Planning the electrical installation
60
3ADW000462R0401 DCS880 Hardware manual e d
Protecting
the drive and the input power and motor cables against thermal overload
The drive protects itself, its mains- and the 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 set to 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, e.g. klixon.
– Motor sizes IEC200 … 250 and larger: PTC or Pt100.
See the
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 not equipped with an internal ground fault protective function to protect the unit against ground
faults in the motor and motor cables.
Residual
current device compatibility
The drive is suitable to be used with residual current devices of Type B.
Note:
The EMC filter in front 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.
