GE Multilin M60 Motor Protection System 5-1475 SETTINGS 5.6 GROUPED ELEMENTS5c) UNDERPOWERPATH: SETTINGS GROUPED ELEMENTS SETTING GROUP 1(6) POWER UNDERPOWER UNDERPOWER 1Two underpower elements are provided.The underpower function uses the source selected by the SYSTEM SETUP MOTOR MOTOR LINE SOURCE setting.Phase currents and voltages must configured on that source, otherwise the underpower function will not be functional. Theunderpower element responds to total three-phase apparent power measured from the phase current and voltages.When the underpower element is enabled, a trip or alarm are initiated once the magnitude of three-phase apparent powerfalls below the pickup level for a period of time specified by the delay. For example, underpower may be used to detectloss-of-load conditions. Loss of load conditions 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 or pump cavitations. This may be espe-cially useful for detecting process related problems.• UNDERPOWER 1 START BLOCK DELAY: This setting specifies the length of time to block the underpower functionwhen motor is starting. If not in the starting state, the motor status is indicated by the MOTOR OFFLINE operand. Referto the Motor setup section for additional information on using the MOTOR OFFLINE operand for state determination.The underpower element is active only when the motor is running and is blocked upon the initiation of a motor start fora period of time specified by this setting. For example, this block may be used to allow pumps to build up head beforethe underpower element trips or alarms. A value of 0 specifies that the feature is not blocked from start. For valuesother than 0, the feature is disabled when the motor is stopped and also from the time a start is detected until the timeentered expires.• UNDERPOWER 1 ALARM PWR PICKUP: This setting specifies a pickup threshold for the alarm stage. The base per-unit power quantity is 3 × VT pu base × CT pu base per source selected as a motor line source. The alarm pickupthreshold should be less than the motor load current during normal operations.• UNDERPOWER 1 ALARM PICKUP DLY: This setting specifies a time delay for the alarm stage. The time delayshould long enough to overcome any short lowering of the current (for example, during system faults).• UNDERPOWER 1 TRIP PWR PICKUP: This setting specifies a pickup threshold for the trip stage. The base per-unitpower quantity is 3 × VT pu base × CT pu base per source selected as a motor line source. This setting should be lessthan the corresponding setting for the alarm stage. UNDERPOWERUNDERPOWER 1FUNCTION: DisabledRange: Enabled, DisabledMESSAGE UNDERPOWER 1 STARTBLOCK DLY: 0.50 sRange: 0.00 to 600.00 s in steps of 0.01MESSAGE UNDERPOWER 1 ALARMPWR PICKUP: 0.50 puRange: 0.05 to 2.00 pu in steps of 0.01MESSAGE UNDERPOWER 1 ALARMPICKUP DLY: 2.00 sRange: 0.00 to 600.00 s in steps of 0.01MESSAGE UNDERPOWER 1 TRIPPWR PICKUP: 0.50 puRange: 0.05 to 2.00 pu in steps of 0.01MESSAGE UNDERPOWER 1 TRIPPICKUP DLY: 1.00 sRange: 0.00 to 600.00 s in steps of 0.01MESSAGE UNDERPOWER 1 TRIPRESET DLY: 1.00 sRange: 0.00 to 600.00 s in steps of 0.01MESSAGE UNDERPOWER 1 BLOCK:OffRange: FlexLogic™ operandMESSAGE UNDERPOWER 1 TARGET:Self-resetRange: Self-reset, Latched, DisabledMESSAGE UNDERPOWER 1 EVENTS:DisabledRange: Enabled, Disabled
