Functions
2.25 Function Control and Circuit Breaker Test
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
457
Figure 2-227
Breaker tripping alarm suppression — sequence examples
2.25.2
Circuit Breaker Test
The universal line protection 7SD5 allows an easy check of the trip circuits and the circuit breakers.
2.25.2.1 Functional Description
The test programs shown in Table 2-20 are available. The single-pole tests are of course only possible if the
device you are using is capable of single-pole tripping.
The output alarms mentioned must be allocated to the relevant command relays that are used for controlling
the circuit breaker coils.
The test is started using the operator panel on the front of the device or using the PC with DIGSI. The procedure
is described in detail in the SIPROTEC 4 System Description. Figure 2-228 shows the chronological sequence
of one TRIP–CLOSE test cycle. The set times are those stated in Section 2.1.2.1 for „Trip Command Duration“
and „Circuit Breaker Test“.
Where the circuit breaker auxiliary contacts indicate the status of the circuit breaker or of its poles to the device
via binary inputs, the test cycle can only be initiated if the circuit breaker is closed.
The information regarding the position of the circuit breakers is not automatically derived from the position logic
according to the above section. For the circuit breaker test function (auto recloser) there are separate binary
inputs for the switching status feedback of the circuit breaker position. These must be taken into consideration
when allocating the binary inputs as mentioned in the previous section.
The alarms of the device show the respective state of the test sequence.
