Siemens Reyrolle 7SR5 Manual page 448

Functional Tests
9.10 Protection Functional Tests
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 with 2 independently variable current limiting resistors as shown in
ariac
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
Table 9-9
87BD Initial
Setting
0.1
0.2
0.3
0.4
0.5
0.5
0.5
Selected Settings
Phase A Pickup
Phase B Pickup
Phase C Pickup
448
Secondary Injection using a V
Results for testing 87BD with a V
87BD 1st Bias
Slope Setting
0
0.1 0.1
0.2 0.2
0.3 0.3
0.4 0.4
0.5 0.5
0.6 0.5
0.7 0.5
0
ariac
ariac
Bias Current (⋅ I
Measured On Ammeter A1
1 1.5
Operate Current Measured on Ammeter A2
0.11 0.16
0.22 0.33
0.35 0.53
0.5 0.75
0.67 1
0.86 1.29
1.08 1.62
Test Results
1 1.5
Reyrolle 7SR5, Transformer Protection Device, Device Manual
Figure 9-12 or from 2 independent
)
rated
2 2.5
0.21 0.26
0.44 0.56
0.71 0.88
1 1.25
1.33 1.67
1.71 2.14
2.15 2.69
2 2.5
C53000-G7040-C015-1, Edition 11.2019