Function And Hardware Description; Contents Of This Chapter; Function Introduction; Sbu Function Description - ABB ACS580MV Hardware Manual

Function and hardware
description

Contents of this chapter

This chapter provides information on the power equipment and cabinet design and briefly
describes the operation principle of the bypass - drive.

Function introduction

SBU function Description


The synchronized bypass unit (SBU) control the transfer of a motor from the drive to a
fixed frequency line. The unit supports the following synchronization method:
Make - before - break (bumpless): Need a decoupling choke is added between the
converter and the motor. The transfer occurs without a power interruption to the motor.
The SBU is designed for use with ACS580MV medium voltage drive and can be equipped
for the transfer of up to 8 motors. It provides all necessary hardware for the communication
with the drive and the remote control place. Information on the project-specific
communication method is provided on the electrical drawings.
The interposing relays for the circuit breakers, which connect/disconnect the motor to the
drive and the line, are mandatory for SBU functionality as well as the inputs for monitoring
the position of these switches. Each motor requires its own set of circuit breakers:
•
The motor starting switch (MSS) connects and disconnects the motor to and from a
drive.
•
The motor breaker (MB) connects and disconnects the motor to and from the line.

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