IS200AEAAH1AAA机械设备卡件
4-8:469标准过载曲线和表4-1:469标准超载曲线乘数）。标准过载曲线方程为：b）自定义过载曲线如果电机启动电流开始侵犯热损伤曲线，则可能需要使用自定义曲线来调整电机保护，以便在不损害保护的情况下成功启动。此外，启动热损伤曲线（锁定转子和加速度）和运行热损伤曲线的特性可能不会很平滑地拟合在一起。在这种情况下，可能需要定制曲线，以根据电机热极限调整电机保护，从而可以成功启动，并在不损害保护的情况下充分利用其潜力。热极限曲线的不同部分现在变得更加关键。对于这些条件，建议使用469自定义曲线热模型。自定义过载曲线功能允许用户通过输入30个预定电流水平的跳闸时间来编程自己的曲线。从第4–34页的图4–9：自定义曲线示例中可以看出，如果运行过载热极限曲线与锁定转子过载曲线平滑成一条曲线，则电机无法在80%线路电压下启动。热模型4设定点编程4图4–9：自定义曲线示例在不连续间隔期间，两个跳闸时间中的较长时间用于减少电机启动期间的误跳闸机会。跳闸时间（秒）0.5 1 10 100 1000注GE Power Management 469电机管理继电器4-35 4设定值编程4.6 S5热模型4 c）电压相关过载曲线如果要求电机驱动高惯性负载，加速时间超过安全失速时间是完全可能的，也是可以接受的（记住，锁定转子条件与加速条件完全不同）。在这种情况下，必须知道热极限曲线的每个不同部分，并且必须根据该曲线协调保护。保护电机的继电器必须能够区分转子锁定状态、加速状态和运行状态。469电压相关
(see Figure 4–8: 469 STANDARD OVERLOAD CURVES and Table 4–1: 469 STANDARD OVERLOAD CURVE MULTIPLIERS on the following pages). The standard overload curves equation is: b) CUSTOM OVERLOAD CURVE If the motor starting current begins to infringe on the thermal damage curves, it may become necessary to use a custom curve to tailor the motor protection so that successful starting may occur without compromising protection. Furthermore, the characteristics of the starting thermal damage curve (locked rotor and acceleration) and the running thermal damage curves may not fit together very smoothly. In this instance, a custom curve may be necessary to tailor motor protection to the motor thermal limits so it may be started successfully and be utilized to its full potential without compromising protection. The distinct parts of the thermal limit curves now become more critical. For these conditions, it is recommended that the 469 custom curve thermal model be used. The custom overload curve feature allows the user to program their own curve by entering trip times for 30 pre-determined current levels. It can be seen in Figure 4–9: CUSTOM CURVE EXAMPLE on page 4–34 that if the running overload thermal limit curve were smoothed into one curve with the locked rotor overload curve, the motor could not start at 80% line voltage. A THERMAL MODEL 4 SETPOINT PROGRAMMING 4 Figure 4–9: CUSTOM CURVE EXAMPLE During the interval of discontinuity, the longer of the two trip times is used to reduce the chance of nuisance tripping during motor starts. TIME TO TRIP IN SECONDS 0.5 1 10 100 1000 NOTE GE Power Management 469 Motor Management Relay 4-35 4 SETPOINT PROGRAMMING 4.6 S5 THERMAL MODEL 4 c) VOLTAGE DEPENDENT OVERLOAD CURVE If the motor is called upon to drive a high inertia load, it is quite possible and acceptable that the acceleration time exceeds the safe stall time (bearing in mind that a locked rotor condition is quite different than an acceleration condition). In this instance, each distinct portion of the thermal limit curve must be known and protection must be coordinated against that curve. The relay that is protecting the motor must be able to distinguish between a locked rotor condition, an accelerating condition and a running condition. The 469 Voltage Dependent
