Measuring The Operate Limit; Completing The Test; Limit Counter L4Ufcnt - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.13.5.1
11.13.5.2
11.13.6
268

Measuring the operate limit

1. Set the test point (|Z| fault impedance and ZF impedance phase angle ) for a
condition that meets the requirements in table 39.
2. Subject the IED to healthy normal load conditions for at least two seconds.
3. Apply a fault condition.
Check that the distance-to-fault value displayed on the HMI complies with
equations 117, 118
Z
x
×
------ - 100
p =
X1
EQUATION123 V1 EN-US
in % for two- and three-phase faults
×
3 Z
= ×
p x 100
+ ×
X0 2 X1
EQUATION124 V1 EN-US
in % for single-phase-to-earth faults
×
3 Z
x
-------------------------------------------- - 100
p =
× ±
X0 2 X1 XM +
EQUATION125 V1 EN-US
in % for single-phase-to-earth faults with mutual zero sequence current.
Where:
p = the expected value of a distance to fault in percent
Z = set test point on the test set
x
X0 = set zero-sequence reactance of a line
X1 = set positive-sequence reactance of a line
XM = set mutual zero-sequence impedance of a line

Completing the test

Continue to test another function or end the test by changing the TESTMODE
setting to Off. Restore connections and settings to their original values, if they were
changed for testing purposes.

Limit counter L4UFCNT

The Limit counter function L4UFCNT can be tested by connecting a binary input
to the counter and applying pulses to the counter. The speed of the pulses must not
exceed the cycle time of the function. Normally the counter will be tested when
testing the function that the counter is connected to, such as the trip function. When
the function is configured, test it together with the function that operates it. Trigger
and 119
×
1MRK 504 165-UEN A
(Equation 117)
(Equation 118)
(Equation 119)
GUID-7EBDC372-3407-4577-8B9A-6AB1758A1F34 v2
Transformer protection RET670 2.2 IEC
Commissioning manual
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