ABB REL670 Installation And Commissioning Manual page 119

Current protection
Procedure
1. Apply the fault condition, including start of BFP, with phase current
well above set value "IP"
2. Arrange switching the current off, with a margin before back-up trip
time, t2 . It may be made at issue of re-trip command.
3. Check that re-trip is achieved, if selected, but no back-up trip.
4. Disconnect AC and start input signals.
The normal mode BuTripMode = "1 out of 3" should have been verified in the tests above. In
applicable cases the modes "1 out of 4" and "2 out of 4" can be checked. Choose the mode be-
low, which corresponds to the actual case.
Checking the case BuTripMode = 1 out of 4
It is assumed that EF current setting IN> is below phase current setting IP>
Procedure
1. Set BuTripMode = 1 out of 4.
2. Apply the fault condition, including start of BFP, with one phase cur-
rent below set IP> but above IN> . The residual (EF) should then be
above set IN>.
3. Verify that back-up trip is achieved after set time. If selected, re-trip
should also appear.
4. Disconnect AC and start input signals.
Checking the case BuTripMode = 2 out of 4
The EF current setting IN> may be equal to or below phase current setting IP>.
Procedure
1. Set BuTripMode = 2 out of 4
2. Apply the fault condition, including start of BFP, with one phase cur-
rent above set IP> and residual (EF) above set IN It can be obtained
by applying a single phase current.
3. Verify that back-up trip is achieved after set time. If selected, re-trip
should also appear.
4. Apply the fault condition, including start of BFP, with at least one
phase current below set IP> and residual (EF) above set IN> . The cur-
rent may be arranged by feeding three (or two) phase currents with
equal phase angle (I0-component) below IP> , but of such value that
the residual (EF) current (3I0) will be above set value IN> .
5. Verify that back-up trip is not achieved.
6. Disconnect AC and start input signals.
Chapter 11
Verifying settings by secondary
injection
111