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.