Section 9
Control functions
9.4.4.6
1008
•
The frequent operation counter limit is reached and new sequence is initiated. The
lockout is released when the recovery timer elapses.
•
The protection trip signal has been active longer than the time set with the Max wait
time parameter since the shot initiation.
•
The circuit breaker is closed manually during an autoreclosing sequence and the
manual close mode is FALSE.
Protection coordination controller
The PROT_CRD output is used for controlling the protection functions. In several
applications, such as fuse-saving applications involving down-stream fuses, tripping and
initiation of shot 1 should be fast (instantaneous or short-time delayed). The tripping and
initiation of shots 2, 3 and definite tripping time should be delayed.
In this example, two overcurrent elements 51P and 50P-2 are used. 50P-2 is given an
instantaneous characteristic and 51P is given a time delay.
The PROT_CRD output is activated, if the SHOT_PTR value is same or higher than the
value defined with the Protection crd limit setting and all initialization signals have been
reset. The PROT_CRD output is reset under the following conditions:
•
If the cut-out time elapses
•
If the reclaim time elapses and the AR function is ready for a new sequence
•
If the AR function is in lockout or disabled, that is, if the value of the Protection crd
mode setting is "AR inoperative" or "AR inop, CB man".
The PROT_CRD output can also be controlled with the Protection crd mode setting. The
setting has the following modes:
•
"no condition": the PROT_CRD output is controlled only with the Protection crd limit
setting
•
"AR inoperative": the PROT_CRD output is active, if the AR function is disabled or
in the lockout state, or if the INHIBIT_RECL input is active
•
"CB close manual": the PROT_CRD output is active for the reclaim time if the circuit
breaker has been manually closed, that is, the AR function has not issued a close
command
•
"AR inop, CB man": both the modes "AR inoperative" and "CB close manual" are
effective
•
"always": the PROT_CRD output is constantly active
1MAC059074-MB A
615 series ANSI
Technical Manual