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Operating instructions
7SV512
V1
103
C53000---G1176---C91
6.7.2 Checking the local trip with
breaker failure criterion from the
auxiliary contacts
The circuit breaker --- isolated by its adjacent dis-
connectors, as mentioned above --- is now switched
on. Note that the pole discrepancy protection of the
circuit breaker may initiate a later three-pole trip dur-
ing these tests. The internal pole discrepancy super-
vision may operate, too. The circuit breaker is
switched on before each test.
a) Initiation by single-pole trip command L1 of the
feeder protection:
Single-pole trip command is issued by the break-
er failure protection after T1---1POLE (address
1205), provided local trip (cross trip) is allowed
(according address 1203) and single-pole trip is
parameterized (address 1204).
b) Initiation by single-pole trip command L2 of the
feeder protection:
Single-pole trip command is issued by the break-
er failure protection after T1---POLE (address
1205), provided local trip (cross trip) is allowed
(according address 1203) and single-pole trip is
parameterized (address 1204).
c) Initiation by single-pole trip command L3 of the
feeder protection:
Single-pole trip command is issued by the break-
er failure protection after T1---1POLE (address
1205), provided local trip (cross trip) is allowed
(according address 1203) and single-pole trip is
parameterized (address 1204).
d) Initiation by three-pole trip command of the feeder
protection:
Three-pole trip command is issued by the breaker
failure protection after T1---3POLE (address
1206), provided local trip (cross trip) is allowed
(according address 1203).
De-energize all binary inputs.
6.7.3 Checking the local trip and the
current circuits
The current transformer connections are checked
with real primary current. Before the protected ob-
ject is energized, it must be ensured, that a back-up
protection is effective in case a real fault should oc-
cur during the tests.
A load current of at least 10 % of the rated current is
necessary. If the measuring circuit connections are
correct, none of the measured value monitoring sys-
tems in the relay will operate. If a fault indication ap-
pears, the possible causes can be found in the op-
erational annunciations (Address 5100).
For current sum errors, the matching factors (Sec-
tion 6.3.3) should be checked.
If the symmetry monitoring appears, it is possible
that asymmetry is in fact present on the line. If this is
a normal operational condition, the corresponding
monitoring function should be set at a less sensitive
value (Section 6.3.6).
Currents can be read off on the display in the front or
via the operating interface in block 57 and compared
with the actual measured values. If substantial devi-
ations occur or if the unit indicates a considerable
earth current, then the current transformer connec-
tions are incorrect. Short-circuit the current trans-
formers and make corrections.
The circuit breaker is closed again for the following
trip tests. Note that the integrated pole discrepancy
supervision may operate and initiate three-pole trip-
ping. As the correct allocation of the individual circuit
breaker poles is already verified during the tests ac-
cording to Section 6.7.2, one single test is sufficient,
here.
a) Initiation by three-pole trip command of the feeder
protection:
Three-pole trip command is issued by the breaker
failure protection after T1---3POLE (address 1206)
provided local trip (cross trip) is allowed (accord-
ing address 1203).
Finally, de-energize all binary inputs. Open circuit
breaker
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