5.6.3 FunctionalityAn emergency condition can arise in cases where the motor needs to be started despiteknowing that this can increase the temperature above limits or cause a thermal overloadthat can damage the motor. The emergency start-up function 62EST allows motor start-ups during such emergency conditions. 62EST is only to force the protection relay toallow the restarting of the motor. After the emergency start input is activated, the motorcan be started normally. 62EST itself does not actually restart the motor.The function contains a blocking functionality. It is possible to block function outputs,timer or the function itself, if desired.5.6.4 Operation principleThe function can be enabled and disabled with the Operation setting. The correspondingparameter values are “Enable” and “Disable”.The operation of 62EST can be described using a module diagram. All the modules in thediagram are explained in the next sections.GUID-18128621-4A78-45D0-A788-9116B5213449 V1 ENFigure 408: Functional module diagramStandstill detectorThe module detects if the motor is in a standstill condition. The standstill condition can bedetected based on the phase current values. If all three phase currents are below the setvalue of Motor standstill A, the motor is considered to be in a standstill condition.TimerThe timer is a fixed 10-minute timer that is activated when the ST_EMERG_RQ input isactivated and motor standstill condition is fulfilled. Thus, the activation of theST_EMERG_RQ input activates the ST_EMERG_ENA output, provided that the motor isin a standstill condition. The ST_EMERG_ENA output remains active for 10 minutes or aslong as the ST_EMERG_RQ input is high, whichever takes longer.The activation of the BLOCK input blocks and also resets the timer.1MAC059074-MB A Section 5Protection related functions615 series ANSI 801Technical Manual
