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
THISEQUIPMENTWITHOUT
READING THIS MANUAL AND
THE SAFETY PRECAUTIONS
CONTAINEDTHROUGHOUT.
And, most importantly, think before
you act and be careful.
10806; 10807; 10893; 11158; 11159
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• World's Leader in Welding and Cutting Products •
• Sales and Service through Subsidiaries and Distributors Worldwide •
iiii
SAFETY
WARNING
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 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.
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 Gasoline Engines
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.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.h. To avoid scalding, do not remove the
radiator pressure cap when the engine is
hot.
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.
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.
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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.
Mar ʻ95
iiiiiiii
SAFETY
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.
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.
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. The operation of welding fume control equipment is affected
by various factors including proper use and positioning of the
equipment, maintenance of the equipment and the specific
welding procedure and application involved. Worker exposure level should be checked upon installation and periodically thereafter to be certain it is within applicable OSHA PEL
and ACGIH TLV limits.
5.c.
Do not weld in locations near chlorinated hydrocarbon
coming from degreasing, cleaning or spraying operations.
The heat and rays of the arc can react with solvent vapors
form phosgene, a highly toxic gas, and other irritating products.
5.d. 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.
vapors
to
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5.e. Read and understand the manufacturerʼs instructions for this
equipment and the consumables to be used, including the
material safety data sheet (MSDS) and follow your
employerʼs safety practices. MSDS forms are available from
your welding distributor or from the manufacturer.
5.f. Also see item 1.b.
Aug ʻ06
iiiiiiiiiiii
SSAAFFEETTYY
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.
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
been “cleaned”. For information, purchase “Recommended
Safe Practices for the
Containers and Piping That Have Held Hazardous
Substances”, AWS F4.1 from the American Welding Society
(see address above).
6.e. Vent hollow castings or containers before heating, cutting or
welding. They may explode.
Sparks and spatter are thrown from the welding arc. Wear oil
6.f.
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.
Remember that welding sparks and hot
though
they have
Preparation
for Welding and Cutting of
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.
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 manufacturerʼs
recommendations.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturerʼs recommendations.
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Mar ʻ95
iivviivv
SSAAFFEETTYY
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:
Sûr
eté Pour Soudage A L’Arc
1. Protegez-vous contre la secousse électrique:
Les circuits à lʼélectrode et à la piéce sont sous tension
a.
quand la machine à souder est en marche. Eviter toujours
tout contact
ou les vétements mouillés. Porter des gants secs et sans
trous pour isoler les mains.
b. Faire trés attention de bien sʼisoler 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 lʼeau 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 sʼapplicuent aussi au pistolet de
soudage.
entre les parties sous tension et la peau nue
6. Eloigner les matériaux inflammables ou les recouvrir afin de
prévenir tout risque dʼincendie 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 dʼincendie.
8. Sʼassurer que la masse est connectée le plus prés possible de
la zone de travail quʼil est pratique de le faire. Si on place la
masse sur la charpente de la construction ou dʼautres 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 dʼincendie ou dʼechauffement des chaines et des
câbles jusquʼà ce quʼils 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
dʼopérations de dégraissage, nettoyage ou pistolage. La
chaleur ou les rayons de lʼarc 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.
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 nʼimporte quelle partie du
corps.
3. Un coup dʼarc peut être plus sévère quʼun coup de soliel, donc:
a. Utiliser un bon masque avec un verre filtrant approprié ainsi
quʼun verre blanc afin de se protéger les yeux du rayonnement de lʼarc et des projections quand on soude ou
quand on regarde lʼarc.
b. Porter des vêtements convenables afin de protéger la peau
de soudeur et des aides contre le rayonnement de lʻarc.
c. Protéger lʼautre personnel travaillant à proximité au
soudage à lʼaide dʼécrans appropriés et non-inflammables.
4. Des gouttes de laitier en fusion sont émises de lʼarc de
soudage. Se protéger avec des vêtements de protection libres
de lʼhuile, 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 lʼon pique le laitier.
PRÉCAUTIONS DE SÛRETÉ POUR
LES MACHINES À SOUDER À
TRANSFORMATEUR ET À
REDRESSEUR
1. Relier à la terre le chassis du poste conformement au code de
lʼélectricité 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, Iʼinstallation et lʼentretien du poste seront
effectués par un électricien qualifié.
3. Avant de faires des travaux à lʼinterieur de poste, la debrancher à lʼinterrupteur à la boite de fusibles.
4. Garder tous les couvercles et dispositifs de sûreté à leur place.
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ALSO CALLED ʻINVERSE TIME" OR "THERMAL/MAGNETIC " CIRCUIT BREAKERS; CIRCUIT BREAKERS WHICH HAVE A DELAY IN TRIPPING ACTION THAT DECREASES AS
THE MAGNITUDE OF CURRENT INCREASES.
* 50/60HZ IEC Max. range exceeds 310A.
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PHYSICAL DIMENSIONS
TEMPERATURE RANGES
STORAGE TEMPERATURE RANGE
-40°C to +85°C (-40° to +185°F)
PRECISION TIG 275
A-4
INSTALLATION
A-4
SAFETY PRECAUTIONS
Read entire Installation Section before installing
the Precision Tig 275.
WARNING
ELECTRIC SHOCK can kill.
•Only qualified personnel should per-
form this installation.
•Turn the input power OFF
at the disconnect switch or
fuse box and discharge input capacitors
before working inside the equipment.
•Do not touch electrically hot parts.
•Always connect the Precision Tig grounding screw (behind
the reconnect panel cover located near the back of the left
case side) to a good electrical earth ground.
•Always connect the Precision Tig to a power supply grounded
in accordance with the National Electrical Code and all local
codes.
SELECT SUITABLE LOCATION
Place the welder where clean cool air can freely circulate in through the rear louvers and out through the bottom opening. Dirt, dust or any foreign material that can
be drawn into the machine should be kept at a minimum. Failure to observe these precautions can result
in excessive operating temperatures and nuisance
trips.
The machine may topple over if this precaution is not
followed.
ENVIRONMENTAL RATING
Precision TIG 275 power sources carry an IP21S
Environmental rating. They are rated for use in damp,
dirty rain-sheltered environments.
HIGH FREQUENCY INTERFERENCE
PROTECTION
The frame of the welder must be grounded. A ground
screw marked with the symbolis located on the
input connection panel (Figure A.1) for this purpose.
See your local and national electrical codes for proper
grounding methods.
The spark gap oscillator in the high frequency generator, being similar to a radio transmitter, can be blamed
for many radio, TV and electronic equipment interference problems. These problems may be the result of
radiated interference. Proper grounding methods can
be reduced or eliminate re-radiated interference.
The Precision TIG 275 has been field tested under recommended installation conditions and has been found
to comply with F.C.C. allowable radiation limits. This
welder has also been found to comply with NEMA standards for high frequency stabilized power sources.
GRINDING
Do not direct grinding particles towards the welder. An
abundance of conductive material can cause maintenance problems.
STACKING
The Precision Tig 275 cannot be stacked.
UNDERCARRIAGE LIFTING AND MOVING
When the Precision TIG 275 is purchased as a welding
package, orusedwith any oftheavailable
Undercarriage optional accessories, proper installation
makes the Precision TIG 275 lift bale nonfunctional.
Do not attempt to lift the power source with an undercarriage attached. The undercarriage is designed for
hand moving only; mechanized movement can lead to
personal injury and/or damage to the Precision TIG
275.
TILTING
Each machine must be placed on a secure, level surface, either directly or on a recommended undercarriage.
Radiated interference can develop in the following four
ways:
* Direct interference radiated from the welder.
* Direct interference radiated from the welding leads.
* Direct interference radiated from the feedback into
the power lines.
* Interference from re-radiation of “pickup” by
ungrounded metallic objects.
Keeping these contributing factors in mind, installing
the equipment per the following instructions should
minimize problems.
1. Keep the welder power supply lines as short as possible and completely enclose them in rigid metallic conduit or equivalent shielding for a minimum distance of
50 feet (15.2 m). There must be good electrical contact
between this conduit must be connected to a driven
ground and the entire length must be continuous.
2. Keep the work and electrode leads as short as possible and as close together as possible. Lengths
should not exceed 25 feet (7.6m). Tape the leads
together when practical.
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PRECISION TIG 275
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A-5
INSTALLATION
A-5
3. Be sure the torch and work cable rubber coverings
are free of cuts and cracks that allow high frequency leakage. Cables with high natural rubber content,
R
such as Lincoln Stable-Arc
better resist high frequency leakage than neoprene and other synthetic
rubber insulated cables.
4. Keep the torch in good repair and all connections
tight to reduce high frequency leakage.
5. The work terminal must be connected to a ground*
within ten feet of the welder, using one of the following methods.
* A metal underground water pipe in direct contact
with the earth for ten feet or more.
* 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. (This is not recommended.)
6. Keep all access panels and covers securely in
place.
7. All electrical conductors within 50 feet (15.2m) of the
welder should be enclosed in grounded rigid metallic conduit or equivalent shielding. Flexible helicallywrapped metallic conduit is generally not suitable.
8. When the welder is enclosed in a metal building,
several earth driven electrical grounds (as in 5
above) around the periphery of the building are recommended.
Failure to observe these recommended installation
procedures can cause radio or TV interference problems and result in unsatisfactory welding performance
resulting from lost high frequency power.
INPUT and GROUNDING CONNECTIONS
WARNING
ELECTRIC SHOCK can kill.
* Turn the input power OFF at the
disconnect switch or fuse box
before working on this equipment.
___________________________________________
Be sure the voltage, phase, and frequency of the
input power is as specified on the rating plate, located
on the rear of the machine.
Fuse the input circuit with the recommended super
lag fuses or delay type1 circuit breakers. Choose an
input and grounding wire size according to local or
national codes or use Section A-2. Using fuses or circuit breakers smaller than recommended may result
in “nuisance” tripping from welder inrush currents
even if not welding at high currents.
Unbalanced AC TIG welding draws higher input currents than those for Stick, DC TIG, or Balanced AC
TIG welding. The welder is designed for these higher
input currents. However, where unbalanced AC TIG
welding above 185 amps is planned, the higher input
currents require larger input wire sizes and fuses per
Section A-2:
Remove the reconnect panel cover located near the
back of the left case side to reveal the reconnected
panel. Welder supply line entry provision is in the
case rear panel. Entry is through a 1.75 inch (44mm)
diameter hole in the case back. Appropriate supply
line strain relief clamp is provided by installer. (See
Figure A.1)
All connections should be made in accordance
FIGURE A.1
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CONNECT INPUT
POWER LEADS
CONNECT INPUT
GROUND LEAD
with all local codes and national electrical codes.
Installation by a qualified electrician is recommended.
PRECISION TIG 275
CONNECT INPUT
VOLTAGE LEVEL
A-6
INSTALLATION
A-6
1. Connect the terminal marked (below the reconnect panel) to an earth ground.
2. Connect the input leads to terminals marked L1 (U)
and L2 (V) on the reconnect panel. Use a single
phase line or one phase of a two or three phase line.
3. On multiple input voltage welders, be sure the
reconnect panel is connected for the voltage being
supplied to the welder.
CAUTION
Failure to follow these instructions can cause
immediate failure of components within the welder.
Welders are shipped connected for the highest input
voltage as listed on the rating plate. To change this
connection, designations on the reconnect panel LOW,
MID, and HIGH correspond to the name plated input
voltages of a triple voltage welder. Dual voltage
welders use only LOW and HIGH.
Recommended Cable Sizes for Combined Lengths of
Copper Work and Electrode Cables using 75
Machine Rating0 to 100 Ft. 101 to 200 Ft 201 to 250 Ft
A 15ʼ (2/0) weld cable with clamp is available (K2150-1), or
included with the Precision TIG Welding Package model.
Otherwise, it is user provided.
With power source off, connect a separate work cable
to the 1/2-13 threaded "WORK" stud of the welder, and
secure a tight connection with the flange nut provided.
The work cable should be routed through the cable
strain relief hole provided in the base directly below the
welding output terminal.
Note: If the Precision TIG is equipped with an UnderCooler or Under-Storage unit, the coiled work cable
and clamp, or excess work cable length, may be conveniently stored in the drawer while remaining connected.
EXAMPLE: On a 208/230/460 volt welder, LOW is
208V, MID is 230V, and HIGH is 460V.
NOTE: Export model has a voltage range for LOW and
MID connections: LOW is 220-230V, MID is 280400V and high is 415V.
Reconnect the jumper strap to the terminal stud corresponding to the input voltage level used. Make sure all
connections are tight.
WARNING
OUTPUT CABLES, CONNECTIONS AND
LIMITATIONS
• To avoid being startled by a high frequency
shock, keep the TIG torch and cables in good
condition
• Turn the power switch of the power source OFF
before installing adapters on cable or when connecting or disconnecting adapter plugs to power
source.
If manual stick welding is desired, with power source
off, connect a stick electrode cable to the 1/2-13
threaded "STICK Electrode" stud of the welder, and
secure a tight connection with the flange nut provided.
The electrode cable should be routed through the
cable strain relief hole provided in the base directly
below the welding output terminal.
WARNING
DISCONNECT STICK ELECTRODE WELDING
CABLE WHEN TIG WELDING.
EVEN THOUGH HI-FREQ IS NOT APPLIED TO THE
PRECISION TIG STICK TERMINAL, IT WILL BE
ELECTRICALLY "HOT" TO WORK WHEN TIG
WELDING.
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Refer to Figure A.2 for the location of the WORK and
STICK terminals, as well as the TIG Torch connection
panel.
PRECISION TIG 275
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A-7
W
ORK
S
TICK
W
ORK
S
TICK
STICK
ELECTRODE
STUD
WORK
STUD
TIG TORCH
CONNECT IO
N
PANEL
FIGURE A
(Shown without hinged stud cover)
REMOTE
CONTROL
RECEPTACLE
CABLE
STRAIN
RELIEF H OLES
INSTALLATION
FIGURE A.2
A-7
TIG TORCH CONNECTION
The Precision TIG torch connection box, located on the
right side of the machine, provides all the input and
output connections for the installation of both aircooled and water-cooled TIG torches with fittings conforming to Compressed Gas Association (CGA) standards:
Note: The Precision TIG provides an insulated Torch
Reel and Holster for handy and safe storage of connected torch when not welding, and excess torch cable
length while welding.
WARNING
Combination connectors (Power/Water and
Power/Gas) are electrically "hot" while welding in
STICK or TIG modes.
If using an Air-Cooled Torch be sure coolant is
shut off and/or Cooler is unplugged from the
Precision TIG Water Cooler Receptacle on the
torch side of the upper case back.
CYLINDER could explode
if damaged.
• Keep cylinder upright and
chained to a support.
• Keep cylinder away from areas
where it could be damaged.
• Never allow the torch to touch the cylinder.
• Keep cylinder away from live electrical circuits.
The Precision TIG machines do not have Hi-Freq.
available at the Stick electrode stud, therefore stud
connection adapters (such as LECO. S19257-series)
cannot be used for torch connection.
Single-piece cable air-cooled torches with a 3/8-24 RH
connector fitting (such as the Magnum PTA-9/-17, or LA9/-17) require the provided S20403-4 Torch Connector,
while those with a 7/8-14 RH connector fitting (such as
the Magnum PTA-26, or LA-26) require the available
K2166-1 Torch Connector. (See Figure A.3)
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Observe the safety precautions necessary for handling and using compressed gas containers.
Contact your supplier for specifics.
Two-piece cable air-cooled torches (such as PTA-, or LAtorches) can be used with the available 1/2” Stud
Connector (S20403-3) with with a 7/8-14 LH male fitting.
Magnum PTW-18/-20 (or LW-) water-cooled Torches
require no adapter for Precision TIG connection.
PRECISION TIG 275
A-8
INSTALLATION
FIGURE A.3
A-8
For Gas Supply hose
with 5/8-18RH male
(Provided with Weld
Package model)
For Coolant Supply
Hoses
with 5/8-18LH male
(Provided with Weld
Package model
or
Under-Cooler Cart)
AUXILIARY POWER CONNECTIONS
The Precision TIG machines provide a standard NEMA
5-15R duplex receptacle, located on the upper case
back on the torch side of the machine:
• The bottom outlet of this duplex receptacle provides
switched 115VAC power for the Under-Cooler, or
Water Solenoid accessory. This Cooler receptacle
turns on when the arc starts and remains on for about
8 minutes after the arc goes out (with the Fan-AsNeeded machine cooling fan, see Maintenance
Section), so the Coolerʼs fan and water pump will not
run continuously in idle, but will run while welding.
• The top outlet of this duplex receptacle provides at
least 8 amps at 115VAC, whenever the Precision TIG
Power switch is ON. This auxiliary circuit is intended
for running 115VAC accessories or small power tools.
Note: Some types of equipment, especially pumps
and large motors, have starting currents which are
significantly higher than their running current. These
higher starting currents may cause the circuit breaker
to open. (See next paragraph)
• Both the receptacle circuits are protected from shorts
and overloads by a 15 amp circuit breaker, located
above the receptacle. if the breaker trips its button
pops out exposing a red ring. When the circuit breaker cools the button can be reset by pressing it back
in.
Note: When the breaker trips not only will the auxiliary and cooler power be interrupted, but so will the
power to the shielding gas solenoid and machine
cooling fan.
The Precision TIG Export models also provide a
grounded 220 VAC Euro type Schuko receptacle and a
5 amp circuit breaker, located on the upper case back
on the reconnect side of the machine, intended for use
with a 220 VAC water cooler.
REMOTE CONTROL (If Used)
The Foot Amptrol (included with the Precision TIG
Welding Package), or other Remote accessory, is
installed by routing the plug of its control cable up
through the left cable strain relief hole provided in the
base (see Figure A.2), then connecting the 6-pin plug
to the mating Remote receptacle behind the stud panel
cover. (See Operation Section B-2 for mating plug
wiring.)
Note: If the Precision TIG is equipped with an UnderCooler or Under-Storage unit, the Foot Pedal (or other
remote control accessory) and coiled control cable, or
excess cable length, may be conveniently stored in the
drawer while remaining connected.
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PRECISION TIG 275
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A-9
+V
C
C
= 70Vdc max.
R = V
C
C
/ 5ma
5ma
Robotic
Common
A
B
C
D
E
F
REMOTE RECEPTACLE
(Front View)
For 18-12P Plug
(LECO S12020-27)
ARC START
INPUT FROM ROBOT
(18Vac,10ma switch)
PRESET CONTROL
INPUT FROM ROBOT
(0 -10Vdc = Rated Output Range)
ARC ESTABLISHED
OUTPUT TO ROBOT
(High = Not Welding)
(Low = Welding)
* Precision TIG Control Common.
Note: The Interface connection
cable may pick up noise
interference. Additional
bypass/filtering circuits may be
needed for the external circuits.
INSTALLATION
ROBOTIC INTERFACE CONNECTION
Robotic interface can be made at the Remote
Receptacle (See Operation Section). The machine is
shipped with the remote receptacle circuit internally
connected to receptacle J5 of the Control board for
standard Amptrol operation. In order to enable the
remote receptacle for robotic interface its connection
plug must be moved from J5 to J5A on the Control
board. (Refer to the machine Wiring Diagram.)
The robotic interface functions with the Precision TIG
set to either TIG or STICK mode, but must be in
REMOTE switch position for the Preset Control interface to function. When in the REMOTE position with
robotic interface neither the MAXIMUM OUTPUT nor
the MINIMUM OUTPUT panel controls limit the interface control setting over the rated output range of the
machine.
The diagram in Figure A.4 below shows the remote
receptacle plug connections and signals for robotic
interface:
A-9
FIGURE A.4
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PRECISION TIG 275
A-10
NOTES
A-10
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PRECISION TIG 275
B-1
TABLE OF CONTENTS
- OPERATION SECTION -
Operation ...............................................................................................................................Section B
Warnings” in the Safety section if
welding must be performed under
electrically hazardous conditions
such as welding in wet areas or on
or in the workpiece.
WELDING SPARKS
can cause fire and explosion
* Keep flammable material away.
* Do not weld on containers that
have held combustibles.
PRODUCT DESCRIPTION
The Precision TIG 275 is part of a new family of industrial arc welding power sources providing constant current, single range square wave AC/DC TIG (GTAW)
with new patented (pending) Micro-Start
Presettable Min. and Max. Output controls, and built-in
high frequency stabilization for continuous AC TIG and
DC TIG starting. It also has AC/DC Stick (SMAW)
capability, with adjustable Arc Force availability. A TIG
Pulse Panel. Power Factor Capacitors and a Water
Solenoid are available as field installed optional kits.
Also, a new Undercarriage (with double gas bottle
rack) is available for field installation, as well as a new
Under-Cooler Cart, which is also included in an available efficiently integrated entire TIG Welding Package
with convenient built-in storage provisions for welding
equipment and components.
The Precision TIG 275 includes advanced features
such as a Digital Meter, Presettable control, Auto
Balance
able Postflow shielding gas and Timers. In addition, 2Step/4-Step and Pulse TIG operation with adjustable
Downslope Time control are included with an available
field installed kit. It also features a Stick stud panel and
a universal TIG torch connection box for simultaneous,
but separated, electrode outputs.
The Precision TIG 275 has enhanced Features which
includes the following:
• MicroStart™ Codes Below 11000
• MicroStart™ II Codes Above 11000
• Auto-Balance optimized
• Menu button added
• Spot On selection added
TM
, Fan As Needed (F.A.N.) fixed Preflow, vari-
TM
Technology,
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Observe additional Safety Guidelines detailed in
the beginning of this manual.
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PIPE THAWING
The Precision TIG 275 is not recommended for pipe
thawing.
Duty Cycle
The duty cycle is based upon a 10-minute time period;
i.e., for 40% duty cycle, it is 4 minutes welding and 6
minutes idling. If the rated duty cycle is significantly
exceeded, the thermostatic protection will shut off the
output until the machine cools to a normal operating
temperature. (Refer to Specification Section A-1)
PRECISION TIG 275
B-3
OPERATION
RECOMMENDED PROCESSES AND
EQUIPMENT
RECOMMENDED PROCESSES
The Precision TIG 275 is recommended for the TIG
(GTAW) and Stick (SMAW) welding processes within
its output capacity range of 2 amps DC, or 5 amps AC,
to 340 amps AC/DC. It is compatible with most
Magnum TIG accessories (refer to Equipment
Limitations), as well as many industry standard items,
such as TIG torches, hoses, and water coolers.
PROCESS LIMITATIONS
Precision TIG machines are not recommended for arc
gouging due to it's limited output capacity, and are also
not recommended for pipe thawing.
B-3
EQUIPMENT LIMITATIONS
The Precision TIG machines are protected from overloads beyond the electrical ratings and duty cycles, per
the Specifications Section A-2, A-3, with Thermostat
protection of the primary and secondary transformer
coils.
The Precision TIG machines do not have Hi-Freq.
available at the Stick electrode stud, therefore stud
connection adapters (such as LECO. S19257-series)
cannot be used for torch connection.
RECOMMENDED EQUIPMENT/INTERFACE FOR CODES ABOVE 11000
TIG (water cooled)TIG (air cooled)
Machine:PT275 Welding Package (K2618-1)PT275(K2619-1,-2)
Input Cable/Clamp:User providedUser provided
Gas Reg./Hose:(included)LE/Harris 3100211
Magnum Torch:(PTW20 included)PTA9 or PTA17
Magnum Parts:(KP510 and K918-2 included)KP507 or KP508
Work Clamp/Lead:(15 ft. included)K2150-1 Work Lead Assembly
Foot Amptrol:(K870 included)K870
RECOMMENDED EQUIPMENT/INTERFACE FOR CODES BELOW 11000
TIG (water cooled)TIG (air cooled)
Machine:PT275 Welding Package (K1825-1)PT275(K1826-1, -2, K1827-1)
Input Cable/Clamp:User providedUser provided
Gas Reg./Hose:(included)LE/Harris 3100211
Magnum Torch:(PTW20 included)PTA9 or PTA17
Magnum Parts:(KP510 and K918-2 included)KP507 or KP508
Work Clamp/Lead:(15 ft. included)K2150-1 Work Lead Assembly
Foot Amptrol:(K870 included)K870 or K870-1
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PRECISION TIG 275
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B-4
OPERATION
B-4
CONTROLS AND SETTINGS
The Front Control Panel contains the knobs and switches necessary for adjusting the operation of the Precision
TIG 275, with function indicator lights and an electronic display for volts and amps. The components are
described below:
FIGURE B.1 - CONTROL PANEL
7
7a
8
3
6
9
5
9
10
4
14
12
13
15
16
17
1. POWER SWITCH
2. POLARITY SWITCH
3. MODE SWITCH
4. AC BALANCE CONTROL
5. LOCAL/REMOTE
SWITCH
6. MAXIMUM OUTPUT CONTROL
7. MINIMUM OUTPUT CONTROL AND
DISPLAY SWITCH
7.a MENU BUTTON AND DISPLAY
SWITCH FOR CODES ABOVE 11000
8.
DIGITAL METE R AND DISP LAY
SWITCH
9. POSTFLOW TIME
10. THERMAL SHUTDOWN LIGHT
11. REMOTE RECEPTACLE
12. TRIGGER SWITCH
13. PULSE MODE SWITCH
14. PULSE FREQUENCY CONTROL
15. PULSE % ON TIME CONTROL
16. PULSE BACKGROUND CURRENT
CONTROL
17. DOWNSLOPE TIME
CURRENT CONTROL
1
2
1. POWER SWITCH - Input line switch turns input
power ON or OFF, as indicated by the on or off status of the front panel displays.
2. POLARITY SWITCH – The 3-position rotary power
switch has detente positions for DC-, AC and DC+
selections for the Electrode output welding polarity.
3. MODE SWITCH – The mode switch allows vertical-
ly positioned selection of the two machine welding
modes. The selected mode is indicated by a lit colored panel light which permits viewing the machine
setting from a distance:
3.a STICK mode (Top position) –Red panel light
WARNING
11
• The CC Stick mode may be used for general purpose stick welding (SMAW ) within the capacity of
the machine. The capacity is too limited for air carbon arc gouging (CAC-A).
• In this mode; the output terminals are activated
electrically HOT, gas flow is not activated and HOT
START and ARC FORCE levels are fixed, or
Advanced Panel selectable (See Section B-7 ), with
no front panel adjustment.
3.b TIG mode (Bottom position) – No panel light.
• When the Polarity Switch is set to AC, the TIG
mode provides continuous high frequency to stabilize the arc for AC TIG welding.
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ELECTRIC SHOCK can kill.
• When the Power Source is ON in
STICK mode the Electrode circuits of
both the Stick and TIG torch cables
are electrically HOT to Work.
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• Hi-Freq. turns on after preflow time with the arc
start switch closure, and turns off when the arc
goes out* after the arc start switch opens.
* Arc voltage and current are sensed to determine if
the arc is established or out.
PRECISION TIG 275
B-5
OPERATION
B-5
• When the Polarity Switch is set to DC (- or +), the
TIG mode provides high frequency only for starting.
• Hi-Freq. turns on after pre-flow time with the arc
start switch closure, and turns off when the arc is
established*
• DC+ polarity can also be used for ”balling” of the
tungsten for AC TIG welding.
4. AC BALANCE CONTROL – The potentiometer
control permits AC wave balance adjustment from
Max. Penetration (~85% negative wave) with the
control at Max. full CW position, to Max. Cleaning
(~65% positive wave) with the control set near minimum CCW position.
• Full minimum CCW position is the Auto Balance
position which is indicated by the Green panel light
turning on. This feature automatically provides the
proper amount of cleaning and penetration for normal AC TIG welding
• The mid position is the Balanced position (~50%
positive and negative waves).
• With the Current Control switch to REMOTE position, this knob sets the maximum welding level that
the Peak output can be set with the remote Amptrol.
TM
• The new MicroStart
circuit provides for low end welding (down to 2
amps) previously unobtainable on an SCR platform
TIG machine.
7. MINIMUM OUTPUT CONTROL AND DISPLAY SWITCH
A smaller knob is used to preset the minimum current level only for TIG mode. Pressing the Display
(momentary) switch toggle left to Minimum Set position displays the Minimum control level setting on the
Digital meter. (See Item 8)
• This knob sets the Start output level. When the arc
lights (using a new built-in TIG start pulse) this level
upslopes quickly (0.5 sec.w/ Advanced Panel, zero
w/o) and smoothly to the weld output level. The setting range for this Start control is the 2 amp minimum range of the machine up to about 50 amps, but
no more than the level set by the Maximum Output
control knob (See Item 6), but otherwise is independent of the Maximum setting.
Technology minimum current
–
• The Balance control is only functional if the machine
is set to AC polarity and TIG mode.
5. LOCAL/REMOTE
2-position switch selects how the welding output is
controlled for both Stick and TIG Modes:
• LOCAL (Top position) selects output control only by
the machine panel Output Control. (See Item 6)
• REMOTE (Bottom position) selects output control to
also be by an Amptrol (See Item 6), or other remote
(10K pot) control connected to the Remote receptacle (See Item 11) This switch selection is indicated
by the Green panel light turning on.
In either position the arc start switch functions when
connected to the Remote receptacle (See Item 11).
6. MAXIMUM OUTPUT CONTROL – The large knob
is used to set the output welding current over the
rated output range of the machine.
• With the Current Control switch to LOCAL position,
this knob sets the welding output level.
CURRENT CONTROL SWITCH
– A
• This setting also serves as the Crater-fill level, but
with a Precision TIG Advanced Panel it can be
selected (see Section B-7) to be either the Minimum
Output control setting (same as Start setting) as
shipped, or the minimum rating of the machine (2
amps).
• The Remote Amptrol range of control is between
this Minimum setting and the Maximum Output control knob setting, so these knobs can set the resolution of the Amptrol. Also, the Minimum setting
serves as both the minimum Amptrol start level
when the arc start switch is closed, as well as the
minimum Amptrol crater-fill level before the arc start
switch is opened to help prevent premature arc out
and Hi-Freq re-initiation.
.
• In STICK mode the Start control is not functional
since Hot Start level is fixed, or internal Advanced
Panel adjustable (see Section B-7). Pressing the
Display (momentary) switch toggle left to Minimum
Output position displays minimum amps rating of
the machine.
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PRECISION TIG 275
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B-6
DIGITAL DISPLAYDIGITAL DISPLAY
(SET)
DISPLAY
(SELECT)
DISPLA Y
OPERATION FOR CODES ABOVE 11000 ONLY
B-6
7aaMENU BUTTON AND DISPLAY SWITCH (Codes
above 11000) – Pressing and holding the (Menu)
Button for about 5 seconds
enters
the menu display
which allows:
Selection
•
of up to seven programmable parameters
(Preflow, Upslope, Hot Start, Arc Force, etc.) on the
digital meter is achieved by momentarily pressing
and releasing the MENU button to step through the
parameters.
Setting
•
of the desired level, displayed on the digital
meter for the selected parameter, is done by pressing the DISPLAY (momentary) switch toggle to the
right to increase the level setting, or to the left to
decrease it.
TIG Mode Menu
Setting:
Selection 1:
0
1 *
2
Selection 2:
0
1
2 *
3
4
5
Selection 3:
0 *
1
2
∆
Description:
HF (High Freq.)
Scratch start TIG (No Hi-Freq.)
Normal Hi-Freq. start and weld
Lift TIG (Touch start w/o Hi-Freq.)
PF (Preflow time)
No Preflow
0.1 sec.
0.5 sec.
1.0 sec.
1.5 sec.
2.0 sec.
SS (MicroStart™ Start Pulse)
No AC pulse/Low DC pulse (soft start)
High AC/DC pulse (forceful start)
HS setting (see below) for each pulse when Pulse
mode welding anodized aluminum.
* Default Factory Setting. (Indicated by "blinking" decimal point.)
∆
Only selectable with Advanced Control Panel installed.
• Any of the following actions will exit the menu display:
1. Pressing and holding the (Menu) Button again for about 5 seconds.
2. Allowing the menu display to be unchanged for about 15 seconds.
3. Closing the arc start switch (TIG Mode) or starting the arc (Stick Mode).
In Stick Mode the machine output will remain on while in menu display.
Note:
TIG Mode Menu (with Advanced Control Panel installed):
Setting:
Selection 4:
0 *
1
2
3
4
5
6
7
8
9
Selection 5:
0
1*
2
3
4
5
* Default Factory Setting. (Indicated by "blinking" decimal point.)
STICK Mode Menu (with Advanced Control Panel installed ◊ ):
Setting:
Selection 6:
0
1
2
3
4
5 *
6
7
8
9
Selection 7:
0
1 *
2
3
4
5
6
7
8
9
* Default Factory Setting. (Indicated by "blinking" decimal point.)
◊
If no Advanced Control Panel the Stick menu
displays “- - -“.
Description:
HS (TIG Hot Start % of output setting)
+0% (Only setting for SS0, above.)
+10%
+20%
+30%
+40%
+50%
+60%
+70%
+80%
+90%
UP (Upslope Time)
None (Only setting for SS1 & SS2, above.)
0.5 sec.
1.0 sec.
1.5 sec.
2.0 sec.
2.5 sec.
Description:
HS (Stick Hot Start % added to output setting)
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• Re-entering the menu displays the last parameter and setting that was displayed when the menu was
exited.
• All settings may be reset to the Factory Default Settings (above) by holding the (Menu) button pressed while
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turning on the machineʼs Power switch. The display will show “rES” to indicate the defaults are reset.
PRECISION TIG 275
B-7
A
B
C
D
E
F
Max
10K ohm
Min
REMOTE RECEPTACLE*
(Front View)
REMOTE OUTPUT
CONTROL
ARC START
SWITCH
*For 18-12P Plug
(LECO S12020-27)
OPERATION
B-7
8. DIGITAL METER AND DISPLAY SWITCH– A 3-
digit LED meter is used to monitor the preset and
actual welding procedure based on the Display
(momentary) switch position:
• Before welding with Display switch in center (normal) position, the digital meter displays the preset
welding amps set by Maximum Output control knob
(See Item 6). If in Stick mode using REMOTE (See
Item 5.), the digital meter displays the preset welding amps set by the Remote control. (See Item 11)
• While welding with Display switch in center (normal)
position, the digital meter displays the actual welding amps with one amp resolution (XXX) and accuracy within 4%+/-2A of reading.
• At any time in TIG mode, pressing the Display
switch to left causes the digital meter displays the
amps preset by the Minimum Output control knob
(See Item 7).
• At any time in Stick mode, pressing the Display
switch to left causes the digital meter to display the
minimum amps rating of the machine (See Item 7).
• In either mode, while pressing the Display switch
right to Volts position, the digital meter displays
actual output volts. Volts is displayed with 0.1 volt
resolution (XX.X) and accuracy within 3%+/-1V of
reading.
• When the Current Control Switch is in either
or REMOTE
positions the arc start switch functions
LOCAL
when connected to the Remote receptacle.
FIGURE B.2
ADVANCED PANEL CONTROLS
The following controls are included only if the Precision
TIG 275 has the Advanced Control Panel (K1829-1)
option installed: (Refer to Figure B.3 Tig Weld Cycle
Chart for graphic illustration of these TIG welding functions.)
12. TRIGGER SWITCH – This 2-position switch
selects how the arc start switch ( connected to the
above Remote receptacle) functions; in 2-Step or
4-Step mode:
9. POSTFLOW TIME – This knob is used to set the
TIG mode shielding gas postflow time over the
range of about 2 to 60 seconds after the arc is shut
off. The postflow on time status is indicated by the
Green panel light.
• Gas preflow time for TIG mode is fixed at 0.5 seconds, with no panel control.
• Both time ranges are x2 extendable, if needed, by
internal control box selection. (See Section B-7)
10. THERMAL SHUTDOWN LIGHT– This yellow LED
panel light turns on if the machine output is shutdown because internal overheating has occurred,
and turns off when the thermostat resets.
11. REMOTE RECEPTACLE – A 6-socket receptacle
is provided for the connection of an Amptrol, or
other remote control: (See Figure B.2)
• When the Current Control Switch (See Item 5) is in
the REMOTE position, the Amptrol or other remote
(10K pot) connected to the Remote receptacle controls the TIG or Stick mode output within the range
preset by the Maximum and Minimum Output controls. (See Item 6, 7, and 8 for meter display.)
CAUTION
• DO NOT USE 4-STEP IF USING AN AMPTROL
REMOTE.
• Neither the arc start switch nor the output control in the amptrol will function normally to shut
off or control the output. ONLY USE 2-STEP.
• In 2-Step position the arc start switch functions the
same as without the Advanced Panel:
1. Closing switch starts preflow, then a fixed
(0.5 sec.) ramp time from Minimum (Start)
setting level (See Item 7) to Weld setting.
2. Opening switch initiates Downslope ramp
time setting (See Item 17), from Weld setting to Crater-fill level (See Item 7), which
then stops the arc and initiates Postflow
time (See Item 9).
Note: See Figure B.3 for 2-Step operation during
Downslope with Restart feature selected to be disabled, instead of enabled (as shipped).
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PRECISION TIG 275
B-8
OPERATION
B-8
• The 4-Step position allows welding without continuously holding the start switch trigger. The arc start
switch functions in the following manner:
1. Closing the switch starts preflow, then arc
starts at Minimum (Start) setting level (See
Item 7). If the trigger is maintained closed
after preflow time the output remains at the
Start level until it is released.
2. Opening the switch initiates fixed (0.5 sec.)
ramp time from Start setting level to Weld
setting.
3. Reclosing the switch initiates Downslope
ramp time setting (See item 17) from Weld
setting down to the Crater-fill level (See
Item 7) of the machine.
4. Reopening the switch after Downslope time
holds Crater-fill level until it times out, then
stops the arc and initiates the Postflow Time
(See Item 9). Reopening switch during
Downslope time immediately stops the arc
and initiates the Postflow.
Note: See Figure B.4 for 4-Step operation during
Downslope with Restart feature selected to be
enabled, instead of disabled (as shipped).
13.PULSE MODE SWITCH (PULSE / SPOT MODE
SWITCH for codes above 11000) – Turns on the
Pulse Mode as indicated by the Green panel light
turning on.
• PULSE ON position provides a Peak current level
set by REMOTE and/or LOCAL control of the output
current (See Item5), for a time determined by the
Pulse Frequency Control setting (See Item 14) and
the % ON Time (See Item 15). The balance of the
cycle time is at the Background Current level (See
Item 16).
14. PULSE FREQUENCY CONTROL – This knob is
used to set the Pulse Frequency over the peak
pulse range of about 0.1 pps to 20 pps. (One pulse
cycle time = 1/pps = 10 to .05 sec. range.)
15. PULSE % ON TIME CONTROL (PULSE% ON /
SPOT TIME CONTROL for codes above 11000) •
• % ON TIME controls the duration of the peak cur-
rent as a percentage (5% to 95%) of one pulse
cycle. The balance of the cycle time will be at the
Background Current setting. (See Item 16)
• SPOT TIME sets the duration of the SPOT pulse
(0.5 to 5.0seconds on the red scale).
16. PULSE BACKGROUND CURRENT CONTROL –
This knob controls the level of the Background
Current as a percentage (MIN.-100%) of the Peak
(REMOTE and/or LOCAL) output level (See Item
6) down to the Minimum Output setting (See Item
7).
17. DOWNSLOPE TIME– This knob is used to set the
time, over the range of zero to about 10 seconds,
to ramp down from weld setting to Crater-fill level
(See Item 7).
• If the arc goes out after the Downslope time is initiated, the Downslope time is interrupted and the
Postflow time is initiated. This prevents Hi-Freq reinitiation during ramp down crater fill
• When using an Amptrol remote control, where the
downslope is controlled by the operator down to the
crater-fill level, the Downslope time should be set to
zero so as not to have the Downslope time delay
when the arc start switch is opened.
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• Pulsing begins after upslope when the output current rises above the Background Current level and
ends when the output current drops below this level
.
• SPOT ON position provides the peak current level
set by the Maximum Output Control for a time determined by the SPOT TIME control. A red panel light
is ON to indicate SPOT mode.
PRECISION TIG 275
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B-9
HOT START
ARCFORCE
^ ON
1 2 3 4 5 6 7
DIP SWITCH (S1)
SF
OPERATION
INTERNAL SET UP CONTROLS
Precision TIG 275 models which have an Advanced
Panel (K1829-1) option installed* have the following
additional control features which are set up using the
DIP Switch (S1) provided on the internal panel of this
option.
B-9
• Switch #7 Arc Force Level(codes below 11000)–
Prevents "stubbing" of the electrode by providing
extra output current if the arc voltage drops below
the level required to sustain the welding arc. High
(+65%) and Low (+12%) factory set levels are
selectable which are good for most stick welding
applications.
Access to this internal panel is obtained by removing
the two screws securing the top corners of the
Precision TIG front control panel and swinging the control panel down to reveal the panel mounted on the surface of the Precision TIG Control board:
CAUTION
• THE CONTROL BOARDS CONTAIN STATIC SENSITIVE COMPONENTS
• To avoid possible damage to these components
be sure to ground yourself by touching the
machineʼs sheet metal while handling or making
settings on the internal control box components.
ON – Higher for a "crisper" arc, often desired for 6010
type electrodes.
OFF – Lower Arc Force (as shipped) for a "softer" arc
with 7018 or general type electrodes.
• Switch #6 & #7 - Not functional on codes
above 11000 - See item 7a for
adjustment of Hot Start and
Arc Force
• Switch #8 - (NOT CURRENTLY FUNCTIONAL)
TIG WELDING FEATURES
The following DIP switch feature selections function
only when the Precision TIG is set to TIG mode (See
Item 3):
• Switch #1 Preflow/Postflow Time Extension*
(See Item 9)
ON – Doubles the time ranges.
OFF – Standard time ranges (as shipped).
ON
12 3 456 7 8
OFF
DIP SWITCH POSITIONS (FACTORY SETTINGS)
STICK WELDING FEATURES
The following DIP switch feature selections function
only when the Precision TIG is set to Stick mode. (See
Item 3):
• Switch #6 Hot Start Level (codes below 11000) –
Provides an extra output "boost" pulse at the arc
strike to enhance arc starting. This is factory set for
a level (about 50% extra) which is usually good for
most stick welding applications
ON – Hot Start level is used (as shipped).
OFF – No Hot Start.
• Switch #2 2-Step Trigger Restart Feature (See
Figure B.3)
ON – Restart Enabled (as shipped).
OFF – Restart Disabled.
• Switch #3 4-Step Trigger Restart Feature (See
Figure B.4)
ON – Restart Enabled.
OFF – Restart Disabled (as shipped)
• Switch #4 (NOT CURRENTLY FUNCTIONAL)
• Switch #5 Crater-Fill Level (See Item 7)
ON - Level is minimum rating of the machine (2A)
OFF – Level (as shipped) is Minimum Output setting
(same as Start level).
The Preflow/Postflow Time doubling feature can also be selected
*
on Precision TIG 275 models without the Advanced Panel by
accessing the Control board in the control box per above instructions, then disconnecting the jumper terminals attached to the
jumper plug connected to receptacle J3 of the Control board.
(Refer to Machine Wiring Diagram.)
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PRECISION TIG 275
B-10
2 Step Trigger Modes
2 Step - Restart Disabled
2 Step - Restart Enabled
Torch
Button
Output
Current
Gas
Pre-Flow
Post Flow
Normal Sequence
T
orch
Button
O
utput
Current
Gas
Pre-Flow
Post Flow
START/CRATER CURRENT
UP-SLOPE
D
OWN-SLOPE
(With DIP Switch #2 OFF)
(With DIP Switch #2 ON. As Shipped)
Actuate the trigger a second
t
ime, during down-slope, to
immediately end down-slope.
Hold the trigger to maintain
crater current.
Torch
Button
Output
Current
Gas
Pre-Flow
Post Flow
Actuate the trigger a second
time, during down-slope, to
activate up-slope and restart.
2 Step.eps
12-17-07
JRH
OPERATION
FIGURE B.3
B-10
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PRECISION TIG 275
B-11
4 Step Trigger Modes
4 Step - Restart Enabled
4 Step - Restart Disabled
Torch
Button
Output
C
urrent
Gas
Pre-FlowPre-Flow
Post Flow
P
ost Flow
Normal Sequence
Torch
Button
Output
Current
Gas
Pre-Flow
Post Flow
START/CRATER CURRENT
UP-SLOPE
DOWN-SLOPE
(With DIP Switch #3 ON)
(With DIP Switch #3 OFF. As Shipped)
Post Flow
H
old the second trigger
pull for more than 1
second to activate the
restart function. When the
trigger is released
up-slope will occur.
A
ctuate the trigger
holding it less than 1
second, to begin
normal down-slope.
The following two
options are available
during the normal
down-slope period.
A
ctuate the trigger
again, during
down-slope, to
immediately end
down-slope and stop.
O
r actuate and hold the trigger,
during down-slope, to immediately
end down-slope and maintain
crater current. Hold the trigger for
more than 1 second to activate the
restart function. When the trigger
is released up-slope will occur.
Hold the first trigger pull to maintain
the starting current and delay
u
p-slope.
Torch
Button
Output
Current
Gas
4 Step.eps
12-17-07
JRH
Pre-Flow
Post Flow
Post FlowPost Flow
Hold the second trigger
pull for more than 1
second to maintain
crater current before
stopping.
Actuate the trigger
holding it less than 1
second, to begin
normal down-slope.
The following two
options are available
during the normal
down-slope period.
Actuate the trigger a third
time, during down-slope, to
immediately end down-slope
and stop.
Or actuate the trigger a third time,
during down-slope, to immediately
end down-slope. Hold the third trigger
pull to maintain crater current.
OPERATION
FIGURE B.4
B-11
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PRECISION TIG 275
B-12
PREFLOW
F
ixed 0.5 sec
or x2
S
TART TIME
Manual
in 4-Step
UPSLOPE
F
ixed<0.5 sec
w/o Amptrol
MINIMUM OUTPUT
(
Start) SETTING
Adjustable 2-50A
MAXIMUM OUTPUT
S
ETTING
Adjustable 2-Max.A
Amptrol or Remote
(PEAK) Range
2 or 4-STEP
Trigger
Closed
4-STEP
Trigger
1ST Open
4-STEP Trigger
Re-closed or
2-STEP Trigger
O
pened
4-STEP Trigger
Re-opened
after
D
ownslope Time
DOWNSLOPE
A
djust 0 –10 sec
w/ Advan. Panel
(
Fixed 0 sec w/o)
POSTFLOW
Adjust 2-60 sec
or x2
CRATER-FILL
L
EVEL
A
dvanced
Panel Select:
Mach. Min.
or
MIN. Setting
(as w/o Panel)
With PULSE ON
N
o Pulsing
During Upslope Time
or
W
hen Downslope
Drops Below
B
ackground Setting
%
ON TIME
Adjustable
5-95%
P
ULSE FREQ.
Adjustable
0.1-20 pps
BACKGROUND
Adjustable
MIN.Setting -100% Peak
CRATER-FILL TIME
Manual in 2/4-Step
w/ Restart Disabled
TIG WELD CYCLE CHART
OPERATION
CCOODDEESSBBEELLOOWW1111000000((KK11882299--11))
B-12
CCOODDEESSAABBOOVVEE1111000000((KK22662211--11))
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PRECISION TIG 275
B-13
Max. to Min.
Amptrol
Min. to Max.
Amptrol
Setup for TIG Amptrol Welding
Advanced Panel
(If used)
Standard Controls
Power Switch
ON
P
olarity Switch
AC or DC-
Mode Switch
TIG
AC Balance
AUTO
or
Set:
More + for alum. oxide “Cleaning“
w/o “spitting”or“wetting“ loss.
B
alanced for equal
+
and
-
current.
More - for higher “Penetration“.
Local/Remote
Switch
REMOTE
Trigger Switch
2-STEP
Pulse Switch
ON or OFF
Pulse Frequency
4-6 pps is a typical initial setting.
Set for bead shape and travel speed:
Higher for thinner plate and faster travel.
Lower for thicker plate and slower travel.
% On Time
40-60% is a typical initial setting.
Set for total heat of Peak current:
Lower reduces distortion and burn-thru.
Background Current
40-60% is a typical initial setting.
Set as low as will maintain a pulse arc
(Will not drop below
Min.Output
setting.)
Downslope
ZERO
For no arc-out delay.
Minimum Output
Press Display switch
and Set to desired min.
A
mptrol (Start/Crater)
o
utput level.
Postflow
Set as low as required.
Higher for larger
t
ungsten and current.
Maximum Output
S
et to desired max.
A
mptrol output level.
OPERATION
FIGURE B.6
B-13
SETUP GUIDELINES FOR TIG WELDING
WITH AN AMPTROL
Both the Hand and Foot Amptrols work in a similar
manner. They are meant to be used for remote current
control for TIG welding using the machineʼs 2-Step trigger mode (See Item 12).
The Amptrol is capable of controlling the output of the
Precision TIG over the range between the level preset
by the Minimum Output control when the Amptrol is at
its inactivated state, and the level preset by the
Maximum Output control when the Amptrol is at fullyactivated state.
AA ddvvaanncceeddPPaanneell
Controls
It is important to note that even with the Precision TIGʼs
new MicroStartTMTechnology, some tungsten may be
difficult to start at the low (2 amps) minimum rating of
the machine. Rather than guessing where to depress
the Amptrol to start the arc reliably, the MinimumOutput control allows presetting the exact level, so reliable starts, as well as minimum crater-fill levels, can be
consistently obtained at the minimum Amptrol (inactivated ) state. FIGURE B.6 shows Precision TIG setup
for TIG welding with an Amptrol.
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PRECISION TIG 275
B-14
OPERATION
B-14
MAKING A TIG WELD WITH AN AMPTROL
1. Install welding equipment per Section A-5.
2. Setup controls per Section B-9.
3. Turn on the shielding gas supply, and torch coolant
input supply (if used).
Note: The Precision TIG Under-Cooler (or Water
Solenoid connected to the Cooler receptacle) runs with
the Fan-As-Needed machine cooling fan (See
Maintenance Section D), so the cooler fan and water
pump will also not run continuously in idle, but will run
while welding.
4. With the torch held safely away from everything,
close the Arc Start Switch of the Amptrol and set the
gas flow meter. Then open the switch. The welder
is now ready for welding.
5. Position the tungsten electrode at the start of the
weld at a 65° to 75° angle with the horizontal, in the
direction of pushing travel, so that the electrode is
approximately 1/8" (4 mm) above the work piece.
Close the arc start switch. This opens the gas valve
to automatically purge air from the hose and torch,
then shields the arc strike area. After the 0.5 second preflow time, the high frequency becomes
available to strike the arc. When the arc strikes the
torch coolant (if used) starts to flow. Also, if welding
DC- TIG, the high frequency shuts off just after the
arc strikes.
6. Hold the arc start switch closed at minimum Amptrol
Start level (See Section B-10) until an arc is established, then increase the output to the desired welding level and push the torch in the direction of travel.
7. At the end of the weld, decrease the Amptrol output
to the crater-fill level before releasing the arc start
switch to start the Postflow time. Hold the torch gas
shielding over the solidifying weld crater while postflow time expires and the gas valve reopens. The
torch coolant (if used) continues to flow for up to 8
minutes after the arc goes out (with the Fan-AsNeeded feature) to assure torch cooling.
• Repeat steps 5 through 7 to make another weld.
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Mild steel procedures are based on recommended procedures listed in C2.10 8/94 and the maximum rating of the PRECISION TIG 275
Excaliber 7018 procedures are based on Jet-LH 78 MR
Blue Max procedures are based on C6.1 6/95
Red Baron Procedure are based on ES-503 10/93
GTAW Process
Electrode PolarityDC-AC*Approximate Argon
Electrode Tip PreparationSharpenedBalledGas Flow Rate
Electrode Type
EWTh-1, EWCe-2EWTh-1, EWTh-2
EWZrC.F.H. (l/min.)
EWTh-2, EWLa-1EWPEWCe-2, EWLa-1Stainless
Electrode Size (in.)EWGEWGAluminumSteel
.010Up to 15 A.Up to 15 A.Up to 15 A.3-8(2-4) 3-8(2-4)
.020Up to 15 A.10 to 15 A.5 to 20 A.5-10(3-5) 5-10(3-5)
.040Up to 80 A.20 to 30 A.20 to 60 A.5-10(3-5) 5-10(3-5)
1/16Up to 150 A.30 to 80 A.60 to 120 A.5-10(3-5) 9-13(4-6)
3/32Up to MAX. A.60 to 130 A.100 to 180 A.13-17(6-8)11-15 (5-7)
1/8X100 to 180 A.160 to 250 A.15-23 (7-11) 11-15 (5-7)
Tungsten electrodes are classified as follows by the American Welding Society (AWS):
Pure .........................................EWP...........green