Manual 37259C
SPM-D11 - Synchronizing Unit
© Woodward
Page 61/79
Protection
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Generator Reverse/Reduced Power Monitoring
Generator real power is monitored to ensure it does not fall below a preset limit. The watchdog assigned to this
relay is at terminals 37/38. The relay contact is a N.O. contact. When operating in normal operations the relay is
continuously energized. If the monitored values leave the configured range, the relay will de-energize, the con-
tact will open, and the message "Reverse/reduced power" will be displayed. If the fault conditions exist for less
than 1 second, the relay returns to normal operations. The fault message on the display may be cleared automati-
cally or by pressing the "Clear" button (see chapter Auto Acknowledge Messages at page 64).
Reverse/min.pow.
Monitoring ON
Reverse/reduced load monitoring
ON/OFF
ON
................ Monitoring of reverse or reduced generator real power is performed.
The following screens of this function are displayed.
OFF
.............. There is no reverse or reduced power monitoring and the following
screens of this function are not displayed
Reverse/min.pow.
Threshold = 00%
Reverse/reduced power monitoring threshold value
-99 to 99 %
The threshold value refers to the configured rated power of the generator.
Reduced power monitoring:
A reduced power condition is detected if the the
measured real power drops below the (positive) limit value.
Reverse power monitoring:
A reverse power condition is detected if the measured
real power drops below the (negative) limit value.
A reverse power condition can only be detected if the current is at least 2% of the
CT’s rating. This must be considered when configuring the reverse power protec-
tion.
Reverse/min.pow.
Delay 00.0s
Delay of reverse/reduced load monitoring
0.1 to 99.9 s
The generator real power must remain below the threshold value without interrup-
tion for at least the period of time specified in this screen for a fault condition to be
recogonized.
