical shock or danger while troubleshooting this equipment.
___________________________________________________________________________________________
Step 3. CONSULT LOCAL AUTHORIZED FIELD
This Troubleshooting Guide is provided to help you
SERVICE FACILITY
locate and correct possible machine misadjustments.
Simply follow the three-step procedure listed below. If you have exhausted all of the recommended tests in
step 2, consult your local Authorized Field Service
Step 1. LOCATE PROBLEM (SYMPTOM) Facility.
Look under the column labeled “PROBLEM
(SYMPTOMS)�. This column describes possible
symptoms that your machine may exhibit. Find the
listing that best describes the symptom that your
machine is exhibiting.
Step 2. PERFORM EXTERNAL RECOMMENDED
TESTS
The second column labeled “POSSIBLE AREAS OF
MISADJUSTMENT(S)� lists the obvious external
possibilities that may contribute to the machine
symptom. Perform these tests/checks in the order
listed. In general, these tests can be conducted
without removing the case wrap-around cover.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 27 �
TROUBLESHOOTING
Troubleshooting Guide Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
OUTPUT PROBLEMS
Major Physical or Electrical 1. Contact The Lincoln Electric
Damage is Evident. Service Dept. (216) 383-2531
Machine is Dead - 1. Make certain that the input
No Output - No Fan power switch is in the “ON�
No Displays. position.
2. Check the input voltage at the
machine. Input voltage must
match the rating plate and
reconnect the panel.
3. Blown or missing fuses in
input line.
Fan runs - Display and control 1. Check for proper input
panel dark. No output from voltages. As per nameplate
machine in either Stick or TIG and reconnect panel.
If all recommended possible areas
modes.
of misadjustment have been
checked and the problem persists,
Contact your local Lincoln
The voltmeter reads �00� in Stick 1. Inspect to assure that the arc
Authorized Field Service Facility.
Mode, and there is no output from start switch is in the on
the machine when in the TIG (closed) position when
2-Step Mode. welding in the TIG Mode.
Machine does not respond (no gas 1. Machine MUST be in one of
flow, no high frequency and no the TIG Modes.
open circuit voltage) when arc
switch or amptrol is activated - 2. The arc start switch or amptrol
displays and fan working. may be defective. Check for
continuity between pins “D�
and “E� on cable connector
when arc switch or amptrol is
activated.
115VAC Receptacle not working 1. Check for 115VAC at
properly (voltage is below 108VAC). receptacle - if low (below
Machine has welding output - fan is 108VAC), then check input
running. voltage to machine.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 28 �
TROUBLESHOOTING
Observe Safety Guidelines Troubleshooting Guide
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
OUTPUT PROBLEMS
Machine regularly over heats - 1. Welding application may
thermostat opens, PL1 (yellow light exceed recommended duty
on front panel) glows. The fan runs cycle.
but machine has no output and no
display. 2. Dirt and dust may have
clogged the cooling channels
inside the machine. Blow out
unit with clean, dry
compressed air.
3. Air intake and exhaust louvers
may be blocked due to
inadequate clearance around
machine.
Machine makes a very loud 1. Inspect output stud insulators
buzzing noise in DC Stick Mode, or for cracks or signs of over-
in DC TIG Mode when the arc start heating.
or amptrol is pressed.
If all recommended possible areas
of misadjustment have been
There is no current draw from
checked and the problem persists,
machine’s output studs.
Contact your local Lincoln
(The machine is not externally
Authorized Field Service Facility.
loaded).
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 29 �
TROUBLESHOOTING
Troubleshooting Guide Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
FUNCTION PROBLEMS
The yellow light (PL1) on the front 1. Normal condition - this light
panel is not lit. will glow only if machine is in
an overheated condition.
(Thermal overload).
One or more keypad lights (LEDS) 1. Be sure that the proper weld
are dark and cannot be lit when mode is selected. For
their respective keys are pressed - example, the high frequency
machine is operable. keys and keypad lights
(LEDS) are not active in the
stick mode.
The Beeper (Piezoelectric Buzzer) 1. Background noise may be too
cannot be heard - machine loud for user to hear beeper.
operating normally.
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
Contact your local Lincoln
Authorized Field Service Facility.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 30 �
TROUBLESHOOTING
Observe Safety Guidelines Troubleshooting Guide
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
TIG MODE PROBLEMS
Machine output is intermittently 1. Problem may be caused by
lost. Gas flow and high frequency high frequency interference.
are also interrupted. Make sure that the machine is
grounded properly according
to the installation instructions.
If there are other high
frequency sources in the area,
make certain that they are
grounded properly.
2. Check arc start switch or
amptrol for proper operation
and loose connections.
Arc “Flutters� when TIG welding. 1. Tungsten electrode may be
too large in diameter.
2. Tungsten not “Sharp� when
welding in DC negative mode.
3. If helium is used as a
If all recommended possible areas
shielding gas, then reduce the
of misadjustment have been
percentage of helium.
checked and the problem persists,
4. Adjust flow rate of shielding
Contact your local Lincoln
gas.
Authorized Field Service Facility.
5. Check hoses and connections
for leaks.
Lack of penetration in AC TIG 1. Manual balance control set
welding. improperly - set to negative
10 (-10) for maximum
penetration.
Black areas along weld bead. 1. Tungsten electrode may be
contaminated. Replace or
sharpen.
2. Shielding gas flow may be
insufficient.
3. Contaminated gas or faulty
gas line or torch.
Black areas along weld bead at or 1. Increase post flow time.
near end of weld.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 31 �
TROUBLESHOOTING
Troubleshooting Guide Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
TIG WELDING PROBLEMS
Machine has low output when in 1. Machine must be in “Local�
TIG 4-Step Mode. Control Mode when 4-Step is
used.
Weak high frequency - machine 1. Spark gap may be misadjusted.
has normal welding output. Check and reset per
maintenance instructions.
2. Improper shielding gas flow.
Adjust for a flow of 10 to 30
CFH (4.7 to 14.1 l/min.) for
most applications.
3. Work and electrode cables in
poor condition allowing high
frequency to “Leak Off�. Use
good quality cables with a high
natural rubber content, such
as Lincoln Stable Arc Cable.
Cables should be as short as
possible.
The display shows zero amps, but If all recommended possible areas
1. The arc start switch or amptrol
indicates open circuit voltage may be defective. There should of misadjustment have been
(approximately 53V). The arc start not be any continuity between checked and the problem persists,
switch or amptrol is not actuated. pins “D� and “E� on the arc start Contact your local Lincoln
cable connector, unless the
Authorized Field Service Facility.
unit is actuated.
2. If an amptrol is not being used,
the machine must be in the
Local Control Mode.
High frequency “Spark� is present 1. Torch may be faulty.
at tungsten electrode, but operator
2. If an amptrol is not being used,
is unable to establish a welding arc.
then the machine must be in
Machine has normal open circuit the Local Control Mode.
voltage (approximately 53V).
3. Tungsten electrode may be
too large for the process.
4. If helium shielding gas is being
used, then reduce percentage
of helium.
5. If TIG welding in the DC
negative mode, then a properly
sharpened thoriated tungsten
should be used.
6. Check the welding cables and
output stud connections.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 32 �
TROUBLESHOOTING
Observe Safety Guidelines Troubleshooting Guide
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
TIG WELDING PROBLEMS
No high frequency. Machine is in 1. In order for the high frequency
the TIG Mode and has normal to operate, the machine must
output. be either in the start only
Mode or the continuous high
frequency mode.
2. The high frequency spark gap
may be too large or shorted.
Check gap as per
maintenance instructions.
No gas or water flow when arc start 1. Gas supply is empty or not
switch or amptrol is activated in the turned on.
TIG Mode. Machine has output -
fan runs. When toggling between 2. Gas or water hose may be
the Stick and TIG Modes a “Click� pinched.
can be heard indicating that the
solenoids are operating. 3. Gas or water solenoid may be
blocked with dirt. Use filters
to prevent reoccurrence.
If all recommended possible areas
Consult your Local welder/gas
of misadjustment have been
distributor.
checked and the problem persists,
Contact your local Lincoln
Arc rectification when AC TIG 1. Tungsten electrode may be
Authorized Field Service Facility.
welding. too small for process.
2. Manual balance control may
be misadjusted. Readjust to
the negative direction.
3. If helium gas is being used,
reduce percentage of helium.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 33 �
TROUBLESHOOTING
Troubleshooting Guide Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS POSSIBLE AREAS OF RECOMMENDED
(SYMPTOMS) MISADJUSTMENT(S) COURSE OF ACTION
STICK WELDING PROBLEMS
Stick electrode “Blasts Off� when 1. Weld current is set too high
arc is struck. for recommended electrode
size. Reduce preset current
adjustment.
Cannot adjust AC Wave Balance 1. This is a normal condition.
when welding in the Stick Mode. Wave balance keys are
automatically disabled in the
Stick Mode.
Machine welds at a very low output 1. If welding in the Remote
regardless of the preset current Control Mode, the remote
setting - arc is stable. amptrol may be defective or
not installed properly.
2. If the output is low when the
machine is in the Local
Control Mode, the problem
could be internal to the
machine.
If all recommended possible areas
of misadjustment have been
Variable or sluggish welding arc 1. Check work and electrode
checked and the problem persists,
when welding in the Stick Mode. cables for loose or poor
Contact your local Lincoln
connections.
Authorized Field Service Facility.
2. The weld cables may be too
small or too long to permit the
desired current to flow.
3. The preset current adjustment
may be set too low.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact your local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
� 34 �
WIRING DIAGRAM - SQUARE WAVE TIG 255 CODE 10022, 10023 & 10024
TO GROUND PER NATIONAL ELECTRIC CODE
PIEZO (-)
BUZZER (+)
X1
C1
� 35 �
235
R3
235A
TO KEYPAD MATRIX
236A
236
C2
R4
239
238A
239A
(2,2) (2,1) (3,1)
238
237
240 (4,2)
(4,1)
230E (1,2)
50/60 HZ
MACHINES ONLY (1,3)
230D
229 232B
(5,2)
(1,1) (5,1)
230B
229A
230 231
230C
232
52A
4-19-96D
G2719
WIRING DIAGRAM
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The specific diagram for a particular code is pasted inside
the machine on one of the enclosure panels. If the diagram is illegible, write to the Service Department for a replacement. Give the equipment code number..
WIRING DIAGRAM - SQUARE WAVE TIG 255 CODE 10451, 10452 & 10453
TO GROUND PER NATIONAL ELECTRIC CODE
PIEZO (-)
BUZZER (+)
X1
WIRING DIAGRAM
C1
� 36 �
235
R3
235A
TO KEYPAD MATRIX
236A
236
C2
R4
239
238A
239A
(2,2) (2,1) (3,1)
238
52 50/60 HZ
237 MACHINES ONLY
240 (4,2)
(4,1)
231D 232C (1,2)
(1,3)
229
(5,2)
(1,1) (5,1)
231
231B
229A
231
231C
232B
50
232
1-24-97H
G3302
NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The specific diagram for a particular code is pasted inside
the machine on one of the enclosure panels. If the diagram is illegible, write to the Service Department for a replacement. Give the equipment code number..
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Account No. Exp Date
______________________
Month Year
USE THIS FORM TO ORDER: Order from: BOOK DIVISION, The Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199
Telephone: 216-383-2211 or, for fastest service, FAX this completed form to: 216-361-5901.
BOOKS OR FREE INFORMATIVE CATALOGS
Lincoln Welding School Titles: Price Code Quantity Cost
(ED-80) New Lessons in Arc Welding $5.00 L
Seminar Information Procedure Handbook “Twelfth Edition� $15.00 PH
(ED-45) How to Read Shop Drawings $4.50 H
Educational Video Information Incentive Management $5.00 IM
(ED-93) A New Approach to Industrial Economics $5.00 NA
James F. Lincoln Arc Welding The American Century of John C. Lincoln $5.00 AC
Foundation Book Information Welding Preheat Calculator $3.00 WC-8
(JFLF-515) Pipe Welding Charts $4.50 ED-89
SUB TOTAL
Additional Shipping Costs if any
TOTAL COST
q Do not touch electrically live parts or q Keep flammable materials away. q Wear eye, ear and body protection.
WARNING electrode with skin or wet clothing.
q Insulate yourself from work and
ground.
Spanish
q No toque las partes o los electrodos q Mantenga el material combustible q Protéjase los ojos, los oÃdos y el
AVISO DE bajo carga con la piel o ropa fuera del área de trabajo. cuerpo.
mojada.
PRECAUCION q Aislese del trabajo y de la tierra.
French q Ne laissez ni la peau ni des q Gardez à l’écart de tout matériel q Protégez vos yeux, vos oreilles et
vêtements mouillés entrer en contact inflammable. votre corps.
ATTENTION avec des pièces sous tension.
q Isolez-vous du travail et de la terre.
German q Berühren Sie keine stromführenden q Entfernen Sie brennbarres Material! q Tragen Sie Augen-, Ohren- und Kör-
Teile oder Elektroden mit Ihrem perschutz!
WARNUNG Körper oder feuchter Kleidung!
q Isolieren Sie sich von den
Elektroden und dem Erdboden!
Portuguese
q Não toque partes elétricas e q Mantenha inflamáveis bem q Use proteção para a vista, ouvido e
electrodos com a pele ou roupa guardados. corpo.
ATENÇÃO molhada.
q Isole-se da peça e terra.
Japanese
Chinese
Korean
Arabic
READ AND UNDERSTAND THE MANUFACTURER’S INSTRUCTION FOR THIS EQUIPMENT AND THE CONSUMABLES TO BE
USED AND FOLLOW YOUR EMPLOYER’S SAFETY PRACTICES.
SE RECOMIENDA LEER Y ENTENDER LAS INSTRUCCIONES DEL FABRICANTE PARA EL USO DE ESTE EQUIPO Y LOS
CONSUMIBLES QUE VA A UTILIZAR, SIGA LAS MEDIDAS DE SEGURIDAD DE SU SUPERVISOR.
LISEZ ET COMPRENEZ LES INSTRUCTIONS DU FABRICANT EN CE QUI REGARDE CET EQUIPMENT ET LES PRODUITS A
ETRE EMPLOYES ET SUIVEZ LES PROCEDURES DE SECURITE DE VOTRE EMPLOYEUR.
LESEN SIE UND BEFOLGEN SIE DIE BETRIEBSANLEITUNG DER ANLAGE UND DEN ELEKTRODENEINSATZ DES
HERSTELLERS. DIE UNFALLVERHÃœTUNGSVORSCHRIFTEN DES ARBEITGEBERS SIND EBENFALLS ZU BEACHTEN.
q Keep your head out of fumes. q Turn power off before servicing. q Do not operate with panel open or
WARNING
q Use ventilation or exhaust to guards off.
remove fumes from breathing zone.
Spanish
q Los humos fuera de la zona de q Desconectar el cable de q No operar con panel abierto o
AVISO DE
respiración. alimentación de poder de la guardas quitadas.
q Mantenga la cabeza fuera de los máquina antes de iniciar cualquier
PRECAUCION
humos. Utilice ventilación o servicio.
aspiración para gases.
French
q N’opérez pas avec les panneaux
q Gardez la tête à l’écart des fumées. q Débranchez le courant avant
ouverts ou avec les dispositifs de
q Utilisez un ventilateur ou un l’entretien.
ATTENTION
protection enlevés.
aspirateur pour ôter les fumées des
zones de travail.
German
q Anlage nie ohne Schutzgehäuse
q Vermeiden Sie das Einatmen von q Strom vor Wartungsarbeiten
oder Innenschutzverkleidung in
Schweibrauch! abschalten! (Netzstrom völlig
WARNUNG
ED
Betrieb setzen!
q Sorgen Sie für gute Be- und öffnen; Maschine anhalten!)
Entlüftung des Arbeitsplatzes!
1 SED
Portuguese
q Mantenha-se afastado das partes
q Mantenha seu rosto da fumaça. q Não opere com as tampas removidas.
moventes.
q Use ventilação e exhaustão para
ATENÇÃO
q Desligue a corrente antes de fazer
q Não opere com os paineis abertos
remover fumo da zona respiratória. serviço.
W ER ou guardas removidas.
q Não toque as partes elétricas nuas.
Japanese
IM P
E SU
S
SE Y
Chinese
NT
RA
Korean
AR
W
Arabic
LEIA E COMPREENDA AS INSTRUÇÕES DO FABRICANTE PARA ESTE EQUIPAMENTO E AS PARTES DE USO, E SIGA AS
PRÃTICAS DE SEGURANÇA DO EMPREGADOR.
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