5-56 L90 Line Current Differential System GE Multilin5.2 PRODUCT SETUP 5 SETTINGS5• DATA LOGGER MODE: This setting configures the mode in which the data logger will operate. When set to “Continu-ous”, the data logger will actively record any configured channels at the rate as defined by the DATA LOGGER RATE. Thedata logger will be idle in this mode if no channels are configured. When set to “Trigger”, the data logger will begin torecord any configured channels at the instance of the rising edge of the DATA LOGGER TRIGGER source FlexLogic™operand. The data logger will ignore all subsequent triggers and will continue to record data until the active record isfull. Once the data logger is full a CLEAR DATA LOGGER command is required to clear the data logger record before anew record can be started. Performing the CLEAR DATA LOGGER command will also stop the current record and resetthe data logger to be ready for the next trigger.• DATA LOGGER TRIGGER: This setting selects the signal used to trigger the start of a new data logger record. AnyFlexLogic™ operand can be used as the trigger source. The DATA LOGGER TRIGGER setting only applies when themode is set to “Trigger”.• DATA LOGGER RATE: This setting selects the time interval at which the actual value data will be recorded.• DATA LOGGER CHNL 1(16): This setting selects the metering actual value that is to be recorded in Channel 1(16) ofthe data log. The parameters available in a given relay are dependent on: the type of relay, the type and number of CT/VT hardware modules installed, and the type and number of Analog Input hardware modules installed. Upon startup,the relay will automatically prepare the parameter list. A list of all possible analog metering actual value parameters isshown in Appendix A: FlexAnalog Parameters. The parameter index number shown in any of the tables is used toexpedite the selection of the parameter on the relay display. It can be quite time-consuming to scan through the list ofparameters via the relay keypad/display – entering this number via the relay keypad will cause the correspondingparameter to be displayed.• DATA LOGGER CONFIG: This display presents the total amount of time the Data Logger can record the channels notselected to “Off” without over-writing old data.5.2.11 DEMANDPATH: SETTINGS PRODUCT SETUP DEMANDThe relay measures current demand on each phase, and three-phase demand for real, reactive, and apparent power. Cur-rent and Power methods can be chosen separately for the convenience of the user. Settings are provided to allow the userto emulate some common electrical utility demand measuring techniques, for statistical or control purposes. If the CRNTDEMAND METHOD is set to "Block Interval" and the DEMAND TRIGGER is set to “Off”, Method 2 is used (see below). IfDEMAND TRIGGER is assigned to any other FlexLogic™ operand, Method 2a is used (see below).The relay can be set to calculate demand by any of three methods as described below:CALCULATION METHOD 1: THERMAL EXPONENTIALThis method emulates the action of an analog peak recording thermal demand meter. The relay measures the quantity(RMS current, real power, reactive power, or apparent power) on each phase every second, and assumes the circuit quan-tity remains at this value until updated by the next measurement. It calculates the 'thermal demand equivalent' based on thefollowing equation:(EQ 5.6)where: d = demand value after applying input quantity for time t (in minutes)D = input quantity (constant), and k = 2.3 / thermal 90% response time. DEMANDCRNT DEMAND METHOD:Thermal ExponentialRange: Thermal Exponential, Block Interval,Rolling DemandMESSAGE POWER DEMAND METHOD:Thermal ExponentialRange: Thermal Exponential, Block Interval,Rolling DemandMESSAGE DEMAND INTERVAL:15 MINRange: 5, 10, 15, 20, 30, 60 minutesMESSAGE DEMAND TRIGGER:OffRange: FlexLogic™ operandNote: for calculation using Method 2ad t D 1 e kt–– =
