22 Function and hardware description
Output Choke
As SBU of ACS580MV is taking the Make - before - Break (Bumpless) method, so an
output choke at the VSD output is needed to limit the inrush current during the
synchronizing period.
An output choke can be used to make a VSD soft-starter line friendly and motor friendly
during startup and synchronization. Such a soft starter would ensure that a minimized
inrush current flows in on the line side and a smooth transfer from VSD operation to DOL
operation occurs on the motor side (no transient torques and no speed oscillation).
PT
The synchronization PTs can provide supply voltage and VSD output voltage, since
voltage magnitude and phase angle are required for synchronization, the PT on the main
supply must measure the same phases as the PT measures on the converter output.
Two pieces of PT can be provided either by customer, or provided by ABB as an option. In
case PT is provided by ABB, the SBU only supports single grid.
Space heater
To prevent condensation being produced inside the cabinet, the cabinet can be equipped
with a space heater for both SBU and MAU cabinet. The SBU space heaters are controlled
on and off together with the ACS580MV heating cable, while the space heaters in MAU
are always running.
RSYC- 01 unit
Overall view of the unit
RSYC - 01 unit
Operation
The RSYC unit monitors two voltage signals, one measured from the supply line and other
from the drive output. The signals indicate the phase shift and frequency.
The unit output signal indicates the synchronization status for the drive. When the signal
reaches specific voltages, the supply line and the drive output voltages are synchronic, i.e.
the phasing and frequency are the same.
HMI
HMI is an option and mounted on MAU. It can display all MSS and MB status (in Main page), IO
status (in IO page), active fault (in Fault page).