Toshiba TOSVERT VFS15-2004PM-W1 Instruction Manual

Also see for TOSVERT VF-S15 series: Function manual Quick start manual Instruction manual Instruction manual Instruction manual

E6581611A-271(2) Influence of leakage current across linesPowersupplyInverterThermal relaysCTAMLeakage current path across wires(1) Thermal relaysThe high frequency component of current leaking into electrostatic capacity between inverter out-put wires will increase the effective current values and make externally connected thermal relaysoperate improperly. If the wires are more than 50 meters long, it will be easy for the externalthermal relay to operate improperly with models having motors of low rated current (severalA(ampere) or less), because the leakage current will increase in proportion to the motor rating.Remedies:1. Use the electronic thermal built into the inverter. (Refer to section 5.6)The setting of the electronic thermal is done using parameter , .2. Reduce the inverter's PWM carrier frequency. However, that will increase the motor's magneticnoise.The setting of PWM carrier frequency is done with the parameter . (Refer to section 6.18)3. This can be improved by installing 0.1μ to 0.5μF - 1000V film capacitor to the input/output terminalsof each phase in the thermal relay.(2) CT and ammeterIf a CT and ammeter are connected externally to detect inverter output current, the leak current's highfrequency component may destroy the ammeter. If the wires are more than 50 meters long, it will beeasy for the high frequency component to pass through the externally connected CT and besuperimposed on and burn the ammeter with models having motors of low rated current (several A(ampere) or less), especially the 500V class low capacity (4.0kW or less) models, because the leakagecurrent will increase in proportion to the motor's rated current.U/T1V/T2W/T3MThermal relays