10 © 2010 SymCom, Inc. All Rights Reserved
PROGRAMMING EXAMPLES
For all examples, use the “Recommended Settings” from Table 1 unless otherwise noted.
NOTE:
Since no network communications are connected in these examples, there are no settings changes
needed for ADDR or COM.
LV cannot be set higher than HV, and UC cannot be set higher than OC., If the 777-P2-DEMO will
not allow setting a parameter, please verify that the values do not overlap.
Example #1
To simulate an Overcurrent Failure on the 777-P2-DEMO, the OC setpoint limit must be changed to
a value lower than the average current. Use the following setpoints to simulate an overcurrent fault
on the 777-P2-DEMO.
OC
-
Set OC to 20.
UC
-
Set UC to 0.
TC
-
Set TC to 5.
The time the 777-P2-DEMO will take to trip on the overcurrent fault can be calculated by using the
overload trip curve in Figure 3. The trip time is calculated by finding the percentage that the actual
current is over the overcurrent setpoint. The highest current leg for the 777-P2-DEMO is 44A.
% of OC Setting = Actual Current / OC setting
Example #2
To simulate an Undercurrent Failure on the 777-P2-DEMO, the UC setpoint limit must be changed
to a value higher than the average current. The time the 777-P2-DEMO will take to trip on the
undercurrent fault is equal to the UCTD (undercurrent trip delay) in seconds. Use the following
setpoints to simulate an undercurrent fault on the 777-P2-DEMO.
OC
-
Set OC to 60.
UC
-
Set UC to 50.
UCTD
- Set UCTD to 5.
Example #3
To simulate a Ground Fault Failure on the 777-P2-DEMO, the GF setpoint limit must be changed to
a value lower than the simulated ground fault current. Use the following setpoints to simulate a
ground fault on the 777-P2-DEMO.
GF
-
Set GF to 3.
The time the 777-P2-DEMO will take to trip on the ground fault failure can be calculated by using the
trip delay table below. The simulated ground fault current is 3.71A. According to the table, the trip
time for this example would be around 8 seconds.
% of GF setting = Actual GF / GF setpoint
Ground Fault Reading
(as Percentage of Setpoint)
Trip Time
101% - 200%
8 seconds ± 1 second
201% - 300%
4 seconds ± 1 second
Table 4: Ground Fault Trip Time
