IS200BICLH1BBA,IS200BPIBG1AEB DCS工控模块备件
2安装2.2电气2如果使用1 A/5 A抽头，469测量的次级电流可达5 A。由于转换范围相对较小，1 A或5 A选项可现场编程。正确选择该设定值可确保正确读取一次接地电流。选择的1 A/5 A接地CT必须能够驱动469接地CT负载（见第1-5页第1.2节：规范）。如果该抽头与GE Power Management核心平衡CT一起使用，469可测量高达25 A的一次接地电流。建议采用零序连接。CT的不均匀饱和、电机的尺寸和位置、电力系统的电阻和电机铁芯饱和密度等可能会导致剩余连接的GF电路中的错误读数。只应连接一个接地输入–另一个输入应未连接。仅检测接地故障电流的零序CT的准确位置如下所示。如果将铁芯平衡CT放置在屏蔽电缆上，则在电机启动期间将相电流电容耦合到电缆屏蔽中，可检测为接地电流，除非屏蔽线也穿过CT窗口。建议在零序CT上使用双绞线。图2-13：堆芯平衡接地CT安装注释：屏蔽电缆无屏蔽电缆2-12 469电机管理继电器GE Power Management 2.2电气2安装2 2.2.6差动电流输入469有三个通道用于差动电流输入，每个通道都有一个隔离变压器。电流输入上没有内部接地连接。如果装置退出，469外壳上的每个差动CT电路都会被自动机构短路。最大差动CT一次电流为5000 A。469测量差动CT输入的二次电流高达5 A。由于转换范围相对较小，1 A或5 A选项可现场编程。正确选择该设定值可确保正确读取初级相位差电流。选择的1 A/5 A差动CT必须能够驱动469差动CT负载（额定值见第1-5页第1.2节：规格）。差分CT可以是如下图所示的堆芯平衡。或者，差动输入中每相两个CT的总和将提供更大的保护区。如果使用两个CT的总和，则观察CT极性很重要。也可以使用如下所示的相位CT来实现求和方法。它们必须具有相同的CT比率。图2–14：铁芯平衡方法图2–15：无相CT和相CT的汇总方法GE Power Management 469电机管理继电器2-13 2安装2.2电气2 2.2.7电压输入469有三个交流电压输入通道，每个通道都有一个隔离变压器。电压输入上没有内部保险丝或接地连接。最大VT比率为150.00:1。两个VT连接为开放三角形（见图2-10：第2-8页的典型接线图）或Y形（见下文）。电压通道在内部以Y形连接，这意味着必须为开放式三角电压互感器安装B相输入和469中性端子之间的典型接线图三角电源连接上所示的跳线。VT的极性对于正确的功率测量和电压相位反转操作至关重要。通常使用1 A保险丝来保护输入。2 INSTALLATION 2.2 ELECTRICAL 2 The 469 measures up to 5 A secondary current if the 1 A / 5 A tap is used. Since the conversion range is relatively small, the 1 A or 5 A option is field programmable. Proper selection of this setpoint ensures proper reading of primary ground current. The 1 A / 5 A ground CT chosen must be capable of driving the 469 ground CT burden (see Section 1.2: SPECIFICATIONS on page 1–5). The 469 measures up to 25 A of primary ground current if this tap is used in conjunction with the GE Power Management core balance CT. The zero-sequence connection is recommended. Unequal saturation of CTs, size and location of motor, resistance of power system and motor core saturation density, etc., may cause false readings in the residually connected GF circuit. Only one ground input should be wired – the other input should be unconnected. The exact placement of a zero-sequence CT to detect only ground fault current is shown below. If the core balance CT is placed over shielded cable, capacitive coupling of phase current into the cable shield during motor starts may be detected as ground current unless the shield wire is also passed through the CT window. Twisted pair cabling on the zero-sequence CT is recommended. Figure 2–13: CORE BALANCE GROUND CT INSTALLATION NOTE NOTE SHIELDED CABLE UNSHIELDED CABLE 2-12 469 Motor Management Relay GE Power Management 2.2 ELECTRICAL 2 INSTALLATION 2 2.2.6 DIFFERENTIAL CURRENT INPUTS The 469 has three channels for differential current inputs, each with an isolating transformer. There are no internal ground connections on the current inputs. Each differential CT circuit is shorted by automatic mechanisms on the 469 case if the unit is withdrawn. The maximum differential CT primary current is 5000 A. The 469 measures up to 5 A secondary current for the differential CT inputs. Since the conversion range is relatively small, the 1 A or 5 A option is field programmable. Proper selection of this setpoint ensures proper reading of primary phase differential current. The 1 A / 5 A differential CT chosen must be capable of driving the 469 differential CT burden (see Section 1.2: SPECIFICATIONS on page 1–5 for ratings). The differential CTs may be core balance as shown in the first figure below. Alternatively, the summation of two CTs per phase into the differential input will provide a larger zone of protection. If the summation of two CTs is used, observation of CT polarity is important. The summation method may also be implemented using the phase CTs as shown below. They will have to have the same CT ratio. Figure 2–14: CORE BALANCE METHOD Figure 2–15: SUMMATION METHOD WITHOUT PHASE CTs WITH PHASE CTs GE Power Management 469 Motor Management Relay 2-13 2 INSTALLATION 2.2 ELECTRICAL 2 2.2.7 VOLTAGE INPUTS The 469 has three channels for AC voltage inputs, each with an isolating transformer. There are no internal fuses or ground connections on the voltage inputs. The maximum VT ratio is 150.00:1. The two VT connections are open delta (see Figure 2–10: TYPICAL WIRING DIAGRAM on page 2–8) or wye (see below). The voltage channels are connected in wye internally, which means that the jumper shown on the delta-source connection of the TYPICAL WIRING DIAGRAM, between the phase B input and the 469 neutral terminal, must be installed for open delta VTs. Polarity of the VTs is critical for correct power measurement and voltage phase reversal operation. A 1 A fuse is typically used to protect the inputs.
