When the load encroachment characteristic is deliberately set
very high in order not to have an influence, then the test points
2 and 5 can be replaced by test point 7.
13.5.2.2 Completing the test
Continue to test another function or end the test by changing the Test mode setting
to Off. Restore connections and settings to their original values, if they were
changed for testing purposes.
13.5.3
Full scheme distance protection, mho characteristic
ZMHPDIS
Prepare the IED for verification of settings as outlined in section
"Overview" and
section "Preparing for test" in this chapter. Consider releasing of the zone to be
tested by setting the phase selector
FDPSPDIS to On.
The programming of the autorecloser function SMBRREC will determine if three-
phase or single-phase trip will be initiated as result of the test.
Keep the current constant when measuring operating characteristics. Keep the
current as close as possible to its rated value or lower. But make sure it is higher
than 30% of the rated current.
Ensure that the maximum continuous current in an IED does not exceed four times
its rated value, if the measurement of the operating characteristics runs under
constant voltage conditions.
To verify the mho characteristic, at least two points should be tested.
In the following, three test points are proposed. The mho characteristic always goes
through the origin, which automatically gives a fourth point for the characteristic.
13.5.3.1 Phase-to-phase faults
1MRK 504 088-UEN C Section 13
Verifying settings by secondary injection
125
Installation and commissioning manual
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