Description Of Power Source Art. 954 - Cebora PLASMA PROF 164 HQC Service Manual

CEBORA S.p.A.
This operation allows both programs to be entered simultaneously into the two
microprocessors, and each automatically in its proper place.
Specifically, the new program is entered into the MASTER processor which, when
programming is finished, checks whether the version resident in the SLAVE is compatible with
its new program. If compatible, the system is ready for operation, with no need for further
programming. If not compatible, the MASTER programs the SLAVE directly, using the data
present in its own memory. This programming stage is highlighted by the shutting off of all
indicators on the Gas Console panel, and may lasts approximately two minutes. During this
phase, it is recommended that you not perform any operation, but wait for programming to be
completed. This will be signaled by the appropriate lights on the Gas Console panel that return
on.
The version of the programs entered can be seen on the start-up screen of display (C) of the
Power Source control panel.
The updated MASTER and SLAVE programs are grouped together with the "Cebora
Downloader" programming software into a single programming file, available along with
instructions from the web site www.cebora.it..

2.4 - Description of Power Source art. 954.

Art. 954 is a direct current Power Source with controlled current, consisting of a three-phase
rectifier bridge and a DC/DC igbt converter.
The cooling unit for the torch is located at the back, consisting of the tank, pump, radiator,
filter and flow meter.
Referring to the electrical diagram in par. 5.1, drawing 4.1 and table 4.2, we can identify the
main blocks that make up the Power Source.
The switch (39) acts on the service transformer (50), which powers the electronic boards and
internal services through the fuse board (50).
The power transformer (27) has the primary circuit consisting of six windings which,
appropriately switched by the voltage change, allow the Power Source to work at 230, 400 or
440 Vac at 50/60 Hz. Near the main voltage change is also the voltage change of the service
transformer (50).
The voltage, always at 230 Vac, is deliverable from one of the windings of the primary circuit
for the fan (20) and pump (13) of the cooling unit.
The transformer (27) is powered through the contactor (44), which is controlled at closing by
the control board (38), once the DC-capacitors, present on the pilot arc board (58), have been
pre-charged and the transformer itself pre-magnetized.
The transformer (27) secondary circuit is connected to the rectifier bridge (23), which powers
the pilot arc board (58), which contains the DC-capacitors, the igbt power module and the two
Hall-effect current transducers to detect the pilot arc and cutting currents.
Inside the igbt module is the switching element, the igbt, and the freewheeling diode,
connected in a "Chopper" configuration.
The RC board (48) mounted near the igbt module of the pilot arc board (58) contains the RC
network to protect the igbt during switching.
The negative output (1) of the igbt module on the pilot arc board (58) is connected to the
inductor (24), to level the arc current and thus the output (53) for the electrode potential, ready
for connection to the Starter Unit HV18 (art. 472).
The terminal TP3 of the pilot arc board (58) corresponds to the positive output (3) of the igbt
module, and constitutes the earth potential output ready to connect to the earth cable.
This connection, inside the pilot arc board (58), leads to the Hall-effect current transducer,
which sends the cutting current signal to the settings board (54).
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