13.3 DELTA PROTECTION SCHEME TESTING
13.3.1 SIGNAL SEND TEST FOR PERMISSIVE SCHEMES
1. Reconnect the test set so that the timer is no longer stopped by the Trip contact, but is now stopped by the
Signal Send contact. This is the contact that would normally be connected to the pilot/signalling channel.
2. Repeat the forward fault injection, and record the Signal Send contact operating time. The measured
operating time should typically be less than 20 ms for 50 Hz, and less than 16.7 ms for 60 Hz applications.
3. Switch OFF the AC supply and reset the alarms.
13.3.2 SIGNAL SEND TEST FOR BLOCKING SCHEMES
Configure the test set to inject a dynamic sequence of injection, as follows:
1. Simulate a healthy three-phase set of balanced voltages, each of magnitude Vn. No load current should be
simulated. The duration of injection should be set to 1 second. Step 1 therefore mimics a healthy unloaded
line, prior to the onset of a fault.
2. Simulate a reverse fault on the A-phase. The A-phase voltage must be simulated to drop by 3 times the Dir.
V Rev setting; Va = Vn – 3(Dir. V Rev)
3. The fault current on the A-phase should be set to 3 times the DI Rev setting, and in antiphase to the forward
injections; Ia = 3 (Dir. I Rev) Ð180°-θ Line
4. Prepare the dynamic A phase reverse fault, as detailed above. Ensure that the test set is simulating Steps 1
and 2 as one continuous transition.
5. Set a timer to start when the fault injection is applied, and to stop when the Delta scheme Signal Send
contact closes.
6. Apply the test, and record the signal send contact response time. The recorded operating time should
typically be less than 20 ms for 50 Hz, and less than 16.7 ms for 60 Hz applications.
7. Switch OFF the AC supply and reset the alarms.
Caution:
When the tests are completed, restore all settings that were disabled for testing
purposes.
Caution:
Remove any wires or leads temporarily fitted to energise the channel receive opto-
input.
Chapter 25 - Commissioning Instructions P543i/P545i
676 P54x1i-TM-EN-1
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