ABB RELION 620 Series Technical Manual page 727

1MAC504801-IB E
620 series ANSI
Technical Manual
A sequence initiation from the INIT_4 line leads to a lockout after two shots. In a
situation where the initiation is made from both the INIT_3 and INIT_4 lines, a third
shot is allowed, that is, CBB3 is allowed to start. This is called conditional lockout. If the
initiation is made from the INIT_2 and INIT_3 lines, an immediate lockout occurs.
The INIT_5 line is used for blocking purposes. If the INIT_5 line is active during a
sequence start, the reclose attempt is blocked and the AR function goes to lockout.
If more than one CBBs are started with the shot pointer, the CBB with the
smallest individual number is always selected. For example, if the
INIT_2 and INIT_4 lines are active for the second shot, that is, the shot
pointer is 2, CBB2 is started instead of CBB5.
Even if the initiation signals are not received from the protection functions, the AR
function can be set to continue from the second to the fifth reclose shot. The AR function
can, for example, be requested to automatically continue with the sequence when the
circuit breaker fails to close when requested. In such a case, the AR function issues a
CLOSE_CB command. When the wait close time elapses, that is, the closing of the circuit
breaker fails, the next shot is automatically started. Another example is the embedded
generation on the power line, which can make the synchronism check fail and prevent the
reclosing. If the autoreclose sequence is continued to the second shot, a successful
synchronous reclosing is more likely than with the first shot, since the second shot lasts
longer than the first one.
Section 9
Control functions
721