Measuring The Operating Time Of The Circuit Breaker (Only 7Sj64) - Siemens SIPROTEC 7SJ62 Manual

Mounting and Commissioning
3.3 Commissioning
3.3.14

Measuring the Operating Time of the Circuit Breaker (only 7SJ64)

Only for Synchronism Check
If device 7SJ64 is equipped with the function for synchronism and voltage check and it is applied, it is necessary
– under asynchronous system conditions – that the operating time of the circuit breaker is measured and set
correctly when closing. If the synchronism check function is not used or only for closing under synchronous
system conditions, this subsection is irrelevant.
For measuring the operating time a setup as shown in Figure 3-39 is recommended. The timer is set to a range
of 1 s and a graduation of 1 ms.
The circuit breaker is connected manually. At the same time the timer is started. After closing the poles of the
circuit breaker, the voltage V
circuit breaker closing time.
If the timer is not stopped due to an unfavourable closing moment, the attempt will be repeated.
It is particularly favourable to calculate the mean value from several (3 to 5) successful switching attempts.
In address 6X20 set this time to T-CB close (under Power System Data of the synchronism check). Select
the next lower settable value.
Figure 3-39
460
appears and the timer is stopped. The time displayed by the timer is the real
Line
Measuring the circuit breaker closing time
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008