Lincoln Electric OPTIMARC AC/DC 350-TP User manual

Rev. 05
OPTIMARC®AC/DC 350-TP
IM7024-1
Nov, 2019
Rev. 05
OPTIMARC®AC/DC 350-TP
For use with machine Part Number K60108-1, Code 76251
•World’s Leader in Welding and Cutting•
THE SHANGHAI LINCOLN ELECTRIC COMPANY
No. 195, Lane 5008, Hu Tai Rd. Baoshan, Shanghai, PRC 201907
www.lincolnelectric.com.cn
Copyright © 2019 The Shanghai Lincoln Electric Company
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
you part. DO NOT INSTALL, OPERATE
OR REPAIR THIS EQUIPMENT
WITHOUT READING THIS MENUAL
AND THE SAFETY PRECAUTIONS
CONTAINED THROUGHOUT. And,
most importantly, think before you act
and be careful.

Rev. 05
OPTIMARC®AC/DC 350-TP
Thank you for selecting QUALITY Lincoln Electric products.
Please examine the packaging and equipment for damage. Claims for material damaged in shipment must be
notified immediately to the authorized dealer from whom you purchased the machine.
For future reference, please record your equipment identification information in the table below. Model Name,
Code & Serial Number can be found on the machine rating plate.
Model Name
□OPTIMARC®AC/DC 350-TP
Code & Serial number
K60108-1
Date & Where Purchased
Authorized dealer’s shop
Declaration of conformity
THE SHANGHAI LINCOLN ELECTRIC COMPANY
Designed in conformance with the following norm:
GB/T 15579.1
EN 60974-1
THE SHANGHAI LINCOLN ELECTRIC COMPANY
No. 195, Lane 5008, Hu Tai Rd. Baoshan, Shanghai, PRC 201907

iSAFETY i
Rev. 05
OPTIMARC®AC/DC 350-TP
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.
BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR
PROCEDURES ARE PERFORMED ONLY BY QUALIFIED INDIVIDUALS.
WARNING
ELECTRIC AND
MAGNETIC FIELDS
may be dangerous.
1.a Electric current flowing through any conductor
causes localized Electric and Magnetic Field
(EMF). Welding current creates EMF fields
around welding cables and welding machines.
1.b EMF fields may interfere with some pacemakers,
and welders having a pacemaker should consult
their physican before welding.
1.c All welders should use the following procedures
in order to minimize exposure to EMF fields from
the welding circuit:
1.c.1 Route the electrode and work cables
together –Secure them with tape when
possible.
1.c.2 Never coil the electrode lead around your
body.
1.c.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.c.4 Connect the work cable to the workpiece
as close as possible to the area being
welded.
ARC RAYS can burn.
2.a Use a shield with the proper filter and cover
plates to protect your eyes from sparks and the
rays of the arc. Headshield and filter lens should
conform to ANSI Z87. I standards.
2.b Use suitable clothing made from durable flame-
resistant material to protect your skin and that of
your helpers from the arc rays.
2.c Protect other nearby personnel with suitable,
non-flammable screening and/or warn them not
to watch the arc nor expose themselves to the
arc rays or to hot spatter or metal.
ELECTRIC SHOCK
can kill.
3.a The electrode and work (or ground) circuits are
electrically “hot” when the welder is on. Do not
touch these “hot” parts with your bare skin or wet
clothing. Wear dry, hole-free gloves to insulate
hand.
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, grating 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 Menual (MMA) 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 holder to two welders because
voltage between the two can be total of the open
circuit voltage of both welders.

ii SAFETY ii
Rev. 05
OPTIMARC®AC/DC 350-TP
FUMES AND GASES
can be dangerous.
4.a Welding may produce fumes and gases
hazardous to health. Avoid breathing these
fumes and gases. When welding, keep your
head out of 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.
4.b Do not weld in locations near chlorinated
hydrocarbon vapors coming from degreasing,
cleaning or spraying operations. The heat and
rays or the arc can react with solvent vapors to
form phosgene, a highly toxic gas, and other
irritating products.
4.c Shielding gases used for arc welding can
displace air and cause injury or death. Always
use enough ventilation, especially in confined
areas, to insure breathing air is safe.
4.d Read and understand the menufacturer’s
instructions for this equipment and the
consumables to be used, including the material
safety data sheet (MSDS) and follow your
employer’s safety practices. MSDS forms are
available from your welding distributor or from
the menufacturer.
FOR ELECTRICALLY
powered equipment.
5.a Turn off input power using the disconnect switch
at the fuse box before working on the equipment.
5.b Install equipment in accordance with the national
standard, all local standards and the
menufacturer’s recommendations.
5.c Ground the equipment in accordance with the
national standards and the menufacturer’s
recommendations.
WELDING SPARKS
can cause fire or
explosion.
6.a Remove fire hazards from the welding area. If
this is not possible, cover them to prevent the
welding sparks from starting a fire. Remember
that welding sparks and hot materials from
welding can easily go through small cracks and
openings to adjacent areas. Avoid welding near
hydraulic lines. Have a fire extinguisher readily
available.
6.b 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.c 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 subtances
inside. They can cause an explosion even
though they have been “cleaned”.
6.d Sparks and spatter are thrown from the welding
arc. Wear oil free protective garments such as
leather gloves, heavy shirt, cuffless trouses, high
shoes and a cap over your hair.
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 Cylinder 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.

CONTENTS
Rev. 05
OPTIMARC®AC/DC 350-TP
INSTALLATION.......................................................................................................................................A-1
TECHNICAL SPECIFICATIONS –OPTIMARC®AC/DC 350-TP ............................................................................. A-1
SAFETY PRECAUTIONS........................................................................................................................................ A-2
SELECT SUITABLE LOCATION ...................................................................................................................... A-2
INPUT POWER AND GROUNDING CONNECTION........................................................................................ A-2
CABLE CONNECTIONS................................................................................................................................... A-2
OPERATION…………………………………………………………………………………………………….B-1
GRAPHIC SYMBOLS THAT APPEAR ON THIS MACHINE OR IN THIS MANUAL................................................ B-1
SAFETY PRECAUTIONS........................................................................................................................................ B-4
OPERATIONAL FEATURES AND CONTROLS...................................................................................................... B-4
FRONT PANEL (SEE FIGURE B.1) ................................................................................................................. B-4
REAR PANEL (SEE FIGURE B.2).................................................................................................................... B-5
FAN WORK STATUS ....................................................................................................................................... B-5
USER INTERFACE OPERATION (SEE FIGURE B.3)..................................................................................... B-5
POWER ON .............................................................................................................................................. B-5
WEIDING MODES..................................................................................................................................... B-6
OUTPUT WAVEFORMS ........................................................................................................................... B-6
CRATER MODES...................................................................................................................................... B-6
PULSE....................................................................................................................................................... B-7
SETTINGS................................................................................................................................................. B-7
MEMORY .................................................................................................................................................. B-7
WELDING STATUS................................................................................................................................... B-8
WELDING WAVEFORM............................................................................................................................ B-8
WELDING PARAMETERS ........................................................................................................................ B-8
CURRENT PARAMETER SETTING ......................................................................................................... B-8
WEIDING CURRENT AND WELDING VOLTAGE .................................................................................... B-8
FUNCTION CONFIGURATION STATUS.................................................................................................. B-8
REMOTE SETTING VALUE...................................................................................................................... B-8
LOCK SCREEN......................................................................................................................................... B-9
RECALLED PROCEDURE NUMBER ....................................................................................................... B-9
FAULT IDENTIFICATION.......................................................................................................................... B-9
TIG TRIGGER SEQUENCES.................................................................................................................................. B-9
2-STEP TRIGGER SEQUENCE....................................................................................................................... B-9
2-STEP REPEAT TRIGGER SEQUENCE........................................................................................................ B-9
4-STEP TRIGGER SEQUENCE....................................................................................................................... B-9
4-STEP REPEAT TRIGGER SEQUENCE.......................................................................................................B-10
AC BALANCE AND AC OFFSET............................................................................................................................B-10
LIST OF PARAMETERS AND FACTORY CONFIGURATION PROGRAM............................................................B-11
TROUBLESHOOTING………………...…………………………………………...………………………….C-1
WIRING DIAGRAM……….……………………………………………………………………………………D-1
NOTES………………………..………………………………………………………………………………….E-1

A-1INSTALLATION A-1
Rev. 05
OPTIMARC®AC/DC 350-TP
TECHNICAL SPECIFICATIONS –OPTIMARC®AC/DC 350-TP
INPUT –THREE PHASE ONLY
Standard Voltage/Phase/Frequency
380V ~ 415V(±10%)/3/50 or 60 Hz
RATED OUTPUT –DC AND AC
Input Power at Rated Output ( MMA )
15 KW (40% DUTY CYCLE)
OUTPUT
MODE
DUTY CYCLE
CURRENT
RATED OUTPUT
VOLTAGE
DC
MMA
40%
60%
100%
350A
300A
250A
34V
32V
30V
TIG
40%
60%
100%
350A
300A
250A
24V
22V
20V
AC
MMA
SQUARE
60%
100%
300A
250A
32V
30V
SINE
TRIANGLE
100%
250A
30V
TIG
SQUARE
60%
100%
300A
250A
22V
20V
SINE
TRIANGLE
100%
250A
20V
OUTPUT RANGE –DC AND AC
OUTPUT
MODE
CURRENT RANGE
OCV
VOLTAGE RANGE
DC
MMA
10A ~ 350A
72V/78V
20.4 V ~ 34V
TIG
4A ~ 350A
72V/78V
10.16 V ~ 24V
AC
MMA
SQUARE
10A ~ 300A
72V/78V
20.4 V ~ 32V
SINE
TRIANGLE
10A ~ 250A
20.4 V ~ 30V
TIG
SQUARE
10A ~ 300A
72V/78V
10.4 V ~ 22V
SINE
TRIANGLE
10A ~ 250A
10.4 V ~ 20V
RECOMMENDED INPUT WIRE AND FUSE SIZES
Input Voltage/
Frequency (Hz)
380V / 415V/
50 Hz / 60 Hz
Maximum
Input Ampere
30A / 24A
Maximum
Effective Supply
Current
19A / 15A
60°C Copper
Wire in
Conduct
Sizes
6mm2
Fuse or Breaker Size
(Super Lag)
40A
Grounding
Conductor
Size
4mm2
PHYSICAL DIMENSIONS
Height
540mm
Width
340mm
Depth
800mm
Weight
56Kg
TEMPERATURE RANGE
Operating Temperature Range
-10°C ~ +40°C
Storage Temperature Range
-25°C ~ +55°C
EMC
EMC CLASS
A （INDUSTRIAL MACHINE）
For any maintenance or repair operation it is recommended to contact the nearest technical service center or directly
consult the machine division of the Shanghai Lincoln Electric. Maintenance or repairs performed by unauthorized service
center or personnel will void the manufacturer’s warranty.

A-2INSTALLATION A-2
Rev. 05
OPTIMARC®AC/DC 350-TP
SAFETY PRECAUTIONS
Read the entire installation section before starting
installation.
ELECTRIC SHOCK can kill.
Only qualified personnel
should perform this installation.
Turn the input power OFF at
the main switch or fuse box before
working on this equipment. Turn
off the input power to any other equipment
connected to the welding system at the main
switch or fuse box before working on the
equipment.
Do not touch electrically “Hot”parts.
Always connect the OPTIMARC®grounding lug
(located at the rear of the case) to a proper safety
(Earth) ground. OPTIMARC®is for use on a 4 wire
system with earthed neutral.
SELECT SUITABLE LOCATION
This power source should not be subjected to falling
water, nor should any parts of it be submerged in water.
Doing so may cause improper operation as well as pose
a safety hazard. The best practice is to keep the machine
in a dry, sheltered area.
The bottom of machine must always be placed on a
firm, secure, level surface. There is a danger of the
machine toppling over if this precaution is not taken.
Place the welder where clean cooling air can freely
circulate in through the back louvers and out through the
case or front sides. Water,dirt, dust or any foreign
material that can be drawn into the welder should be kept
to a minimum. Failure to observe these precautions can
result in excessive operating temperatures and nuisance
shutdowns.
Locate the OPTIMARC®machine away from radio
controlled machinery. Normal operation of the welder
may adversely affect the operation of RF controlled
equipment, which may result in bodily injury or damage to
the equipment.
INPUT POWER AND GROUNDING
CONNECTION
Only a qualified electrician should connect the input
leads to the OPTIMARC®. Connections should be
made in accordance with the connection diagram.
Failure to do so may result in bodily injury or death.
Open the input box on the rear of the case. Use a three-
phase supply line, the three live wires should go through
the three holes of the input wire holder and be securely
clamped and fixed. Connect L1, L2, L3 and ground
according to the Input Supply Connection Diagram decal,
refer to Figure A.1 on this page.
Make sure the amount of power available from the input
connection is adequate for normal operation of the
machine. Refer to the Technical Specifications at the
beginning of this Installation section for recommended
fuse and wire sizes. Fuse the input circuit with the
recommended super lug fuse or delay type breakers.
Using fuses or circuit breakers smaller than
recommended may result in “nuisance” shut-offs from
welder inrush currents, even if the machine is not being
used at high currents.
FIGURE A.1
CABLE CONNECTIONS
Connect electrode and work leads with sufficient size
between the proper output studs on the power source
and the electrode or the work. Be sure the connection to
the work makes tight metal to metal electrical contact.
Poor work lead connections can result in poor welding
performance.
To avoid interference problems with other equipment
and to achieve the best possible operation, route all
cables directly to the electrode and the work. Avoid
excessive lengths and do not coil excess cable.
Cable sizes are increased for greater lengths primarily for
the purpose of minimizing voltage drop in the cable.
Minimum work and electrode cable sizes are as follows:
TABLE A.1
Current (60% Duty Cycle)
Minimum Copper
Work Cable Size
200A
300A
400A
Up To 30m Length
30 mm2
50 mm2
70 mm2
Note: The recommended cable size may need to change
depending on its quality. When the rated current flow
goes through, the total voltage drop on the ground cable
and electrode cable must not exceed 4 volts.
WARNING
CAUTION
WARNING

B-1 OPERATION B-1
Rev. 05
OPTIMARC®AC/DC 350-TP
GRAPHIC SYMBOLS THAT APPEAR ON THIS MACHINE OR IN THIS MANUAL
MMA
HIGH FREQUENCY
TIG
TOUGH START TIG
SPOT TIG
DC
AC-SQUARE WAVE
AC-SINE WAVE
AC-TRIANGLE
WAVE
2-STEP
2-STEP REPEAT
4-STEP
4-STEP REPEAT
PULSE OFF
PULSE
LOW FREQUENCY
PULSE
HIGH FREQUENCY
SETTING
MEMORY
SAVE PROCEDURE
RECALL
PROCEDURE
FACTORY SETTING

B-2 OPERATION B-2
Rev. 05
OPTIMARC®AC/DC 350-TP
WATER-COOLING
MMA WELDING
SWITCH
REMOTE CONTROL
BRIGHTNESS
CONNECTION
NORMAL
CONNECTION
FAULTY
SCREEN LOCKED
WATER-COOLING
PROTECTION
OUTPUT IGBT TOP
TUBE PROTECTION
OUTPUT IGBT
DOWN TUBE
PROTECTION
OVER/LOW
VOLTAGE
PROTECTION
OVER CURRENT
PROTECTION
THERMAL
PROTECTION
RELAY
PROTECTION
MMA-DC
MMA-SQUARE
WAVE
MMA-SINE WAVE
MMA-TRIANGLE
WAVE
TIG-DC
TIG-DC PULSE
TIG-SQUARE WAVE
TIG-SINE WAVE

B-3 OPERATION B-3
Rev. 05
OPTIMARC®AC/DC 350-TP
TIG-TRIANGLE
WAVE
TIG-SPOT
ARC FORCE
LANGUAGE

B-4 OPERATION B-4
Rev. 05
OPTIMARC®AC/DC 350-TP
SAFETY PRECAUTIONS
Read this entire section of the operating
instructions before operating the machine.
ELECTRIC SHOCK can kill.
Do not touch electrically live
parts or electrode with skin or wet
clothing.
Insulate yourself from work
and ground.
Always wear dry insulating gloves.
FUMES AND GASES can be
dangerous.
Keep your head out of
fumes.
Use ventilation or exhaust
to remove fumes from breathing
zone.
WELDING SPARKS can cause fire
or explosion.
Keep flammable material
away.
Do not weld on closed
containers.
ARC RAYS can burn eyes and
skin.
Wear eye, ear and body
protection.
PLEASE SEE ADDITIONAL WARNING
INFORMATION AT THE FRONT OF THIS
OPERATOR’S MENUAL.
DUTY CYCLE
The duty cycle of a welding machine is the percentage of
time in a 10 minute cycle at which the welder can operate
the machine at rated welding current.
60% duty cycle:
Weld for 6 minutes
Break for 4 minutes
Excessive extension of the duty cycle may cause the
thermal protection circuit to activate.
THERMAL PROTECTION
The OPTIMARC®machine is equipped with thermal
protection devices. When the machine has gone into
thermal overload, the output will be shut off and the
thermal protection symbol will be displayed on the
screen. When the machine has been cooled to a safe
temperature, the thermal protection symbol will disappear
and the machine may resume normal operation.
Note:
The machine’s welding output will be available after a
thermal protection shutdown.
OPERATIONAL FEATURES AND
CONTROLS
FRONT PANEL (SEE FIGURE B.1)
1
2
3
4
5
6
7
8 9 10 11
FIGURE B.1
1. ON/OFF POWER SWITCH
Place the lever in the upside position to energize the
machine.
2. TFT DISPLAY ZONE
Please see FIGURE B.3 for more detailed instruction.
3. PARAMETERS SELECTIONS KNOB
The knob and button are to be used for parameters’
selection and confirmation, please see FIGURE B.3 for
more detailed instruction.
4. RETURN BUTTON
The button is to be used for returning to main interface,
please see FIGURE B.3 for more detailed instruction.
5. PARAMETERS ADJUSTING KNOB
The knob and button are to be used for parameters’
adjusting and confirmation, please see FIGURE B.3 for
more detailed instruction.
6. COOLED WATER INLET
External cooled water input connector.
WARNING

B-5 OPERATION B-5
Rev. 05
OPTIMARC®AC/DC 350-TP
7. COOLED WATER OUTLET
Connected with water inlet of water-cooling TIG torch as
being operated.
8. PROTECTIVE GAS OUTLET
Connected with gas inlet of TIG torch as being operated.
9.NEGATIVE OUTPUT TERMINAL
10. AMPHENOL SOCKET
This socket is used for remote control box connection.
Refer to the following connection form for specific
informaiton on being connected.
Power Source
PIN
SIGNAL NAME
LEAD #
A
Output control pot A
77
B
Output control pot wiper
76
C
Output control pot B
75
D
Output control trigger return
2
E
Output control trigger
4
F
Grounding lead ( case )
G2
11. POSITIVE OUTPUT TERMINAL
Note:
For positive polarity welding connect the electrode cable
to the positive terminal and the work cable to the negative
terminal. For negative polarity welding, reverse the
electrode and work cables.
REAR PANEL (PLEASE SEE FIGURE B.2).
12. INPUT BOX
This insulation box is used to cover the input connections
to provide insulation proection for operators.
This insulation box must be secure before turning on
the main power supply.
13. INPUT CABLE HOLDING BRACKET
This bracket securely holds the three phase power cables
in place.
14. AMPHENOL SOCKET
The socket is used for remote control. Refer to the
following connection form for specific informaiton on
being connected.You should short Pin A and C as used.
The range of input control voltage is 0-10V, the range of
output signal reflecting the welding current is 0-10V.
Note: This remote control can’t use simultaniously
with the remote control box described in Section 10
above.
POWER SOURCE
PIN
FUNCTIONALITY
LEAD
S #
A
Input control voltage compensation
270
B
Input control voltage +
271
C
Input control voltage -
272
D
Output control switch return
273
E
Output control switch
274
F
output signal +
275
G
output signal -
276
H
Reserve
277
I
Reserve
278
15. GROUNDING CABLE CONNECTION
Connect the grounding cable to the paint-free location on
the case back.
16. PROTECTIVE GAS INLET
External protective gas input connector.
12
13
14
15
16
FIGURE B.2
FAN WORK STATUS
The fan motor work continuously in MMA welding mode.
In TIG welding mode, the fan motor will not work right
now when machine power on. Once the output current is
produced, the fan motor will be started. As the output
current is disabled for over 6 minutes, the fan motor’s
power will be shut off. The functionality will extend fan
motor’s operation life, and save customer’s operation cost
too.
USER INTERFACE OPERATION
POWER ON
Self-inspection will be executed when machine power on.
If no malfunction occurs, it will enter the initial interface
(See FIGURE B.3). It will be back to initial interface while
there is no action within 20 seconds
WARNING

B-6 OPERATION B-6
Rev. 05
OPTIMARC®AC/DC 350-TP
FIGURE B.3
Click the selector button (item 3 in FIGURE B.1), menu
bar on the bottom will be selected with a black square
box. The ‘current parameter setting’zone will display the
selected menu name or the current settings. Click the
return button (item 4 in FIGURE B.1), it will be back to the
‘welding modes and parameters’display interface.
WELDING MODES
Select the welding mode menu by rotating the selector
button, then click the selector button , it will enter the
welding mode setting menu. The mode with a black
background is current setup. If you want to change the
mode, rotate the selector button to choose the target
pattern, then click the selector button, it will be chosen. It
contains four modes as follows:
MMA, you can add output control
function in MMA mode, please refer to
‘SETTING’ in B-7 section for more
details.
Touch Start TIG;
High-Frequency TIG;
Spot TIG.
OUTPUT WAVEFORMS
The setup procedures are same as above. It contains
four output waves as follows:
DC;
AC-Square wave;
Ac-Sine wave;
AC-Triangle wave.
You can refer to the output parameters’ranges of
different waveforms in A-1 Technical Specification.
CRATER MODES
The setup procedures are same as above.Trigger mode
is used in TIG modes, It contains four trigger modes as
follows:
2-Step
2-Step Repeat
FUNCTION
CONFIGURATION STATUS
REMOTE
SETTING
RECALLED
PROCEDURE
NUMBER
LOCK
SCREEN
FAULTS
IDENTIFICATION
WELDING
CURRENT &
VOLTAGE
WELDING
PARAMETERS
CURRENT
PARAMETER
SETTING
WELDING
MODES
OUTPUT
WAVEFORMS
MEMORY
SETTINGS
PULSE
CRATER
MODES
WELDING
WAVEFORM
WELDING
STATUS

B-7 OPERATION B-7
Rev. 05
OPTIMARC®AC/DC 350-TP
4-Step
4-Step Repeat
You can refer to the ‘TIG Trigger Sequences’ in B-9
section for more details.
PULSE
The setup procedures are same as above.Pulse only can
be enabled in DC TIG modes. It contains three choices
as follows:
Pulse OFF
Pulse Low Frequency
Pulse High Frequency
You can refer to the ‘List of Parameters and Factory
Configuration program’ in B-11 section for more details.
SETTINGS
Select the setting menu by rotating the selector button,
then click the selector button , it will enter the setting
menu. For changing the parameter, rotate the selector
button to choose the target, then alter the value by
rotating the adjusting button (item 5 in FIGURE B.1), so
the new displayed value has been chosen.
Water-cooling switch, 0-OFF, 1-ON.
Set it to 1 as a water-cooling TIG
Torch is used, it will cause water-
cooling fault and output will be shut off
if there is no pressure through water
route. Factory default setting is 0;
MMA welding switch, 0-OFF, 1-
ON.The output can be controlled by
the remote trigger In MMA mode when
it is set to 1. Factory default setting is 0;
Remote control, 0-OFF, 1-ON. It will
enable the remote control function.
Factory default setting is 0;
Brightness, the range is 1-10. The
factory default setting is 7;
Language, 0-English,1-Chinese. The
factory default setting is 0.
FUNCTION
VALUE
FACTORY
SETTING
Water-cooling switch
0: OFF
1: ON
0
MMA welding switch
0: OFF
1: ON
0
Remote control
0: OFF
1: ON
0
Brightness
1-10
7
Language
0: English
1: Chinese
0
MEMORY
Select the memory menu by rotating the selector button,
then click the selector button , it will enter the save/recall
menu.
Save procedure. Enter the memory
menu, select the save function by
rotating the selector button, then rotate
the adjusting button to choose the
target precedure number, click the
adjusting button to preselect, finally
click the adjusting button again, all the
current welding setup will be preserved
under the selected precedure number
You can keep 10 sets of welding
procedures, and all the procedures will
be removed after restoring the factory
default setting.
Recall procedure, the setup procedures
are same as save procedure.
Factory setting. Enter the memory
menu, select the factory setting
function by rotating the selector button,
then rotate the adjusting button to alter
the value to 1, click the adjusting button
to preselect, it will be chosen after
clicking the adjusting button again.
Note: The procedure number will be displayed as 11.
WELDING STATUS
It illustrates the current welding status, like pre-flow,
upslope, welding, etc.

B-8 OPERATION B-8
Rev. 05
OPTIMARC®AC/DC 350-TP
WELDING WAVEFORM
It illustrates the various welding waveforms.
MMA-DC
MMA-AC Square wave
MMA-AC Sine wave
MMA-AC triangle wave
TIG-DC
TIG-DC Pulse
TIG-AC
Square wave
TIG-AC
Sine wave
TIG-AC
Triangle wave
TIG-SPOT
Arc force
WELDING PARAMETERS
It illustrates the welding parameters. For changing the
welding parameter, choose the target parameter by
rotating the selector button (the name and unit of
parameter will be displayed on the ‘current parameter
setting’zone). rotate the adjusting button to change the
value (the step rate will be increased by pressing &
rotating the button), then the parameter setup will be
done. You can refer to all the value range in various
modes in ‘List of parameters and Factory Configuration
program’ in B-11 section.
CURRENT PARAMETER SETTING
Display the name and unit of the current chosen welding
parameter.
WELDING CURRENT AND VOLTAGE
Display the welding current and voltage.
FUNCTION CONFIGURATION STATUS
Display the function configuration status.It will display the
corresponding symbol when the function is open.
The communication between display
board and control board is normal.
The communication between display
board and control board is abnormal.
REMOTE SETTING
When remote control is ON and the control signal of
current setup switches on, the remote current value will
be displayed. It will be disabled in 4-Step and 4-Step
Repeat modes. The maximum remote current setting
value will be limited by the local current setting.
LOCK SCREEN
Hold the return button for 5 seconds, the screen will be
locked, unlocking will follow the same operation.
Lock screen
RECALLED PROCEDURE NUMBER
Display the recalled procedure number.It will disappear
once the welding parameter is changed.When you
choose the factory setting, it will display number 11.
FAULT IDENTIFICATION
Display the fault identification, when the faults occur more
than one kind, they will be displayed in turn.
Low/Over voltage protection
Thermal protection

B-9 OPERATION B-9
Rev. 05
OPTIMARC®AC/DC 350-TP
Water-cooling protection
Output IGBT Top tube protection
Output IGBT Down tube protection
Relay fault
Over current protection
TIG Trigger Sequences
TIG welding can be operated in 2-Step, 2-Step Repeat, 4-
Step and 4-Step Repeat modes. The specific sequences
of operations for the trigger modes are explained below.
Symbols used:
Torch Button
Output Current
Gas Pre-flow
Gas
Gas Post-flow
2-Step Trigger Sequence
With the 2-step trigger mode and a TIG welding mode
selected, the following welding sequence will occur.
1. Press and hold the TIG torch trigger. The machine
will open the gas valve to start the flow of the
shielding gas. After the Pre-flow time to purge air
from the torch hose, the output of the machine is
turned ON. At this time the arc is started according to
the selected welding mode. After the arc is started,
the output current will be increased and reached set
current at the end of upslope time.
2. Release the TIG torch trigger. The machine will
decrease the output current in downslope time, the
output is turned OFF until reached the crater current.
The gas valve will remain open to continue the flow
of the shielding gas until post flow time is over.
2-Step Repeat Trigger Sequence
With the 2-Step Repeat trigger mode and a TIG welding
mode selected, the following welding sequence will occur.
This sequence is the same as 2-Step, except when the
switch is pressed while in final slope the welding current
will ramp again and resume. This process can be
repeated as many times as necessary. When finished
welding, simply release the trigger and allow the finishing
current to end and the output to switch OFF followed by
the post flow time.
4-Step Trigger Sequence
With the 4-step trigger mode and a TIG welding mode
selected, the following welding sequence will occur.
1. Press and hold the TIG torch trigger. The machine
will open the gas valve to start the flow of the
shielding gas. When the pre-flow time is over,
machine is in OCV mode, and then begin arc starting
and keep the output current at the value of arc-
starting current.
2. Release the TIG torch trigger to start the upslope
function. The output current will be increased at
upslope time, until the Welding current is reached.
3. Press and hold the TIG torch trigger. The machine
will now decrease the output current at downslope
time, until the Crater current is reached.

B-10 OPERATION B-10
Rev. 05
OPTIMARC®AC/DC 350-TP
4. When the TIG torch trigger is released, the output of
the machine is turned OFF and the post flow time will
start. The gas valve will remain open to continue the
flow of the shielding gas until post flow time is over.
4-Step Repeat Trigger Sequence
With the 4-step Restart trigger mode and a TIG welding
mode selected, the following welding sequence will occur.
This sequence is the same as 4-step, except when
the switch is released during the finishing current
time, welding current will ramp up again to the
operating amperage. This process can be repeated
as many times as necessary. When welding is
finished, quickly press and release the trigger to
start the final slope, which will be followed by the
finishing current at which point output is switched
OFF, and the post flow will initiate.
AC BALANCE AND AC OFFSET
AC balance and AC offset are enabled in TIG mode
when output wave is AC square, but you can only
change one parameter at the same time.
The following picture indicates the output waveform
when the AC balance and AC offset are set to 30%
at 100A/100Hz Square wave.
The AC balance only change the duty cycles of the
postive and negtive.
The AC offset only change the values of the postive and
negtive,and the values are affected by the preset current
as follows.
100A
100A
50%
100A
50%
70%
30%
70%
30%
AC balance 30%
AC offset 30%
Normal

B-11 OPERATION B-11
Rev. 05
OPTIMARC®AC/DC 350-TP
List of parameters and Factory Configuration program:
Mode
Parameter Name
Selectable Value Range
Min Step
Rate *
Factory
Setting
TIG
Pre-flow time
0.1～15S
0.1S
0.5S
Initial current
0～200% (Percentage of the welding current)
1
75%
Upslope
0～15S
0.1S
0.5S
Welding Current
4～350A
1A
150A
Downslope
0～15S
0.1S
0.5S
Crater Current
0～100% (Percentage of the welding current)
1
30%
Post-flow time
0.1～15S
0.1S
2.0S
DC
&
Pulse
OFF
/
/
/
Low frequency
0.2～20Hz
0.1Hz
2Hz
High frequency
20～2000Hz
1Hz
20Hz
Duty cycle
5%～95%
1
50%
Base current
0～100% (Percentage of the welding current)
1A
50%
AC
Frequency
20-400
1Hz
50Hz
AC Offset
(AC-Square wave)
30-70 (Amplitude of negative cycle,SEE B-10)
1
50%
AC Balance
(AC-Square wave)
30-70 (Duty of negative cycle, SEE B-10 )
1
30%
MMA
Set Current
10～350A
1A
150A
Hot start
0～10
( Value X 50ms; 1.5 X Welding current )
1
0
Arc force
0～10
1
5
Frequency
(AC)
20-400Hz
1Hz
50Hz
SPOT
TIG
Set current
4～350A
1A
150A
Spot time
0.1～5S
0.1S
1S
Post-flow time
0.1～15S
0.1S
2.0S
Frequency
(AC)
20-400Hz
1Hz
50 Hz
* NOTE:
The step rate will be increased as you adjust the parameter values by pressing & rotating
the adjusting button.

C-1TROUBLESHOOTING C-1
Rev. 05
OPTIMARC®AC/DC 350-TP
CAUTION
If for any reason you do not understand the test procedures or are unable to
perform the tests/repairs safely, contact your local authorized Lincoln Electric
Field Service Facility for technical assistance.
Observe all Safety Guidelines detailed in the beginning and throughout this menual.
Problems (Symptoms)
Possible Areas of Misadjustment(s)
Recommended Course of Action
Output Problems
Major physical or electrical damage
is evident when the sheet metal
covers are removed.
None
Contact your local authorized
Lincoln Electric Field Service
facility for technical assistance.
Input breaker keeps tripping.
1. Make certain that fuses or
breakers are properly sized. See
Installation section of this manual
for recommended fuse and
breaker sizes.
2. Welding procedure is drawing too
much output current, or duty cycle
is too high. Reduce output current,
duty cycle, or both.
3. There is internal damage to the
power source.
If there is internal damage, contact
an authorized Lincoln Electric
Service facility for technical
assistance.
Machine will not power up
(no display, no fan running, etc.).
1. Make certain that the power to the
machine is energized normally
and is within the operating range.
Check if the main power switch in
control box of power cabin is
turned on.
Thermal protection symbol display.
1. Check for proper fan operation.
(Fan should run whenever output
power is on.) Check for material
blocking intake or exhaust louvers,
or for excessive dirt clogging
cooling channels in machine.
2. Machine may have been operated
above it’s duty cycle.
Clear obstruction or repair fan.
After machine has cooled, reduce
load, duty cycle, or both.
Machine won’t weld, can’t get any
output.
1. Red fault identifications appear
2. If the thermal protection symbol
displays, see thermal protection
symbol display section.
Refer to error symbol
Contact your local authorized
Lincoln Electric Field Service
facility for technical assistance.
Machine won’t produce full output.
1. Input voltage may be too low,
limiting output capability of the
power source.
2. Current or voltage display meter is
not properly calibrated.
3. The welding cable and work cable
are too long, or their across area
art too small.
Correct input voltage level.
Contact your local authorized
Lincoln Electric Field Service
facility for technical assistance.
Shorten welding cable and work
cable, or use bigger size cables
for reducing the voltage drop on
cables.
General degradation of the weld
performance.
1. Check for electrode holding
problems, bad connections,
excessive loops in cabling, etc.
2. Verify weld mode is correct for
processes.
3. The power source may require
calibration.
Contact an authorized Lincoln
Electric Service facility for
technical assistance.
The welding arc is not stable and
soft.
1. Verify the proper polarity is being
used for the weld procedure.
2. Check all electrode and work
connections.
3. Verify the parameters of output
current and shielding gas(TIG
mode) are proper for the welding
procedure.
If PC board in machine is at fault,
contact an authorized Lincoln
Electric Service facility for
technical assistance.

C-2TROUBLESHOOTING C-2
Rev. 05
OPTIMARC®AC/DC 350-TP
CAUTION
If for any reason you do not understand the test procedures or are unable to
perform the tests/repairs safely, contact your local authorized Lincoln Electric
Field Service Facility for technical assistance.
Observe all Safety Guidelines detailed in the beginning and throughout this menual.
Problems (Symptoms)
Possible Areas of Misadjustment(s)
Recommended Course of Action
4. Try to adjust arc force value
5. PC board in machine possibily at
fault.
Starting arc is difficult.
1. Verify the proper polarity is being
used for the weld procedure.
2. Check all electrode and work
connections.
3. Verify the parameters of output
current and shielding gas(TIG
mode) are proper for the welding
procedure.
4. Try to adjust hot start value.
5. PC board in machine possibily at
fault.
If PC board in machine is at fault,
contact an authorized Lincoln
Electric Service facility for
technical assistance.
Remote output control not
functioning. The machine operates
normally on LOCAL control.
1. Make sure the remote control
must be set to 1 (enable remote
control).
2. Make sure a remote control
device is attached to the remote
receptacle properly.
3. The remote control device may be
faulty, Replace.
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
contact your local Lincoln
Authorized Field Service Facility.
Poor MMA electrode welding
performance. The arc pops out.
1. Check for loose or faulty welding
cables.
2. Is the electrode DRY? Try welding
with another electrode from a
different container. Make sure you
have the correct electrode for the
application.
3. Make sure the machine settings
are correct for the weld process
being used.
Poor welding, weld setting drift, or
output power is low.
1. Make sure the machine settings
are correct for the welding
process being used.
2. Check machine performance on
LOCAL control. If OK then the
remote control device maybe
faulty. Check and replace.
3. Check for loose or faulty welding
cables.
HF arc starting is difficult
1. Check if the high-frequency
generator is covered dust.
2. The discharging gap is too
smaller.
3. The harnesses aren’t connected
tightly.
4. The arc-striking coil is broken.
Clean off the dust on the HF
generator.
Re-adjust the discharging gap,
and make it ranging from 0.75mm
to 0.85mm.
Note: too bigger gap will make
the control circuit damaged.
Reconnection.
Note: the high voltage on the
high-frequency arc-striking
generator!
contact your local Lincoln
Authorized Field Service Facility.