GE Multilin B30 Bus Differential System 5-1995 SETTINGS 5.9 TRANSDUCER INPUTS AND OUTPUTS5Figure 5–88: DCMA OUTPUT CHARACTERISTICThe DCmA output settings are described below.• DCMA OUTPUT H1 SOURCE: This setting specifies an internal analog value to drive the analog output. Actual values(FlexAnalog parameters) such as power, current amplitude, voltage amplitude, power factor, etc. can be configured assources driving DCmA outputs. Refer to Appendix A for a complete list of FlexAnalog parameters.• DCMA OUTPUT H1 RANGE: This setting allows selection of the output range. Each DCmA channel may be set inde-pendently to work with different ranges. The three most commonly used output ranges are available.• DCMA OUTPUT H1 MIN VAL: This setting allows setting the minimum limit for the signal that drives the output. Thissetting is used to control the mapping between an internal analog value and the output current. The setting is enteredin per-unit values. The base units are defined in the same manner as the FlexElement base units.• DCMA OUTPUT H1 MAX VAL: This setting allows setting the maximum limit for the signal that drives the output. Thissetting is used to control the mapping between an internal analog value and the output current. The setting is enteredin per-unit values. The base units are defined in the same manner as the FlexElement base units.The DCMA OUTPUT H1 MIN VAL and DCMA OUTPUT H1 MAX VAL settings are ignored for power factor base units (i.e. ifthe DCMA OUTPUT H1 SOURCE is set to FlexAnalog value based on power factor measurement).Three application examples are described below.EXAMPLE: CURRENT MONITORINGThe phase A current (true RMS value) is to be monitored via the H2 current output working with the range from 4 to 20 mA.The CT ratio is 5000:5 and the maximum load current is 4200 A. The current should be monitored from 0 A upwards, allow-ing for 50% overload.The phase current with the 50% overload margin is:(EQ 5.21)The base unit for current (refer to the FlexElements section in this chapter for additional details) is:(EQ 5.22)The minimum and maximum power values to be monitored (in pu) are:(EQ 5.23)The following settings should be entered:DCMA OUTPUT H2 SOURCE: “SRC 1 Ia RMS”DCMA OUTPUT H2 RANGE: “4 to 20 mA”DCMA OUTPUT H2 MIN VAL: “0.000 pu”DCMA OUTPUT H2 MAX VAL: “1.260 pu”842739A1.CDRDRIVING SIGNALOUTPUT CURRENTMIN VALI minI maxMAX VALNOTEI max 1.5 4.2 kA× 6.3 kA= =I BASE 5 kA=minimum current 0 kA5 kA------------ 0 pu, maximum current 6.3 kA5 kA----------------- 1.26 pu= == =
