Siemens Reyrolle 7SR5, Руководство пользователя

Страница: 448 / 504

The relay characteristic can however be tested manually by recording a sequence of operating points for
increasing levels of restrain current. This can be achieved phase by phase using a single current source such as
a V
ariac
with 2 independently variable current limiting resistors as shown in Figure 9-12 or from 2 independent
single or 3 phase current sources. When 2 separate sources are used the phase of the 2 sinusoidal supplies
must be the same and the restrain and operate currents must be calculated from the sum and difference of
the 2 currents.
During manual testing the operate and restrain currents can be monitored on the relay in the
Differential
Meters
in the
Instruments
menu.
For manual testing, the bias slope is usually checked for restrain current up to 250 % of nominal current. For
testing above this level the continuous current rating of the relay inputs is likely to be exceeded, equipment or
test procedure should be arranged in such a way that the short term thermal withstand of the relay current
inputs is not exceeded during testing.
[lo_7SR5_87TFunctionalTests, 1, en_US]
Figure 9-12 Secondary Injection using a V
ariac
Table 9-9 Results for testing 87BD with a V
ariac
87BD Initial
Setting 87BD 1st Bias
Slope Setting Bias Current (⋅ I
rated
)
Measured On Ammeter A1
0 1 1.5 2 2.5
Operate Current Measured on Ammeter A2
0.1 0.1 0.1 0.11 0.16 0.21 0.26
0.2 0.2 0.2 0.22 0.33 0.44 0.56
0.3 0.3 0.3 0.35 0.53 0.71 0.88
0.4 0.4 0.4 0.5 0.75 1 1.25
0.5 0.5 0.5 0.67 1 1.33 1.67
0.5 0.6 0.5 0.86 1.29 1.71 2.14
0.5 0.7 0.5 1.08 1.62 2.15 2.69
Selected Settings Test Results
0 1 1.5 2 2.5
Phase A Pickup
Phase B Pickup
Phase C Pickup
Functional Tests
9.10 Protection Functional Tests
448 Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019