Description Of The System; Introduction; Technical Specifications; Description Of Power Source Art. 337 - Cebora 337 Manual De Servicio

CEBORA S.p.A.

2 DESCRIPTION OF THE SYSTEM

2.1 Introduction

The PLASMA SOUND PC 130/T is a system designed for plasma arc cutting of
electro-conducting materials.
It is composed of an electronic power source (art. 337) and a set of torches and
accessories, to be used both in manual applications and on automated systems (see
list in the Sales Catalogue).
The power source is controlled by microprocessor-based circuits, which manage the
operative functions of the cutting system and the operator interface.

2.2 Technical specifications

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

2.3 Description of power source art. 337

Art. 337 is a direct voltage, current controlled power source consisting of a three
phase bridge rectifier, a DC/AC converter (inverter), and an output bridge rectifier.
It can be powered indifferently at 208/220/230 or 400/440 VAC; it will adapt
automatically based on the voltage applied at the power source input. For simplicity,
hereinafter the 208/220/230 VAC voltage interval will be indicated as 220 VAC and the
400/440 voltage interval as 400 VAC.
With reference to the wiring diagram of par. 7.1, drawing 6.1 and table 6.2, you can
identify the main blocks that make up the power source.
The main switch (10) powers the filter board (7), which contains the filter to reduce
electromagnetic interference in the mains.
A bridge rectifier (41) is connected to the filter board (7) to rectify the mains voltage
present at the output. The value of the direct voltage exiting the bridge rectifier (41)
depends on the value of the mains voltage.
For example, with a mains voltage of 230 V, the value of the direct voltage is
approximately 320 V, whereas with a mains voltage of 400 V it is approximately 560 V.
The direct voltage is then applied to the IGBT board (31). The IGBT board (31) is fixed
to two IGBT power modules (30) which, in turn, are fixed to the dissipater (42). The two
IGBT modules form the full-bridge inverter.
The power transformer (52) is commanded by the full-bridge inverter. The power
transformer (52) has two separate primary coils. If the mains voltage lies within the 208
- 230 V range, the two coils are placed in parallel, whereas if the mains voltage lies
within the 400 - 440 V range they are placed in series.
connection of the primary coils allows the secondary coil to have the same voltage,
with the power source powered indifferently at 220 or 400 VAC.
The secondary coil of the transformer consists of a single winding whose extremities
are brought to the input of a bridge rectifier. The bridge rectifier is formed by two
ISOTOP modules (35). Each ISOTOP module (35) contains two fast diodes. The four
diodes present in the two modules (35) are electrically connected to each other to form
a Graetz bridge. The ISOTOP modules (35) are fixed to the dissipater (39).
At both ends of the bridge rectifier output there is a snubber network formed by two
non-inductive resistors (36) and two film capacitors. The two non-inductive resistors
3302336-B
The series or parallel
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