PACSystems RX3i - Page 44

User Manual Chapter 3
GFK-2749A Jan 2020
Configuration and Data Transfer 40
Parameter
Function
ANSI 60 VI Imbalance Threshold
(%)
The amount any one phase voltage or phase current reading
must vary, as a percentage of the average of all three phases
within the same grid, to trigger the VI Imbalance alarm (after
the VI Balance Delay).
The VI Imbalance alarm compares voltage phases to voltage
phases, and current phases to current phases within a grid. No
comparison is made between grids. If any voltage varies from
the average of all three voltages, or if any current varies from
the average of all three currents (by more than the VI
Imbalance Threshold) for longer than the
VI Imbalance Delay, that grid’s VI Imbalance Alarm is set.
Range: 1 to 100
Default: 10
ANSI 60 VI Imbalance Delay
2
(sec)
The amount of time anyone phase voltage or phase current
reading can exceed the VI Balance Threshold before the VI
Balance Alarm status is set.
Range: 0.1 to 3276.7
Default: 10.0
ANSI 81U Under Frequency
Threshold (Hz)
The frequency difference from the Nominal Frequency below
which the Under-Frequency Alarm status is set (after the
Under-Frequency Delay).
0Range: 0.01 to 10.0
Default: 0.5
ANSI 81U Under Frequency Delay
(sec)
2
The amount of time a grid's frequency must remain below the
Under-Frequency Threshold before the Under-Frequency
Alarm status is set.
Range: 0.1 to 3276.7
Default: 10.
ANSI 81O Over Frequency
Threshold (Hz)
The frequency difference from the Nominal Frequency above
which the Over Frequency Alarm status is set (after the Over
Frequency Delay).
Range: 0.01 to 10.0
Default: 0.5
ANSI 81O Over Frequency
Delay (sec)
2
The amount of time a grid's frequency must remain Above the
Over Frequency Threshold before the Over Frequency Alarm
status is set.
Range: 0.1 to 3276.7
Default: 10
2
For all alarm conditions, the clear time is the same as the set time. The alarm condition must be absent continuously for the Delay Time
for the alarm to be cleared.