GE P24DM Technical Manual

Also see for MiCOM P40 Agile: Technical manual Technical manual Technical manual Technical manual Technical manual

2 DC SUPPLY MONITORThis product can be powered using either a DC or AC supply. As a DC supply is normally used, a DC SupplyMonitoring feature is included to indicate the DC supply status. The nominal DC Station supply is 48 V DC, which isprovided by a bank of batteries. It is sometimes possible for this nominal supply to fall below or rise aboveacceptable operational limits. If the voltage is too high, it may indicate overcharging. If the voltage is too low, itmay indicate a failing battery.In such cases it is very useful to have DC supply monitoring functionality. The P40 Agile products provide suchfunctionality by measuring the auxiliary DC supply fed into the device and processing this information usingsettings to define certain limits. In addition, the DC Auxiliary Supply value can be displayed on the front panel LCDto a resolution of 0.1 V DC. The measuring range is from 19 V DC to 300 V DC.2.1 DC SUPPLY MONITOR IMPLEMENTATIONThe P40Agile products provide three DC supply monitoring zones; zone 1, zone 2, and zone 3. This allows you tohave multiple monitoring criteria. Each zone must be configured to correspond to either an overvoltage conditionor an undervoltage condition. A single zone cannot be configured to provide an alarm for both undervoltage andovervoltage conditions. Typically, you would configure zones 1 and 2 for undervoltage conditions, whereby thelowest limit is set very low, and zone 3 for an overvoltage condition whereby the upper limit is very high.This is best illustrated diagrammatically:V01221Zone 2 (undervoltage)Vdc nominalZone 1 (undervoltage)Vdc2 lower limitVdc3 lower limitVdc1 upper limitVdc1 lower limitZone 3 (overvoltage)Vdc3 upper limitVdc2 upper limitFigure 130: DC Supply Monitor zonesIt is possible to have overlapping zones whereby zone 2 upper limit is lower than zone 1 lower limit in the aboveexample.The DC Supply Monitoring function is implemented using settings in the DC SUP. MONITOR column. There are threesets of settings; one for each of the zones. The settings allow you to:● Enable or disable the function for each zone● Set a lower voltage limit for each zone● Set an upper voltage limit for each zone● Set a time delay for each zoneChapter 14 - Supervision P24xM274 P24xM-TM-EN-2.1