Lincoln Electric POWERTEC 305C PRO User manual

IM3022
12/2020
REV06
POWERTEC 305C PRO, 355C PRO, 425C PRO
OPERATOR’S MANUAL
ENGLISH
Lincoln Electric Bester Sp. z o.o.
ul. Jana III Sobieskiego 19A, 58-260 Bielawa, Poland
www.lincolnelectric.eu

English English
I
12/05
THANKS! For having choosen the QUALITY of the Lincoln Electric products.
Please Examine Package and Equipment for Damage. Claims for material damaged in shipment must be notified
immediately to the dealer.
For future reference record in the table below your equipment identification information. Model Name, Code & Serial
Number can be found on the machine rating plate.
Model Name:
………………...…………………………….…………………………………………………………………………………………..
Code & Serial number:
………………….……………………………………………….. …………………………………………………….……………..
Date & Where Purchased:
…………………………………………………………………... ……………………….…………………………………………..
ENGLISH INDEX
Technical Specifications...............................................................................................................................................................1
ECO design information ...............................................................................................................................................................2
Electromagnetic Compatibility (EMC) ..........................................................................................................................................4
Safety............................................................................................................................................................................................5
Introduction...................................................................................................................................................................................7
Installation and Operator Instructions ..........................................................................................................................................7
WEEE .........................................................................................................................................................................................16
Spare Parts.................................................................................................................................................................................16
REACh........................................................................................................................................................................................16
Authorized Service Shops Location...........................................................................................................................................16
Electrical Schematic ...................................................................................................................................................................16
Suggested Accessories..............................................................................................................................................................17

English 1 English
Technical Specifications
NAME INDEX
POWERTEC 305C PRO K14057-1
POWERTEC 355C PRO K14058-1
POWERTEC 425C PRO K14059-1A
INPUT
Input Voltage U1EMC Class Frequency
305C PRO
230/400V ± 10%
3-phase A 50/60Hz
355C PRO
425C PRO
Input Power at Rated Cycle Input Amperes I1max cos φ
305C PRO 13,5 kVA @ 40% Duty Cycle 35,2A 0,95
355C PRO 17,5 kVA @ 40% Duty Cycle 45,5A 0,95
425C PRO 22,8 kVA @ 40% Duty Cycle 58A 0,96
RATED OUTPUT
Duty Cycle 40°C
(based on a 10 min. period) Output Current Output Voltage
305C PRO 100% 175A 22,8 Vdc
60% 230A 25,5 Vdc
40% 280A 28 Vdc
355C PRO 100% 220A 25 Vdc
60% 285A 28,2 Vdc
40% 350A 31,5 Vdc
425C PRO 100% 265A 27,3 Vdc
60% 345A 31,3 Vdc
40% 420A 35 Vdc
OUTPUT RANGE
Welding Current Range Open Circuit Voltage
305C PRO 30A – 280A 17 – 46 Vdc
355C PRO 30A – 350A 18 – 48 Vdc
425C PRO 30A – 420A 17 – 52 Vdc
RECOMMENDED INPUT CABLE AND FUSE SIZES
Fuse or Circuit Breaker Size Power Lead
230V 400V
305C PRO D 32A D 20A 4 Conductor, 4mm2
355C PRO D 40A D 25A 4 Conductor, 4mm2
425C PRO D 50A D 32A 4 Conductor, 6mm2
DIMENSION
Weight Height Width Length
305C PRO 145 kg 890 mm 565 mm 1040 mm
355C PRO 147 kg 890 mm 565 mm 1040 mm
425C PRO 162 kg 890 mm 696 mm 1040 mm
WIRE FEED SPEED RANGE / WIRE DIAMETER RANGE
WFS RANGE Solid wires Aluminum wires Cored wires
305C PRO 1 ÷ 20m/min 0.6 ÷ 1.6 1.0 ÷ 1.2 0.9 ÷ 1.6
355C PRO 1 ÷ 20m/min 0.6 ÷ 1.6 1.0 ÷ 1.2 0.9 ÷ 1.6
425C PRO 1 ÷ 20m/min 0.6 ÷ 1.6 1.0 ÷ 1.2 0.9 ÷ 1.6
Protection Rating Operating Humidity (t=20°C) Operating Temperature Storage Temperature
IP23 ≤90 % from -10 ºC to +40 ºC from -25 ºC to +55 ºC

English 2 English
ECO design information
The equipment has been designed in order to be compliant with the Directive 2009/125/EC and the Regulation
2019/1784/EU.
Efficiency and idle power consumption:
Index Name Efficiency when max power consumption
/ Idle power consumption Equivalent model
K14057-1 POWERTEC 305C PRO 64 % / 35W No equivalent model
K14058-1 POWERTEC 355C PRO 69,8 % / 35W No equivalent model
K14059-1A POWERTEC 425C PRO 65,8 % / 22W No equivalent model
Idle state occurs under the condition specified in below table
IDLE STATE
Condition Presence
MIG mode
TIG mode
STICK mode
After 30 minutes of non-working
Fan off X
The value of efficiency and consumption in idle state have been measured by method and conditions defined in the product
standard EN 60974-1:20XX.
Manufacturer’s name, product name, code number, product number, serial number and date of production can be read from
rating plate.
XXXXXXXXXX
Code: XXXXX XXXXXX-X
S/N: P1YYMMXXXXX
12
34
5
P1 YY MM XXXXX
5A5A 5B 5D5C
XXXXXXX
Where:
1- Manufacturer name and address
2- Product name
3- Code number
4- Product number
5- Serial number
5A- country of production
5B- year of production
5C- month of production
5D- progressive number different for each machine

English 3 English
Typical gas usage for MIG/MAG equipment:
Material type
Wire
diameter
[mm]
DC electrode positive Wire Feeding
[m/min] Shielding Gas Gas flow [l/min]
Current
[A]
Voltage
[V]
Carbon, low
alloy steel 0,9 ÷ 1,1 95 ÷ 200 18 ÷ 22 3,5 – 6,5 Ar 75%, CO225% 12
Aluminium 0,8 ÷ 1,6 90 ÷ 240 18 ÷ 26 5,5 – 9,5 Argon 14 ÷ 19
Austenic
stainless steel 0,8 ÷ 1,6 85 ÷ 300 21 ÷ 28 3 - 7 Ar 98%, O22% / He 90%, Ar 7,5% CO22,5% 14 ÷ 16
Copper alloy 0,9 ÷ 1,6 175 ÷ 385 23 ÷ 26 6 - 11 Argon 12 ÷ 16
Magnesium 1,6 ÷ 2,4 70 ÷ 335 16 ÷ 26 4 - 15 Argon 24 ÷ 28
Tig Process:
In TIG welding process, gas usage depends on cross-sectional area of the nozzle. For comonnly used torches:
Helium: 14-24 l/min
Argon: 7-16 l/min
Notice: Excessive flow rates causes turbulence in the gas stream which may aspirate atmospheric contamination into the
welding pool.
Notice: A cross wind or draft moving can disrupt the shielding gas coverage, in the interest of saving of protective gas use
screen to block air flow.
End of li
f
e
At end of life of product, it has to be disposal for recycling in accordance with Directive 2012/19/EU (WEEE), information
about the dismantling of product and Critical Raw Material (CRM) present in the product, can be found at
https://www.lincolnelectric.com/en-gb/support/Pages/operator-manuals-eu.aspx

English 4 English
Electromagnetic Compatibility (EMC)
11/04
This machine has been designed in accordance with all relevant directives and standards. However, it may still generate
electromagnetic disturbances that can affect other systems like telecommunications (telephone, radio, and television) or
other safety systems. These disturbances can cause safety problems in the affected systems. Read and understand this
section to eliminate or reduce the amount of electromagnetic disturbance generated by this machine.
This machine has been designed to operate in an industrial area. To operate in a domestic area it is necessary
to observe particular precautions to eliminate possible electromagnetic disturbances. The operator must install
and operate this equipment as described in this manual. If any electromagnetic disturbances are detected the
operator must put in place corrective actions to eliminate these disturbances with, if necessary, assistance from
Lincoln Electric.
Before installing the machine, the operator must check the work area for any devices that may malfunction because of
electromagnetic disturbances. Consider the following.
Input and output cables, control cables, and telephone cables that are in or adjacent to the work area and the machine.
Radio and/or television transmitters and receivers. Computers or computer controlled equipment.
Safety and control equipment for industrial processes. Equipment for calibration and measurement.
Personal medical devices like pacemakers and hearing aids.
Check the electromagnetic immunity for equipment operating in or near the work area. The operator must be sure that
all equipment in the area is compatible. This may require additional protection measures.
The dimensions of the work area to consider will depend on the construction of the area and other activities that are
taking place.
Consider the following guidelines to reduce electromagnetic emissions from the machine.
Connect the machine to the input supply according to this manual. If disturbances occur if may be necessary to take
additional precautions such as filtering the input supply.
The output cables should be kept as short as possible and should be positioned together. If possible connect the work
piece to ground in order to reduce the electromagnetic emissions. The operator must check that connecting the work
piece to ground does not cause problems or unsafe operating conditions for personnel and equipment.
Shielding of cables in the work area can reduce electromagnetic emissions. This may be necessary for special
applications.
WARNING
The Class A equipment is not intended for use in residential locations where the electrical power is provided by the public
low-voltage supply system. There can be potential difficulties in ensuring electromagnetic compatibility in those locations,
due to conducted as well as radio-frequency disturbances.
WARNING
This equipment complies with IEC 61000-3-12 provided that the short-circuit power Ssc is greater than or equal to:
POWERTEC 305C PRO: Ssc ≥1,7 MVA
POWERTEC 355C PRO: Ssc ≥2 MVA
POWERTEC 425C PRO: Ssc ≥3,5 MVA
at the interface point between the user’s supply and the public system. It is the responsibility of the installer or user of the
equipment to ensure, by consultation with the distribution network operator if necessary, that the equipment is connected
only to a supply with a short circuit power Ssc greater than or equal to data on the table above.

English 5 English
Safety
01/11
WARNING
This equipment have to be used by qualified personnel. Be sure that all installation, operation, maintenance and repair
procedures are performed only by qualified person. Read and understand this manual before operating this equipment.
Failure to follow the instructions in this manual could cause serious personal injury, loss of life, or equipment damage. Read
and understand the following explanations of the warning symbols. Lincoln Electric is not responsible for damages caused
by improper installation, improper care or abnormal operation.
WARNING: This symbol indicates that instructions must be followed to avoid serious personal injury, loss
of life, or equipment damage. Protect yourself and others from possible serious injury or death.
READ AND UNDERSTAND INSTRUCTIONS: Read and understand this manual before operating this
equipment. Arc welding can be hazardous. Failure to follow the instructions in this manual could cause
serious personal injury, loss of life, or equipment damage.
ELECTRIC SHOCK CAN KILL: Welding equipment generates high voltages. Do not touch the electrode,
work clamp, or connected work pieces when this equipment is turned on. Insulate yourself from the
electrode, work clamp, and connected work pieces.
ELECTRICALLY POWERED EQUIPMENT: Turn off the input power using the disconnect switch at the
fuse box before working on this equipment. Ground this equipment in accordance with local electrical
regulations.
ELECTRICALLY POWERED EQUIPMENT: Regularly inspect the input, electrode, and work clamp
cables. If any insulation damage exists replace the cable immediately. Do not place the electrode holder
directly on the welding table or any other surface in contact with the work clamp to avoid the risk of
accidental arc ignition.
ELECTROMAGNETIC FIELD MAY BE DANGEROUS: Electric current flowing through any conductor
creates electromagnetic field (EMF). EMF fields may interfere with some pacemakers, and welders having
a pacemaker shall consult their physician before operating this equipment.
CE COMPLIANCE: This equipment complies with the European Community Directives.
ARTIFICIAL OPTICAL RADIATION: According with the requirements in 2006/25/EC Directive and
EN 12198 Standard, the equipment is a category 2. It makes mandatory the adoption of Personal
Protective Equipment (PPE) having filter with a protection degree up to a maximum of 15, as required by
EN169 Standard.
FUMES AND GASES CAN BE DANGEROUS: Welding may produce fumes and gases hazardous to
health. Avoid breathing these fumes and gases. To avoid these dangers the operator must use enough
ventilation or exhaust to keep fumes and gases away from the breathing zone.
ARC RAYS CAN BURN: 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. To protect the skin, use suitable clothing made
of durable, fireproof material. Protect other nearby personnel with suitable, non-flammable screening and
warn them not to watch the arc nor expose themselves to the arc.

English 6 English
WELDING SPARKS CAN CAUSE FIRE OR EXPLOSION: Remove fire hazards from the welding area
and have a fire extinguisher easily accessible. Welding sparks and hot materials from the welding process
can easily go through small cracks and openings to adjacent areas. Do not weld on any tanks, drums,
containers, or material until the proper steps have been taken to insure that no flammable or toxic vapors
will be present. Never use this equipment when flammable gases, vapors or flammable liquids are
present.
WELDED MATERIALS CAN BURN: Welding generates a large amount of heat. Hot surfaces and
materials in work area can cause serious burns. Use gloves and pliers when touching or moving
materials in the work area.
CYLINDER MAY EXPLODE IF DAMAGED: Use only certificate, compressed gas cylinders containing
the correct shielding gas for the process used and properly operating regulators designed for the gas and
pressure used. Always keep cylinders in an upright position securely chained to a fixed support. Do not
move or transport gas cylinders with the protection cap removed. Do not allow the electrode, electrode
holder, work clamp or any other electrically live part to touch a gas cylinder. Gas cylinders must be
located away from areas where they may be subjected to physical damage or the welding process
including sparks and heat sources.
MOVING PARTS ARE DANGEROUS: There are moving mechanical parts in this machine, which can
cause serious injury. Keep your hands, body and clothing away from those parts during machine starting,
operating and servicing.
SAFETY MARK: This equipment is suitable for supplying power for welding operations carried out in an
environment with increased risk of electric shock.
The manufacturer reserves the right to make changes and/or improvements in design without upgrade at the same time the
operator’s manual.

English 7 English
Introduction
The welding machines of the POWERTEC C PRO enable:
Welding MGAW (MIG/MAG)
Welding FCAW-GS / FCAW-SS
The following equipment has been added to POWERTEC
305C PRO and 355C PRO:
USB with Operator’s Manual
Gun holder with screw material
Work lead - 3m
Gas hose - 2m
Hose clamp
Slow-blow fuse - 3A
Galvanized chain - 0,35m
The following equipment has been added to POWERTEC
425C PRO:
USB with Operator’s Manual
Gun holder with screw material
Work lead - 3m
Gas hose - 2m
Hose clamp
Water-cooler hoses – blue (0,4m) and red (0,4m)
Hose with quick water connector - 0,2m.
Slow-blow fuse - 3A.
POWERTEC 425C PRO is designed to work with cooler
COOL ARC 25.
Recommended equipment, which can be bought by user,
was mentioned in the chapter "Accessories".
Installation and Operator Instructions
Read this entire section before installation or operation of
the machine.
Location and Environment
This machine will operate in harsh environments.
However, it is important that simple preventative
measures are followed to assure long life and reliable
operation.
Do not place or operate this machine on a surface with
an incline greater than 15° from horizontal.
Do not use this machine for pipe thawing.
This machine must be located where there is free
circulation of clean air without restrictions for air
movement to and from the air vents. Do not cover the
machine with paper, cloth or rags when switched on.
Dirt and dust that can be drawn into the machine
should be kept to a minimum.
This machine has a protection rating of IP23. Keep it
dry when possible and do not place it on wet ground
or in puddles.
Locate the machine away from radio controlled
machinery. Normal operation may adversely affect
the operation of nearby radio controlled machinery,
which may result in injury or equipment damage.
Read the section on electromagnetic compatibility in
this manual.
Do not operate in areas with an ambient temperature
greater than 40°C.
Duty cycle and Overheating
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.
Example: 60% duty cycle:
Welding for 6 minutes Break for 4 minutes
Excessive extension of the duty cycle will cause the
thermal protection circuit to activate.
The machine is protected from overheating by a
temperature sensor.
Minutes or decrease
duty cycle
Input Supply Connection
WARNING
Only a qualified electrician can connect the welding
machine to the supply network. Installation the outlet plug
to power lead and connecting the welding machine had to
be made in accordance with the appropriate National
Electrical Code and local regulations.
Check the input voltage, phase, and frequency supplied to
this machine before turning it on. Verify the connection of
grounding wires from the machine to the input source.
POWERTEC 305C PRO, 355C PRO and 425C PRO can
only be connected to a mating grounded receptacle.
The allowable input voltages are 3x230V 50/60Hz and
3x400V 50/60Hz (3x400V: factory default). For more
information about input supply refer to the technical
specification section of this manual and to the rating plate
of the machine.
If it is necessary to change the input voltage:
The input cable must be disconnected from the mains
supply and the machine switched OFF.
Remove the left side panel from the machine.
Reconnect X11 and X12 according to the diagram
below:
400V 230V
230V 0 400V
WVU
YXZ
230V 0 400V
X12
WVU
YXZ YXZ
WVU
230V 0 400V
X12
X11X11
Figure 1.

English 5 English
Replace the left side panel.
Make sure that the amount of mains power available from
the input supply is adequate for normal operation of the
machine. The necessary delayed fuse (or circuit breaker
with "D" characteristic) and cable sizes are indicated in
the technical specification section of this manual.
Refer to points [1], and [18] of the images below.
Output Connections
Refer to points [6], [7] and [8] of the images below.
Controls and Operational Features
1. Power Switch ON/OFF (I/O): Controls the input power
to the machine. Be sure the power source is
connected to the mains supply before turning power
on ("I"). After input power is connected and the power
switch is turned on, the indicator will light up to
indicate the machine is ready to weld.
2. Thermal Overload Indicator: This lamp will
light up when the machine is overheated
and the output has been turned off. This
can occur if the ambient temperature is
above 40°C or the duty cycle of the machine has been
exceeded. Leave the machine on to allow the internal
components to cool, when the lamp turns off normal
operation is possible.
3. Welding Load Voltage Switch: Adjust the
welding load voltage. POWERTEC 305C
PRO has 2 switches (2 and 10 steps).
POWERTEC 355C PRO and 425C PRO have 2
switches (3 and 10 steps).
WARNING
Do not switch Welding Load Voltage [3] during welding.
4. Digital Display Panel: Parameters of welding process
are shown.
Mode Indicators: These lamps show the work mode of
the machine:
the machine works in synergic mode
(automatic mode)
the machine works in manual mode
Display A: It shows the actual welding current value (in
A), and after finishing welding process, it shows the
average value of the welding current. Depending on
Work Mode, after the WFS value is changed [5], the
display A shows;
Correction of the speed automatically
matched by the machine, in the range
0.75-1.25
The value of adjusted WFS in m/min
Display V: It shows the actual value of welding load
voltage (in V), and after finishing welding process, it
shows the average value of welding voltage. When the
WFS value is changed [5], the display is blank.
5. WFS (Wire Feed Speed) Control Knob:
Depending on the work mode of the
machine, this knob controls:
Enables correction of the speed
automatically matched by the machine in
the range ±25%.
Enables continuous control of wire
feeding speed in the range from 1.0 to
20m/min.
VA
B
A
SYNER GIC
1
2
5
78
6
4
3
Figure 2.
VA
SYNER GIC
1
2
5
78
6
4
3
Figure 3.

English 6 English
VA
C
B
A
1
2 4
5
6
9
10
7
8
3
SYNERGIC
Figure 4.
6. EURO Socket: For connecting a welding gun (for
GMAW, FCAW-GS / FCAW-SS process).
7. High Inductance Output Socket: For
connecting a work lead.
8. Low Inductance Output Socket: For
connecting a work lead.
9. Quick Connect Coupling (POWERTEC
425C PRO only): Coolant outlet (supplies
cool coolant to the gun).
10. Quick Connect Coupling (POWERTEC
425C PRO only): Coolant inlet (takes
warm coolant from the gun).
WARNING
Maximum coolant pressure is 5 Bar.
11. Quick Connect Coupling (POWERTEC
425C PRO only): Coolant inlet (supplies
cool coolant to the welding machines).
12. Quick Connect Coupling (POWERTEC
425C PRO only): Coolant outlet (takes
warm coolant from welding machines.)
WARNING
Maximum coolant pressure is 5 Bar.
WARNING
Read and understand operator’s manual of cooler before
connecting it to the machine.
WARNING
To ensure the failure-free work, use only recommended
coolant by manufacturer of welding gun and/or cooler (see
"Accessories" chapter).
13
15
14
18
POWERTEC 305C PRO & 355C PRO
Figure 5.
11
12 16
18
15
14
17
13
POWERTEC 425C PRO
Figure 6.
13. Hole Plug: For CO2gas heater socket (see
"Accessories" chapter - K14009-1 CO2Heater
Connection Kit).
14. Gas Connector: Connection for gas line.
WARNING
The welding machine supports all suitable shielding gases
at a maximum pressure of 5,0 Bar.
15. Slow-Blow Fuse: It shut off the supply power when the
current exceed 3A. After burn out it need to be
replaced by new one. (See "Spare Parts" chapter).
POWERTEC
305C PRO 355C PRO 425C PRO
Slow-blow
fuse 3A 3A 3A

English 7 English
16. Cooler Power Supply Socket (only POWERTEC 425C
PRO): For supplying the cooler unit only.
WARNING
The socket has an output of 230V, 2.5A and is protected
by the circuit breaker [17].
17. Circuit Breaker (only POWERTEC 425C PRO):
Protects the Cooler Power Supply socket [16]. It shuts
off the power supply when the current exceeds 2.5A.
Press it to restore the power supply.
18. Power lead (5m): Connect the supply plug to the
existing input cable that is rated for the machine as
indicated in this manual, and conforms to all applicable
standards. This connection shall be performed only by
a qualified person.
20 21 22
23
2425
26
27
28
29
30 31 32
19
Figure 7.
19. Work Lead.
20. Wire Drive (for GMAW, FCAW-GS / FCAW-SS
process): 4-Roll wire drive.
21. Welding Wire (for GMAW, FCAW-GS / FCAW-SS).
22. Spooled Wire (for GMAW, FCAW-GS / FCAW-SS):
The machine does not include a spooled wire.
23. Wire Spool Support: Maximum 15kg spools. Accepts
plastic, steel and fiber spools onto 51mm spindle. Also
accepts Readi-Reel®type spools onto included
spindle adapter.
WARNING
Be sure that the right side panel of machine is closed
during welding.
24. Shield of Changing Polarity.
25. Terminal Block of Changing Polarity (for GMAW,
FCAW-GS / FCAW-SS process): This terminal block
enables to set the welding polarity (+ ; -), which will be
given at the welding holder.
WARNING
Positive (+) polarity is set at the factory.
WARNING
Before welding check the polarity for using wires.
If the welding polarity has to be changed, user should:
Switch off the machine.
Determine the wire polarity for the wire to be used.
Consult the wire data for this information.
Take off the terminal block’s shield [24].
The tips of the wire on the terminal block [25] fix as is
shown in the Table 1.
Put on the terminal block’s shield.
WARNING
The right side panel has to be completely closed during
welding.

English 8 English
Table 1.
POSITIVE POLARITY
(factory setting) NEGATIVE POLARITY
25
25
25
25
26. Cold Inch / Gas Purge Switch: This switch enables
wire feeding or gas flow without turning on output
voltage.
27. Gun Mode Switch: It enables selection of 2-step or 4-
step gun mode. The functionality of 2T/4T mode is
shown in the Figure8.
28. Burnback Time Control Knob: Sets the time that the
weld output continues after the wire stops feeding. It
prevents the wire from sticking in the puddle and
prepares the end of the wire for the next arc start.
29. Run-in WFS Control Knob: Sets the wire feed speed
from the time the trigger is pulled until an arc is
established, in the range from 0.1 to1.0 of the value
set by the "WFS Control Knob" [5].
30. Wire Diameter Knob: It allows the choice of the wire
diameter requested for the desired welding process.
This feature is available only for the synergic mode.
31. Synergic/Manual Mode Control Knob: Enables the
choice the work of the machine:
Synergic mode: enables a choice of the welded
material and its appropriate gas.
Manual mode.
32. Preflow Gas Control Knob: Adjusts the time that
shielding gas flows after the trigger is pulled and prior
to feeding.
Welding Cables Connections
Insert the plug of the work lead into the socket [7] or [8].
The other end of this lead connects to the welding piece
with the work clamp.
Connect the necessary gun for GMAW, FCAW-GS or
FCAW-SS process to the Euro Socket [6]. Contact tip and
gun’s liner must be adjusted to the type and diameter of
using wire.
Trigger pressed
Trigger released
A Welding current
B Burnback time
C WFS
G Gas
Figure 8.

English 9 English
Wire Spool Loading
Wire spool type S300 and BS300 cab be installed on the
wire spool support [23] without adapter.
Wire spool type S200, B300 or Readi-Reel® can be
installed, but the applicable adapter must be purchased.
The applicable adapter can be purchased
separately(see "Accessories" chapter).
Wire Spool Type S300 & BS300 Loading
WARNING
Turn off the power source while mounting electrode wire.
3334 36
35
Figure 9.
Turn the machine off.
Open the right side panel.
Unscrew the Locking Nut [35] and remove it from the
Spindle [33].
Place the spool type S300 or BS300 [36] on the
Spindle [33] making certain the Spindle Brake Pin [34]
is put in the hole in back side of spool type S300 or
SB300.
WARNING
Position the spool type S300 or SB300 so that it will rotate
in a direction when feeding so as to be de-reeled from
bottom of the spool.
Re-install the locking nut [35]. Make sure that the
locking nut is tightened.
Wire Spool Type S200 Loading
WARNING
Turn off the power source while mounting electrode wire.
35
39
373334
38
Figure 10.
Turn the machine off.
Open the right side panel.
Unscrew the Locking Nut [35] and remove it from the
Spindle [33].
Place the adapter of spool type S200 [37] on the
spindle [33] making certain the spindle brake pin [34]
is put in the hole in back side of the adapter [37]. The
adapter of spool type S200 can be purchased
separately (see "Accessories" chapter).
Place the spool type S200 [39] on the spindle [33]
making certain that the adapter brake pin [38] is put in
the hole in the back side of the spool.
WARNING
Position the spool type S200 so that it will rotate in a
direction when feeding so as to be de-reeled from bottom
of the spool.
Re-install the locking nut [35]. Make sure that the
locking nut is tightened.
Wire Spool Type B300 Loading
WARNING
Turn off the power source while mounting electrode wire.
33
35
40
34
41
Figure 11.
Turn the machine off.
Open the right side panel.
Unscrew the Locking Nut [35] and remove it from the
spindle [33].
Place the adapter of spool type B300 [40] on the
spindle [33].Make certain that the spindle brake pin
[34] is put in the hole in the back side of the adapter.
The adapter of spool type B300 can be purchased
separately (see "Accessories" chapter).
Re-install the locking nut [35]. Make sure that the
locking nut is tightened.
43
40
41
42
44
Figure 12.
Rotate the spindle and adapter so the retaining spring
[41] is at the 12 o'clock position.

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Place the spool type B300 [43] on the adapter [40].
Set one of the B300 inside cage wires [44] on the slot
[42] in the retaining spring tab [41] and slide the spool
onto the adapter.
WARNING
Position the spool type B300 so that it will rotate in a
direction when feeding so as to be de-reeled from bottom
of the spool.
41
43
Figure 13.
Wire Spool Type Readi-Reel®Loading
WARNING
Turn off the power source while mounting electrode wire.
33
34 45
35
48
44
46
47
Figure 14.
Turn the machine off.
Open the right side panel.
Unscrew the locking nut [35] and remove it from the
spindle [33].
Place the adapter of spool type Readi-Reel®[45] on
the spindle [33].Make certain that the spindle brake pin
[34] is put in the hole in the back side of the adapter.
The adapter of spool type Readi-Reel®can be
purchased separately (see "Accessories" chapter).
Re-install the locking nut [35]. Make sure that the
locking nut is tightened.
Rotate the spindle and adapter so the retaining spring
[46] is at the 12 o'clock position.
Place the spool type Readi-Reel®[48] on the adapter
[45]. Set one of the Readi-Reel®inside cage wires [44]
on the slot [47] in the retaining spring tab [46].
WARNING
Position the spool type Readi-Reel®so that it will rotate in
a direction when feeding so as to be de-reeled from
bottom of the spool.
Loading the Electrode Wire
Turn the machine off.
Open the right side panel of the machine.
Unscrew the fastening cap of the sleeve.
Load the spool with the wire [22] on the sleeve such
that the spool turns clockwise when the wire [21] is fed
into the wire feeder.
Make sure that the spool locating pin goes into the
fitting hole on the spool.
Screw in the fastening cap of the sleeve.
Put on the wire roll using the correct groove
corresponding to the wire diameter.
Free the end of the wire and cut off the bent end
making sure it has no burr.
WARNING
Sharp end of the wire can hurt.
Rotate the wire spool clockwise and thread the end of
the wire into the wire feeder as far as the Euro Socket.
Adjust force of pressure roll of the wire feeder
properly.
Adjustments of Brake Torque of Sleeve
To avoid spontaneous unrolling of the welding wire the
sleeve is fitted with a brake.
Adjustment is carried by rotation of its screw M10, which
is placed inside of the sleeve frame after unscrewing the
locking nut of the sleeve.
50
49
35
Figure 15.
35. Locking Nut.
49. Adjusting Screw M10.
50. Pressing Spring.
Turning the screw M10 clockwise increases the spring
tension and you can increase the brake torque
Turning the screw M10 anticlockwise decreases the
spring tension and you can decrease the brake torque.
After finishing of adjustment, you should screw in the
locking nut again.
Adjusting Pressure Roll Force
The pressure arm controls the amount of force the drive
rolls exert on the wire.
Pressure force is adjusted by turning the adjustment nut
clockwise to increase force, counterclockwise to decrease
force. Proper adjustment of pressure arm gives the best
welding performance.

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WARNING
If the roll pressure is too low the roll will slide on the wire.
If the roll pressure is set too high the wire may be
deformed, which will cause feeding problems in the
welding gun. The pressure force should be set properly.
Decrease the pressure force slowly until the wire just
begins to slide on the drive roll and then increase the
force slightly by turning of the adjustment nut by one turn.
Inserting Electrode Wire into Welding
Gun
Turn the welding machine off.
Depending on welding process, connect the proper
gun to the euro socket, the rated parameters of the
gun and of the welding machine should be matched.
Remote the nozzle from the gun and contact tip or
protection cap and contact tip. Next, straighten the gun
out flat.
Insert the wire through the guide tube, over the roller
and guide tube of Euro Socket into liner of gun. The
wire can be pushed into the liner manually for a few
centimeters, and should feed easily and without any
force.
WARNING
If force is required it is likely that the wire has missed the
liner of gun.
Turn the welding machine on.
Depress the gun trigger to feed the wire through the
gun liner until the wire comes out of the threaded end.
Or the Cold Inch / Gas Purge Switch [26] can be used
– keep in "Cold Inch" position until the wire comes out
of the threaded end.
When trigger or the Cold Inch / Gas Purge Switch [26]
is released spool of wire should not unwind.
Adjust wire spool brake accordingly.
Turn the welding machine off.
Install a proper contact tip.
Depending on the welding process and the type of the
gun, install the nozzle (GMAW process, FCAW-GS
process) or protection cap (FCAW-SS process).
WARNING
Take precaution to keep eyes and hands away from the
end of the gun while the wire is being come out of the
threated end.
Changing Driving Rolls
POWERTEC 305C PRO, 355C PRO & 425C PRO is
equipped with drive roll V1.0/V1.2 for steel wire. For
others wire sizes, is available the proper drive rolls kit (see
"Accessories" chapter) and follow instructions:
Turn the welding machine off.
WARNING
Turn the input power off of the welding power source
before installation or changing drive rolls.
Release the pressure roll levers [51].
Unscrew the fastening caps [52].
Open the protection cover [53].
Change the drive rolls [54] with the compatible ones
corresponding to the used wire.
WARNING
Be sure that the gun liner and contact tip are also sized to
match the selected wire size.
WARNING
For wires with the diameter larger than 1.6mm, the
following parts are to be changed:
The guide tube of the feeding console [55] and [56].
The guide tube of the Euro Socket [57].
Replace and tighten the protection cover [53] to the
drive rolls.
Screw fastening caps [52].
Manually feed the wire from the wire reel, the wire
through the guide tube, over the roller and guide tube
of Euro Socket into liner of gun.
Lock the pressure roll levers [51].
51 56
55
54
53 5257
51
Figure 16.
Gas Connection
Connect the gas hose to the Gas Connector [18]
located on the rear panel of the machine.
Put the gas cylinder on the machine shelf and secure
it with the chain.
A gas cylinder must be installed with a proper flow
regulator.
Once a gas cylinder with a flow regulator has been
securely installed, connect the gas hose to the
regulator using the hose clamp.
WARNING
The welding machine supports all suitable shielding gases
at a maximum pressure of 5,0 Bar.
WARNING
Always fasten gas cylinder properly in vertical position in a
special holder on the wall or on a carriage. Remember to
close gas cylinder valve after having finished welding.

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Connection and Cooler control (only
POWERTEC 425C PRO)
POWERTEC 425C PRO is designed to work with cooler
COOL ARC 25 (see "Accessories" chapter).
To connect COOL ARC 25 to POWERTEC 425C PRO
see operator’s manual for cooler.
The POWERTEC 425C PRO allows the cooler to the
automatic work:
When a weld is started, the cooler is automatically
switched on.
When the weld is stopped, the cooler continues to run
for about 5min., after this time, it is automatically
switched off.
If the weld is restarted in a time lower than 5min., the
cooler continues to run.
The POWERTEC 425C PRO has the possibility to switch
the automatic work of the cooler off and set it in
continuously work. If it is necessary to change the cooler
kind of work:
Switch the POWERTEC 425C PRO off.
Set the knob of the choice wire diameter selection [30]
in "1.0" position. Set the knob of the choice welded
material and gas [31] in "CRNI (98%AR 2%CO2)"
position.
Switch the POWERTEC 425C PRO on.
Within 15s switch the knob of the choice wire diameter
selection [30] in "1.2" position and the knob of the
choice welded material and gas mixture [31] in
"STEEL (100%CO2)" position – the cooler has been
switched on and the display "V" has displayed "on".
If it is necessary to return the automatic work of the cooler
you should do the foregoing actions again (the display "V"
has displayed "5'').
WARNING
The display "V" displays information about work mode of
the water cooler ("5" / "on") for 2 seconds after the supply
of the POWERTEC 425C PRO is switched on.
Welding GMAW, FCAW-GS, FCAW-SS
Process
POWERTEC 305C PRO, 355C PRO & 405C PRO can be
used to welding GMAW, FCAW-GS and FCAW-SS
process in Manual Mode.
POWERTEC 305C PRO, 355C PRO & 405C PRO have
been provided with synergic GMAW and FCAW-GS
process.
POWERTEC 305C PRO, 355C PRO & 405C PRO do not
include the gun necessary for GMAW, FCAW-GS or
FCAW-SS welding. Depending on the welding process
can be purchased separately (see "Accessories" chapter).
Preparation the Machine for Welding
GMAW, FCAW-GS and FCAW-SS
Process.
Procedure of begin welding of GMAW, FCAW-GS or
FCAW-SS process:
Turn the machine off.
Place the machine conveniently near the work area in
a location to minimize exposure to weld spatter and to
avoid sharp bends in the gun cable.
Determine the wire polarity for the wire to be used.
Consult the wire data for this information. If it is
necessary, change polarity. See [25] point – Terminal
Block of Changing Polarity
Connect output the gun to GMAW, FCAW-GS or
FCAW-SS process to Euro Socket [6].
Connect the work lead [19] to output socket [7] or [8].
Connect the work lead to the welding piece with the
work clamp.
Make sure, if it is needed (POWERTEC 425C PRO
with cooler), that the cooler has been connected.
Install the proper wire.
Install the proper drive rolls.
Manually push the wire into the gun’s liner.
Turn the machine on.
Insert the wire into the welding gun.
WARNING
Keep the gun cable as straight as possible when loading
electrode through cable.
WARNING
Never use defected gun.
Check gas flow with Gas Purge Switch [26] – GMAW
and FCAW-GS process.
Close the right side panel.
The welding machine is now ready to weld.
WARNING
The right side panel has to be completely closed during
welding.
WARNING
Keep the gun cable as straight as possible when welding
or loading electrode through cable.
WARNING
Do not kink or pull cable around sharp corners.
By applying the principle of occupational health and
safety at welding, welding can be begun.

English 13 English
Welding in Manual Mode
When the Control Knob [31] is set in "Manual" position,
welding in Manual Mode is possible.
Manual Mode enables welding:
GMAW
FACW-GS
FCAW-SS
In Manual Mode can be set:
The welding load voltage
WFS
Burnback
Run-in WFS
Preflow Time
2-Step/4-Step
The chart below can be useful for welding setting
selection:
The 2-Step - 4-Step changes the function of the gun’s
trigger.
2 Step trigger operation turns welding on and off in
direct response to the trigger. Welding process is
performed when the gun’s trigger is pulled.
4-Step mode allows to continue welding, when the
gun’s trigger is released. To stop welding, the gun’s
trigger is pulled again. 4-step mode facilitates to
making long welds.
The Burnback Time is the amount of time that the weld
output continues after the wire stops feeding. It prevents
the wire from sticking in the puddle and prepares the end
of the wire for the next arc start.
Run-in WFS sets the wire feed speed from the time the
trigger is pulled until an arc is established.
Preflow Time adjusts the time that shielding gas flows
after the trigger is pulled and prior to feeding.
Welding in Synergic Mode
Synergic Mode enables welding GMAW and FCAW-GS
process according to Table 2.
Table 2.
POWERTEC
305C PRO 355C PRO 425C PRO
Steel
(80%Ar/20%CO2)
Ø0.8 X X X
Ø1.0 X X X
Ø1.2 X X X
Steel (100%CO2)
Ø0.8 X X X
Ø1.0 X X X
Ø1.2 X X X
CRNI
(98%Ar/2%CO2)
Ø0.8 X X X
Ø1.0 X X X
Ø1.2 X X X
Aluminum
(100% Ar)
Ø1.0 X X X
Ø1.2 X X X
CORE*
(80%Ar/20%CO2)
Ø1.2 X X X
Ø1.6 X X X
*Flux-cored wire for FCAW-GS process.
Welding in Synergic Mode is possible when Diameter
Wire [30] and Welded Material and Appropriate Gas [31]
are set.
WARNING
If the selected welding process does not have synergic
mode, three horizontal dashes will appear on the display
"A".
In Synergic Mode can be set:
Wire Diameter
Welded Material and Appropriate Gas
The welding load voltage
WARNING
For Synergic Welding Mode the machine automatically
select the proper Wire Feeding Speed for each position of
the Welding Load Voltage Switch [3]. The automatic
speed value can be adjusted in the range of the 25% by
the WFS Control Knob [5].

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Burnback
Run-in WFS
Preflow Time
2-Step/4-Step
The 2-Step - 4-Step changes the function of the gun’s
trigger.
2 Step trigger operation turns welding on and off in
direct response to the trigger. Welding process is
performed when the gun’s trigger is pulled.
4-Step mode allows to continue welding, when the
gun’s trigger is released. To stop welding, the gun’s
trigger is pulled again. 4-step mode facilitates to
making long welds.
The Burnback Time is the amount of time that the weld
output continues after the wire stops feeding. It prevents
the wire from sticking in the puddle and prepares the end
of the wire for the next arc start.
Run-in WFS sets the wire feed speed from the time the
trigger is pulled until an arc is established.
Preflow Time adjusts the time that shielding gas flows
after the trigger is pulled and prior to feeding.
Transport & Lifting
WARNING
Falling equipment can cause injury and
damage to unit.
max 45°
Figure 17.
To safety transport and lift POWERTEC 305C PRO, 355C
PRO & 425C PRO (see the Figure 17):
Use equipment of adequate capacity to lift and support
unit.
Always lift and support unit using both eye bolts.
Do not use one eye bolt to lift or support unit.
Lift only power source without gas cylinder, cooler and
wire feeder, or any other accessories.
Screw down an eye bolt and apply load axially in 45
degree angle in accordance to the Figure 17.
Ensure equal length of lifting lines.
Do not use handle to lift or support unit.
Maintenance
WARNING
For any repair operations, modifications or maintenances,
it is recommended to contact the nearest Technical
Service Center or Lincoln Electric. Repairs and
modifications performed by unauthorized service or
personnel will cause, that the manufacturer’s warranty will
become null and void.
Any noticeable damage should be reported immediately
and repaired.
Routine maintenance (everyday)
Check condition of insulation and connections of the
work leads and insulation of power lead. If any
insulation damage exists replace the lead
immediately.
Remove the spatters from the welding gun nozzle.
Spatters could interfere with the shielding gas flow to
the arc.
Check the welding gun condition: replace it, if
necessary.
Check condition and operation of the cooling fan.
Keep clean its airflow slots.
Periodic maintenance (every 200 working hours but at
list once every year)
Perform the routine maintenance and, in addition:
Keep the machine clean. Using a dry (and low
pressure) airflow, remove the dust from the external
case and from the cabinet inside.
If it is required, clean and tighten all weld terminals.
The frequency of the maintenance operations may vary in
accordance with the working environment where the
machine is placed.
WARNING
Do not touch electrically live parts.
WARNING
Before the case of welding machine will be removed, the
welding machine had to be turned off and the power lead
had to be disconnected from mains socket.
WARNING
Mains supply network must be disconnected from the
machine before each maintenance and service. After
each repair, perform proper tests to ensure safety.

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Customer Assistance Policy
The business of The Lincoln Electric Company is
manufacturing and selling high quality welding equipment,
consumables, and cutting equipment. Our challenge is to
meet the needs of our customers and to exceed their
expectations. On occasion, purchasers may ask Lincoln
Electric for advice or information about their use of our
products. We respond to our customers based on the best
information in our possession at that time. Lincoln Electric
is not in a position to warrant or guarantee such advice,
and assumes no liability, with respect to such information
or advice. We expressly disclaim any warranty of any
kind, including any warranty of fitness for any customer’s
particular purpose, with respect to such information or
advice. As a matter of practical consideration, we also
cannot assume any responsibility for updating or
correcting any such information or advice once it has
been given, nor does the provision of information or
advice create, expand or alter any warranty with respect
to the sale of our products
Lincoln Electric is a responsive manufacturer, but the
selection and use of specific products sold by Lincoln
Electric is solely within the control of, and remains the sole
responsibility of the customer. Many variables beyond the
control of Lincoln Electric affect the results obtained in
applying these types of fabrication methods and service
requirements.
Subject to Change – This information is accurate to the
best of our knowledge at the time of printing. Please refer
to www.lincolnelectric.com for any updated information.