Sel Genesis 302 AC/DC Operating instructions

REPAIRS MANUAL
E
N
G
L
I
S
H
Genesis
302-382 AC/DC
WU21

Code: 92.08.01001
Edition: 05/03
Rev.: 1.0
SELCO s.r.l.
Via Palladio, 19
I - 35010 ONARA DI TOMBOLO (Padova) Italy
Tel. + 39 049 9413111
Fax + 39 049 9413311
e-mail: [e-mail]
How to contact Selco Service Department:
SELCO s.r.l.
Service Department
c/o SELCO 2
Via Macello, 61
I - 35010 CITTADELLA (Padova) Italy
Tel. + 39 049 9413111
Fax + 39 049 9413311
e-mail: [e-mail]
All translation, reproduction and adaptation rights, total or par-
tial and by any means (including photostat copies, films and
micro films), are reserved and forbidden without the written
authorisation of Selco S.r.l.
INDEX :
1) PURPOSE OF THE MANUAL . . . . . . . . . . . . . . . . .3
2) WARNINGS, PRECAUTIONS AND
GENERAL NOTICES FOR PERFORMING REPAIRS . .4
3) INSTRUMENTS AND CONVENTIONS
FOR PERFORMING DIAGNOSIS AND REPAIR . . . .5
4) DESCRIPTION OF OPERATION OF THE POWER
SOURCES AND TECHNICAL DATES . . . . . . . . . . . .7
5) WIRING AND CONNECTION DIAGRAMS . . . . . . .22
6) PC BOARDS’ LOCATION . . . . . . . . . . . . . . . . . . . .28
7) DESCRIPTION OF DIAGNOSTIC INDICATIONS . .30
8) SET-UP PARAMETERS . . . . . . . . . . . . . . . . . . . . . .36
9) DESCRIPTION, TESTING AND REPLACEMENT
OF THE ELECTRONIC BOARDS,
CURRENT CALIBRATION . . . . . . . . . . . . . . . . . . . .38
10) AVAILABLE SPARE PARTS . . . . . . . . . . . . . . . . . . . .62
2

Purpose of the manual 3
1) PURPOSE OF THE MANUAL
This manual is designed to provide authorised service centres
with the basic information necessary for performing repairs on
the models Genesis 302 AC/DC and 382 AC/DC.
In order to avoid serious injury to persons or damage to things,
this manual must be used only by qualified technicians.
Selco S.r.l. accepts no liability for any injury to personsor dama-
ge to things that may occur during performance of repairs, even
after reading or practical application of this manual.
For a detailed description of the operation, use and ordinary
maintenance of the machine, please refer to the "Instructionsfor
use and maintenance manual" which must always accompany
the machine. The purchaser must follow the directions contai-
ned in the above manual. Failure to do so will exempt Selco
from all liability.
The operations described in this manual require the use of a
digital multimeter, an AC/DC ammeter clamp and a basic kno-
wledge of how the machine works. Basic electrotechnical kno-
wledge is also required.
Repair consists in identification of the faulty part, included in
the list of available spare parts, and replacement of it.
In the event of failure of an electronic board, repair entails
replacement of the board and not replacement of the faulty
electronic component on the board.
For troubleshooting advice, see introduction to chapter 9.
Do not carry out modifications or maintenance not scheduled
in this manual.
If the problem cannot be solved by following the instructions
provided in this manual, contact the Selco Service Department
or send the machine to Selco for repair.

4 Warnings, precautions and general notices for performing repairs
2) WARNINGS, PRECAUTIONS AND GENERAL
NOTICES FOR PERFORMING REPAIRS
Repairs must be performed by qualified personnel only.
Before performing the repair, you should read and assimilate the
contentsof thismanual, in particular the safety precautions.
Avoid performing repairs without the presence of another person
able to provide help in the event of an accident.
The repair of a machine requiresaccessto itsinternal partsand con-
sequently removal of some of the protective panels. Additional pre-
cautions are therefore necessary with respect to use of the machi-
ne for welding in order to prevent possible injury or damage cau-
sed by contact with
- live parts
- moving parts
- partsat high temperature
Live parts:
CAUTION ! When handling internal parts of the
machine, remember that opening of the switch does
not prevent the risk of electric shocks: the machine
must be unplugged from the power supply.
Wait approx. one minute before carrying out work on the
internal parts as the capacitors may be loaded at high voltage.
CAUTION ! When taking measurements, remem-
ber that the measuring instruments can be live and
you should therefore avoid touching their metal
parts.
CAUTION! When TIG operation is selected with HF
start, the machine generates a series of high volta-
ge impulses (approx. 10,000 V) to spark the wel-
ding arc. When an arc sparking test in TIG with HF dischar-
ge is not specifically scheduled in the diagnostic phase, you
are therefore advised to disconnect the terminals FN1 and
FN2 of the HF 15.14.286 board.
After carrying out the repair, remember to reconnect FN1
and FN2 of the board 15.14.286 before finally closing the
machine, then perform a few welding tests, including TIG HF
sparking.
Moving parts:
CAUTION ! Keep your hands well away from the
fan when the machine is connected to the power
supply. Ensure that the machine is unplugged and
that the fan is at a standstill before replacing it.
Parts at high temperature:
CAUTION ! When handling internal parts of the
machine, remember that some of them may be
very hot. In particular avoid contact with heat
sinks.

Instruments and conventions for performing diagnosis and repair 5
3) INSTRUMENTS AND CONVENTIONS FOR PERFOR-
MING DIAGNOSIS AND REPAIR
3.1) Instruments for basic diagnosis
The following are required:
- a multimeter with the following scales:
Ohm: from 0 to a few Mohm
Diode testing
Direct voltage (Vdc): from mVdc to 1000 Vdc
Alternating voltage (Vac): from 10 Vac to 700 Vac
NOTE: You are advised to use an instrument with
automatic scale since it is not theoretically possible to
predict the electrical quantity to be measured when
the machine has broken down.
- an AC/DC ammeter clamp at least in class2.5 with e.o.s. 400A pk
- alternatively to the ammeter clamp, a shunt can be used with
value 60 mV @ 400 A.
NOTES:
* remember that other typesof shuntscan also be used,
but accuracy is reduced with higher capacities, whe-
reas with lower capacities the measurement must be
taken quickly to avoid overheating of the shunt
* once fitted, the shunt is at welding potential (be
careful especially with discharges during arc stri-
king in TIG HF)
* the ammeter clamp is preferable as it is more practi-
cal
3.2) Repair tools
- complete set of fork spanners
- complete set of pipe spanners for hexagonal nuts
- complete set of blade screwdrivers
- complete set of Phillips screwdrivers
- complete set of Allen keys
- Phillips torque screwdriver for M3 screws with tigh-
tening torque adjustable range from 1 to 3 Nxm,
accuracy 0.1 Nxm
- crimper for insulated wire terminals (blue, red and
yellow)
- pliers for AMP contacts
- tweezers and cutting nippers - type commonly used
for electronic components
- tongs (dimensions suitable for closing gas pipe
clamps)
- welder for electronic components, minimum power
50 W
- portable electric drill
3.3) Grid load
Use of grid load can speed up fault tracing and machine testing.
Just remember that a fixed power resistor applied to machine's
output is somewhat equivalent to a welding arc, but only inside
of a narrow output voltage range, whose center value can be
determined by the formula:
TIG DC WELDING:
V OUT 10 + 0.04 x I OUT
Es.: 12Vdc @ 50A
14Vdc @ 100A
18Vdc @ 200A etc.
STICK WELDING::
V OUT 20 + 0.04 x I OUT
Es.: 22Vdc @ 50A
24Vdc @ 100A
28Vdc @ 200A etc.
If output voltage goes too much above or below the rated value,
the generator could either saturate or go into arc force or other
special features could be performed (such as anti-flashing): in
both cases real output current could be much different from
expected value and the generator could even show an intermit-
tent output power (output power led blinking, see also sec.7.1
in the following).
Grid load resistor's rated power is also important, 'cos a 24Vdc
@ 100A grid load produces 2400W to be dissipated by air
cooling.
So, when using grid load, pay attention to both out-
put current & output voltage and use correct resistan-
ce value & power!

6 Instruments and conventions for performing diagnosis and repair
3.4) Conventions
By convention, when a measurement has to be taken between
two points, for example a b , the arrow point indicates
where to apply the red tip of the multimeter (a),while the black
tip is applied at the other end (b).
When a double arrow appears between two measuring points
(e.g.: c d ), the voltage to be measured is alternating
(normally at 50 Hz), therefore it does not matter in which order
the multimeter terminals are applied.
In drawings and tables, when a voltage measurement appears
referring to terminals of components such as DIODES, BJT,
MOSFET and IGBT, the multimeter is used in "diode test" mode
(these measurements are always taken with the machine swit-
ched off and normally give values in the range + 0.10 … + 0.90
Vdc). In this case the following symbol is affixed beside the
value to be measured
Junction measurement (multimeter in "diode test" mode)
The following symbolswill be used in the same way:
AC or DC voltage measurement (multimeter in voltmeter
mode)
Resistance measurement (multimeter in ohmmeter mode)
Current measurement (ammeter clamp or shunt + multi-
meter in millivoltmeter mode)
Frequency measurement (multimeter in frequency meter
mode)
The measuring conditions(power source on/off, MMA/TIG ope-
rating mode, etc.) are always clearly indicated beside the values
to be measured.
In the tables the various auxiliary power supply voltages are
marked with the initials V1, V2, etc. to permit identification
when present in several boards. When a power supply voltage
derivesfrom another one, the second takesthe name of the first
with the addition of a letter in increasing order (e.g.: V1a, V1b,
etc.). In these cases, all the derived voltageshave the same earth
in common.
The connector terminals are indicated by the name of the con-
nector followed by a slash and the number of the terminal; for
example CN1/2 indicates terminal 2 of connector CN1.
Unless otherwise specified, all the measurements must be per-
formed with the boards fitted, together with their connections.
Remember that the first of the tests to be perfor-
med is the VISUAL CHECK!
The visual check reduces troubleshooting times
and directs any subsequent tests towards the
damaged part!

1.0 SAFETY
Prior to performing any operation on the machine, make sure
that you have thoroughly read and understood the contents of
this manual.
Do not perform modificationsor maintenance operationswhich
are not prescribed.
For any doubt or problem regarding the use of the machine,
even if not described herein, consult qualified personnel.
The productor cannot be held responsible for damage to per-
sons or property caused by the operator's failure to read or
apply the contents of this manual.
1.1 Operator and other persons' protection
The welding process is a noxious source of radiations, noise,
heat and gas emissions. Persons fitted with pacemakers must
consult their doctor before undertaking arc welding or plasma
cut operations. If the above prescription is not observed, the
manufacturer accepts no liability for any damages sustained in
the event of an accident.
Personal protection:
- Do not wear contact lenses!!!
- Keep a first aid kit ready for use.
- Do not underestimate any burning or injury.
- Wear protective clothing to protect your skin from the arc rays,
sparks or incandescent metal, and a helmet or a welding cap.
- Wear masks with side face guards and suitable protection fil-
ter (at least NR10 or above) for the eyes.
- Use headphones if dangerous noise levels are reached
during the welding.
Always wear safety goggles with side guards, especially
during the manual or mechanical removal of welding slags.
lf you feel an electric shock, interrupt the welding ope-
rations immediately.
Other persons' protection:
- Position a fire-retardant partition to protect the surroun-
ding area from rays, sparks and incandescent slags.
- Advise any person in the vicinity not to stare at the arc or at
the incandescent metal and to get an adequate protection.
- lf the noise level exceeds the limits prescribed by the law,
delimit the work area and make sure that anyone getting
near it is protected with headphones or earphones.
1.2 Fire/explosion prevention
The welding process may cause fires and/or explosions.
- Compressed gas cylinders are dangerous; consult the sup-
plier before handling them.
Protect them from:
- direct exposure to sun rays;
- flames;
- sudden changes in temperature;
- very low temperatures.
Compressed gas cylinders must be fixed to the walls or to
other supports, in order to prevent them from falling.
- Clear the work area and the surrounding area from any
infiammable or combustible materials or objects.
- Position a fire-fighting device or material near the work
area.
- Do not perform welding or cutting operations on closed
containers or pipes.
- lf said containers or pipes have been opened, emptied and
carefully cleaned, the welding operation must in any case be
performed with great care.
- Do not weld in places where explosive powders, gases or
vapours are present.
- Do not perform welding operations on or near containers
under pressure.
- Don’t use this machine to defrost pipes.
1.3 Protection against fumes and gases
Fumes, gases and powders produced during the welding pro-
cess can be noxious for your health.
- Do not use oxygen for the ventition.
- Provide for proper ventilation, either natural or forced, in the
work area.
- In case of welding in extremely small places the work of the
operator carrying out the weld should be supervised by a col-
league standing outside.
- Position gascylindersoutdoorsor in placeswith good ventilation.
- Do not perform welding operations near degreasing or
painting stations.
1.4 Positioning the power source
Keep to the following rules:
- Easy access to the equipment controls and connections
must be provided.
- Do not position the equipment in reduced spaces.
- Do not place the generator on surfaces with inclination
exceeding 10° with respect to the horizontal plane.
1.5 lnstalling the apparatus
- Comply with the local safety regulations for the installation
and carry out the maintenance service of the machine accor-
ding to the constructor's directions.
- Any maintenance operation must be performed by qua-
lified personnel only.
- The connection (series or parallel) of the generators is prohi-
bited.
- Before operating inside the generator, disconnect the
power supply.
- Carry out the routine maintenance on the equipment.
- Make sure that the supply mains and the earthing are suffi-
cient and adequate.
- The earth cable must be connected as near the area to be
welded as possible.
- Take the precautions relevant to the protection degree of the
power source.
- Before welding, check the condition of the electric cablesand
of the torch, and if they are damaged repair or change them.
- Neither get on the material to be welded, nor lean against it.
- The operator must not touch two torches or two electrode
holders at the same time.
The manufacturer accepts no liability if the above prescription
is not duly observed and complied with at all times.
Description of operation of the power sources and technical dates 7
WARNING
4) DESCRIPTION OF OPERATION OF THE POWER SOURCES AND TECHNICAL DATES
4.1) Use and routine maintenance (excerpt from the "Instructions for use" manual provided with each power source).

2.0 ELECTROMAGNETIC COMPATIBILITY (EMC)
Thisdevice is built in compliance with the indicationscontained
in the harmonized standard EN50199, to which the operator
must refer for the use of this apparatus.
- lnstall and use the apparatus keeping to the instructions
given in this manual.
- This device must be used for professional applications
only, in industrial environments It is important to remem-
ber that it may be difficult to ensure the electromagnetic
compatibility in other environments.
2.1 Installation, use and area examination
- The user must be an expert in the sector and as such is
responsible for installation and use of the equipment accor-
ding to the manufacturer's instructions.
lf any electromagnetic disturbance is noticed, the user must
soave the problem, if necessary with the manufacturer's tech-
nical assistance.
- In any case electromagnetic disturbances must be reduced
until they are not a nuisance any longer.
- Before installing this apparatus, the user must evaluate the
potential electromagnetic problems that may arise in the
surrounding area, considering in particular the health con-
ditions of the persons in the vicinity, for example of per-
sons fitted with pacemakers or hearing aids.
2.2 Emission reduction methods
MAINS POWER SUPPLY
- The welding power source must be connected to the
supply mains according to the manufacturer's instructions.
In case of interference, it may be necessary to take further pre-
cautions like the filtering of the mains power supply.
lt isalso necessary to consider the possibility to shield the power
supply cable.
WELDING POWER SOURCE MAINTENANCE
The welding power source needs routine maintenance accor-
ding to the manufacturer's instructions.
When the equipment is working, all the access and operating
doors and covers must be closed and fixed.
The welding power source must not be modified in any way.
WELDING AND CUTTING CABLES
The welding cablesmust be kept asshort aspossible, positioned
near one another and laid at or approximately at ground level.
EQUIPOTENTIAL CONNECTION
The earth connection of all the metal componente in the wel-
ding installation and near it must be taken in consideration.
However, the metal componente connected to the work-piece
will increase the risk of electric shock for the operator, if he tou-
ches said metal componente and the electrode at the same
time.
Therefore, the operator must be insulated from all the earthed
metal componente.
The equipotential connection must be made according to the
national regulations.
EARTHING THE WORKPIECE
When the workpiece is not earthed for electrical safety reasons
or due to its size and position, the earthing of the workpiece
may reduce the emissione. It is important to remember that the
earthing of the workpiece should neither increase the risk of
accidents for the operators, nor damage other electric equip-
ment.
The earthing must be made according to the national regula-
tions.
SHIELDING
The selective shielding of other cables and equipment present
in the surrounding area may reduce the problems due to inter-
ference. The shielding of the entire welding installation can be
taken in consideration for special applications.
8 Description of operation of the power sources and technical dates
WARNING
3.0 RISK ANALYSIS
Risks posed by the machine
Risk of wrong installation.
Electrical risks.
Risks connected with electromagnetic disturbances produced
by the welding power source and induced on the welding
power source.
Solutions adopted to pervent them
A manual with the instructions for use has been pro-
duced for this purpose.
Application of the EN 60974-1 Standard.
Application of the EN 50199 Standard.

Description of operation of the power sources and technical dates 9
The contents of this chapter are of vital importance and the-
refore necessary for operation of the warranties. The manu-
facturer accepts no liability if the operator fails to observe
the above precautions and instructions.
4.0 MACHINE DESCRIPTION
The Genesis 302 AC/DC e Genesis 382 AC/DC power sources
offer excellent performance in the following welding procedures:
- TIG AC with square, sine and triangular wave;
- TIG DC with remote arc striking with high frequency (TIG HF-
START) and gas delivery control via torch button;
- TIG DC with contact start with reduction of short circuit current
(TIG LIFT-START) and gas delivery control via torch button;
- MMA.
In inverter welders the output current is insensitive to variations
in the power supply voltage and length of the arc and is per-
fectly levelled, providing best weld quality.
On all the power sources features the following devices:
- a positive socket (+ ), a negative socket (-) and a central soc-
ket for connection of the TIG torch
- a front control panel with socket for remote controls
- RC16 potentiometer remote control for MMA and TIG
welding (optional)
- RC12 pedal remote control for TIG welding (optional)
- a rear control panel with gas socket
The Genesis 302 AC/DC and Genesis 382 AC/DC can be sup-
plied with WU21 cooling unit for liquid cooling of the TIG
torch.
4.1 Front control panel (fig. 1)
Fig.1
* L1 : Power on: green led.
Comeson when the ignition switch on the rear panel (Fig. 2) "I1"
is in position "I". Indicates that the system is on and powered.
* L2: Protection device: yellow led.
Indicatescut-in of the thermal protection device or protection
due to incorrect power supply voltage. With “ L2” on, an
alarm code blinks on “ D1”. The power source remains con-
nected to the mainsbut does not deliver power at the output.
If an overtemperature hasoccurred, “L2” remainson until the
internal temperatures have returned to normal; in this case,
leave the power source on and wait for the welder to cool. In
the event of alarms connected to the mains voltage, press any
button to resume operations.
* Alarm codes.
The system manages the following alarms:
10 mains alarm: no phases, undervoltage or overvoltage
11 no cooling liquid
12 primary module thermal switch
13 AC module thermal switch
19 load too inductive: inversions not possible
20 memory fault
24 incorrect system parameters or memory still empty
(first switch-on)
25 system parameters could not be stored (24C08)
26 standard parameterschecksum incorrect: either the memory
has failed or powerful interferences have damaged it
27 advanced parameterschecksum incorrect: either the memo-
ry hasfailed or powerful interferenceshave damaged it
* L3: Voltage output (work): red led.
Indicates presence of voltage at the output.
* Display D1.
Displays the welding current or value of the welding parame-
ter chosen via “S5” on the graph “ G1”. It is used to show
alarm and error messagesand to enter the set-up parameters.
* E1 : Encoder for entering the welding current, welding
parameters and set-up values.
Allows you to change the value shown in “D1” of the para-
meter selected via “S5” in graph “G1” (also during welding).
Allows you to enter the required set-up line and vary the
value.
Allows you to continuously adjust the welding current both in
TIG and MMA. (This current remains unchanged during wel-
ding when the power supply and welding conditions vary
within the ranges declared in the technical specifications).
In MMA the presence of HOT-START and ARC-FORCEmeans
that the mean output current can be higher than the one set.
* S1 : Current regulation system key.
Selects the welding current regulation system:
- from front panel in "internal" mode
- from remote control in "external" mode
In this case via “ E1” it is possible to enter the maximum cur-
rent value that can be selected via the remote control.
* J1 : 7-pole military standard connector.
For connection of the remote controls RC16 and RC12.
* S2 : Tasto selezione tipo di corrente per saldatura TIG.
Key for selecting type of TIG welding current
- CONSTANT current with or without SLOPES.
- PULSED current with or without SLOPES.
- MEDIUM FREQUENCY current with or without SLOPES.
Switch-on of the led at the side of the symbol confirms the
selection.
The MEDIUM FREQUENCY function is not enabled in AC.
* S3 : Key for selecting control mode in TIG.
- 2-stroke welding (2T)
- 4-stroke welding (4T)
- 2-level welding (BILEVEL)
Switch-on of the led at the side of the symbol confirms the
selection.
With the RC12 pedal control, only the 2T mode is possible.
In 2-stroke, when the button is pressed the gas flows and the
arc is struck; when the button is released, the current goes to
zero in the slope-down time; once the arc is off, the gas flows
for the post-gas time.
In 4-stroke, the first time the button is pressed the gas flows
for the manual pre-gas time; when the button isreleased, the
arc is struck. If the button is pressed again and definitively
released, the current slope-down and post-gas time begin.
In BILEVEL the welder can weld with 2 different currents pre-
viously set via “S5”.

10 Description of operation of the power sources and technical dates
The first time the torch button is pressed, the pre-gas time is
run, the arc is struck and welding is performed with the initial
current.
The first time it is released, slope-up to current "I1" occurs. If
the welder presses and quickly releases the button, the
machine will go to "I2"; by pressing and quickly releasing the
button it returns to "I1" and so on.
If the button is pressed for longer, the current slope-down
begins which leads to the final current.
When the button is released the arc goes out while the gas
continues to flow for the post-gas time.
* S4: Welding procedure selection key.
Permits selection of the welding procedure.
Switch-on of the led at the side of the symbol confirms the
selection.
Procedures:
- MMA (electrode)
- TIG DC
- TIG AC
* S5: SET-UP/parameters key.
Permits access to the SET-UP and welding parameter values.
When pressed at switch-on, it permits access to the set-up
parameters while the software version appears on “D1”.
If pressed after the end of the welder switch-on procedure, it
selects in sequence the welding parameters presented in the
graph “G1” with value shown by “D1” and variable with “E1” .
Tu Slope-up time
l Welding current
lb Basic current in pulsed and medium frequency
welding
Tp Peak time in pulsed and medium frequency welding
Tb Basic time in pulsed and medium frequency welding
Td Slope-down time
lf Final current
Pg Post-gas time
l2 Second welding current in BILEVEL
When in MEDIUM FREQUENCY operation, the leds
Tp and Tb come on simultaneously and the pulse
frequency value appears on the display “ D1” .
By keeping the key "S5" pressed for 1 second, you access
adjustment of the following parameters:
- frequency in AC (Led L4);
- electrode diameter setting in AC (Led L5);
by setting this value on the power source the Genesis
302/382 AC/DC can optimise (using the FUZZY LOGIC )
the welding start parameters in AC;
- balance AC (Led L6); adjustment in % of the positive wave
value during the AC period.
A higher value indicatesgreater cleaning action of the elec-
tric arc on the weld pool; a lower value indicates greater
penetration and melting action of the arc.
* Set-up parameters.
When “ S5” is pressed after switch-on, the set-up menu is
accessed (confirmed by a central "0" on the display “D1”)
while the software version appearson “ D1”. Via E1 the set-up
line is varied, via “S5” the required line is confirmed, via “E1”
the value is varied, via “S5” the value is confirmed and so on.
0 Quit and save
1 Initial current as a percentage with respect to
welding current
2 Pre-gas time
3 HOT-START percentage
4 ARC-FORCE percentage
5 Waveform in AC
The following table shows the correspondence between the
numbers and the half waves:
Number Half wave - Half wave +
0 Sine Sine
1 Triangle Triangle
2 Square Square
3 Sine Triangle
4 Sine Square
5 Triangle Sine
6 Triangle Square
7 Square Sine
8 Square Triangle
6 Min current value in TIG EXT
7 Max current value in TIG EXT welding
8 LIFT start in TIG DC (1) or HF start (0)
(default= 0)
9 Reset of parameters
12 Welding in DC+ (1) or DC - (0) (default= 0)
14 Pulsed TIG basic l setting mode (0= in amps,
1= percentage of peak l) (default= 0)
15 HF first pulse polarity (1= on same side as current,
0= inverted, improved sparking)
16 Cooling unit activity time from end of welding (s);
if 0 is set, the unit never comes on.
17 With "1" in AC in the fastpulse position the mix AC/DC
procedure is enabled.
18 Current reference during the HF start in TIG DC
19 Current reference during HF start in TIG AC
20 Extra energy (% of positive wave amplitude in respect of
negative wave amplitude)
23 TIMER mode setting
(23 = 0: 2-stage mode, 23 ≠0: welding time)
99 Reset of all parameters
If we enter lines "9" and "99" and press “ S5” , all the
set-up parameters will go to the factory-set values.
To quit set-up and save the set values, return to
line “ 0” and press “ S5” .

Description of operation of the power sources and technical dates 11
4.2 Rear control panel (Fig. 2)
* I1 : Ignition switch
Controls electric ignition of welder.
It has two positions: "O" off and "l" on.
* With l1 set to the position "l" on, the welder is operational
and voltage is present between the positive (+ ) and nega-
tive sockets (-) on the electrode. In TIG the welder requi-
res the pedal or torch button start for voltage to be present
between the sockets (+ ) and (-).
* When the welder is connected to the mains, even with l1
set to the "O" position some of the internal parts will be
live. Carefully follow the warnings given in this manual.
* 1 : Power supply cable
* 2 : Gas fitting
Fig.2
4.3 Operation
The machine stores the last welding status and dis-
plays it when switched back on.
* Set the ignition switch “l1” to “l”; switch-on of the power led
“L1” (green led) confirms that the system is powered.
* The display “D1” shows the figure 302/382 and all the leds
come on (for control) for 3 seconds. The leds on the front
panel then go out and “D1” shows the welder software ver-
sion (e.g. 1.0) for 4 seconds; during this time it is possible:
- to enter the SET-UP mode by pressing the key “ S5”;
- or proceed with welding (or parameter variation).
* If chosen, entry to the SET-UP mode is confirmed by a central
“0“ on the display “ D1”:
- Turn the potentiometer “ E1”: the numbers corresponding
to the parameters appear (in sequence) on the display
“D1”; stop on the parameter required and press “S5”. Via
parameter (9) all the modifications performed in the SET-
UP are cancelled and you return to the standard values set
by SELCO.
- The number on the display “D1” is replaced by the value
of the parameter which is modified via the potentiometer
“E1”.
* If it isnecessary to modify the welding parameter valuesof the
graph “G1”:
- Let 4 seconds elapse from switch-off of the panel leds; led
“l” (welding current) will remain on in the graph.
- Press “ S5” ; every time it is pressed one of the leds in the
graph “G1” will come on (in clockwise sequence) and the
value of the related parameter will appear on the display
“D1”; stop on the parameter required.
- Turn the potentiometer “E1” and modify the parameter
value.
- Press the “S5” SET-UP/parameters key again to go on to
another parameter or wait 5 seconds (led "l" in the graph
“G1” will automatically come back on).
The machine is always ready to weld and the status
is indicated by the set of leds lit up on the panel.
The fan only starts once the system has warmed up.
WARNING
Parameter
Pre-gas time
Initial current
Slope-up time tu
Welding curr. l
Back curr. lb
Pulse time tp
Frequency tp & tb
AC frequency
AC balance
AC waveforms
Electrode diameter
Back time tb
Slope-down time td
Final current lf
Post-gas time
Current in MMA
l max in external mode
l min in external mode
l2 in BILEVEL
Hot-Start
Arc-Force
um
s
%
s
A
A (%)
s
Hz
Hz
%
n°
mm
s
s
A
s
A
A
A
A
%
%
min
0.0
2
0.0
6
6 (1%)
0.02 (AC 0.05)
20
20
15
0
1.0
0.02 (AC 0.05)
0.0
6
0.0
6
6
6
6
0
0
max
25.0
200
10.0
300/380
300/380 (100%)
2.00
500
150
65
8
5.0
2.00
10.0
300/380
25.0
300/380
300/380
300/380
300/380
500
500
predef.
0.0
50
0.0
100
6 (50%)
0.24
100
50
35
2
2.4
0.24
0.0
8
5.0
100
300/380
6
50
80
30
Notes
Can be entered only from set-up
Percentage of welding current, only set-up
Can be entered from front panel
Can be entered from front panel
Only pulsed, adjustable from front panel
Only pulsed slow, adjustable from front panel
Only in fastpulse, adjustable from front panel
Adjustable from panel
Adjustable from panel
Selectable from set-up
Selectable from panel
Only pulsed slow, adjustable from front panel
Can be entered from front panel
Can be entered from front panel
Can be entered from front panel
Can be entered from front panel
Adjustable from front panel and from set-up
Can be entered only from set-up
Regolabile da frontale
MMA, can be entered only from set-up
MMA, can be entered only from set-up

12 Description of operation of the power sources and technical dates
4.4 Cooling unit WU21
It is optional and permits liquid cooling of the TIG torch. There
is one single electrical connection between WU21 and Genesis
302/382 AC/DC and once assembled, they form one single
body.
*All WU21 replacement, repair or connection ope-
rations must be performed by expert personnel
instructed by SELCO.
* Filling or topping up of the tank with cooling liquid
must be performed with the power source and
WU21 assembled and positioned on a horizontal
surface.
*Filling or topping up of the tank must be performed
with Selco cooling liquid, code 18.91.001.
*In order not to damage the cooling unit, always fit
the by-pass pipe when the torch isnot connected to
the cooling liquid inlet/outlet terminals.
4.5 Remote controls
4.5.1 RC16 potentiometer remote control for MMA and TIG
welding.
This device allows you to vary, by
remote control, the amount of cur-
rent necessary without interrupting
the welding process or abandoning
the work area. 5, 10 and 20 m con-
nection cables are available.
4.5.2 RC12 pedal remote control for TIG welding.
Once the power source has been
switched to the EXTERNAL CON-
TROL mode, the output current is
varied from a minimum to a maxi-
mum value (can be entered from
SETUP) by varying the angle bet-
ween the pedal surface (where the
foot rests) and base. A microswitch
provides the weld start signal at
minimum pressure.
RATING PLATE
4.6 Technical specifications
G 302 AC/DC G 382 AC/DC
Power supply voltage
(50/60Hz) 3x400V ± 15% 3x400V ± 15%
Maximum power absorbed
in TIG 9.7kW (x= 40%) 13kW (x= 35%)
Maximum current absorbed
in TIG 16 A (x= 40%) 21.5 A (x= 35%)
Current absorbed
in TIG (x= 100%) 9 A 13 A
Maximum power absorbed
in MMA 11.8kW (x= 40%) 15kW (x= 35%)
Maximum current absorbed
in MMA 17 A (x= 40%) 22.8 A (x= 35%)
Current absorbed
in MMA (x= 100%) 11 A 16 A
Power factor 0.95 0.95
Cos
ϕ0.99 0.99
Welding current in TIG
(x= 40%) 300 A 380 A
(x= 60%) 250 A 320 A
(x= 100%) 220 A 280 A
Welding current in MMA
(x= 35%) 300 A 350 A
(x= 60%) 250 A 320 A
(x= 100%) 220 A 280 A
TIG (MMA)
Adjustment range 6-300 6-380 (350 A)
Loadless voltage 80 V 80 V
Protection rating IP23C IP23C
Insulation class H H
Construction standards EN60974-1 EN60974-1
EN50199 EN50199
Dimensions (lxdxh) 275x620x500 mm 275x620x500 mm
Weight 33 Kg. 33 Kg.
Data at 40°C ambient temperature
WU21
Power supply voltage (50/60 Hz) 1x400 V ± 15%
Rated current absorbed 0.8 A
Tank capacity 6 l
Cooling power 2000 W
Protection rating IP23C
Dimensions (lxdxh) 250x655x280 mm
Weight with liquid 16 Kg.

Dimensions and mass
5.0 TRANSPORT - UNLOADING
Never underestimate the weight of the equip-
ment, (see technical specifications).
Never make the cargo pass or leave it suspended
over people or things.
Neither let the equipment or the single unit fall,
nor put it down with force.
Once it has been removed from the packing, the
power source is supplied with an extendible belt
which can be used to move it in the hand or on the
shoulder.
6.0 INSTALLATION
Choose an adequate installation area by following
the criteria provided in Section "1.0 SAFETY" and
“ 2.0 ELECTROMAGNETIC COMPATIBILITY
(EMC)” .
Do not position the power source and the equip-
ment on surfaces with inclination exceeding 10°
with respect to the horizontal plane.
Protect the installation from heavy rain and sun.
Do not use the power source to thaw pipes.
6.1 Electrical connection to mains
The system is provided with one single electrical connection
with 5 m cable at the rear of the power source.
Power source input cable and fuse sizing table:
Power source G 302 AC/DC
Rated voltage 3x400 V ± 15%
Voltage range 340 V - 460 V
Delayed fuses 20 A
Power supply cable 4x6 mm2
Power source G 382 AC/DC
Rated voltage 3x400 V ± 15%
Voltage range 340 V - 460 V
Delayed fuses 30 A
Power supply cable 4x6 mm2
* The electrical system must be made by skilled technicians
with the specific professional and technical qualifications
and in compliance with the regulations in force in the
country where the equipment is installed.
* The welding power source supply cable is provided with a
yellow/green wire that must ALWAYS be earthed. This yel-
low/green wire must NEVER be used with other voltage
conductors.
* Verity the existence of the earthing in the used plant and
the good condition of the socket/s
* lnstall only plugs that are homologated according to
the safety regulations.
6.2 Connecting the equipment components
Keep to the safety regulations contalned in section
“ 1.0 SAFETY” .
Connect the componente carefully, in order to
avoid power losses.
Description of operation of the power sources and technical dates 13
WARNING
Model
G. 302
G. 382
Trolley
29
29
Power
source
33
33
WU21
with liquid
16
16
Tot. Kg
78
78
GT23 930 1000 610 29
Trolley
type
Mass
Kg
A B C
Dimensions in mm

14 Description of operation of the power sources and technical dates
7.0 ASSEMBLING THE EQUIPMENT
7.0.1 Assembling the movable trolley
For the assembly of the generator trolley GT23, see SPARE
PARTS TABLES.
7.0.2 Installing the WU21 and the generator (Fig. 3)
* Rest the WU21 on the GT23 and fix it with the 4 screws.
* Remove the left side panel of the power source.
* Remove the plastic plug on the bottom near the rear cover.
* Rest the power source on the unit, passing the unit wiring
through the hole.
* Fasten the power source to the WU21 with the 4 screws.
7.1 CONNECTING THE UNIT
7.1.1 Electric/electronic connection between the generator
and the WU21 (Fig. 4)
Make the connection
with the generator plug
disconnected from the
mains socket.
* Insert the connector as shown in
the figure.
* Close the power source side
panel, connecting the yellow-
green wire (ground or earth).
7.1.2 Filling the coolant tank (Fig. 5)
Fill the coolant
tank with the
generator plug
d i sco nn ect ed
from the mains socket.
* Unscrew the plug and
remove it.
* Remove the sealed plug
from the inlet channel,
levering by means of a
tool on the edge of the
plug.
* Keep the sealed plug for future transport of the unit.
* Filling or topping up of the tank must be performed with Selco
cooling liquid, code 18.91.001.
* Tighten the plug completely.
Periodically check the coolant level in the tank. If
the tank is completely empty andlor there is air in
the pump, this may fail to start.
In this case, proceed as follows:
* With the tank full and power source off, open the unit
right-hand side panel by unscrewing the two screws at the
bottom.
* Partially unscrew the screw valve.
* Wait for a few seconds, close the valve and the side panel
and restart the power source.
7.1.3 Hydraulic connection to the WU21
Failure to carry out the operations indicated below
may cause irreparable damage to the torches.
Check the tightening of the connections.
For TIG welding opera-
tions in which the torch is
liquid-cooled, carry out
the following connec-
tions:
Ref. Fig. 6
* Make the connection
illustrated in Fig. 6.
Ref. Fig. 7
Connect the torch pipes as
follows:
* torch delivery: generally
blue (cold water) at the
quick-fit coupling indica-
ted by the symbol
( )
* torch return: generally
red (hot water) at the
quick-fit coupling indica-
ted by the symbol
( )
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Description of operation of the power sources and technical dates 15
For TIG welding in the
torch is NOT liquid-
cooled, it is advisable to
close the cooling circuit
and make the connec-
tions illustrated in Fig.8:
7.1.4 Connection for MMA welding
Carefully read 6.2.
* Connect the earth clamp
to the negative socket of
the generator.
* Connect the electrode
holder to the positive soc-
ket (+ ) of the generator.
The connection described above ensures welding
with reverse polarity. To weld with straight pola-
rity, reverse the connection.
7.1.5 Connection for TIG welding
Carefully read 6.2.
1) Connect the earth clamp
(Fig. 10) to the positive
socket (+ ) of the genera-
tor.
2) Connect the TIG torch
coupling to the torch
socket ( ) of the gene-
rator.
* Connect the gas pipe
coupling (Fig.11) to the
gas coupling ( ) on
the generator rear panel.
If the TIG torch is cooled with liquid:
* Connect the hydraulic
pipes of the torch to
the cooling unit, see
7.1.3 (Hydraulic con-
nection to the WU21).
3) Connect the gas pipe
coupling (Fig.11) to the
gas coupling ( ) on
the generator rear
panel.
8.0 PROBLEMS - CAUSES
8.1 Possible faults in the MMA welding
8.2 Possible faults in the TIG welding
Fault
Oxidations
Tungsten inclusions
Porosity
Hot cracks
Cause
1) lnsufficient gas.
2) No protection on the re-
verse.
1) lncorrect electrode shar-
pening.
2) Electrode too small.
3) Operating failure (contact
of the tip with the work-
piece).
1) Dirt on the edges.
2) Dirt on the filler material.
3) High advancement speed.
4) Current intensity too low.
1) Unsuitable filler material.
2) High heat supply.
3) Dirty materials.
Fig. 8
Fault
Excessive spatter
Craters
Inclusions
Insufficient penetration
Sticking
Blow-hole and porosity
Cracks
Cause
1) Long arc.
2) High current.
1) Fast movement of the
electrode away from piece.
1) Poor cleanliness or distri-
bution of the passes.
2) Defective movement of
the electrode.
1) High progression speed.
2) Welding current too low.
3) Narrow chamfering.
4) Deseaming failure on top.
1) Arc too short.
2) Current too low.
1) Humidity in electrode.
2) Long arc.
1) Current too high.
2) Dirty materials.
3) Hydrogen in weld
(present on electrode
coating).
Fig. 9
Fig. 10
Fig. 11

16 Description of operation of the power sources and technical dates
8.3 Possible electrical failures
If you have any doubts or problems, do not hesitate to con-
sult your nearest technical service centre.
9.0 NECESSARY ORDINARY MAINTENANCE
Avoid accumulation of metal dust near and on the ventilation fins.
Disconnect the system before all operations!
Periodical checks on the power source and
WU21:
* Clean the inside using compressed air at low
pressure and soft bristle brushes.
* Check the electrical connections and all connec-
tion cables.
For maintenance and use of the pressure redu-
cers, consult the specific manuals.
For maintenance and replacement of the compo-
nents of the TIG torches, electrode gun and/or
ground cables:
* Disconnect the system before all operations.
* Check the temperature of the components and ensure
that they are not overheated.
* Always use gloves in compliance with regulations.
* Use suitable spanners and tools.
Note: Failure to perform said maintenance will invalidate all
warranties and exempt the manufacturer from all liability.
Fault
Machine does not come on
(Green led off)
Power delivery not correct
(Green LED on)
No current at output
(Green LED on)
Cause
1) No voltage at power supply
socket.
2) Faulty power supply plug or
cable.
3) Internal fuse blown.
1) Incorrect setting of welding
parameters.
2) Mains voltage low.
3) Faulty current regulation
potentiometer.
1) Yellow led on and ERROR
code blinking on display.

Description of operation of the power sources and technical dates 17
4.2) Operating principle - Block diagram
General overview
1. EMI input filter
2. Three phases input rectifier
3. Smoothing capacitor
4. Quasi-resonant full bridge inverter
5. Snubbing inductor
6. Primary current transformer
7. Resonant inductor
8. Power transformer
9. Secondary power rectifier
10. Secondary inverter
11. Hall-effect secondary current sensor
12. Output filter
13. HF transformer
14. HF generator
15. Auxiliary multi-output switching power supply
16. Resonant inverter logic
17. Synchronisation unit
18. Microprocessor logic
19. Superimposition & AC control
20. Smoothing inductor

18 Description of operation of the power sources and technical dates
Quasi-resonant full bridge power inverter
- 30kHz switching frequency*
= Fast response welding current loop
= High stability welding arc
- ZVS/ZCSfor power switches (IGBTs)
= Improved efficiency + lower EMI
= Space saving
= Low weight
- Primary overcurrent fast protection circuit
- Auixiliary power supplies switching frequency derived from
inverter logic
= System synchronization for noiseless Tig welding arc
(audible subarmonic frequency generation avoided in TIG
welding arc)
* Note: due to resonant topology of primary power inverter,
switching frequency is not constant: it varies in [27 ... 33]kHz
range, depending on actual output power; due to full bridge
topology, secondary rectifier works at double inverter
frquency, that is 55...65kHz, thus allowing a very precise arc
control.

Description of operation of the power sources and technical dates 19
Output Rectifier & AC Inverter
- Full bridge FRED rectifier
- Microprocessor AC current shaping
- Microprocessor controlled inversion
= Minimized voltage clamp
- Superimposition pulse generator
= Easy arc inversion and stable arc in AC welding
- Microprocessor triggered arc striking circuit
- Superimposition pulse + arc striking pulse
= Very easy arc striking even in worst operational contidions
(hard oxide on workpiece)

20 Description of operation of the power sources and technical dates
Auxiliary Switching Mode Power Supply (SMPS)
- Flyback topology running @ 30kHz switching frequency*
- Buck topology running @ 30kHz switching frequency*
- Directly derived from 560V DC link
- Post-regulated primary side auxiliary supplies
- Post-regulated secondary side auxiliary supplies
- Regulated secondary side auxiliary supplies
- Synchronization circuit for noise free TIG welding arc
* Note: due to resonant topology of primary power inverter,
switching frequency is not constant: it varies in [27 ... 33]kHz
range, depending on actual output power.