Stability Tests; Figure 1.4-1 -Connections For Overall Fault Setting Tests By Primary Injection; Table 1.4-1 Test Of Fault Settings - Siemens 7PG2113 Technical Manual

C-E
A-B
A-C
C-A
3 P
If it is convenient to permit operation of the circuit breaker at this stage, repeat one of the tests with the trip links
inserted. Increase the primary current to the setting of the protection; the circuit breaker should then operate thus
proving the tripping circuit.
Repeat the tests at the other end of the feeder.
When all the tests have been completed at both ends of the feeder, compare results between ends. Check that
the most sensitive earth fault setting at each end refers to the same phase, i.e. the red phase, the next sensitive
the Yellow phase and the least sensitive the Blue phase.
It should be noted that primary fault settings vary slightly with the current transformers used and the capacitance
of the pilots. With average current transformers the fault settings at zero pilot capacitance are as given in Table 3.
Values are expressed as percentages of relay rating.
Fault settings will be practically unchanged for pilot capacitance values between zero and approximately 80% of
the maximum capacitance values specified in Table
effect of increasing the fault settings.
A
B
C
E

Figure 1.4-1 -Connections for Overall Fault setting Tests by Primary Injection

1.4.1

Stability Tests

The purpose of these tests is to ensure that the pilots are correctly connected and that the current transformers at
each end are starred correctly relative to one another in order to permit stabilisation of the protection under
through fault conditions.
©2010 Siemens Protection Devices Limited
C-E 22
A-B 110
A-C 110
C-A 55
3 P 63
Table 1.4-1 Test of fault settings
1.3-2. Values of pilot capacitance higher than this have the
7PG2113/4/5/6 Commissioning & Maintenance
37 25 42 31
125 155
125 155
62 77.5
72 89
Chapter 6 Page 13 of 77
52 35 59
177
177
88.5
101
E