Siemens siprotec 7SD5 User Manual page 319

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
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
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.
Addresses 3510 to 3519 are relevant to the check conditions before automatic reclo-
Synchronism
Check Conditions sure of the circuit breaker. When setting the parameters for the internal automatic re-
before Automatic closing function (Section 2.15.2), it is decided with which automatic reclosing cycle
Reclosure 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.
7SD5 Manual
C53000-G1176-C169-1
2.16 Synchronism and Voltage Check (optional)
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. Depending on the con-
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