Stub Protection (Ptoc, 50Stb) - ABB REL670 Installation And Commissioning Manual

6.7.9
6.8
Current protection
3. Apply the fault condition, including start of BFP, with current above
the set IP> value.
4. Check that the re-trip, if selected, and back-up trip commands are
achieved.
5. Disconnect injected AC and start input signals.
Checking the case with fault current below set value I>BlkCont
The case shall simulate a case where the fault current is very low and operation will depend on
CB position signal from CB auxiliary contact. It is suggested that re-trip without current check
is used; setting Retrip = No I> check.
Procedure
1. Set FunctionMode = Curr&Cont Check
2. Apply input signal for CB closed to relevant input or inputs CBCLDL*
3. Apply the fault condition with input signal(s) for start of BFP. The val-
ue of current should be below the set value I>BlkCont
4. Verify that re-trip (if selected) and back-up trip are achieved after set
times. Failure to trip is simulated by keeping the signal(s) CB closed
activated.
5. Disconnect the AC and the start signal(s). Keep the CB closed sig-
nal(s).
6. Apply the fault and the start again. The value of current should be be-
low the set value I>BlkCont.
7. Arrange disconnection of BC closed signal(s) well before set
back-up trip time t2 . It simulates a correct CB tripping.
8. Verify that back-up trip is not achieved. Re-trip can appear, e.g. due
to selection "Re-trip without current check".
9. Disconnect injected AC and start input signals.
Completing the test
Continue to test another function or end the test by changing the settings for the function and
IED to their original state.

Stub protection (PTOC, 50STB)

Prepare the IED for verification of settings as outlined in
"Preparing for test" in this chapter.
Chapter 11
Verifying settings by secondary
section 1 "Overview" and
injection
section 2
113