Functions
6-222 7SA6 Manual
C53000-G1176-C156-2
Synchronism
Check Conditions
before Automatic
Reclosure
Addresses 3510 to 3519 are relevant to the check conditions before automatic reclos-
ure of the circuit breaker. When setting the parameters for the internal automatic re-
closing function (Section 6.14.2) it was 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. Set this parameter to
with T-CB close, if asynchro-
nous closing shall be allowed; the relay will then consider the circuit breaker closing
time before determining the correct instant for the closing 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 au-
tomatic reclosure only under synchronous system conditions, set this address to
w/o T-CB close.
The permissible magnitude difference of the voltages is set under address
3511 Max.
Volt. Diff
. Setting is in volts secondary. When operating the device from a person-
al computer using DIGSI
®
4, setting may be in secondary or primary values. Depend-
ing on the connection of the bus-bar voltage (phase–phase or phase–earth) the
phase–phase or the phase–earth voltage is decisive.
The permissible frequency difference between the voltages is set under address
3512
Max. Freq. Diff
, the permissible phase angle difference under address 3513
Max. Angle Diff
.
The further release conditions for automatic reclosing are set under addresses
3515A
to 3519:
3515A SYNC-CHECK = synchronism check: the bus-bar (Ubus) and the
feeder (Uline) must both be live (
Live Volt.
Thr.
,address3503); the conditions for synchro-
nism
Max. Volt. Diff (address 3511), Max.
Freq. Diff
(address 3512), and Max. Angle
Diff
(address 3513) are checked before automatic
reclosure;
3516 Usync> U-line< = dead-line check: the bus-bar (Ubus) must be live
(
Live Volt. Thr., refer to address 3503), the
feeder (Uline) must be dead (
Dead Volt. Thr.,
refer to address
3502);
3517 Usync< U-line> = dead-bus check: the bus-bar (Ubus) must be dead
(
Dead Volt. Thr., refer to address 3502), the
feeder (Uline) must be live (
Live Volt. Thr.,re-
fer to address
3503);
3518 Usync< U-line< = dead-bus and dead-line check: the bus-bar (Ubus)
and the feeder (Uline) must both be dead (
Dead
Volt. Thr.
, refer to address 3502);
3519 OVERRIDE = automatic reclosure is released without any check.
The five possible release conditions are independent of each other and can be com-
bined.
Synchronism
Check Conditions
before Manual
Closing
The release conditions for manual closing are set under addresses 3530 to 3539.
When setting the general protection data (Power System Data 2, Section 6.1.3) it was
decided whether synchronism and voltage check should be carried out before manual
closing. With the following setting in address
1151 MAN. CLOSE = w/o Sync-
check
, no checks are performed before manual closing. The following parameters are
then irrelevant.