TRIPLEX T9431 DCS模块卡件
1+TC使用余量)并存储为A3学习数据\电机启动\学习启动容量。该热容量裕度确保电机启动成功。如果数字大于100%,则100%存储为学习起动容量。成功的电机启动是指相电流从0上升到大于过载拾取,然后在加速后下降到过载曲线拾取水平以下。如果启动抑制功能启用,则每次电机停止时,可用的热容量(100%–使用的热容量)与学习的启动容量进行比较。如果可用的热容量不超过学习的启动容量,或不等于100%,则启动抑制块将激活,直到有足够的热容量。当发生阻塞时,锁定时间将等于电机冷却到可接受的启动温度所需的时间。该时间是S5热模型\热模型\冷却时间常数停止设定值的函数。如果此功能被“关闭”,则在过载锁定复位之前,所用热容量必须降低至15%。如果负载因不同的起动而变化,则应关闭此功能。b) 示例:如果最后5次启动的热容量分别为24%、23%、27%、25%和21%,则学习启动容量为27%×1.25=33.75%。如果电机在使用90%热容量的情况下停止,将发出启动块。当电机冷却且所用热容量降至66%时,允许启动。如果冷却时间恒定停止设定点编程30分钟,锁定时间将等于:❙ 启动禁止❙ [输入]更多起动抑制块:关闭范围:打开,关闭TC已用余量:25%范围:0至25%,step:1 ENTER ESCAPE♥信息ESCAPE TCused TCused GE Power Management 469 Motor Management Relay 4-55 4 SETPOINT PROGRAMMING 4.8 S7 Motor STARTING 4 4.8.3 JOGGING BLOCK(点动块)功能点动块功能可用于防止操作员点动电机(快速连续进行多次启动和停止)。它由两个不同的元素组成:开始/小时和开始之间的时间。启动/小时功能不能保证在一小时内允许一定数量的启动或启动尝试;相反,它确保在一小时内不会超过一定数量的启动尝试。同样,如果在最近一次启动之后,“允许启动之间的时间”已过,则“启动之间的间隔”功能不保证允许再次启动。相反,它确保了两次启动之间的最小时间。然而,如果第一次尝试冷启动由于堵塞而失败,或者因为过程过载而需要很长时间,则热模型可能会减少一小时内可以尝试的启动次数。
1 + TC USED MARGIN) and stored as A3 LEARNED DATA\MOTOR STARTING\LEARNED STARTING CAPACITY. This thermal capacity margin ensures that a motor start will be successful. If the number is greater than 100%, 100% is stored as LEARNED STARTING CAPACITY. A successful motor start is one in which phase current rises from 0 to greater than overload pickup and then, after acceleration, falls below the overload curve pickup level. If the Start Inhibit feature is enabled, each time the motor is stopped, the amount of thermal capacity available (100% – THERMAL CAPACITY USED) is compared to the LEARNED STARTING CAPACITY. If the thermal capacity available does not exceed the LEARNED STARTING CAPACITY, or is not equal to 100%, the Start Inhibit Block will become active until there is sufficient thermal capacity. When a block occurs, the lockout time will be equal to the time required for the motor to cool to an acceptable temperature for a start. This time will be a function of the S5 THERMAL MODEL\THERMAL MODEL\COOL TIME CONSTANT STOPPED setpoint. If this feature is turned "Off", the THERMAL CAPACITY USED must reduce to 15% before an overload lockout resets. This feature should be turned off if the load varies for different starts. b) EXAMPLE If the THERMAL CAPACITY USED for the last 5 starts is 24, 23, 27, 25, and 21% respectively, the LEARNED STARTING CAPACITY is 27% × 1.25 = 33.75% used. If the motor stops with 90% thermal capacity used, a start block will be issued. When the motor has cooled and the level of thermal capacity used has fallen to 66%, a start will be permitted. If the COOL TIME CONSTANT STOPPED setpoint is programmed for 30 minutes, the lockout time will be equal to: ❙ START INHIBIT ❙ [ENTER] for more START INHIBIT BLOCK: Off Range: On, Off TC USED MARGIN: 25% Range: 0 to 25%, step: 1 ENTER ESCAPE ð ð MESSAGE ESCAPE TCused TCused GE Power Management 469 Motor Management Relay 4-55 4 SETPOINT PROGRAMMING 4.8 S7 MOTOR STARTING 4 4.8.3 JOGGING BLOCK a) FUNCTION The Jogging Block feature may be used to prevent operators from jogging the motor (multiple starts and stops performed in rapid succession). It consists of two distinct elements: Starts/Hour and Time Between Starts. The Starts/Hour feature does not guarantee that a certain number of starts or start attempts will be allowed within an hour; rather, it ensures that a certain number of start attempts will not be exceeded within an hour. Similarly, the Time Between Starts feature does not guarantee another start will be permitted if the TIME BETWEEN STARTS PERMISSIBLE elapses after the most recent start. Rather, it ensures a minimum time between starts. If however, the first start attempt from cold is unsuccessful due to a jam or it takes long because the process is overloaded, the Thermal Model might reduce the number of starts that can be attempted within an hour.