GARD Metering Module
GARD 8000 SYS RFL Electronics
April 1, 2007 15-8 973.334.3100
Frequency Thresholds Definitions:
The following values have frequency threshold settings; each one has three different set points with
different delays for pickup and drop out.
Over Frequency (81M-1,2,3)
Under frequency (81m-1,2,3)
Frequency Rate of Change (81D-1,2,3)
For each point, there are four settings as shown in the following for 81M-1.
Enable Over Frequency (81M-1)
When this is enabled, the corresponding status indication and logic bit will be driven when the
measured value exceeds the pickup value for the required time delay.
81M-1 Pick Up
This setting determines the threshold point
81M-1 Time Delay
This sets a minimum delay, during which the measured value must exceed the threshold before the
indications are set.
81M-1 Drop Out
This sets the time that the value must be under the threshold before the indication is reset.
In addition, there is a setting that determines the minimum voltage below which frequency
measurements are not made. This is named 81 Inhibit Voltage; additionally it has pick up and drop
out delay settings included.
Once all the settings have been entered click save.
To Next Page