P44x/EN AP/Hb
MiCOM P40 Agile P442, P444
(AP) 5-
closure according to system check logic. If the system check criteria are not satisfied before
that time-delay elapses, the relay will lockout and issue alarm.
In addition, a CB Healthy information (from the CB), connected to one of the relay’s opto-
isolators, will indicate the circuit breaker condition for closing availability. When “CB Healthy
input” (DDB: 'CB Healthy') is used, the ‘Healthy Window’ time-delay can be set to adjust
the manual close of the CB. If the CB does not indicate a healthy condition during this time-
delay period, the relay will lockout and issue an alarm.
Where auto-reclose is used it may be desirable to block its operation when performing a
manual close. In general, the majority of faults following a manual closure will be permanent
faults and it will be undesirable to auto-reclose. The "man close" input without CB Control
selected OR the "CBClose in progress" with CB control enabled: will initiate the SOTF logic
for which auto-reclose will be disabled following a manual closure of the breaker during
500 msec (see SOTF logic in section P44x/EN AP).
If the CB fails to respond to the control command (indicated by no change in the state of CB
Status inputs) a ‘CB Fail Trip Control’ or ‘CB Fail Close Control’ alarm will be generated
(Figure 92) after the relevant trip (1) or close (2) command has expired. These alarms can
be viewed on the relay LCD display, remotely via the relay communications, or can be
assigned to operate output contacts for annunciation using the relays programmable scheme
logic (PSL).
Figure 92: CB Fail to trip or to close
P0561ENa
CBA_3P
SUP_Close OR
INP_CB_Man
CBC_ Fail_To_Close
CBC_Recl_3P
0.1 to 10 Sec
0 to 60 Sec
CBC_Close_In_Progress
Figure 93: Status of CB is incorrect CBA3P (3Poles are opened) stays – an alarm is
generated “CB Fail to Close”
Note that the ‘Healthy Window’ and ‘C/S Window’ time-delay settings are applicable to
manual circuit breaker operations only. These are duplicated in the Auto-reclose menu for
Auto-reclose applications.
To Next Page
Loading...
Need help?
General
