5.8 L: Protection FunctionsYASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual 267Parameter Details55.8 L: Protection Functions L1: Motor Protection L1-01: Motor Overload Protection SelectionThe drive has an electronic overload protection function that estimates the motor overload level based on output current,output frequency, thermal motor characteristics, and time. An oL1 fault will be triggered when motor overload isdetected and drive output will be shut off.L1-01 sets the overload protection function characteristics according to the motor being used.Note: 1. When the motor protection function is enabled (L1-010), an oL1 alarm can be output through one of the multi-function outputs bysetting H2-01 to 1F. The output will close when the motor overload level reaches 90% of the oL1 detection level.2. Select a method to protect the motor from overheat by setting L1-01 between 1 and 6 when running a single motor from the drive. Anexternal thermal relay is not needed.Setting 0: Disabled (motor overload protection is not provided)This setting should be used if no motor overheat protection is desired or if multiple motors are connected to a singledrive. In this case it is recommended that you install a thermal relay for each motor as shown in Figure 5.89.Figure 5.89Figure 5.89 Example of Protection Circuit Design for Multiple MotorsNOTICE: Thermal protection cannot be provided when running multi-motors simultaneously with the same drive, or when usingmotors with a current rating that is relatively high when compared with other standard motors (such as a submersible motor). Failure tocomply could result in motor damage. Disable the electronic overload protection of the drive (L1-01 = “0: Disabled”) and protect eachmotor with individual motor thermal overloads.NOTICE: Close MC1 and MC2 before operating the drive. (MC1 and MC2 cannot be switched off during run.)Setting 1: General-purpose motor (standard self-cooled)Because the motor is self-cooled, the overload tolerance drops when the motor speed is lowered. The drive appropriatelyadjusts the electrothermal trigger point according to the motor overload characteristics, protecting the motor fromoverheat throughout the entire speed range.No. Name Setting Range DefaultL1-01 Motor Overload Protection Selection 0 to 6 Determined by A1-02Overload Tolerance Cooling Ability Overload CharacteristicsMotor designed to operate from line power.Motor cooling is most effective when running atrated base frequency (check the motor nameplate orspecifications).Continuous operation at less than line powerfrequency with 100% load can trigger motoroverload protection (oL1). A fault is output and themotor will coast to stop.ThermalrelaysmotorsPower supplyM1oL1oL2M2DriveS3(external fault)N.C.oL1oL2SCA: Max. speed for 200LJ and aboveB: Max. speed for 160MJ to 180 LJC: Max. speed for 132MJ and belowRated Speed = 100% Speed
