The function starts when the measured current exceeds the breakdown torque level,that is, above the set limit. The operation characteristic is definite time.The function contains a blocking functionality. It is possible to block the functionoutputs.4.1.7.4 Operation principleThe function can be enabled and disabled with the Operation setting. Thecorresponding parameter values are "On" and "Off".The operation of the motor load jam protection can be described with a modulediagram. All the modules in the diagram are explained in the next sections.GUID-93025A7F-12BE-4ACD-8BD3-C144CB73F65A V2 ENFigure 121: Functional module diagramLevel detectorThe measured phase currents are compared to the set Start value. The TRMSvalues of the phase currents are considered for the level detection. The timermodule is enabled if at least two of the measured phase currents exceed the setStart value.TimerOnce activated, the internal START signal is activated. The value is available onlythrough the Monitored data view. The time characteristic is according to DT. Whenthe operation timer has reached the Operate delay time value, the OPERATE outputis activated.When the timer has elapsed but the motor stall condition still exists, the OPERATEoutput remains active until the phase currents values drop below the Start value,that is, until the stall condition persists. If the drop-off situation occurs while theoperating time is still counting, the reset timer is activated. If the drop-off timeexceeds the set Reset delay time, the operating timer is reset.The timer calculates the start duration value START_DUR, which indicates thepercentage ratio of the start situation and the set operating time. The value isavailable in the monitored data view.1YHT530004D05 D Section 4Protection functions615 series 241Technical Manual
