The drive is equipped with internal AC fuses as standard. In case of a short-circuit insidethe drive, the AC fuses protect the drive, restrict drive damage, and prevent damage toadjoining equipment.￭ Protecting the motor and motor cable in short-circuitsThe drive protects the motor cable and motor in a short-circuit situation when the motorcable is sized according to the nominal current of the drive. No additional protection devicesare needed.￭ Protecting the drive and the power cables against thermal overloadThe drive protects itself and the input and motor cables against thermal overload when thecables are sized according to the nominal current of the drive. No additional thermal protectiondevices are needed.WARNING!If the drive is connected to multiple motors, use a separate circuit breaker or fusesfor protecting each motor cable and motor against overload. The drive overloadprotection is tuned for the total motor load. It may not trip due to an overload inone motor circuit only.￭ Protecting the motor against thermal overloadAccording to regulations, the motor must be protected against thermal overload and thecurrent must be switched off when overload is detected. The drive includes a motor thermalprotection function that protects the motor and switches off the current when necessary.Depending on a drive parameter value, the function either monitors a calculated temperaturevalue (based on a motor thermal model) or an actual temperature indication given by motortemperature sensors. The user can tune the thermal model further by feeding in additionalmotor 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 theconnection and use of the temperature sensors.Protecting the drive against ground faultsThe drive is equipped with an internal ground fault protective function to protect the unitagainst ground faults in the motor and motor cable in TN (grounded) networks. This is nota personnel safety or a fire protection feature. The ground fault protective function can bedisabled with a parameter, refer to the firmware manual.￭ Residual current device compatibilityThe 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 theframe. These capacitors and long motor cables increase the ground leakage current andmay cause fault current circuit breakers to function.66 Guidelines for planning the electrical installation
