Parameter Value Description
start T2 after T1
The retrip on the local circuit breaker is a safety mechanism to avoid
false tripping of the superordinated circuit breaker. With generating a
retrip, only the local circuit breaker is tripped in the event of a false
start. Afterwards the Circuit-breaker restrike protection function drops
out during the T2 delay time.
Siemens recommends applying a retrip on the local circuit breaker.
Siemens also recommends applying the parameter value start T2
after T1. The parameter value provides a clear chronological separa-
tion of the processes for trip repeat and backup tripping. Remember that
the overall fault-clearance time in case of circuit-breaker restriking is the
sum of T1 and T2.
no
No retrip is given
parallel start T2, T1
As an alternative to the setting parallel start T2, T1 the
customer can start T2 and T1 in parallel.
Parameter: Delay T1 for 3-pole retrip
•
Default setting (_:109) Delay T1 for 3-pole retrip = 0.00 s
The parameter is visible only when the parameter Retrip after T1 is set to start T2 after T1 or
parallel start T2, T1 .
The retrip on the local circuit breaker is as a safety mechanism to avoid false tripping of the superordinated
circuit breaker. In the event of a false start, only the local circuit breaker is tripped by the retrip. Afterwards the
Circuit-breaker restrike protection function will drop out during the T2 delay time.
Siemens recommends applying a retrip on the local circuit breaker. Since the retrip is a safety mechanism, it
can be given without a delay time. Siemens recommends setting the delay time to 0 s.
Parameter: Delay T2 for 3-pole trip
•
Default setting (_:110) Delay T2 for 3-pole trip = 0.15 s
This parameter defines the duration of restriking after the backup tripping is sent. The following should be
considered:
•
When using the retrip functionality, this delay time must ensure a safe function dropout after giving the
retrip on the local circuit breaker.
Siemens recommends applying a delay time of 150 ms which is the default setting.
Parameter: Minimum operate time
•
Default setting (_:109) Minimum operate time = 0.15 s
The Minimum operate time parameter is used to set the minimum duration for the trip command of the
function.
CAUTION
Do not set a time that is too short.
If you set a time that is too short, there is a danger (dropout of the function without the current-flow
criterion) that the device contacts interrupt the control circuit. If this happens, the device contacts
burn out.
²
Set a duration that is long enough to ensure that the circuit breaker reliably reaches its final position
(open) after a control operation.
Protection and Automation Functions
6.42 Circuit-Breaker Restrike Protection
SIPROTEC 5, Overcurrent Protection, Manual 859
C53000-G5040-C017-8, Edition 07.2017
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