Operating instructions7SV512
V1
103C53000---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, asmentioned above --- is now switched
on. Note that the pole discrepancy protection of the
circuit breaker mayinitiate alater three-pole trip dur-
ingthese 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 bythree-pole tripcommand ofthe feeder
protection:
Three-pole tripcommand isissued 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 isenergized, 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 ofthe measured value monitoringsys-
tems in the relay will operate. If afault 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 canbe read offonthe display inthe frontor
viathe operating interface inblock 57and 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. Asthecorrectallocation ofthe individual circuit
breaker poles is already verified during the tests ac-
cording to Section 6.7.2, one single test issufficient,
here.
a) Initiation bythree-pole tripcommand ofthe feeder
protection:
Three-pole tripcommand isissued by the breaker
failure protection afterT1---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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