GE Power ManagementL90 Line Differential Relay6-156 ACTUAL VALUES 6.3 METERING6A maximum of 6 identical Source menus are available, numbered from SRC 1 to SRC 6. "SRC 1" will be replaced by what-ever name was programmed by the user for the associated source (see SETTINGS ÖØ SYSTEM SETUP ÖØ SIGNALSOURCES).The relay measures (absolute values only) SOURCE DEMAND on each phase and average three phase demand for real,reactive, and apparent power. These parameters can be monitored to reduce supplier demand penalties or for statisticalmetering purposes. Demand calculations are based on the measurement type selected in the SETTINGS Ø PRODUCT SETUPÖØ DEMAND menu. For each quantity, the relay displays the demand over the most recent demand time interval, the maxi-mum demand since the last maximum demand reset, and the time and date stamp of this maximum demand value. Maxi-mum demand quantities can be reset to zero with the COMMANDS Ø CLEAR RECORDS ÖØ CLEAR DEMAND RECORDScommand.SOURCE FREQUENCY is measured via software-implemented zero-crossing detection of an AC signal. The signal is either aClarke transformation of three-phase voltages or currents, auxiliary voltage, or ground current as per source configuration(see SETTINGS ÖØ SYSTEM SETUP ÖØ POWER SYSTEM). The signal used for frequency estimation is low-pass filtered. Thefinal frequency measurement is passed through a validation filter that eliminates false readings due to signal distortions andtransients.6.3.4 SYNCHROCHECKPATH: ACTUAL VALUES ÖØ METERING ÖØ SYNCHROCHECK Ö SYNCHROCHECK 1The Actual Values menu for SYNCHROCHECK2 is identical to that of SYNCHROCHECK1. If a Synchrocheck Functionsetting is set to "Disabled", the corresponding Actual Values menu item will not be displayed.MESSAGE SRC 1 DMD W:0.000 WMESSAGE SRC 1 DMD W MAX:0.000 WMESSAGE SRC 1 DMD W DATE:200/07/31 16:30:07MESSAGE SRC 1 DMD VAR:0.000 varMESSAGE SRC 1 DMD VAR MAX:0.000 varMESSAGE SRC 1 DMD VAR DATE:200/07/31 16:30:07MESSAGE SRC 1 DMD VA:0.000 VAMESSAGE SRC 1 DMD VA MAX:0.000 VAMESSAGE SRC 1 DMD VA DATE:200/07/31 16:30:07 FREQUENCY SRC 1SRC 1 FREQUENCY:0.00 Hz SYNCHROCHECK1SYNCHROCHECK 1 DELTAVOLT: 0.000 VMESSAGE SYNCHROCHECK 1 DELTAPHASE: 0.0°MESSAGE SYNCHROCHECK 1 DELTAFREQ: 0.00 Hz
