3 Mounting and Commissioning
500
7SD5 Manual
C53000-G1176-C169-1
• If not, first check whether one of the before named messages 2947
„Sync.
Udiff>“
or 2949
„Sync.
ϕ
-diff>“
is available in the spontaneous messages.
The message
„Sync. Udiff>“
indicates that the magnitude (ratio) adaptation is
incorrect. Check address
215
U-line / Usync
and recalculate the adaptation
factor, if necessary.
The message
„Sync.
ϕ
-diff>“
indicates that the phase relation of the busbar
voltage does not match the setting under address
212
Usync connect.
(see
Section 2.1.2.1). When measuring across a transformer, address
214
ϕ
Usync-
Uline
must also be checked; this must adapt the vector group (see Section
2.1.2.1). If these are correct, there is probably a reverse polarity of the voltage
transformer terminals for Ubus.
• The program
Usync< U-line>
=
YES
(address
3517
) and
SYNC-CHECK
=
YES
(address
3515
) is set for synchronism check.
• Open the VT mcb of the busbar voltage.
• Via binary input (No. 2906
„>Sync. Start AR“
) initiate the measuring request.
There is no close release. If there is, the VT mcb for the busbar voltage is not allo-
cated. Check whether this is the required state, alternatively check the binary input
„>FAIL:Bus VT“
(No.362).
• The VT mcb of the busbar voltage is to be closed again.
• Open the circuit breaker.
• The program
Usync> U-line<
=
YES
(address
3516
) and
Usync> U-line<
=
NO
(address
3517
) is set for synchronism check.
• Via binary input (No. 2906
„>Sync. Start AR“
) initiate the measuring request.
The synchronism check must release closing (message
„Sync. release“
, No.
2951). If not, check all voltage connections and the corresponding parameters
again carefully as described in Section 2.1.2.1.
• Open the VT mcb of the feeder voltage.
• Via binary input (No. 2906
„>Sync. Start AR“
) initiate the measuring request.
No close release is given.
• Open the VT mcb of the feeder voltage again.
Addresses
3515
to
3519
must be restored as they were changed for the test. If the
allocation of the LEDs or signal relays was changed for the test, this must also be re-
stored.
Polarity Check for
the Current Mea-
suring Input
I
4
If the standard connection of the device is used whereby current input
I
4
is connected
in the starpoint of the set of current transformers (refer also to the connection circuit
diagram in the Appendix A.3), then the correct polarity of the earth current path in
general automatically results.
If, however, the current
I
4
is derived from a separate summation CT an additional di-
rection check with this current is necessary.
If the device is provided with the sensitive current input
I
4
and it is connected to an
isolated or resonant-earthed system, the polarity check for
I
4
was already carried out
with the earth fault check according to the previous section. Then this section can be
ignored.
Otherwise the test is carried out with a disconnected trip circuit and primary load cur-
rent. It must be noted that during all simulations that do not exactly correspond with
situations that may occur in practice, the non-symmetry of measured values may
cause the measured value monitoring to pickup. This must therefore be ignored during
such tests.
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