5.9 L: Protection Functionsu L1: Motor Protectionn L1-01: Motor Overload Protection SelectionThe drive has an electronic overload protection function that estimates the motor overload level based on output current, outputfrequency, thermal motor characteristics, and time. When the drive detects a motor overload an oL1 fault is triggered and thedrive output shuts off.L1-01 sets the overload protection function characteristics according to the motor being used.No. Name Setting Range DefaultL1-01 Motor Overload Protection Selection 0, 1 1Note: 1. When the motor protection function is enabled (L1-01≠ 0), an oL1 alarm can be output through one of the multi-function outputs bysetting H2-01 to 1F<1>. The output closes when the motor overload level reaches 90% of the oL1 detection level.2. Set L1-01 to a value between 1 and 5 when running a single motor from the drive to select a method to protect the motor from overheat.An external thermal relay is not necessary.<1> Details on this function can be found in the standard Z1000 Programming Manual (SIEPC71061645) atwww.yaskawa.com.Setting 0: Disabled (Motor Overload Protection Is not Provided)Use this setting if no motor overheat protection is desired or if multiple motors are connected to a single drive. If multiplemotors are connected to a single drive, install a thermal relay for each motor as shown in Figure 5.41.DrivePowersupplyM1MC1MC1, MC2: Magnetic contactorsL10, L20: Thermal relaysL10MC2 L20M2Figure 5.41 Example of Protection Circuit Design for Multiple MotorsNOTICE: Thermal protection cannot be provided when running multi-motors simultaneously with the same drive, or when using motors witha relatively high current rating compared to other standard motors (such as a submersible motor). Failure to comply could result in motordamage. Disable the electronic overload protection of the drive (L1-01 = “0: Disabled”) and protect each motor with individual motor thermaloverloads.Note: 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 from overheatthroughout the entire speed range.Overload Tolerance Cooling Ability Overload CharacteristicsA: Max. speed for 200LJ and aboveB: Max. speed for 160MJ to 180 LJC: Max. speed for 132MJ and below05 33 100 120 167 200Speed (%)ContinuousA BCRated Speed=100% Speed60 s150100906050Torque (%)Motor designed to operate from linepower.Motor cooling is most effective whenrunning at rated base frequency (checkthe motor nameplate or specifications).Continuous operation at less than linepower frequency with 100% load cantrigger motor overload protection(oL1). A fault is output and the motorwill coast to stop.5.9 L: Protection Functions168 YASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual
