Lincoln Electric INVERTEC V160 User manual

Rev.0205/2006
INVERTECV160
SERVICE MANUAL
Europe Version
LINCOLN ELECTRIC ITALIA S.r.l
www.lincolnelectric.it

2
SAFETY
WARNING
This equipment must be used by qualified personnel. Be sure that all installation, operation,
maintenance and repair procedures are preformed only by qualified individuals. 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 damage to this equipment.
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 damage to this equipment. 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 damage to this equipment.
ELECTRIC SHOCK CAN KILL: Welding equipment generates high voltages. Do not touch the
electrode, work clamp, or connected work pieces when this equipment is on. Insulate yourself from
the electrode, work clamp, and connected work pieces.
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. Use suitable clothing made from
durable flame-resistant material to protect you skin and that of your helpers. Protect other nearby
personnel with suitable, non-flammable screening and warn them not to watch the arc nor expose
themselves to the arc.
WELDING SPARKS CAN CAUSE FIRE OR EXPLOSION: Remove fire hazards from the welding
area and have a fire extinguisher readily available. 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 operate this equipment when flammable gases, vapors or liquid
combustibles are present.
ELECTRICALLY POWERED EQUIPMENT: Turn off 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. No 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.
ELECTRIC AND MAGNETIC FIELDS MAY BE DANGEROUS: Electric current flowing through
any conductor creates electric and magnetic fields (EMF). EMF fields may interfere with some
pacemakers, and welders having a pacemaker should consult their physician before operating this
equipment.
CYLINDER MAY EXPLODE IF DAMAGED: 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. 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.

3
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.
HF CAUTION: The high frequency used for contact-free ignition with TIG (GTAW) welding, can
interfere with the operation of insufficiently shielded computer equipment, EDP centers and industrial
robots, even causing complete system breakdown. TIG (GTAW) welding may interfere with
electronic telephone networks and with radio and TV reception.
CE COMPLIANCE: This equipment complies to the Central European directives.
SAFETY MARK: This equipment is suitable for supplying power for welding operations carried out
in an environment with increased hazard of electric shock.

4
Electromagnetic Compatibility (EMC)
This machine has been designed in accordance with all relative directives and norms. 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.
WARNING: 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 Italia. Do not modify this machine without the written approval of
Lincoln Electric Italia.
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.
•Personal medical devices like pacemakers and hearing aids.
•Equipment for calibration and measurement.
•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.

5
INDEX
Technical specification…………………………………………………………………………………………6
Installation and Operator Instructions……………………………………………………………………..7
Accessories……………………………………………………………………………………………………….11
Maintenance……………………………………………………………………………………………………..12
Major Component Location.…………………………………………………………………………………14
Theory of Operation……………………………………………………………………………………………15
Troubleshooting and Reapair………………………………………………………………………………..21
Electrical Diagram……………………………………………………………………………………………….48

6
INVERTEC V160 Technical Specifications
INPUT
Input Voltage
230V ±15%
Single Phase
Input Power at Rated Output
5.4kW @ 100% Duty Cycle
7.0kW @ 35% Duty Cycle
Frequency
50/60 Hertz (Hz)
RATED OUTPUT AT 40°C
Duty Cycle
(Based on a 10 min. period)
100%
35%
Output Current
130A
160A
Output Voltage
25.2 Vdc
26.4 Vdc
OUTPUT RANGE
Welding Current Range
5-160 Amps
Maximum Open Circuit Voltage
48 Vdc
RECOMMENDED INPUT CABLE AND FUSE SIZES
Fuse or Circuit Breaker Size
16A Superlag
Type of Plug
SCHUKO 16A/250V
(Included with Machine)
Input Power Cable
3 Conductor, 2.5mm2
PHYSICAL DIMENSIONS
Height
320 mm
Width
200 mm
Length
430 mm
Weight
10.5 – 11.0 Kg
Operating Temperature
–20°C to +40°C
Storage Temperature
-25°C to +55°C

7
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.
•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.
Input Supply Connection
Check the input voltage, phase, and frequency supplied
to this machine before turning it on. The allowable input
voltage is indicated in the technical specification section
of this manual and on the rating plate of the machine.
Verify the connection of grounding wires from the
machine to the input source.
Make sure the amount of power available from the input
connection is adequate for normal operation of the
machine. The necessary fuse and cable sizes are
indicated in the technical specification section of this
manual.
This machine is designed to operate on engine driven
generators as long as the 230Vac auxiliary can supply
adequate power as indicated in the technical
specification section of this manual. The auxiliary
supply of the generator must also meet the following
conditions.
•The AC waveform peak voltage is below 410V.
•The AC waveform frequency is between 50 and 60
hertz.
•The RMS voltage of the AC waveform is always
equal to 230Vac ± 10%.
It is important to check these conditions because many
engine driven generators produce high voltage spikes.
Operation of this machine on engine driven generators
not conforming to these conditions is not recommended
and may damage the machine.
Output Connections
A quick disconnect system using Twist-MateTM cable
plugs is used for the welding cable connections. Refer to
the following sections for more information on
connecting the machine for operation of stick welding
(MMA) or TIG welding (GTAW).
Stick Welding (MMA)
First determine the proper electrode polarity for the
electrode to be used. Consult the electrode data for this
information. Then connect the output cables to the
output terminals of the machine for the selected polarity.
For example, if DC(+) welding will be used then connect
the electrode cable to the (+) terminal of the machine and
the work clamp to the (-) terminal. Insert the connector
with the key lining up with the keyway and rotate
approximately ¼ turn clockwise. Do not over tighten.
For DC(-) welding switch the cable connections at the
machine so that the electrode cable is connected to (-)
and the work clamp is connected to (+).
TIG Welding (GTAW)
This machine does not include a TIG torch necessary for
TIG welding, but one may be purchased separately.
Refer to the accessories section for more information.
Most TIG welding is done with DC(-) polarity; connect
the torch cable to the (-) terminal of the machine and the
work clamp to the (+) terminal. Insert the connector
with the key lining up with the keyway and rotate
approximately ¼ turn clockwise. Do not over tighten.
For V160-S machines, connect the gas hose from the
TIG torch to a gas regulator on the cylinder of gas to be
used.
For V160-T machines, connect the gas hose from the
TIG torch to the gas connector (B) on the front of the
machine. If necessary, an extra gas connector for the
fitting on the front of the machine is included in the
package. Next, connect the fitting on the back of the
machine to a gas regulator on the cylinder of gas to be
used. An input gas line and the required fittings are also
included in the package. Connect the TIG torch trigger
to the trigger connector (A) on the front of the machine.
Remote Control Connection
For V160-T machines only, refer to the accessories
section for a list of remote controls. If a remote control
is used, it will be connected to the remote connector (C)
on the front of the machine. The machine will
automatically detect the remote control, turn on the

8
REMOTE LED, and switch to remote control mode.
More information on this mode of operation will be
given in the next section.
Controls and Operational Features
A. Power Switch: Controls the input power to the
machine. Make sure the machine is properly
connected to the input supply before turning the
machine on.
B. Fan: The cooling fan will turn ON when the
machine is turned ON and it will continue to run
whenever the output of the machine is ON. If the
output of the machine is OFF for more than five
minutes, the fan will turn OFF. This reduces the
amount of dirt that is deposited inside the machine
and reduces power consumption.
Refer to the Output LED section below for more
information about conditions when the output of the
machine is ON. The V160-S always has the output
turned ON so the fan will not turn OFF.
Additionally, when the V160-T machines are in Stick
mode, the fan will not turn OFF because the output
remains ON.
C. Gas Inlet (V160-T machines only): Connector for
the TIG shielding gas. Use the supplied gas line and
connector to connect the machine to the gas source.
The gas source must have a pressure regulator and
flow gage installed.
D. Mode Switch: This switch changes the welding
modes of the machine. The V160-S has two
welding modes: Stick (SMAW) and Lift TIG
(GTAW). The V160-T machines have three
welding modes: Stick (SMAW), Lift TIG (GTAW)
and HF TIG (GTAW).
When the mode switch is in the Stick position, the
following welding features are enabled.
•Hot Start: This is a temporary increase in the output
current during the start of the stick welding process.
This helps ignite the arc quickly and reliably.
•Arc Force: This is a temporary increase in the
output current during normal stick welding. This
temporary increase in output current is used to clear
intermittent connections between the electrode and
the weld puddle that occur during normal stick
welding. The amount of arc force can be adjusted
on the V160-S, refer to Arc Control, described
below.
•Anti-Sticking: This is a function which decreases
the output current of the machine to a low level
when the operator makes an error and sticks the
electrode to the work piece. This decrease in current
allows the operator to remove the electrode from the
electrode holder without creating large sparks which
can damage the electrode holder.
When the mode switch is in the Lift TIG position, the
stick welding functions are disabled and the machine
is ready for Lift TIG welding. Lift TIG is a method
of starting a TIG weld by first pressing the TIG torch
electrode on the work piece in order to create a low
current short circuit. Then, the electrode is lifted
from the work piece to start the TIG arc.
The last mode switch position, HF TIG, is only
available on the V160-T machines. When the mode
switch is in this position, the stick welding functions
are disabled and the machine is ready for HF TIG
welding. During the HF TIG mode, the TIG arc is
started by HF without pressing the electrode on the
work piece. The HF used for starting the TIG arc
will remain on for 6.5 seconds; if the arc is not
started in this time limit, the trigger sequence must be
restarted.
E. Trigger Mode Switch (V160-T machines only):
This switch changes between 2-step and 4-step
trigger sequences. For an explanation of these
trigger sequences refer to the trigger sequences
explained below.
F. Power LED: This indicator will blink on and off
when the machine is first turned on. After
approximately 2 seconds it will stop blinking and
remain on to signal that the machine is ready.
G. Thermal LED: This indicator will turn on when the
machine is overheated and the output has been
disabled. This normally occurs when the duty cycle
of the machine has been exceeded. Leave the
machine on to allow the internal components to
cool. When the indicator turns off, normal
operation is again possible.
H. Remote LED (V160-T machines only): This
indicator will turn on when a remote control is
connected to the machine via the remote control
connector. Using a remote control will change the
function of the output current control, refer to the
output current control section below.
I. Output LED: This indicator turns on when the
output of the machine is on. Both the type of
machine and the position of the mode switch
determine when the output of the machine is turned
on.
V160-S: In both welding modes, selected by the
mode switch, the output of the machine is always
turned on.
V160-T: In stick welding mode, the output of the
machine is automatically turned on. However, in
both of the TIG welding modes, the output of the
machine is turned ON and OFF by the TIG torch
connected to the trigger connector on the front of the
machine.

9
J. Arc Control (V160-S only): In stick welding mode,
this controls the amount of current used during arc
force. In TIG welding mode, this is not used.
K. Output Current Control: This controls the output, or
welding, current of the machine.
For V160-T machines, the function of this control
knob is changed if a remote control is connected. If
the Remote LED is ON, this indicates that a remote
control is connected and the function of the output
current control will be:
Stick Welding Mode: The remote control will
adjust the output current of the machine from 5 to
160A. The output current control knob on the
display panel is not used.
TIG Welding Modes: The maximum output current
of the machine is set by the output current control
knob. Then the remote control adjusts the output
current from the minimum output (5A) to the value
set by the output current control knob. For example,
if the output current control knob on the machine is
set to 100A then the remote control will adjust the
output current from a minimum of 5A to a maximum
of 100A.
L. Downslope Control (V160-T machines only): In the
TIG welding modes, this control knob will adjust
the downslope time from 0.5 to 20 seconds. (The
upslope time is always 0.5 seconds.) Refer to the
trigger sequence section below to understand how
downslope is activated. In Stick welding mode, this
is not used.
M. Postflow Control (V160-T machines only): In the
TIG welding modes, this control knob will adjust
the shielding gas postflow time from 0.5 to 30
seconds. (The preflow time is always 0.5 seconds.)
In Stick welding mode, this is not used.
N. Meter (V160-T Pulse only): This meter displays the
preset welding current before welding and the actual
welding current during welding. Like the output
current control, the function of the meter is changed
if a remote control is connected. If the Remote LED
is ON, this indicates that a remote control is
connected and the meter will display the following
information before welding (during welding, the
meter always displays the actual welding current):
Stick Welding Mode: The meter displays the preset
welding current but this is adjusted from the remote
control as explained in the Output Current Control
section.
TIG Welding Modes: The meter displays the
maximum output current which is set by the output
current control knob. The preset welding current is
then adjusted by the remote control, but it is not
displayed on the meter.
O. Pulsing Mode Switch (V160-T Pulse only): In the
TIG welding modes, this switch turns the pulsing
function ON and controls the pulsing frequency
range (20Hz or 300Hz). In Stick welding mode, this
is not used.
P. Pulsing LED (V160-T Pulse only): This indicator
shows the pulsing frequency when pulsing is turned
ON. With this indication, the operator can adjust
the frequency to the desired value before welding.
(Note: At higher frequencies the LED blinks very
fast and seems to be continuously ON however it is
pulsing.) If pulsing is turned OFF or if the machine
is in Stick welding mode, the indicator will be OFF.
Q. Pulsing Frequency Control (V160-T Pulse only):
When the pulsing function is ON, this control knob
will adjust the pulsing frequency. The pulsing
frequency adjustment range is 0.2 - 20Hz or 3 -
300Hz depending on the Pulsing Mode Switch
position.
R. Pulsing Background Current Control (V160-T Pulse
only): When the pulsing function is ON, this
control knob will adjust the pulsing background
current. This is the current during the low portion of
the pulse waveform; it can be adjusted from 10% to
90% of the welding current.
TIG Trigger Sequences
For V160-T machines only, TIG welding can be done in
either the 2-step or 4-step mode which is selected with
the Trigger Mode switch. The specific sequences of
operation for these two trigger modes are explained
below.
In these sequences, the Start/Crater current will be used.
This current is 20% of the welding current. For
example, if the welding current is 100A, the Start/Crater
current will be 20A. (If necessary, other values of the
Start/Crater current are possible; contact your Lincoln
Electric sales representative for more information.)
2-Step TIG Sequence
With the Trigger Mode switch in the 2-step position, and
a TIG welding mode selected, the following welding
sequence will occur. To setup the machine for TIG
welding refer to the Output Connections section.
1. Press and hold the TIG torch trigger to start the
sequence.
The machine will open the gas valve to start the
flow of the shielding gas. After a 0.5 second
preflow 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
(Lift TIG or HF TIG). For more information on the
Lift or HF TIG starting methods, refer to the Mode
switch section above.

10
After the arc is started the output current will be
increased to the welding current. This increase, or
upslope, of the output current takes 0.5 seconds to
complete.
2. Release the TIG torch trigger to stop welding.
The machine will now decrease the output current at
a controlled rate, or downslope time, until the
Start/Crater current is reached and the output of the
machine is turned OFF. The downslope time is
adjusted by the Downslope Control knob.
After the arc is turned OFF, the gas valve will
remain open to continue the flow of the shielding
gas to the hot electrode and work piece. The
duration of this postflow shielding gas is adjusted by
the Postflow Control knob.
Possible variations of this standard sequence are shown
below. (If necessary, other variations are also available;
contact your Lincoln Electric sales representative for
more information.)
As shown above, it is possible to press and hold the TIG
torch trigger a second time during downslope to end the
downslope time and maintain the output current at the
Start/Crater current. When the TIG torch trigger is
released the output will turn OFF and the postflow time
will start.
4-Step Sequence
With the Trigger Mode switch in the 4-step position, and
a TIG welding mode selected, the following welding
sequence will occur. To setup the machine for TIG
welding refer to the Output Connections section.
1. Press and hold the TIG torch trigger to start the
sequence.
The machine will open the gas valve to start the
flow of the shielding gas. After a 0.5 second
preflow 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
(Lift TIG or HF TIG). For more information on the
Lift or HF TIG starting methods, refer to the Mode
switch section above.
After the arc is started the output current will be at
the Start/Crater current. This condition can be
maintained as long or as short as necessary.
If the Start/Crater current is not necessary, do not
hold the TIG torch trigger as described at the
beginning of this step. Instead, quickly press and
release it. In this condition, the machine will
automatically pass from Step 1 to Step 2 when the
arc is started.
2. Release the TIG torch trigger to start the main part
of the weld.
The output current will be increased to the welding
current. This increase, or upslope, of the output
current takes 0.5 seconds to complete.
3. Press and hold the TIG torch trigger when the main
part of the weld is complete.
The machine will now decrease the output current at
a controlled rate, or downslope time, until the
Start/Crater current is reached. The downslope time
is adjusted by the Downslope Control knob. This
Start/Crater current can be maintained as long or as
short as necessary.
This sequence has an automatic restart so welding
will continue after this step. If the weld is
completely finished, use the following sequence
instead of step 3 described above.
3A. Quickly press and release the TIG torch
trigger.
The machine will now decrease the output
current at a controlled rate, or downslope time,
until the Start/Crater current is reached and the
output of the machine is turned OFF. After the
arc is turned OFF the postflow time will start.
4. Release the TIG torch trigger.
The output current will again increase to the welding
current, like in step 2, to continue welding. When
the main part of the weld is complete go to step 3.
Possible variations of this standard sequence are shown
below. (If necessary, other variations are also available;
contact your Lincoln Electric sales representative for
more information.)
As shown here, after the TIG torch trigger is quickly
pressed and released from step 3A, it is possible to press
and hold the TIG torch trigger another time to end the
downslope time and maintain the output current at the
Start/Crater current. When the TIG torch trigger is
released the output will again increase to the welding
current, like in step 4, to continue welding. When the
main part of the weld is complete go to step 3.
As shown here, again after the TIG torch trigger is
quickly pressed and released from step 3A, it is possible
to quickly press and release the TIG torch trigger a
second time to end the downslope time and stop welding.

11
Accessories
Welding Cables & Connectors
W79X0281R Work and Electrode Cable Kit
W79X0263R Work Cable Kit
W8800072R Male Quick Connect Gas Fitting (For V160-T and V160-T Pulse)
Remote Controls
K10095-1-10 Hand Amptrol (For V160-T and V160-T Pulse)
K870 Foot Amptrol (For V160-T and V160-T Pulse)

12
MAINTENANCE
WARNING
ELECTRIC SHOCK can kill
•Have an electrician install and service this
equipment
•Turn the input power off at the fuse box before
working on equipment
•Do not touch electrically hot parts
•Prior to performing preventive maintenance,
perform the following capacitor discharge
procedure to avoid electric shock
INPUT FILTER CAPACITOR
DISCHARGE PROCEDURE
1. Remove input power to V160S / T machine
2. Remove the rear panel using a screwdrivers
3. Remove the ground connection from the case
wraparound
4. Remove the case wraparound
5. Obtain a high resistance and high wattage resistor
( 25-1000 ohms and 25 watts minimum ). This
resistor is not supplied with the machine. NEVER
USE A SHORTING STRAP FOR THIS
PROCEDURE.
6. Locate the two terminals DC+ and DC – on the
input board. See Figure 1
7. Use electrically insulate gloves and insulated
pliers. Hold the body of the resistor and connect
the resistor leads across the two terminals. Hold
the resistor in place for 10 seconds. DO NOT
TOUCH CAPACITOR TERMINALS WITH
YOUR BARE HANDS.
8. Check the voltage across the two terminals.
Voltage should be zero. If any voltage remains,
repeat this procedure.
Figure 1 – Location of DC+ and DC- terminals
The input PCB is located in the left side of the machine
DC+
DC-
Terminals

13
ROUTINE MAINTENANCE
1. Keep the welding area around the machine clean
and free of combustible materials. No debris
should be allowed to collect which could obstruct
air flow to the machine
2. Every 6 months the machine should be cleaned
with a low pressure and dry airstream. Keeping
the machine clean will result in cooler operation
and higher reliability.
3. Examine the sheet metal case for dents or
breakage. Repair the case as required. Keep the
case in good condition to insure that high voltage
parts are protected and correct spacing are
maintained. All external sheet metal screw must be
in place to ensure case strength and electrical
ground continuity.
THERMAL PROTECTION
Thermal detection device protect the machine from
excessive operating temperatures. Excessive
temperatures may be caused by a lack of cooling air or
operating the machine beyond the duty cycle and
output rating. If excessive operating temperatures
should occur, the yellow LED will light and the
detection device will prevent output voltage or current.
These detection device are self-resetting once the
machine cools sufficiently. If the thermostat shutdown
was caused by excessive output or duty cycle and the
fan is operating normally, the power switch may be
left on and the reset should occur within a 15 minute
period. If the fan is not turning or the air intake louvers
were obstructed , then the power must be switched off
and the fan problem or air obstruction must be
corrected.

14
MAJOR COMPONENTS LOCATION
1. Cover
2. Input board
3. Inverter board
4. Rear panel
5. Front panel
1
2
3
4
5

15
THEORY OF OPERATION
General description…………………………………………………………………………………16
Input Line Voltage, Auxiliary Voltage, Precharge…………………………………………………16
Inverter Board , Main Transformer, Output Rectifier and Choke………………………………….17
Control board……………………………………………………………………………………….18
Protection Circuits………………………………………………………………………………….19
Over Current Protection………………………………………………………………………..19
IGBT operation……………………………………………………………………………………..20
Block diagram

16
Input Line Voltage, Auxiliary Voltage and Precharge
GENERAL DESCRIPTION
The Invertec V160 series is an inverter based welding
power sources that offers Tig and Stick process.
Depending of the type of the power sources ( V160S,
V160T or V160TP ) the machine has different
functions:
V160S: Is a Stick machine and lift Tig
V160T: Is a Stick and Tig machine with HF
V160TP: Is a Stick and Tig pulser machine with HF
INPUT LINE VOLTAGE, AUXILIARY
VOLTAGE AND PRECHARGE
The Invertec V160 can be connected to a 230 single-
phase input voltage.
The initial power is applied to the Invertec V160
trough to a line switch ( S1 ) located on the back of the
machine and after it goes to the RFI filter that is
located on the input board.
The voltage is after rectified by the input rectifier and
the resultant DC voltage is applied filtered by the filter
capacitors.
During the precharge time the DC input voltage is
applied to the filter capacitors through a start resistance
that limits the current. After this time the start relays go
closed and it by-pass the start resistance( there are two
start relays in parallel ).
The filtered DC voltage is also applied :
•to a switching circuit, that gives the necessary low
voltage for the logic circuit, fan and gas solenoid
•to the HF circuit ( V160T /TP only )

17
Inverter board , Main transformer, Output rectifier and Choke
INVERTER BOARD , MAIN TRANSFORMER,
OUTPUT RECTIFIER AND CHOKE
When the input capacitors are fully charged they act as
power supplies for the IGBT switching circuit.
The IGBTs supply the main transformer winding with
80KHz current flow.
The inverter board also monitors the filter capacitors
for overvoltage. If this occurs, the appropriate signal is
sent to the control board to disable the machines output
and to turn on the thermal/voltage Overload LED.
A pair of IGBTs act as a switch assembly. This
assembly feeds the primary winding of the main
transformer. When current is pulsed through this
primary winding, a resultant current is produced on a
secondary winding of the main transformer. The DC
current flow through the primary winding is redirected
back to the filter capacitors when the IGBTs are turned
off. This is due to the inductance of the transformer
primary winding.
The secondary winding supplies the electrode-to-work
voltages and the resulting current.
The output current is regulated via Pulse Width
Modulation.
The control circuitry, on the inverter board , receives a
signal from the control board and regulates the output
current to the desired level.
The output rectifier receives the AC output from the
main transformer secondary winding and rectifies it to
a DC voltage level. Since the output choke is in series
with the positive leg of the output rectifier.
A filtered DC output is applied to the machine’s output
terminals.

18
Control board
CONTROL BOARD
The control board receives status and analog feedback
from the inverter board, input board and various
sensor. The control circuitry interprets these signals,
makes decisions and changes the machine mode and
output to satisfy the requirements as defined by the
circuitry. The control board sends a signal to the
inverter board to control the output current. The control
board is composed in three parts:
-Display board
-Weld controller
-Meter Board ( only for V160TP )
There are 3 status indicators for the V160S and four for
the V160T and TP:
-Power On
-Thermal Overload
-Output Voltage On
-Remote LED On ( only V160T/TP )

19
OVERLOAD PROTECTION
The Invertec V160 is electrically protected from
producing higher than normal output currents. An
electronic protection circuit limits the current to within
the capabilities of the machine.
THERMAL PROTECTION
One thermal device, located on the output heatsink,
protect the machine from excessive operating
temperatures.
Excessive temperatures may be caused by a lack of
cooling air or by operating the machine beyond the
duty cycle and output rating. If excessive operating
temperatures should occur,the thermal status indicator
will turn ON and the thermostat will prevent output
current.
The thermal protection device is self-resetting once the
machine cools sufficiently. If the shut down was
caused by excessive output or duty cycle and the fan is
operating normally, the power switch may be left on
and the reset should occur within about 15 minute
period. If the fan is not turning or the air intake louvers
are obstructed, the input power must be removed and
the fan problem or air obstruction must be corrected.

20
INSULATED GATE BIPOLAR
TRANSISTOR (IGBT) OPERATION
An IGBT is a type of transistor. IGBTs are semicon-
ductors well suited for high frequency switching and
high current applications.
Drawing A shows an IGBT in a passive mode. There
is no gate signal, zero volts relative to the source, and
therefore, no current flow. The drain terminal of the
IGBT may be connected to a voltage supply; but since
there is no conduction the circuit will not supply
current to components connected to the source. The
circuit is turned off like a light switch in the OFF
position.
Drawing B shows the IGBT in an active mode. When
the gate signal, a positive DC voltage relative to the
source, is applied to the gate terminal of the IGBT, it
is capable of conducting current. A voltage supply
connected to the drain terminal will allow the IGBT to
conduct and supply current to circuit components
coupled to the source. Current will flow through the
conducting IGBT to downstream components as long
as the positive gate signal is present. This is similar
to turning ON a light switch
IGBT