Siemens 7SJ82 Manual page 931

With the 3 dead-time parameters, you can determine after which dead time the automatic reclosing function
will be executed. Please set the times as desired for the respective type of short circuit.
•
The parameter Dead time aft.1ph. pickup applies to dead times after 1-phase short circuits and
the following protection tripping: A, B, C, or A-Gnd, B-Gnd, C-Gnd
•
The parameter Dead time aft.2ph. pickup applies to dead times after 2-phase short circuits and
the following protection tripping: A-B, B-C, C-A, or A-B-gnd, B-C-gnd, C-A-gnd
•
The parameter Dead time aft.3ph. pickup applies to dead times after 3-phase short circuits and
the following protection tripping: A-B-C or A-B-C-Gnd
NOTE
i i
If you would like to avoid automatic reclosing during individual short-circuit types, please set the respective
dead times to oo (invalid).
Example:
After 1-phase short-circuits, the automatic reclosing function should occur after 1.2 s. The automatic reclosing
function should not occur for 2-phase and 3-phase short circuits.
For this application, the parameters should be set as follows:
•
Dead time aft.1ph. pickup = 1.2 s
•
Dead time aft.2ph. pickup = oo (invalid)
•
Dead time aft.3ph. pickup = oo (invalid)
Parameter: Dead time aft. evolv. fault
These parameters are only significant if the parameter (_:6601:109) Response to evolv. faults is
set to strt. evol.flt.dead time .
•
Default setting (_:6571:109) Dead time aft. evolv. fault = 1.2 s
With the parameter Dead time aft. evolv. fault , you can determine after which dead time the auto-
matic reclosing function should be executed, if based on an evolving fault during the current dead time, a 3-
pole trip has occurred. For this 3-pole dead time, stability concerns for the system are also important. Often,
this dead time as well as the parameter (_:6571:108) Dead time aft. 3-pole trip can be set.
Detailed information about the function during evolving faults during dead time are described in Chapter
6.45.4.13 Evolving-Fault Detection During Dead
Parameter: CB ready check bef.close
•
Default setting (_:6571:111) CB ready check bef.close = no
With the parameter CB ready check bef.close you can determine if after the expiration of the dead
time (meaning, directly prior to assigning the close command) readiness of the circuit breaker should be
queried.
Parameter Value
no
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
Time.
Description
With the setting no , the automatic reclosing function does not check again
the readiness of the circuit breaker prior to assigning the close demand.
Siemens recommends this setting, if it is sufficient to check the readiness of the
circuit breaker for the entire switching cycle once before the start of a reclosing
function, consisting of tripping-reclosing-tripping. The setting for checking the
readiness of the circuit breaker prior to the start of the automatic reclosing
function is done using the parameter (_:6601:102) CB ready check
bef. start .
Protection and Automation Functions
6.45 Automatic Reclosing Function
931