Important Note On Main Circuit Breaker - ABB ACS5000 User Manual

ABB

Important note on main circuit breaker

5k A UM
The main circuit breaker (MCB) is a major protection device of the drive.
If a serious fault occurs in the drive, the MCB must disconnect the main
power supply to the drive immediately. The main power supply must be
disconnected without delay on an open or trip command from the drive to
prevent hazard to the personnel and further damage to the equipment.
The MCB is located on the primary side of the input transformer.
Main power supply
MCB
Protection
relay
Input
transformer
Drive
Motor
Fig. 1 Drive system overview
Fig. 1 shows the conceptual single-line diagram of a typical drive system,
including main power supply, MCB, input transformer, drive and electric
motor.
The MCB is defined as a switching device to disconnect the power supply
whenever required by the process or when a fault occurs. Typical devices
used as MCBs are:
3BHS221906 ZAB E01 Rev. D
CT
M
MCB control interface
Higher-level
control system
Local MCB control
1 (4)