ABB ACS1000i air-cooled, User Manual

Page: 25 / 174

02 IMPORTANT SAFETY INFORMATION
3BHS206977 E01 REV H ACS1000I AIR-COOLED USER MANUAL 25/174
2.8 Important note - main circuit breaker
This note applies to a drive system where the main circuit breaker is
external to the drive. It does not apply to a drive that is equipped with
the option "integrated fused input contactor".
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 converter transformer.
Figure 2-2: Drive system overview
An MCB is a switching device that disconnects the power supply when required by the process
or when a fault occurs. Typical MCBs are:
- Vacuum circuit breakers
- SF6 circuit breakers
- Fused contactors or motor control centers
Note:
The MCB is not included in the drive supply.
A dedicated protection relay is used for:
- Transformer protection
- Backing up the drive protection
(1) Main power supply
(2) MCB control interface
(3) Higher-level control system
(4) Local MCB control
(5) MCB
(6) Protection relay
(7) Converter transformer
(8) Drive
(9) Motor
1
2
3
4
5 6 7
8
9