2.16 Synchronism and Voltage Check (optional)
319
7SD5 Manual
C53000-G1176-C169-1
Different interrogation conditions can be parameterized for automatic reclosure on the
one hand and for manual closure on the other hand. Each closing command is con-
sidered a manual reclosure if it was initiated via the integrated control function or via
a serial interface.
The general limit values for synchronism check are set at address
3501
to
3508
. Ad-
ditionally, addresses
3510
to
3519
are relevant for automatic reclosure, addresses
3530
to
3539
are relevant for manual closure. Moreover, address
3509
is relevant for
closure via the integrated control function.
The complete synchronism check function is switched
ON
or
OFF
in address
3501
FCT
Synchronism
. If switched off, the synchronism check does not verify the synchroni-
zation conditions and release is not granted. You can also set
ON:w/o CloseCmd
:
the CLOSE command is in this case not included in the common device alarm
„Relay
CLOSE“
(No. 510), but the alarm
„Sync.CloseCmd“
(No. 2961) is issued.
Address
3502
Dead Volt. Thr.
indicates the voltage threshold below which the
feeder or the busbar can safely be considered dead (for checking a de-energized
feeder or busbar). The setting is applied in Volts secondary. This value can be entered
as a primary value when parameterizing with a PC and DIGSI
®
. Depending on the con-
nection of the voltages these are phase-to-earth voltages or phase-to-phase voltages.
The voltage above which the feeder or busbar is regarded as being definitely live, is
set under address
3503
Live Volt. Thr.
(for energized line or busbar check and
for the lower limit of synchronism check). It must be set below the anticipated opera-
tional undervoltage. The setting is applied in Volts secondary. This value can be
entered as a primary value when parameterizing with a PC and DIGSI
®
. Depending
on the connection of the voltages these are phase-to-earth voltages or phase-to-
phase voltages.
The maximum permissible voltage for the operating range of the synchronism check
function is set in address
3504
Umax
. The setting is applied in Volts secondary. This
value can be entered as a primary value when parameterizing with a PC and DIGSI
®
.
Depending on the VT connection these are phase-to-earth voltages or phase-to-
phase voltages.
Verification of the release conditions via synchronism check can be limited to a con-
figurable synchronous monitoring time
T-SYN. DURATION
(address
3507
). The con-
figured conditions must be fulfilled within this time. If not, closure will not be released.
If this time is set to
∞
, the conditions will be checked until they are fulfilled or the mea-
surement request is cancelled.
If the conditions for synchronous operation must be checked to be maintained for a
certain duration, this minimum duration
T SYNC-STAB
can be set under address
3508
before closing is released.
Synchronism
Check Conditions
before Automatic
Reclosure
Addresses
3510
to
3519
are relevant to the check conditions before automatic reclo-
sure of the circuit breaker. When setting the parameters for the internal automatic re-
closing function (Section 2.15.2), it is decided with which automatic reclosing cycle
synchronism and voltage check should be carried out.
Address
3510
Op.mode with AR
determines whether closing under asynchronous
system conditions is allowed for automatic reclosure. Set this parameter to
with T-
CB close
to allow asynchronous closing; the relay will then consider the circuit
breaker operating time before determining the correct instant for the close command.
Remember that closing under asynchronous system conditions is allowed only if the
circuit breaker closing time is set correctly (see above under „Preconditions“)! If you
wish to permit automatic reclosure only under synchronous system conditions, set this
address to
w/o T-CB close
.
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