Protecting The Motor And Motor Cable In Short-Circuits; Protecting The Drive And The Power Cables Against Thermal Overload; Protecting The Motor Against Thermal Overload; Protecting The Drive Against Ground Faults - ABB ACS560 Hardware Manual

56 Planning the electrical installation

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 drive and the power cables against thermal overload

The drive protects itself and the input and motor cables against thermal overload when the
cables are sized according to the nominal current of the drive. No additional thermal protection
devices are needed.
WARNING!
If the drive is connected to multiple motors, use a separate circuit breaker or fuses
for protecting each motor cable and motor against overload. The drive overload
protection is tuned for the total motor load. It may not trip due to 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 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, and the
connection and use of the temperature sensors.

Protecting the drive against ground faults

The drive is equipped with an internal ground fault protective function to protect the unit
against ground faults in the motor and motor cable. This is not a personnel safety or a fire
protection feature. The ground fault protective function can be reduced with a parameter .
￭

Residual current device compatibility

The drive is suitable to be used with residual current devices of Type B.
Note:
The EMC filter of the drive includes capacitors connected between the main circuit and the
frame. These capacitors and long motor cables increase the ground leakage current and
may cause fault current circuit breakers to function.
￭

Implementing the Emergency stop function

For safety reasons, install the emergency stop devices at each operator control station and
at other operating stations where emergency stop may be needed. Design the emergency
stop according to relevant standards.
Note: