Speed2 Undecurrent - GE MI-869 Instruction Manual

PROTECTION

Speed2 Undecurrent

4–170
Path:
Setpoints > Protection > Group1(6) > 2-Speed Motor > Speed2 Undercurrent
If the Speed2 Undercurrent function is enabled, a trip or alarm is initiated once the IA, IB or
IC current magnitude falls below the pickup level for a period of time specified by the delay.
For example, the undercurrent can be used to detect loss-of load conditions. This can be
especially useful for detecting process related problems. This element is active if the motor
is running at Speed 2. The undercurrent function at speed 2 becomes functional only if
undercurrent at speed 1 is enabled. When the undercurrent function at any speed is not
required, it can be permanently blocked.
START BLOCK DELAY
Range: 0.00 to 600.00 in steps of 0.01
Default: 0.50 s
This setting specifies a time to block the undercurrent function when the motor is
starting directly at speed 2. Prior to starting, the motor state is determined from the
Motor Stopped operand. Refer to the Motor Status section for additional information on
the motor stopped state determination. The speed 2 undercurrent element is active only
when the motor is running at speed 2 and is blocked upon the initiation of a motor start
for a period of time defined by the Start Block DLY setting (for example, this block can be
used to allow pumps to build up head before the undercurrent element trips or alarms).
A value of zero (0) specifies that the feature is not blocked from start. For values other
than zero (0), the feature is disabled when the motor is stopped and also from the time a
start is detected until the time entered expires. A one second delay is added to prevent
wrong operation of the element when motor is switched from speed 1 to speed 2.
TRIP PICKUP
Range: 0.10 to 0.95 x FLA in steps of 0.01 x FLA
Default: 0.70 x FLA
TRIP PICKUP DELAY
Range: 0.00 to 180.00 s in steps of 0.01 s
Default: 1.00 s
TRIP DROPOUT DELAY
Range: 0.00 to 180.00 s in steps of 0.01 s
Default: 1.00 s
ALARM PICKUP
Range: 0.10 to 0.95 x FLA in steps of 0.01 x FLA
Default: 0.70 x FLA
ALARM PICKUP DELAY
Range: 0.00 to 180.00 s in steps of 0.01 s
Default: 1.00 s
ALARM DROPOUT DELAY
Range: 0.00 to 180.00 s in steps of 0.01 s
Default: 1.00 s
BLOCK
Range: Off, Any operand from the list of FlexLogic operands
Default: Off
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS