ABB RET670 Commissioning Manual page 237

1MRK 504 165-UEN A
Transformer protection RET670 2.2 IEC
Commissioning manual
Testing functionality by secondary injection
No operation
IEC05000551 V1 EN-US
Figure 53: Test of phase difference
3. Change the phase angle between +dφ and -dφ and verify that the two outputs
are activated for phase differences between these values but not for phase
differences outside, see figure 53.
Testing the frequency difference
The frequency difference test should verify that operation is achieved when the
FreqDiffA and FreqDiffM frequency difference is lower than the set value for
manual and auto synchronizing check, FreqDiffA and FreqDiffM respectively and
that operation is blocked when the frequency difference is greater.
Test with frequency difference = 0 mHz
Test with a frequency difference outside the set limits for manual and auto
synchronizing check respectively.
1. Apply voltages U-Line equal to 100% GblBaseSelLine and U-Bus equal to
100% GblBaseSelBus, with a frequency difference equal to 0 mHz and a
phase difference lower than the set value.
2. Check that the AUTOSYOK and MANSYOK outputs are activated.
3. Apply voltage to the U-Line equal to 100% GblBaseSelLine with a frequency
equal to 50 Hz and voltage U-Bus equal to 100% GblBaseSelBus, with a
frequency outside the set limit.
4. Check that the two outputs are not activated. The test can be repeated with
different frequency values to verify that the function operates for values lower
than the set ones. If a modern test set is used, the frequency can be changed
continuously.
Testing the reference voltage
1. Use the same basic test connection as in figure 51.
U-Bus
+dj
U-Line operation
-dj
U-Bus
en05000551.vsd
Section 11
M2377-232 v9
M2377-249 v5
231