Cebora 305 Manual De Servicio página 19

power transformer terminal, connected to VITE1 terminal
of power board (34).
From power board (34) VITE2 and VITE1 output
terminals, is picked up, through the inductors L6 and L4,
the power source output voltage signal, used by the INV
board in order to adapt the power source behaviour to the
arc welding conditions.
An other secondary winding of the TF5 power transformer,
during inverter operation, generates the supply voltage for
the wire feeder motor control circuits, present on the panel
board (19).
In some particularly critical situations, such as welds with
very low currents, this voltage may be not sufficient to
ensure the wire feeder motor proper operation.
To overcome this energy lack, the supply board (40) is
inserted in the circuit, the output of which is connected in
parallel to the source coming from the power board (34)
and contributes to the panel board (19) powering.
In the power source art. 305.00 the wire feeder unit is in-
tegrated and is composed by the gear-motor and the holder
coil support, enclosed by a protection carter.
The panel board (19) contains the main power source
microprocessor and supervises management of the
complete power source functions.
On panel board (19) are generated the reference signal
to be sent to the INV board, for the inverter control and
the power supply voltage for the wire feeder motor (12),
adjusted according to the requirements of the welding
program selected.
The welding programs predefined by Cebora (synergic
curves) are stored in the panel board (19).
3302327/A
Fig. 2.3.2
For their update and for the power source firmware update,
on panel board (19) the BD1 programming connector is
present (see par. 2.4).
The panel board (19) also acts as power source control
panel and contains the display A and multifunction knob
B to perform the supervision and management of the com-
plete power source (see Instructions Manual).
The power board (34) receives the temperature signals from
the thermo-switches located on boost converter igbt dissipater
(connected to TP22 and TP23) and on the secondary diodes
group dissipater (connected to TP14 and TP21).
The fan (32) operation is subject only to the flyback
operation and is independent of the power source working
conditions.
In case of flyback circuit or fan (32) failure, for example
due to a fault, the DC-capacitors discharge time can
become much longer (several minutes).
In this case, before working on the power board (34)
wait until the DC-capacitors voltage, measured between
R32 SHUNT(-) terminal, in proximity of inductor L3
and the DISS2(+) dissipater on power board (34), falls
to a safe level (<40 Vdc).
The power source output terminals are located on the front
panel.
For MIG torch it is predisposed a central adapter C that in-
cludes a power socket, two contacts for the start command
and a pneumatic fitting for the gas.
WARNING
EN
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