ABB ACS880-07XT Series, Hardware Manual, Page: 132 / 168

132 Maintenance
Reduced run
A “reduced run” function makes it possible to continue operation with one drive module if
the other module is out of service, for example, because of maintenance work. In principle,
reduced run is possible with only one module, but the physical requirements of operating
the motor still apply; the remaining module in use must be able to provide the motor with
enough magnetizing current.

Starting reduced run operation
WARNING! Obey the instructions in chapter Safety instructions . If you
ignore them, injury or death, or damage to the equipment can occur.
1. Stop the drive and do the steps in section Precautions before electrical work before
you start the work.
2. If the control unit is powered from the faulty module, connect the control unit to
another 24 V DC power supply. We strongly recommend using an external power
supply with parallel-connected drive modules.
3. Disconnect all cables from the module to be serviced and remove it from its bay.
4. Switch on the power to the remaining drive module. Enter the number of drive
modules present into parameter 95.13 Reduced run mode.
5. Reset all faults and start the drive module. The maximum current is now automatically
limited according to the new drive module configuration. A mismatch between the
number of detected modules (95.14) and the value set in 95.13 will generate a fault.
6. If the STO function is in use, validate it.

Resuming normal operation
1. Stop the drive and do the steps in section Precautions before electrical work before
you start the work.
2. Reinstall the module into its bay.
3. Connect all wires and fibres.
4. Switch on the power to the drive module package.
5. Enter “0” into parameter 95.13 Reduced run mode.
6. If the STO function is in use, validate it.