ABB Relion 670 Series Commissioning Manual page 156

Section 11
Primary injection testing
4. Check that the current is present only in the phase being tested.
5. If the injected current is high enough, check that trip contacts operate accordingly to the scheme
wiring.
6. Check that trip information is stored in the disturbance recorder and event list (if connected).
7. Switch off the current.
8. Check the function in the same way by injecting current in phases B and C.
It is recommended that each primary CB is tripped directly from the protection scheme at least once
during these tests. This will confirm the trip-circuit connection between the protection scheme and the
CB.
11.2 Stability of the busbar differential protection
For stability testing, one current circuit shall always be used as a reference input. The reference current
circuit shall then be tested for stability against all other current circuits connected to a busbar protection
scheme on a one-by-one basis. Use the current circuit connected to the CT1 current input as the
reference current circuit. A typical connection for the primary current test set for this type of tests is
shown in figure 24.
Primary
Injection
Test Set
ANSI05000307 V1 EN-US
Figure 24:
For this type of primary injection tests a suitable current source should be applied across the primary
windings of two CTs connected in series as shown in figure 24. The testing is normally done on one
phase at the time. The currents in the secondary winding of these CTs are then opposite in phase. The
differential current displayed by the IED should be negligible while the incoming current displayed should
be equal to the value of the injected primary current. The IED must not issue the trip command during
these tests. If it trips or the differential current has a high value it usually means that there is a wiring
problem in the CT circuits connected to the current input CTx (that is, a differential current equal to twice
the injection current probably indicates wrong polarity of the main CT connected to the CTx current
input). This problem must be solved before the protection scheme is put in service.
Procedure
150
52 52
52 52 52
Typical test connection for primary injection, which should confirm the stability of the
main CT connected to current inputs of the IED
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REB 670
CT1 Input
CT2
Input
CT3 Input
CT4 Input
CT5 Input
en05000307_ansi.vsd
1MRK 505 372-UUS Rev. K
M12210-2 v5
Busbar protection REB670
Commissioning manual