Siemens 7SJ82, Manual

Page: 1391 / 1638

Primary and Secondary Testing of the Synchronization Function
Measuring the Circuit-Breaker Closing Time
Under asynchronous system conditions, the circuit-breaker closing time must be measured and set correctly.
This achieves an exact parallel switching with a phase angle 0
o . If switching occurs only in synchronous system
conditions, this section can be skipped.
The closing time can be determined via the following 2 methods:
•
1. By reading from a fault record (recommended method)
•
2. With external timer
1. A simple option for determining the closing time involves reading out the time between the close command
and closure of the switch pole via the fault record. The time determined here is the real closing time and not
the operating time of the circuit beaker. You do not have to add any further time.
Siemens recommends the following procedure:
²
Establish a condition in which the circuit breaker can be closed without hazard.
²
If V2 switching through, activate the operating mode
Close cmd. at V1< & V2>
for the synchroni-
zation stage by setting to
yes
.
If V1 is switched through, activate the operating mode
Close cmd. at V1> & V2<
.
²
Make sure that the fault recorder is turned on. Via a temporary CFC chart, link the signal
Release
close cmd.
of the active synchronization stage to the binary input signal
>Manual start
(of the
fault recorder). With the release of closure, a fault record of the parameterized duration is set up (the
default setting of 500 ms is more than adequate for this).
²
Starting the synchronization stage. The device activates immediately.
²
Read the fault record and determine the closing time via SIGRA (see Figure 11-8 ).
Use the 2 cursors and the time-measuring function for this. Position the first cursor on the raising close
command. The occurrence of the second voltage signals the closed power-switching poles. Place the
second cursor on the raising second voltage.
²
Set the determined time with the
CB make time
parameter. Round off to the next lower adjustable
value. Proceed in the same way for all other sync stages.
²
Set the parameter
Close cmd. at V1< & V2>
or parameter
Close cmd. at V1< & V2<
back to
its original value.
²
Delete the CFC chart.
11.12
Functional Tests
11.12 Primary and Secondary Testing of the Synchronization Function
SIPROTEC 5, Overcurrent Protection, Manual 1391
C53000-G5040-C017-8, Edition 07.2017