11010
172
CIN10
2
Close
11011
172
CIN10
3
Bad
5.5.5. Synchrocheck function ΔV/Δa/Δf (25)
To ensure safe closing of the circuit breaker between two systems it is important to check the
synchronization. Closing the circuit breaker while the systems are in asynchronous state can cause
several problems like current surges which damage the interconnecting elements. Synchrocheck has
three stages SYN1, SYN2 and SYN3. SYN1 supervises the synchronization condition between U4
channel and the selected input voltage. SYN2 supervises the synchronization condition between U3
channel and the selected input voltage. SYN3 supervises the synchronization condition between U3
and U4 channels.
Figure. 5.5.5. - 127. Example connection of synchrocheck function in 3LN+U4 mode when the SYN1 stage is in use and UL1 is
the reference voltage.
AQ-T257
Instruction manual
Version: 2.00
243
© Arcteq Relays Ltd