Digitax DBE1100S, Руководство пользователя

Страница: 10 / 96

DigitAx User Guide
Issue code: dgxu4
1-2
1.2 Method of operation
Power circuits
The
AC
supply is rectified and smoothed to apply a
constant voltage on a
DC
bus. This
DC
bus supplies a
pulse-width modulated IGBT power stage that
delivers
AC
power at variable frequency and voltage
to the motor.
Depending on the model, an external
DC
choke is
required for the
DC
bus.
In order to enhance the braking capabilities of the
Drive, all but the two most powerful models have an
internal braking resistor, and all models can be used
with an external braking resistor.
When the recommended wiring techniques are used,
the Drive retains
EMC
compatibility.
Controlling the Drive
Operation of the Drive is controlled by programming
a number of software parameters. These parameters
have default values that enable the Drive to be run
without any initial programming.
The Drives have a Control Keypad which is located on
the front panel of the case. The Control Keypad is
used for the following:
To change parameter values
To stop and start the Drive
To display the operating status of the Drive
An
RS485
serial communications port allows the Drive
to be controlled remotely using a host PC or plc.
Warning
Enabling the Drive when zero
speed reference is applied
can sometimes cause the
motor shaft to be rotated in
either direction by up to 10
°°
.
Even though all DigitAx
Drives are affected in this
way, only a small percentage
cause rotation in excess of
2
°°
. This effect is caused by
tolerances in the current
sensors.
The effect is usually of no
consequence when the
motor is driving a belt or
gearbox, but may sometimes
cause problems in
applications involving
material held in tension (eg.
film).
If the effect is likely to be
unacceptable for the
application, before installing
the Drive refer to this User
Guide for making just basic
AC
power and signal
connections, and test the
Drive for the effect.
If necessary, obtain a
replacement Drive.
1.3 How best to use this
User Guide
This User Guide is arranged logistically: reading from
beginning to end will take you in the correct order
through the basic steps of installing the Drive and
getting it running with a motor.
To make subsequent adjustments to the parameters,
refer to Chapter 11,
List of Parameters .