Description Of The System; Introduction; Technical Specifications; Description Of Power Source Item No 334 - Cebora PLASMA SOUND PC 70/T Manual De Servicio

CEBORA S.p.A.

2 DESCRIPTION OF THE SYSTEM

2.1 Introduction

The PLASMA SOUND PC 70/T is a system designed for plasma arc cutting of
electro-conducting materials.
It comprises an electronic power source (Item No 334) and a set of torches and
accessories, to be used in manual applications and on automated systems (see list in
the Sales Catalogue).
The power source is controlled by microprocessor circuits that manage the cutting
system's operating functions and interface with the operator.

2.2 Technical specifications

To verify the technical specifications, see the machine plate, Instruction Manual, and
Sales Catalogue.

2.3 Description of power source Item No 334

Item No 334 is a direct voltage, current controlled power source consisting of a
three phase bridge rectifier, a DC/AC converter (inverter), and a full wave output
rectifier.
Regardless of whether it is supplied at 208/220/230 or 400/440 Vac, it will adapt
automatically based on the voltage applied at the power source input.
The plasma arc is not ignited using high tension (high-frequency) discharges but
through contact ignition. Torches with high-voltage discharge ignition cannot be used
on this power source.
Refer to the wiring diagram in section 5.1, drawing 4.1 and table 4.2to identify the
main blocks making up the power source.
Main switch (10) powers filter board (7), which contains a filter to reduce main
electromagnetic interference, the inverter capacitor precharging circuit and mains
voltage analysis and selection circuits.
Bridge rectifier (41) is connected to service filter board output (7) to rectify the mains
voltage present at output of service filter board (7). The direct voltage reading at bridge
rectifier (41) depends on the mains voltage reading.
For example, with a mains voltage of 230 V, the direct voltage will be approximately
320 V, whereas with a mains voltage of 400 V it will be approximately 560 V. The direct
voltage is then applied to IGBT board (31). IGBT board (31) is fixed to two IGBT power
modules (30) which are in turn fixed to heatsink (42). Both IGBT modules form the full-
bridge inverter.
Power transformer (52) is controlled by the full-bridge inverter. The power
transformer (52) contains two separate primary windings. If the mains voltage lies
within the range 208 - 230 V, the two coils are connected in parallel. If the mains
voltage lies within the range 400 - 440 V, they are connected in series. Series or
parallel connection of the primary windings allows the secondary winding to carry the
same voltage regardless of whether the power source is powered at 220 or 400 Vac.
The secondary winding of power transformer (52) is made up of four equal windings
interconnected to make up two windings with a central socket.
Terminals 2 identify the central socket of the first winding, while terminals 1 and 3
identify its ends. Terminals 5 identify the central socket of the second winding, while
terminals 4 and 6 identify its ends.
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10/07/2019