Installation and Operating Instructions - Crompton Instruments

Parameter details
Range of Phase Difference (PhAngle)
Range of Voltage Difference (VDelta)
Minumum Voltage Level (Vmin)
Range of Bus Voltage Trip point
Range of Time Delay (TimeDelay)
Range of slip frequency (SlipFreq)
Voltage Accuracy
2 — 20 degrees
0 — 20% of nominal input voltage
5-119% of nominal input voltage
5 — 50% of nominal input
0 to 5 seconds
0.1 — 1 Hz
± 2% of nominal input voltage
There is a relationship between the phase angle and the slip frequency settings. When one
parameter is adjusted, the setting range of the other may be automatically adjusted to prevent a
condition where the relay may never close.
CAUTION: This trip relay can be configured to Latch. This feature may be
undesirable, if enabled in error.
TYPE 27 — UNDER VOLTAGE
Brief details
The relay will operate (trip) when the signal level on any of the “generator” voltage inputs is
less than the selected value for the duration of the time delay. The relay will return to the “not
tripped” condition (provided that latched operation has not been selected) when all “generator”
voltage inputs rise above the selected trip point by at least the hysteresis value. The time delay
is not used on the transition to the “not tripped” condition.
Parameters
You must specify the following parameters for operation of the under voltage relay:
●
The minimum permitted voltage on any of the voltage inputs from the “generator”.
●
The time for which the under voltage conditions must be true.
●
The voltage above the previously defined minimum that all inputs from the “generator”
must exceed to return operation to the not tripped condition following a
trip. (Hysteresis)
Range of Voltage Trip point (Trip Point)
Range of Diff (Diff)
Range of Time Delay (TimeDelay)
5-119% of nominal input
1 — 15% of nominal input
0 to 30 seconds
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