ICS TRIPLEX 9431工控模塊卡件
小于額定相位CT初級的50%。理想情況下，應選擇CT初級相位，以使FLA為CT初級相位的100%，或稍小，絕不超過。訂購時必須指定1或5 A的輔助值，以便安裝正確的硬件。還必須輸入電機滿載振幅（FLA）值。該值可取自電機銘牌數據表。服務系數可作為過載傳感器輸入（見第4–28頁第4.6節：S5熱模型）。對于高電阻接地系統，如果使用50:0.025接地CT輸入，則可以進行靈敏的接地電流檢測。要使用50:0.025輸入，請為地面CT設置點選擇“Multiline 50:0.025”。不會出現其他地面CT信息。在故障電流可能相當大的可靠接地系統上，469 1A或5A次級接地CT輸入應用于零序或剩余接地傳感。如果連接是剩余的，則接地CT次級和初級值應與相位CT相同。但是，如果連接是零序，則必須輸入接地CT二級和初級值。應選擇接地CT一次，使潛在故障電流不超過一次額定值的20倍。當購買繼電器級CT時，該預防措施將確保接地CT在故障條件下不會飽和。如果要使用差動特性，必須輸入相位差動CT主設定點。如果在矢量求和配置中每相使用兩個CT，則應選擇CT以確保電機啟動期間沒有飽和。然而，如果每相的差動保護使用鐵芯平衡CT，則50或100 a的低CT額定值允許非常靈敏的差動保護。使用雙速電機功能時，必須在此處為速度2輸入第二組相位CT和電機FLA的值。如果相位CT與速度1相位CT相同，只需在此處輸入相同的值。示例1：考慮一臺469，其5 a相位CT二次和接地故障檢測設置為殘余，電機規格如下：電機銘牌FLA:87 a；低電阻接地；最大故障：400 A需要以下設置：n電流傳感n[ENTER]更多相位CT主：未編程范圍：1到5000 A，步長為1，未編程電機滿載振幅FLA：未編程的范圍：1至5000 A，步進為1，非編程接地CT：多線50:0.025范圍：無，1A次級，5A次級，多線50:0.025接地CT主電流：100 A范圍：1至5000 A，步長為1。僅當接地CT為“1A次級”或“5A次級”相位差CT時可見：無范圍：無，1A次級，5A次級相位差CT初級：100 A范圍：1至5000，步長為1。
less than 50% of the rated phase CT primary. Ideally, the phase CT primary should be chosen so the FLA is 100% of the phase CT primary or slightly less, never more. The secondary value of 1 or 5 A must be specified at the time of order so that the proper hardware is installed. A value for MOTOR FULL LOAD AMPS (FLA) must also be entered. The value may be taken from the motor nameplate data sheets. The Service Factor may be entered as Overload Pickup (see Section 4.6: S5 THERMAL MODEL on page 4–28). For high resistance grounded systems, sensitive ground current detection is possible if the 50:0.025 ground CT input is used. To use the 50:0.025 input, select "Multilin 50:0.025" for the GROUND CT setpoint. No additional ground CT messages will appear. On solidly grounded systems where fault currents may be quite large, the 469 1A or 5A secondary ground CT input should be used for either zero-sequence or residual ground sensing. If the connection is residual, the Ground CT secondary and primary values should be the same as the phase CT. If however, the connection is zero-sequence, the Ground CT secondary and primary values must be entered. The Ground CT primary should be selected such that potential fault current does not exceed 20 times the primary rating. When relaying class CTs are purchased, this precaution will ensure that the Ground CT does not saturate under fault conditions. The PHASE DIFFERENTIAL CT PRIMARY setpoint must be entered if the differential feature is to be used. If two CTs are used per phase in a vectorial summation configuration, the CTs should be chosen to ensure there is no saturation during motor starting. If however, a core balance CT is used for the differential protection in each phase, a low CT rating of 50 or 100 A allows for very sensitive differential protection. When the two-speed motor feature is used, a value for a second set of Phase CTs and motor FLA must be entered here for Speed 2. If the Phase CTs are the same as the speed 1 phase CTs, simply enter the same value here as well. Example 1: Consider a 469 with a 5 A Phase CT secondary and Ground Fault Detection set to Residual and a motor with the following specifications: Motor Nameplate FLA: 87 A; Low Resistance Grounded; Maximum Fault: 400 A The following settings are required: n CURRENT SENSING n [ENTER] for more PHASE CT PRIMARY: Not Programmed Range: 1 to 5000 A in steps of 1, Not Programmed MOTOR FULL LOAD AMPS FLA: Not Programmed Range: 1 to 5000 A in steps of 1, Not Programmed GROUND CT: Multilin 50:0.025 Range: None, 1A Secondary, 5A Secondary, Multilin 50:0.025 GROUND CT PRIMARY: 100 A Range: 1 to 5000 A in steps of 1. Seen only if GROUND CTis "1A Secondary" or "5A Secondary" PHASE DIFFERENTIAL CT: None Range: None, 1A Secondary, 5A Secondary PHASE DIFFERENTIAL CT PRIMARY: 100 A Range: 1 to 5000 in steps of 1.
