Reduced Run; Starting Reduced Run Operation; Resuming Normal Operation - ABB ACS880-207 Hardware Manual

86 Maintenance

Reduced run


The reduced run function is available for IGBT supply units consisting of parallel-
connected IGBT supply modules. The function makes it possible to continue operation
with limited current even if one (or more) module is out of service, for example, because of
maintenance work.
In principle, reduced run in possible with only one module, but the physical requirements of
operating the drive still apply; for example, the modules that remain in use must be able to
provide enough current.

Starting reduced run operation

WARNING! Only qualified electricians are allowed to this work. Read the
complete safety instructions of the drive. Ignoring the instructions can cause
physical injury or death, or damage to the equipment.
WARNING! Wear protective gloves and long sleeves! Some parts have sharp
edges.
1. Disconnect the drive from the AC power line and make sure it is safe to start the work.
See section Electrical safety precautions
2. If the IGBT supply control unit is powered from the faulty module, connect the control
unit to another 24 V DC power supply. It is strongly recommended to use an external
power supply with IGBT supply units that consist of parallel-connected modules.
3. Remove the module to be serviced from its bay.
4. Install an air baffle (for example, plexiglass, sheet metal etc.) to the top module guide
to block the airflow through the empty module bay.
5. Switch on the power to the IGBT supply unit.
6. Enter the number of IGBT supply modules present into parameter 195.13 Reduced
run mode.
7. Reset all faults and start the IGBT supply unit. The maximum current limit is now
automatically set according to the new IGBT supply configuration. A mismatch
between the number of detected modules (parameter 195.14) and the value set in
195.13 will generate fault.

Resuming normal operation

WARNING! Only qualified electricians are allowed to this work. Read the
complete safety instructions of the drive. Ignoring the instructions can cause
physical injury or death, or damage to the equipment.
1. Remove the air baffle from the module bay.
2. Reinstall the module into its bay.
3. Switch on the power to the IGBT supply unit.
4. Enter "0" into parameter 195.13 Reduced run mode.
on page 42.