CD Automation srl
MULTIDRIVE-1PH 850A
User’s Manual
7
2
Introduction
A thyristor unit is semiconductor device which acts as a switch formed by two thyristors in ant parallel.
To switch on the alternating current the input signal will be on and the thyristor will switch off at first
Zero Crossing voltage with no input signal.
The benefits of thyristor units compared with elettromechanical contactors are numerouses: no moving
parts, no maintenance and capacity to switch very fast. Thyristors are the only solution to control
transformers and special loads that change resistance with temperature and with age.
2.1
Advantages compared with analog thyristor unit
MULTIDRIVE is an universal Thyristor unit, designed to control resistive or inductive loads including
three phase transformers. The electronic circuit is completely digital and is based on a powerful
microprocessor with high performance that allow the use in different ways:
•
Single cycle
•
Burst Firing with soft start and current limit
•
Delayed triggering
•
Phase Angle with soft start and current limit
On same unit can be used different feed back that define the control mode:
•
Voltage
•
Current
•
Power VxI
•
External 0÷10Vdc
On same unit can be used different input:
•
4÷20mA
•
0÷10Vdc
•
Potentiometer 10KΩ
•
SSR
Communication RS485 is a standard feature of MULTIDRIVE this allows the use of many information
like: tension, current, power, load state and all the parameters for diagnostic and configuration. Ulterior
advantages of the digital system vs the analogical is the flexibility and the possibility of implement
special characteristics without change the hardware. Several strategies can be implemented and
selected through the configuration parameters.
With CD-KP, you can have access to the configuration parameters without expose at the dangerous
voltage inside the cabinet and without stop the plant.