16GeneralInstallation of a line choke is recommended and can be used prevent nuisanceerrors and protection caused by voltage spikes. Additionally, the use of a linechoke will double the operational lifetime of the DC bus capacitors in the unit.1.5.6 Motor Thermal ProtectionThe F5 series inverters are UL approved as a solid state motor overloadprotection device. It is necessary to adjust the current trip level in parameter LF.9or LF.12. The function assumes the use of a non-ventilated motor. The functionmeets the requirements set forth in VDE 0660 Part 104, UL508C section 42,NFPA 70 Article 430 part C. See the description for parameter LF.9 for the tripcharacteristics.A motor winding sensor can also be used for additional safety and the highestlevel of protection. Either a normally closed contact (rating: 15V / 6mA) or aPTC (positive temperature coefficient) resistor can be connected to the T1, T2terminals on the inverter. The thermal device should be connected as indicatedin Section 2.5.1.5.7 Motor Cable LengthIn some conventional installations and many MRL applications, the motor canbe a considerable distance (greater then 40 feet) from the elevator drive. Underthese circumstances the long cable length can cause high voltage peaks or highdv/dt (rate of voltage rise) on the motor windings. Depending on the design ofthe motor, these can lead to damage of the motor winding. Therefore, in theseinstallations use of a special dv/dt filter is highly recommended.The standard approved solution is a special output choke. The choke is designedto be used with a maximum of 16kHz switching frequency and low inductance soit does not drastically infl uence the motor's equivalent circuit model.There are three sizes available for motors rated up to 100A. The part numbersand current ratings are listed below.Part Number Rated Current15Z1F04-1005 22A17Z1F04-1005 42A21Z1F04-1005 100AThe use of a conventional line or motor choke on the output of the drive is notrecommend since the inductance value is high enough that it would distort thevalues in the motor model and result in poor control of the motor.
