GE 869 Instruction Manual page 524

FLEXLOGIC
4–392
Path:
Setpoints > FlexLogic > FlexElements > FlexElement 1
FUNCTION
Range: Disabled, Enabled
Default: Disabled
NAME
Range: Up to 13 alphanumeric characters
Default: FlexEl 1
INPUT 1 (+)
Range: Off, any FlexAnalog signal
Default: Off
This setting specifies the first input (non-inverted) to the FlexElement. Zero is assumed
as the input if this setting is set to "Off". For proper operation of the element at least one
input must be selected. Otherwise, the element will not assert its output operands.
INPUT 2 (-)
Range: Off, any FlexAnalog signal
Default: Off
This setting specifies the second input (inverted) to the FlexElement. Zero is assumed as
the input if this setting is set to "Off". For proper operation of the element at least one
input must be selected. Otherwise, the element will not assert its output operands.
This input should be used to invert the signal if needed for convenience, or to make the
element respond to a differential signal such as for a top-bottom oil temperature
differential alarm.
A warning message is displayed and the element does not operate if the two input
signals are of different types, for example if one tries to use active power and phase
angle to build the effective operating signal.
OPERATING MODE
Range: Signed, Absolute
Default: Signed
The element responds directly to the differential signal if this setting is set to "Signed".
The element responds to the absolute value of the differential signal if this setting is set
to "Absolute".
Sample applications for the "Absolute" setting include monitoring the angular difference
between two phasors with a symmetrical limit angle in both directions; monitoring
power regardless of its direction, or monitoring a trend regardless of whether the signal
increases or decreases.
INPUT COMPARISON MODE
Range: Level, Delta
Default: Level
The element responds directly to the differential signal – as defined by the Input 1 (+),
Input 2 (-) if the Operating Mode setting is set to Level.
The element responds to the rate of change of its operating signal if this setting is set to
"Delta". The setpoint's Rate of Change Time Unit (dt), and Rate of Change Time (dt)
specify how the rate of change is derived. Providing the conditions (Under or Over) for
the actual rate-of-change are satisfied, in Delta mode the FlexElement can operate in
either direction, no matter if the operating signal is increased or decreased. The
operating signal is the difference between the two selected inputs.
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS