ABB RELION RET670, Commissioning Manual, Page: 267 / 328

11.11.1.5 Checking of unblocking logic
Check the unblocking function (if the function is required) when checking the
communication scheme.
Command function with continuous unblocking (
Unblock = 1)
Procedure
1. Activate the guard input signal (CR_GUARD) of the IED.
2. Using the scheme selected, check that a signal accelerated trip (TRIP) is obtained
when the guard signal is deactivated.
11.11.1.6 Completing the test
Continue to test another function or end the test by changing the TESTMODE setting to
Disabled . Restore connections and settings to their original values, if they were changed
for testing purposes.
11.11.2 Phase segregated scheme communication logic for distance or
overcurrent protection ZC1PPSCH (85)
Prepare the IED for verification of settings outlined in Section "Preparing the IED to
verify settings" .
Check the scheme logic during the secondary injection test of the impedance protection
functions.
Activating of the different zones and phases verifies that the CS_x signal are issued from
the intended zones. The CS_x signal from the independent tripping zone must have a
tSendMin minimum time.
Check the tripping function by activating the CRLx inputs with the overreaching zone
used to achieve the CACCLx signals.
It is sufficient to activate the zones with all types of fault with the secondary injection.
11.11.2.1 Testing permissive underreaching
1. Activate the receive (CRLx) signal in the IED.
2. Apply healthy normal load conditions to the IED for at least two seconds.
3. Apply a fault condition within the permissive zone.
4. Check that correct trip outputs, external signals, and indications are obtained for all
the actual types of fault generated.
1MRK 504 165-UUS -
Section 11
Testing functionality by secondary injection
Transformer protection RET670 2.2 ANSI 261
Commissioning manual