Basler BE1-CDS220, Instruction Manual

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6-14 Reporting and Alarm Functions BE1-CDS220
Setting Differential Current Monitoring Alarms
The differential function continuously monitors the input current in CT Circuits 1 and 2. If a mismatch due
to current loading is approaching the trip level, the differential alarm may be activated. This alarm is alarm
point number three in the relay programmable alarms. The alarm point must be mapped to activate an
alarm and/or light an LED. For more information on mapping the alarm functions, see Alarms Function,
Major, Minor, and Logic Programmable Alarms later in this section. The differential alarm is set as a
percentage of the percentage restrained differential characteristic. See Figure 6-5 for a graph showing the
percentage restrained differential and differential alarm characteristics. To set the differential alarm
threshold level, use BESTCOMS (Figure 6-6). Pull down the Screens menu and select Differential
Protection. Select the Diff Alarm tab. Alternately, settings can be made using ASCII command SA-DIFF
(setting alarm, differential). This setting is not available via the front panel HMI. Table 6-7 summarizes the
differential alarm threshold setting.
Table 6-7. Differential Alarm Threshold Setting
Function Range Increment Unit of Measure Default
Differential Alarm Level
0 - Disable
50 - 100
1 Percent (%) 67
SA-DIFF Command
Purpose:
Read/Set differential alarm setting
Syntax: SA-DIFF[={alarm level}] where alarm level=Percentage (between 50 and 100)
SA-DIFF Command Example:
Example 1. Set the differential alarm threshold to 75.
>SA-DIFF=75
Retrieving Differential Current Monitoring Information
To retrieve the differential check record, use the ASCII command RA-DIFF.
RA-DIFF Command
Purpose:
Read/Trigger Differential Report Data
Syntax: RA-DIFF[=TRIG] where TRIG triggers a Differential Report
RA-DIFF Command Examples:
Example 1. Retrieve the differential check record.
>RA-DIFF
Example 2. Trigger a differential check record.
>RA-DIFF=TRIG