Figure 247: Reset Circuit Breaker Lockout Logic Diagram (Module 57) - GE MiCOM P40 Agile Technical Manual

P543i/P545i
If set to CB Close, a timer setting, CB mon LO RstDly, becomes visible. When the circuit breaker closes, the CB
mon LO RstDly time starts. The lockout is reset when the timer expires.
If set to User Interface then a command, CB mon LO reset, becomes visible. This command can be used to
reset the lockout from a user interface.
An Autoreclose lockout generates an Autoreclose lockout alarm. Autoreclose lockout conditions can be reset by
various commands and setting options found under the CB CONTROL column.
If Res LO by CB IS is set to Enabled, a lockout is reset if the circuit breaker is successfully closed manually. For
this, the circuit breaker must remain closed long enough so that it enters the "In Service" state.
If Res LO by UI is set to Enabled, the circuit breaker lockout can be reset from a user interface using the reset
circuit breaker lockout command in the CB CONTROL column.
If Res LO by NoAR is set to Enabled, the circuit breaker lockout can be reset by temporarily generating an AR
disabled signal.
If Res LO by TDelay is set to Enabled, the circuit breaker lockout is automatically reset after a time delay set in
the LO Reset Time setting.
If Res LO by ExtDDB is Enabled, the circuit breaker lockout can be reset by activation of an external input
mapped in the PSL to the relevant reset lockout DDB signal.
5.7.1 RESET CB LOCKOUT LOGIC DIAGRAM
Res LO by CB IS
Enabled
CB1CRLO
Res LO by UI
Enabled
Reset CB LO
Yes
Res LO by NoAR
Enabled
AR Disabled
Res LO by ExtDDB
Enabled
Reset Lockout
Res LO by TDelay
Enabled
LO Reset Time
A/ R Lockout
V03382

Figure 247: Reset Circuit Breaker Lockout Logic Diagram (Module 57)

5.8 APPLICATION NOTES
5.8.1 SETTING THE THRESHOLDS FOR THE TOTAL BROKEN CURRENT
Where power lines use oil circuit breakers (OCBs), changing of the oil accounts for a significant proportion of the
switchgear maintenance costs. Often, oil changes are performed after a fixed number of CB fault operations.
However, this may result in premature maintenance where fault currents tend to be low, because oil degradation
P54x1i-TM-EN-1
&
&
&
&
&
t
0
Chapter 17 - Monitoring and Control
1
RESCB1LO
441