en/ACS800-04/U4 Hardware Manuals - VAE ProSys sro

48Thermal overload protection of the motorAccording to regulations, the motor must be protected against thermal overload andthe current must be switched off when overload is detected. The drive includes amotor thermal protection function that protects the motor and switches off the currentwhen necessary. Depending on a drive parameter value, the function either monitorsa calculated temperature value (based on a motor thermal model) or an actualtemperature indication given by motor temperature sensors. The user can tune thethermal 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 firmware manual for more information on the motor thermal protection, andthe connection and use of the temperature sensors.Protection against short-circuit in the motor cableThe drive protects the motor cable and motor in a short-circuit situation when themotor cable is dimensioned according to the nominal current of the drive. Noadditional protection devices are needed.Protection against short-circuit inside the drive or in the supply cableArrange the protection according to the following guide lines.Distributionboard1)Circuit diagramInput cableDrive or drivemodule~ ~ M3~Short-circuitprotectionProtect the drive andinput cable with fusesor a circuit breaker.See footnotes 1) and2).2)I >~ ~ M3~1) Size the fuses according to instructions given in chapter Technical data. The fuses will protect the inputcable in short-circuit situations, restrict drive damage and prevent damage to adjoining equipment incase of a short-circuit inside the drive.Planning the electrical installation