Multidrive Modules; Protecting The Motor And Motor Cable In Short-Circuits; Protecting The Motor Cables Against Thermal Overload; Protecting The Motor Against Thermal Overload - ABB ACS880 Series Electrical Planning Instructions

32 Electrical planning guidelines

Multidrive modules

Equip the drive with input fuses listed in the Technical data of the appropriate supply unit
hardware manual. Fuses restrict drive damage and prevent damage to adjoining equipment
in case of a short-circuit inside the drive.
Addition: Equip the input power cables feeding a diode supply unit with D6D or D7D supply
module with the ABB specified fuses. Fuses protect the cable and limit short-circuit current
in the supply unit. Cabinet-installed multidrives: See ACS800-307 (+A003) diode supply
units hardware manual [3AUA0000102453 (English)]. Multidrive modules: See ACS800-304
(+A003) diode supply modules hardware manual [3AUA0000102452 (English)].
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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.
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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.
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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 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, eg. Klixon
• motor sizes IEC200...250 and larger: PTC or Pt100.
See the firmware manual for more information on the motor thermal protection function.