IOP351模拟量输入模块
如果发生意外跳闸，该时间可能会增加。当电机启动时，启动电流（感应电机通常为6×FLA）具有不对称分量。这种不对称电流可能导致一个相位的RMS启动电流高达正常RMS启动电流的1.6倍。如果短路跳闸传感器设置为对称启动电流的1.25倍，则在电机启动过程中可能会出现有害跳闸。随着时间的推移，已经制定了一条经验法则，即短路保护至少是对称启动电流值的1.6倍。这允许电机启动，而不会造成意外跳闸。过载滤波器从故障发生时出现的不对称电流中去除直流分量。这不会导致任何过度响应，然而，响应时间稍微变慢（10到15毫秒），但时间仍保持在规范范围内。❙ 短路跳闸❙ [输入]了解更多短路跳闸：关范围：关、闭锁、未闭锁短路跳闸超范围过滤器：关范围；开、关分配跳闸继电器：跳闸范围：报警、辅助2、辅助3、报警和辅助2、报警和辅3、辅助2和辅助3、警报和辅助2和辅3短路跳闸传感器：0.2 x CT范围：0.2至20.0 x CT，步长：0.1有意S/C跳闸延迟：0 ms范围：0至1000 ms，步骤：10短路跳闸备份：关闭范围：打开、关闭分配备份继电器：辅助2范围：辅助2、辅助2和辅助3、辅助3短路跳闸备份延迟：200 ms范围：10至2000 ms，步骤：10输入退出消息退出消息退出退出消息退出警告GE电源管理469电机管理继电器4-47 4设定点编程4.7 S6电流元件4 4.7.2过载警报如果启用为“锁定”或“未锁定”，过载警报功能如下。电机启动后，当等效电机加热电流超过过载拾取水平时，将发出警报。如果编程为Unlatched（未锁定），当电机不再过载时，过载报警会自动复位。如果编程为“Latched”（锁定），则在过载条件消失后，必须按下该键以重置警报。所有报警功能的事件记录都是可选的。例如，可能需要将未锁定警报连接到控制电机负载的PLC。4.7.3机械堵塞如果打开，机械堵塞元件的功能如下。电机启动后，一旦Ia、Ib或Ic的幅值超过拾取电平×FLA一段由机械阻塞延迟设置点指定的时间，就会发生跳闸。此功能可用于指示运行时的失速状态。它不仅通过比热模型更快地使电机离线来保护电机
This time may be increased if nuisance tripping occurs. When a motor starts, the starting current (typically 6 × FLA for an induction motor) has an asymmetrical component. This asymmetrical current may cause one phase to see as much as 1.6 times the normal RMS starting current. If the SHORT CIRCUIT TRIP PICKUP was set at 1.25 times the symmetrical starting current, it is probable that there would be nuisance trips during motor starting. A rule of thumb has been developed over time that short circuit protection at least 1.6 times the symmetrical starting current value. This allows the motor to start without nuisance tripping. The overreach filter removes the DC component from the asymmetrical current present at the moment a fault occurs. This results in no overreach whatsoever, however, the response time slows slightly (10 to 15 ms) but times still remain within specifications. ❙ SHORT CIRCUIT TRIP ❙ [ENTER] for more SHORT CIRCUIT TRIP: Off Range: Off, Latched, Unlatched SHORT CIRCUIT TRIP OVERREACH FILTER: Off Range: On, Off ASSIGN TRIP RELAYS: Trip Range: Alarm, Auxiliary2, Auxiliary3, Alarm & Aux2, Alarm & Aux3, Aux2 & Aux3, Alarm & Aux2 & Aux3 SHORT CIRCUIT TRIP PICKUP: 0.2 x CT Range: 0.2 to 20.0 x CT, step: 0.1 INTENTIONAL S/C TRIP DELAY: 0 ms Range: 0 to 1000 ms, step: 10 SHORT CIRCUIT TRIP BACKUP: Off Range: On, Off ASSIGN BACKUP RELAYS: Auxiliary2 Range: Auxiliary2, Aux2 & Aux3, Auxiliary3 SHORT CIRCUIT TRIP BACKUP DELAY: 200 ms Range: 10 to 2000 ms, step: 10 ENTER ESCAPE ð ð MESSAGE ESCAPE MESSAGE ESCAPE MESSAGE ESCAPE MESSAGE ESCAPE MESSAGE ESCAPE MESSAGE ESCAPE MESSAGE ESCAPE CAUTION GE Power Management 469 Motor Management Relay 4-47 4 SETPOINT PROGRAMMING 4.7 S6 CURRENT ELEMENTS 4 4.7.2 OVERLOAD ALARM If enabled as "Latched" or "Unlatched", the Overload Alarm functions as follows. After a motor start, when the equivalent motor heating current exceeds the OVERLOAD PICKUP LEVEL, an alarm will occur. If programmed as Unlatched, the overload alarm resets itself when the motor is no longer in overload. If programmed as "Latched", the key must be pressed to reset the alarm once the overload condition is gone. Event recording for all alarm features is optional. For example, it may be desirable to have an unlatched alarm connected to a PLC that is controlling the load on a motor. 4.7.3 MECHANICAL JAM If turned On, the Mechanical Jam element function as follows. After a motor start, a Trip occurs once the magnitude of Ia, Ib, or Ic exceeds the Pickup Level × FLA for a period of time specified by the MECHANICAL JAM DELAY setpoint. This feature may be used to indicate a stall condition when running. Not only does it protect the motor by taking it off-line quicker than the thermal model
