Procedure:
1. Stop, de-energize and ground the drive following the steps in section
the drive for maintenance
2. Switch off all miniature circuit breakers in the control compartment.
3. Unplug all connectors on the BCU.
4. Loosen the end brackets of BCU.
5. Keep the top of the BCU (looking to the back in cabinet) in place and twist the bottom
(looking towards you) to pull it out of the mounting rail.
View from bottom of cabinet
When a BCU is replaced, the parameter settings can be retained by transferring the
memory unit (ZMU) from the defective BCU to the new BCU. The ZMU is located on the
control unit, see B in figure
before you start the work.
Replacement of BCU components
Maintenance 133
Shutting down
below.