ABB ACS880 Series, Electrical Planning Manual

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￭ Protecting against short-circuit inside the drive
Cabinet-installed multidrives
The drive is equipped with input fuses that restrict the drive damage and prevent damage
to adjoining equipment in case of a short-circuit inside the drive.
Multidrive modules
Equip the drive with input fuses listed in the technical data of the appropriate supply unit
hardware manual. Fuses restrict the drive damage and prevent damage to adjoining
equipment in case of a short-circuit inside the drive.
￭ Protecting the motor and motor cable in short-circuits
The drive protects the motor cable and motor in a short-circuit situation when the motor
cable is sized according to the nominal current of the drive. No additional protection devices
are needed.
￭ Protecting the motor cables against thermal overload
The drive protects the motor cables against thermal overload when the cables are sized
according to the nominal output current of the drive (single drive) or inverter (multidrive).
No additional thermal protection devices are needed.
WARNING!
If the drive (single drive) or inverter (multidrive) is connected to multiple motors,
use a separate circuit breaker or fuses for protecting each motor cable and motor
against overload. The overload protection of the drive (single drive) or inverter
(multidrive) is tuned for the total motor load. It may not detect an overload in one
motor circuit only.
￭ Protecting the motor against thermal overload
According to regulations, the motor must be protected against thermal overload and the
current must be switched off when overload is detected. The drive includes a motor thermal
protection function that protects the motor and switches off the current when necessary.
Depending on a drive parameter value, the function either monitors a calculated temperature
value (based on a motor thermal model) or an actual temperature indication given by motor
temperature sensors.
The motor thermal protection model supports thermal memory retention and speed sensitivity.
The user can tune the thermal model further by feeding in additional motor and load data.
The most common temperature sensors are:
• motor sizes IEC180…225: thermal switch, for example Klixon
• motor sizes IEC200…250 and larger: PTC or Pt100.
See the firmware manual for more information on the motor thermal protection.
Electrical planning guidelines 31