1541MRS751802-MUMProtection RelayTechnical Reference Manual, Standard ConfigurationsREX 521The recording can be triggered by any of the alternatives listed below:• Triggering on the rising or falling edge of the protective start signals• Triggering on current measurement• Manual triggering via the HMI or with the external input signal• Triggering via communication by a parameter• Periodic triggeringRegardless of the triggering type, each recording generates the event E31. Thetriggering time and reason are included in the recording. Number of recordings canbe viewed in Main menu\Measurements\DREC\Control setting\# records.External triggering can be made by means of the reserved input signal “DREC trig”connected to one of the digital inputs. The settings can be found inMain menu\Configuration\Input Signals\DREC trig.Refer to the CD-ROM Technical Descriptions of Functions (MEDREC16) for moreinformation about the disturbance recorder.9.2.4.6. Power qualityThe power quality function (PQ 3Inf) can be found in Main menu\PowerQuality\PQ 3Inf. The function is used for measuring the harmonics andmonitoring the power quality in distribution networks.The power quality function can be triggered by any of the alternatives listed below:• Manual triggering via the HMI• With the external input signal• Triggering via communication parameter• Preset time and dateExternal triggering can be made by means of the reserved input signal “PQ 3Inf trig”connected to one of the digital inputs. The settings can be found inMain menu\Configuration\Input Signals\PQ 3Inf trig.The function can deliver the alarm signals “PQ 3Inf cum”, an output signal forexceeding a setting limit for cumulative probability of a harmonic and the “PQ 3Infhar”, an output signal for exceeding a setting limit for a harmonic. The alarm signalscan be routed to the output contacts via the switchgroups. The connection settingscan be made in Main menu\Configuration\Output SWGRP\Alarm 1\or \Alarm 2\. The “Alarm 1” or “Alarm 2” output signal can be then connectedto an output relay and the settings are done inMain menu\Configuration\Output Signals\.Refer to the CD-ROM Technical Descriptions of Functions (PQCU3H) for moreinformation about the power quality function.
