ABB RET670 Commissioning Manual page 189

1MRK 504 165-UEN A
Transformer protection RET670 2.2 IEC
Commissioning manual
Testing functionality by secondary injection
IEC06000652 V3 EN-US
Figure 47: Example characteristic
Non-directional earth fault current protection
Procedure
1. Measure that the operate current is equal to the INNonDir> setting.
The function activates the START and STDIRIN output.
2. Measure the operate time of the timer by injecting a current of 200% of the
operate value.
3. Compare the result with the expected value.
The expected value depends on whether definite time tINNonDir or inverse
time was selected.
4. Continue to test another function or complete the test by setting the test mode
to Off.
Residual overvoltage release and protection
Procedure
1. Measure that the operate voltage is equal to the UN> setting.
The function activates the START and STUN signals.
2. Measure the operate time by injecting a voltage 1.2 times set UN> operate
value.
3. Compare the result with the set tUN operate value.
4. Inject a voltage 0.8 · UNRel> and a current high enough to operate the
directional function at the chosen angle.
5. Increase the voltage until the directional function is released.
6. Compare the measured value with the set UNRel> operate value.
RCADir = 0º
ROADir = 80º
Operate area
3I
0
-3U
IEC06000652-3-en.vsd
Section 11
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SEMOD175060-117 v10
SEMOD175060-131 v6
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