CHAPTER 5: SETTINGS469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL 5–835.11.4 UnderpowerPATH: SETTINGS ZV S10 POWER ELEMENTS ZV UNDERPOWERIf enabled, once the magnitude of 3Φ total power falls below the Pickup Level for a periodof time specified by the Delay, a trip or alarm will occur. The Underpower element is activeonly when the motor is running and will be blocked upon the initiation of a motor start for aperiod of time defined by the BLOCK ELEMENT FROM START settings (e.g. this block may beused to allow pumps to build up head before the underpower element trips or alarms). Avalue of 0 means the feature is not blocked from start. If a value other than 0 is entered,the feature will be disabled when the motor is stopped and also from the time a start isdetected until the time entered expires. The pickup level should be set lower than motorloading during normal operations.For example, underpower may be used to detect loss of load conditions. Loss of loadconditions will not always cause a significant loss of current. Power is a more accuraterepresentation of loading and may be used for more sensitive detection of load loss orpump cavitation. This may be especially useful for detecting process related problems.UNDERPOWER [BLOCK UNDERPOWERFROM START: 0 sRange: 0 to 15000 s in steps of 1MESSAGE UNDERPOWERALARM: OffRange: Off, Latched, UnlatchedMESSAGE ASSIGN ALARMRELAYS:Range: Alarm, Alarm & Auxiliary2,Alarm & Aux2 & Aux3, Alarm &Auxiliary3, Auxiliary2, Aux2 &Aux3, Auxiliary3MESSAGE UNDERPOWER ALARMLEVEL: 2 kWRange: 1 to 25000 kW in steps of 1MESSAGE UNDERPOWER ALARMDELAY: 1 sRange: 1 to 30 s in steps of 1MESSAGE UNDERPOWER ALARMEVENTS: OffRange: On, OffMESSAGE UNDERPOWERTRIP: OffRange: Off, Latched, UnlatchedMESSAGE ASSIGN TRIPRELAYS:Range: Trip, Trip & Auxiliary2, Trip &Aux2 & Aux3, Trip & Auxiliary3MESSAGE UNDERPOWER TRIPLEVEL: 1 kWRange: 1 to 25000 kW in steps of 1MESSAGE UNDERPOWER TRIPDELAY: 1 sRange: 1 to 30 s in steps of 1
