GUID-200BC4CB-8B33-4616-B014-AFCC99ED9224 V2 ENFigure 276: Time delay for cumulative startThis module also protects the motor from consecutive startups. When theLOCK_START output is active, T_RST_ENA shows the possible time for nextrestart. The value of T_RST_ENA is calculated by the difference of Restart inhibittime and the elapsed time from the instant LOCK_START is enabled.When the ST_EMERG_ENA emergency start is set high, the value of thecumulative startup time counter is set to Cumulative time Lim - 60s × Emg startRed rate. This disables LOCK_START and in turn makes the restart of the motorpossible.This module also calculates the total number of startups occurred, START_CNT.The value can be reset from the clear menu.The calculated values of T_RST_ENA, T_ST_CNT and START_CNT are availablein the monitored data view.The activation of the BLK_LK_ST input signal deactivates the LOCK_STARToutput. The activation of the BLOCK input signal resets the cumulative startupcounter module.4.8.5 ApplicationWhen a motor is started, it draws a current well in excess of the motor's full-loadrating throughout the period it takes for the motor to run up to the rated speed. Themotor starting current decreases as the motor speed increases and the value ofcurrent remains close to the rotor-locked value for most of the acceleration period.The full-voltage starting or the direct-on-line starting method is used out of themany methods used for starting the induction motor. If there is either an electricalor mechanical constraint, this starting method is not suitable. The full-voltage1YHT530004D05 D Section 4Protection functions615 series 527Technical Manual
