Elettro C.F. TIG 2015 DC-HF User manual

Elettro C.F. s.r.l. 1
07/06/16
TIG 2015 DC-HF
POWER SOURCE art. 168
SERVICE MANUAL

Elettro C.F. s.r.l. 2
07/06/16
TABLE OF CONTENTS
1- GENERAL INFORMATION..........................................................................................................................3
1.1 - Introduction................................................................................................................................................3
1.2 - General assistance philosophy...................................................................................................................3
1.3 - Safety information. ....................................................................................................................................3
1.4 - Electromagnetic compatibility...................................................................................................................3
2- DESCRIPTION OF SYSTEM ........................................................................................................................4
2.1 - Introduction................................................................................................................................................4
2.2 - Technical specifications.............................................................................................................................4
2.3 - Description of power source art. 168.........................................................................................................4
3 - MAINTENANCE ...........................................................................................................................................6
3.1 - Periodical inspection, cleaning..................................................................................................................6
3.2 - Operating sequence....................................................................................................................................6
3.2.1 - Power source controls and signals.............................................................................................................6
3.2.2 - Switching on power source........................................................................................................................7
3.2.3 - TIG operation.............................................................................................................................................8
3.2.4 - MMA operation. ........................................................................................................................................9
3.3 - Troubleshooting.......................................................................................................................................10
3.3.1- The power source does not switch on, control panel off..........................................................................10
3.3.2 - Power source supplied, fan (7) stopped...................................................................................................11
3.3.3 - Power source supply, signals do not indicate correct values. ..................................................................11
3.3.4 - In TIG mode, the start button has no effect. ............................................................................................13
3.3.5 - In TIG mode, gas does not come out the torch. .......................................................................................13
3.3.6 - In TIG mode, gas comes out the torch but does not ignite the arc, high frequency missing.................... 14
3.3.7 - In no-load operation, the output voltage is not regular. ...........................................................................15
3.3.8 - In resistive load operation, the output voltage is not regular. ..................................................................16
3.3.9 - In TIG mode, arc unstable, welding irregular..........................................................................................17
3.3.10 - In AC mode, arc unstable, welding irregular........................................................................................... 17
3.4 - Error codes............................................................................................................................................... 18
3.4.1 - Symbol on display. .........................................................................................................................18
3.4.2 - Symbol on display ..........................................................................................................................18
3.4.3 - Error E01. ................................................................................................................................................18
3.4.4 - Error E02 .................................................................................................................................................18
4- LIST OF COMPONENTS ............................................................................................................................19
4.1 - Power source art. 168...............................................................................................................................19
4.2 - Components table. ................................................................................................................................. 19
4.3 - Spare parts list. ......................................................................................................................................... 19
5- WIRING DIAGRAMS..................................................................................................................................20
5.1 - Power source art. 168...............................................................................................................................20
5.2 - Power board (14). ....................................................................................................................................20
5.3 - Display board (18). ................................................................................................................................. 21
5.4 - Connector board (28). .............................................................................................................................22
5.5 - AC-board (38)..........................................................................................................................................23

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1 - GENERAL INFORMATION
1.1 - Introduction.
This manual is intended to instruct maintenance personnel of the power source art. 168 for
TIG and MMA welding systems.
1.2 - General assistance philosophy.
The customer and/or operator has the responsibility of appropriate use of the equipment in
compliance with the requirements of the Instruction Manual and of the Safety Rules Manual. He is
also responsible for keeping the appliance and relative accessories in good working conditions, in
compliance with the requirements of the Service Manual.
Any internal inspection or repair must be carried out by qualified personnel who is responsible
for interventions on the appliance.
It is forbidden to try to repair damaged circuit boards or electronic modules. Replace them with
original Elettro CF spare parts.
1.3 - Safety information.
The following information regarding safety is an integral part of that provided in the Instruction
Manual and the Safety Rules Manual. Therefore before operating on the machine, read the
paragraph relative to the safety provisions in the above-mentioned manual.
Always disconnect the power cable from the mains and wait for the internal capacitors to
discharge (2 minutes) before accessing the parts inside the equipment.
Some internal parts, such as terminal boards and heat sinks, can be connected to mains
potentials and in any case are dangerous. Therefore do not operate without the protective covers
on the equipment unless absolutely necessary. In that case, take special precautions such as
wearing insulated gloves and footwear and operating in environments and wearing clothing which
are perfectly dry.
1.4 - Electromagnetic compatibility.
Please read and follow the instructions in the paragraph “Electromagnetic compatibility” of
the Safety Manual.

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2 - DESCRIPTION OF SYSTEM
2.1 - Introduction.
The TIG 2015 AC/DC-HF INVERTER is a system for MMA and TIG welding, with both
contact and high frequency arc ignition.
It consists of an electronic power source (art. 168), and a series of accessories to adapt it to
different types of use.
The power source is controlled by microprocessor circuits which manage the operating
functions of the welding system and the interface with the operator.
2.2 - Technical specifications.
Read the machine data plate and the Instruction Manual to verify the technical specifications.
2.3 - Description of power source art. 168.
Art. 168 is a direct voltage current-controlled power source, consisting of single-phase
bridge rectifier, a PFC module, a DC/AC converter (inverter) and another bridge rectifier.
Furthermore, an additional DC/AC converter downstream of the second rectifier converts the
welding current back to AC.
The main blocks making up the power source can be identified on the wiring diagram of par.
5.1 and on drawing of par. 4.1
The main switch (5) powers the service transformer (44) and the power circuit (14), which
contains the filter for reducing conducted interferences reflected in the mains, the circuits for
preload and the transformer for supplying the control circuits.
The power board (14) also supplies the fan (7) and the gas solenoid valve (23).
The power board (14) is the real power source, as it generates square wave alternating voltage
for the power transformer. The welding current is adjusted by modulating this voltage.
The AC-inverter unit, made up of the AC board (38) and of the igbt (42), reverses the polarity
of the power source output voltage in AC operating mode.
The four igbt (42) are connected in “H-bridge” configuration, so that the alternating closing of
the four igbt provides once positive voltage and once negative voltage at the “+” (D) output of the
power source, present on the output terminals of the inverter unit. These voltages obviously refer
to the potential of the “-“ (F) terminal.
The AC-board (38) is the main board of the AC-inverter stage and contains the drive circuits
for the igbts (42) and for the arc maintenance system. These commands come directly from the
microprocessor placed on the power board (14).
The AC-board (38) also contains the “AC-capacitor”, having the purpose to store energy for the
arc maintenance pulse during AC operation
The display board (18) gathers the display for viewing the welding parameters and the encoder
for setting and programming operating parameters.
The display board (18) is fully managed by the power board microprocessor (14), which also
powers it.
The connector board (28) is the interface for connecting the external control devices to the
power source, such as the start button of the TIG torch, the potentiometer for external adjustment
of welding current, the UP/DOWN buttons for digital current adjustment. These signals are
appropriately filtered by components on the connector board (28), against conducted interferences
coming from the welding field. The connector board (28) also has the task of preventing high-
voltage pulses at high frequency generated by the HF transformer (33) from returning along the
wiring into the power board (14), where they would cause malfunctions or failures.
The HF transformer (33) is connected to the power board output (14) for ignition of the
welding arc, in ignitions without contact between electrode and workpiece. It is supplied by the

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power board (14) which generates high-voltage pulses at high frequency for the transformer (33).
The fan (7), for cooling the power elements of the power source, is controlled by the
microprocessor of the power board (14). Its operation depends on the selected welding mode:
- If the machine is on in MMA mode or it switches to MMA mode, the fan is always on.
- If the machine is on and used in the four TIG modes, the fan runs for the first 10
seconds, and reactivates when the torch button is pressed, again for 10 seconds, until the
machine returns to the initial temperature condition when welding.
The signals processed by the circuit boards and present on the connectors are listed in the tables
in chapter 5 of this manual.

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3 - MAINTENANCE
WARNINGS
ANY INTERNAL INSPECTION OR REPAIR MUST BE CARRIED OUT BY
QUALIFIED PERSONNEL.
BEFORE PERFORMING MAINTENANCE, DISCONNECT THE MACHINE FROM THE
MAINS AND WAIT FOR THE INTERNAL CAPACITORS TO DISCHARGE (2 MINUTES)
3.1 - Periodical inspection, cleaning.
Periodically check the correct air inflow inside the ventilation tunnel.
Remove any filth or dust to guarantee appropriate heating of the internal parts of the power
source.
Check the conditions of the output terminals, output and power cables of the power source;
replace them if damaged.
Check the conditions of the internal power connections and connectors of the circuit boards; if
any connections have been loosened, tighten them or replace the connectors.
3.2 - Operating sequence.
The following sequence reflects correct operation of the machine. It can be used as a guide
procedure for troubleshooting.
At the end of every repair, it must be able to be carried out without running into any problems.
3.2.1 - Power source controls and signals.

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Correct?
Correct?
Correct?
NOTE
Operations preceded by this symbol refer to actions of the operator.
♦Operations preceded by this symbol refer to responses of the machine to the operation carried
out by the operator.
3.2.2 - Switching on power source.
System off and disconnected.
Connect the power source to the mains.
Close the switch (5).
♦System powered, light on switch (5) on.
♦Display (B) on.
♦After a few seconds, the display views the last welding settings detected prior to the
last switch off and the fan starts to run.
NO (see 3.3.1, 3.3.2, 3.3.3).
YES
Turning the encoder (A) selects the various welding functions (see machine instruction manual)
which are displayed.
NO (see 3.3.3).
YES
Turn the encoder (A); by rotating anticlockwise, the indication on the display (B) decreases to a
minimum of (005 in TIG, 010 in MMA); by rotating clockwise, the indication on the display
(B) increases to a maximum of (200 in TIG, 160 in MMA) (these values are also affected by
the position of the potentiometer on the torch and by the UP/DOWN buttons, if present).
NO (see 3.3.3).
YES
REGULAR OPERATION.

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Correct?
Correct?
3.2.3 - TIG operation.
NOTE
The TIG-AC operating sequence is described below, because it involves all of the internal power
source units, including those for TIG-DC operation.
WARNINGS
DURING THE FOLLOWING TESTS, DO NOT AIM THE TORCH TOWARDS PERSONS OR
BODY PARTS BUT TOWARDS AN OPEN SPACE OR THE PIECE TO BE WELDED.
DO NOT TRY TO MEASURE OUTPUT VOLTAGE DURING THESE PHASES. THE
PRESENCE OF HIGH FREQUENCY COULD DAMAGE THE INSTRUMENT OR THE
POWER SOURCE ITSELF.
Switch the power source off by using the switch (5).
Connect the gas supply to the specific fitting (K) on the rear panel.
Connect the TIG torch to the negative pole (F) of the power source, to the gas fitting (E)
and to the connector of the controls (C) on the front panel.
Connect the earth cable to the positive pole (D) of the power source and to the piece to be
welded.
Switch the power source back on by using the switch (5).
Using the encoder (A), select “Process” and “Mode” TIG-CONTINUOUS with HF, icon ,
, viewed on display (B)
Quickly press the start button of the torch.
♦The pre-gas phase begins with gas coming out from the torch as long as the
button is pressed.
♦After having released the torch start button, gas continues to come out the torch
for the set post-gas time (see the Instruction Manual for the post-gas setting).
NO (see 3.3.4, 3.3.5).
YES
Press and hold the start button for about 5 seconds.
♦The pre-gas phase begins, followed by generation of high frequency for arc ignition
and generation of output voltage of the power source.
♦After approximately 2 seconds, generation of output voltage and of high frequency
for arc ignition ends and the post-gas phase begins (TIG operation with HF is
interrupted if there is no current at the power source output after the start).
NO (see 3.3.6, 3.3.7).
YES
Approach the torch to the piece to be welded and press the start button.
♦Start welding. Turn the encoder (A) or the potentiometer on the torch to have the
appropriate current level for the welding operation.
♦The display (B) indicates the welding current.

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Correct?
Correct?
Correct?
Correct?
NO (see 3.3.8, 3.3.9).
YES
Release the start button on the torch.
♦The arc switches off immediately (if long slope-down times are not set).
♦Gas continues to come out to protect the welding bath (post-gas).
NO (see 3.3.5, 3.3.9).
YES
REGULAR OPERATION
3.2.4 - MMA operation.
Switch the power source off by using the switch (5).
Connect the electrode clamp to the positive pole (D) of the power source.
Connect the earth cable to the negative pole (F) of the power source and to the piece to be
welded.
Switch the power source back on by using the switch (5).
After the display switches on, with the encoder (A), select MMA “Process” and “Mode”, icon
viewed on the display (B).
♦Voltage generation begins at the power source output.
♦Display (B) indicates the programmed welding current.
NO (see 3.3.7).
YES
Set the current using the encoder (A) or the potentiometer on the remote control based on the
electrode intended to be used.
Approach the clamp with electrode to the piece to be welded.
♦Start welding. Adjust the encoder (A) or the potentiometer on the remote control to
optimise welding quality.
♦Display (B) indicates the welding current.
NO (see 3.3.8.)
YES
REGULAR OPERATION

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Correct?
Correct?
Correct?
3.3 - Troubleshooting. WARNINGS
ANY INTERNAL INSPECTION OR REPAIR MUST BE CARRIED OUT BY QUALIFIED
PERSONNEL.
DISCONNECT THE POWER SOURCE FROM THE MAINS AND WAIT FOR THE
INTERNAL CAPACITORS TO DISCHARGE (2 MINUTES) BEFORE REMOVING THE
PROTECTIVE COVERS AND ACCESSING THE INTERNAL PARTS.
NOTE
The problems which the machine could have (symptoms).are described in boldface.
Operations preceded by this symbol refer to situations which the operator must check
(causes).
♦Operations preceded by this symbol refer to actions with the operator must carry out to
resolve problems (remedies).
3.3.1 - The power source does not switch on, control panel off.
MAINS SUITABILITY TEST.
Power failure due to triggering of mains protections.
NO
YES
♦Eliminate any short circuits on connections between power cable (10), switch (5),
power board (14) and fan (7).
♦Check that the terminals J4 and J9 on the power board (14) are not short-circuited
one with another or towards earth.
♦Mains unsuitable to power the power source (e.g. insufficient power installed).
POWER BOARD (14) POWER SUPPLY TEST.
Power board (14), terminals J4-J9 = 230 Vac
YES
NO
♦Check wiring between power board (14) and switch (5).
♦Check switch (5) and replace it if necessary.
♦Check power cable (10) and replace it if necessary.
PANEL BOARD (18) POWER SUPPLY TEST.
Panel board (18), connector J2, terminals 25 (+) – 24 (-) = +5 Vdc.
YES
NO

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Correct?
♦Check wiring between J1 power board (14) and J2 panel board (18).
♦With power source off, temporarily disconnect the connector J2 on panel board
(18) and verify that the terminals 25 and 24 of J2 panel board (18) are not short-
circuited. If necessary, replace panel board (18), and verify, while powering the
power source with connector J2 disconnected, the presence of 5 Vdc on terminals
25 and 24 of the loose connector J1, left free. If missing, replace power board (14)
as well.
♦Check correct assembly of impedance (35) on terminals J8 and J16 of power
board (14).
♦Replace panel board (18) and/or power board (14).
NOTE
The fan (7) on the power source is managed by the microprocessor of the power board (14) and
its operation is subordinated to the conditions of the power board, as described in par. 2.3 -
description of power source art. 168. To perform the following tests, it is recommended to be
set in MMA mode.
3.3.2 - Power source supplied, fan (7) stopped.
FAN (7) TEST.
Fast-on terminals of fan (7) = 230 Vac approximately, with switch (5) closed.
NO
YES
♦Check that there are no mechanical obstructions blocking the fan.
♦Replace fan (7).
♦Check wiring between fan (7) and power board (14).
♦Check conditions of the mains voltage.
♦Replace power board (14).
3.3.3 - Power source supply, signals do not indicate correct values.
SIGNALS TEST.
A few seconds after switch on, the display views the last welding settings detected prior to the
last switch off. By acting on the encoder (A) you may perform all the steps described in par.
3.2.2 of the operating sequence.
YES
NO
♦Check wiring between J1 power board (14) and J2 panel board (18).
♦Replace power board (14) and/or panel board (18).
EXTERNAL CURRENT REGULATION TEST (potentiometer or buttons on torch).
Power board (14), connector J7, terminals 1(+) and 3(-) = 0 – +5 Vdc, by turning the
potentiometer on the torch.

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Correct?
Power board (14), connector J7, terminals 6(+) and 8(-) = 0 Vdc (UP command), with UP
button pressed (+5 Vdc with button released).
Power board (14), connector J7, terminals 5(+) and 8(-) = 0 Vdc (DOWN command), with
DOWN button pressed (+5 Vdc with button released).
YES
NO
♦Check wiring between J7 power board (14) and J3 connector board (28).
♦Check remote control potentiometer and UP/DOWN buttons and replace them if
faulty.
♦Check +5 Vdc terminals 7 (-) and 9 (+) of CN2 connector board (28)
(potentiometer power supply). If missing, check same voltage on terminals 3
(-) and 1 (+) of J7 power board (14), check wiring between the two
connectors or replace power board (14).
♦Replace connector board (28).
♦Replace power board (14).

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Correct?
3.3.4 - In TIG mode, the start button has no effect.
START COMMAND TEST.
Power board (14), connector J7, terminals 4(+) and 8(-) = 0 Vdc (start), with start button
pressed (+5 Vdc with button released).
YES
NO
♦Check wiring between J7 power board (14) and J3 connector board (28).
♦Check correct insertion of connector of torch on connector (C).
♦Check torch cable and button. Replace them if faulty.
♦Replace connector board (28) and/or power board (14).
♦Replace power board (14).
3.3.5 - In TIG mode, gas does not come out the torch.
SOLENOID VALVE TEST.
Solenoid valve terminals (23) = 230 Vac with torch button pressed (the duration the solenoid
valve is open also depends on the set post-gas time).
NO
YES
♦Check for gas at the specific fitting (K) on the rear panel and that pressure and
flow rate in the supply duct comply with the specification values (see
specifications in Instruction Manual).
♦Check that no gas pipe in the power source is obstructed.
♦With power source off and disconnected, check resistance on the solenoid valve
terminals (23) = 2500 ohm. If >Mohm (winding interrupted), replace solenoid
valve (23).
♦Replace solenoid valve (23).
♦Check wiring of connector J5 of power board (14) and solenoid valve (23).
♦Check operation of the start command, if necessary performing the START COMMAND
TEST in par. 3.3.4.
♦With power source off and disconnected, check resistance on the solenoid valve terminals
(23) = 2500 ohm. If 0 ohm (short-circuit), replace solenoid valve (23).
♦Replace power board (14).

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Correct?
3.3.6 - In TIG mode, gas comes out the torch but does not ignite the arc, high frequency
missing.
WARNING
DURING THE FOLLOWING TESTS, LEAVE THE NEGATIVE OUTPUT TERMINAL (F)
OF THE POWER SOURCE FREE FROM CONNECTIONS AND DO NOT TOUCH.
THE PRESENCE OF HIGH VOLTAGE AND HIGH FREQUENCY IS
DANGEROUS FOR THE OPERATOR AND COULD DAMAGE THE
INSTRUMENTS OR THE POWER SOURCE
SECONDARY RECTIFIER OUTPUT VOLTAGE TEST.
Set TIG operation without high frequency.
Terminal J20 (+) e J21 (-) on power board (14) = +96 Vdc approximately, with start button
pressed (output voltage of secondary rectifier upstream of HF transformer (33).
YES
NO
♦Check functioning of start command (see par. 3.3.4).
♦Check conditions of mains voltage and, if necessary, perform tests in par. 3.3.1.
♦Replace power board (14).
HF OSCILLATOR TEST.
Set TIG operation with high frequency.
Power board (14), surge arrester SC1 emits discharges at regular intervals, with start button
pressed.
NO
YES
♦With power source off, temporarily disconnect the wires from terminals J22 and
J23 of power board (14) and make sure there is no short-circuit in connectors J22
and J23 of the power circuit (14).
♦Check connections of the secondary HF transformer (33), spacer (32), AC-board
(38) and output terminal “-” of the power source. If there are loose connections,
tighten them or replace damaged components.
♦Check cable and torch electrode; replace them if worn or damaged.
♦Check that torch connection (Gifas) is not leaking, namely is not carrying high-
voltage surface discharges. If so, replace it with a new one.
♦Second the distance between the tips of the surge arrester SC1 (correct = 0.9 mm.).
♦Replace HF transformer (33).
♦Replace power board (14).
♦Check proper insulation of the components of the HF power source circuit on the printed circuit of
the power board (14), and remove any filth or dust which could short-circuit the components.
♦Second the distance between the tips of the surge arrester SC1 (correct = 0.9 mm.).
♦Replace power board (14).

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Correct?
3.3.7 - In no-load operation, the output voltage is not regular.
WARNING
FOR THE FOLLOWING TESTS, DISCONNECT THE TERMINALS OF THE PRIMARY
WINDING OF THE HF TRANSFORMER (33) FROM TERMINALS J22, J23 OF
POWER BOARD (14), TO PREVENT GENERATION OF HIGH FREQUENCY
NO-LOAD OUTPUT VOLTAGE TEST.
Output terminal (F) of power source (-) and output terminal (D) of power source (+) =
voltages according to table.
Process
Voltage
Condition
TIG-DC
+96 Vdc
Start button pressed
MMA
+83 Vdc
Power source supplied
TIG-AC
+96 Vac
Start button pressed
YES
NO
♦Check connection between terminal J21 on power board (14), AC-board (38),
insulator (32), HF transformer (33) and output terminal of power source, and
connection between terminal J20 on power board (14), AC-board (38) and output
terminal + of power source (D). If there are loose connections, tighten them or
replace damaged terminals.
♦In TIG mode, check functioning of start command (see par. 3.3.4).
♦Check conditions of mains voltage and, if necessary, perform tests in par. 3.3.1.
♦Check correct assembly of impedance (35) on terminals J6 and J16 of power
board (14).
♦Replace power board (14).
♦Regular operation.
AC-BOARD (38) SERVICES POWER SUPPLY TEST.
AC-board (38), connector CN2, terminals 1 (+) and 2 (-) = 27 Vac;
YES
NO
♦Replace the service transformer (44).
♦Check that between ~ and ~ terminals of AC board (38) you have approx. 95V (DC if you are
in MMA or TIG DC mode, AC if you are in TIG AC mode) (in TIG mode with start button
pressed or in MMA mode with power source powered).
♦Replace the AC-board (38) and/or IGBT (42).

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Correct?
POWER RESISTOR (6) TEST
AC-board (38), resistor connection CN8= 15 Ω approx.;
YES
NO
♦Replace resistors (6).
♦Regular operation.
AC-BOARD (38) ENABLE TEST.
AC-board (38), connector CN1, terminals 2(+) and 4(-) = +5 Vdc approximately, in TIG-DC
and MMA mode, with power source powered.
AC-board (38), connector CN1, terminals 3(+) and 4(-) = +5 Vdc approximately, in TIG-AC
mode, with power source powered.
AC-board (38), connector CN1, terminals 2(+) and 4(-) = +5 Vdc approximately, in TIG-AC
mode, with power source powered.
YES
NO
♦Check the wiring between CN1 AC-board (38) and CN1 power board (14).
♦Replace the power board (14).
♦Make sure the AC-board (38) is properly mounted on the igbt modules (42), especially that
the holding screws that create the electrical connections between the AC-board (38) and igbt
(42) are properly tightened. If you find short-circuits or deteriorated connections, restore the
original connections, replacing any components with damaged terminals.
♦Replace AC-board (38).
♦Make sure the igbt (38) are intact, measuring with a digital multimeter in “diodes test” on the
following terminals of the AC-board (38):
+ (+) and ~ (-) = >Mohm; + (-) and ~ (+) = junction of one diode.
~ (+) and - (-) = >Mohm; ~ (-) and - (+) = junction of one diode.
If incorrect, replace the igbt module (42), along with the AC-board (38).
WARNING
In case of a fault on an igbt module (42), it is recommended to replace both the igbt module
(42) and the AC-board (38), containing the igbt driver circuit, at the same time. A damaged
igbt frequently damages the driver board to which it is connected. Similarly, a defective driver
board frequently damages the igbt to which it is connected.
3.3.8 - In resistive load operation, the output voltage is not regular.
WARNING
FOR THE FOLLOWING TESTS, SET TIG OPERATION WITH HIGH FREQUENCY AND
DISCONNECT THE TERMINALS OF THE PRIMARY WINDING OF THE HF
TRANSFORMER (33) FROM TERMINALS J22, J23 OF POWER BOARD (14), TO
PREVENT GENERATION OF HIGH FREQUENCY.
NOTE
For the following tests, use a resistive load capable of withstanding the maximum current of the
power source. The suitable values are shown on the table.

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Correct?
Correct?
Process
Resistive load
resistance
Maximum output
current
Power source
output voltage
Condition
TIG-DC
0.090 ohm
200 A
+ 18 Vdc
Start button pressed
TIG-AC
0.090 ohm
200 A
18 Vac
Start button pressed
MMA
0.165 ohm
160 A
+ 26.4 Vdc
Power source powered
OUTPUT VOLTAGE ON RESISTIVE LOAD TEST.
Set the maximum output current with the encoder (A).
Output terminal (F) of power source (-) and output terminal (D) of power source (+) = voltage
values as in table, adjustable with encoder (A).
YES
NO
♦Check connection between terminal J21 on power board (14), AC-board (38),
insulator (32), HF transformer (33), and output terminal – (F) of power source,
and connection between terminal J20 of power board (14), AC-board (38) and
output terminal “+” (D) of power source. If there are loose connections, tighten
them or replace components of damaged terminals.
♦Check wiring between J1 power board (14) and J2 panel board (18).
♦In TIG mode, check functioning of start command (see par. 3.3.4).
♦Check conditions of mains voltage and, if necessary, perform tests in par. 3.3.1.
♦Replace power board (14) and/or panel board (18).
♦Carry out AC-BOARD (38) SERVICES POWER SUPPLY TEST (par. 3.3.7).
♦Regular operation.
3.3.9 - In TIG mode, arc unstable, welding irregular.
NOTE
In TIG, welding quality might not be acceptable due to current instability. In this case, it is
recommended to switch to MMA operation and to perform welding tests.
MMA WELDING QUALITY TEST
Power source in MMA, welding tests = good welding quality.
YES
NO
♦Perform “no-load operation” (par. 3.3.7) and “resistive load operation” tests (par. 3.3.8).
♦Replace power board (14).
♦Check conditions of the torch and of the electrode. If necessary, remake the tip of the electrode.
♦Check presence and continuity of the gas flow (vibration of solenoid valve) exiting the torch
(see par. 3.3.5).
♦Replace power board (14) and/or panel board (18).
3.3.10 - In AC mode, arc unstable, welding irregular.
NOTE
In AC operation, the welding quality may not be acceptable due to current instability. We
therefore recommend that you make sure the power source works properly in DC, by carrying

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out welding tests in DC and, if necessary, the “open circuit operation” test (par. 3.3.7) and
“operation on resistive load” test (par. 3.3.8).
3.4 - Error codes.
3.4.1 - Symbol on display.
Temperature exceeded limit alarm.
The thermostat is placed on the power IGBT heat sink of the power board (14).
The power source does not provide current, but the fan keeps running; therefore, we
recommend leaving the power source supplied in the event the over-temperature alarm is
triggered.
Check the temperature of the power modules' heat sinks on the power board (14) and wait
until they are completely cold, if required. If the alarm persists, replace the power board (14). If
the alarm is restored, make sure that the fan is efficient, that the room temperature is not too
high, and that the work cycle does not exceed that specified.
3.4.2 - Symbol on display.
This icon lights up in the following situations:
High supply voltage alarm (over 290 Vac approximately) at ignition and during operation.
The power source does not supply current.
This system also protects the power source against accidental power at 400 Vac. Both the
electronic circuits and the fan are protected under this condition.
To restore operation, switch off the power source and supply it with the correct voltage.
3.4.3 - Error E01
Fault in internal power supply circuits of power board (14). The power source does not supply
current. To restore operation, switch the power source off, wait until the internal capacitors
discharge completely (4 minutes) and then switch the power source on with rated voltage. If the
E1 code appears again, it means that the power board (14) is faulty and must be replaced.
3.4.4. - Error E02
Power board anomaly (14). Generally, a phenomenon has occurred that may damage the
power source if it keeps running. To restore operation, switch the power source off, wait until the
internal capacitors discharge completely (4 minutes) and then switch the power source on with
rated voltage. If the E2 code appears again, replace the power board (14).

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4 - LIST OF COMPONENTS
4.1 - POWER SOURCE art. 168: see diagram on page 26
4.2 – Components table: see table on page 24
4.3 – Spare parts list.
Essential spare parts.
Ref. Description Q.ty
18 display board 1
28 connector board 1
14 power board 1
38 AC-board 1
Recommended spare parts.
Ref. Description Q.ty
5 switch 1
07 fan 1
42 IGBT 4

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5 - WIRING DIAGRAMS
5.1 - Power source art. 168: see diagram on page 26
5.2 - Power board (14)
5.2.1 - Topographic drawing.