ABB RET670 Commissioning Manual page 127

1MRK 504 165-UEN A
Transformer protection RET670 2.2 IEC
Commissioning manual
Testing functionality by secondary injection
Consider releasing Zone 1 with the Phase selection with load encroachment,
quadrilateral characteristic (FRPSDPIS). If the autorecloser is not released and in
service, trip will always be three phase.
Measure operating characteristics during constant current conditions. Keep the
measured 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.
The test procedure has to take into consideration that the shaped load encroachment
characteristic is active. It is therefore necessary to check the setting. To verify the
settings with the shaped load encroachment characteristic the test should be carried
out according to figures
encroachment characteristic is activated tests according to the adjusted figures
should be carried out.
To verify the settings for the operating points according to the following fault types
should be tested:
• One phase-to-phase fault
• One phase-to-earth fault
The shape of the operating characteristic depends on the values of the setting
parameters.
The figures illustrating the characteristic for the distance protection
function can be used for settings with and without load
encroachment. The solid lines designate the diagram applicable
when the load current compensation is active. The solid line and all
test points except 13 are valid for this case.
When the load current compensation is inactive, the dotted lines
and test point 13 are valid. Test points 5, 6, and 7 are not valid for
this measurement.
29 and 30 and tables 26
Section 11
and 27. In cases where the load
121