28 S&C Instruction Sheet 1041-540
Overcurrent Fault Protection
Full count reached; Load-side fault; Noted
The full count was reached on the recloser operations counter. Because the first voltage
loss in the sequence was preceded by an overcurrent fault, as well as all subsequent voltage
losses, if the
Fault Current Required Before First/All Voltage Loss(es)
value is set
to “All”, the control will take the appropriate sectionalizing action.
Full count reached with sectional. disabled; Noted
The full count was reached on the recloser operations counter. Because sectionalizing
was disabled, the switch control did not trip open the switch.
Note:
To identify the exact events that led to this action, review the earlier log
messages.
Full count reached; Open operation executed
The full count was reached on the recloser operations counter, so the switch control
tripped open the switch.
NOTE:
To identify the exact events that led to this action, review the earlier log
messages.
No OC before VL; Source-side open; Counting
The switch control detected a three-phase voltage outage that was not preceded by an
overcurrent fault. The control assumed a source-side fault occurred and the condition was
cleared by a source-side device. The control added one count to the recloser operations
counter.
OC then VL; Source-side fuse blown for load-side fault
The switch control detected a phase or ground overcurrent fault. This was followed
within 0.6 seconds by a loss of voltage on the same phase, without all other phases losing
voltage. The control assumed a load-side fault occurred and the condition was cleared
on the source side by a fuse or single-phase recloser.
No OC then VL; Source-side (SS) fuse blown - SS fault
The switch control detected a loss of voltage on one or two phases, which was not preceded
by an overcurrent fault. The control assumed that a source-side fault occurred and the
condition was cleared on the source side by a fuse or a single-phase recloser.
CLOSE operation executed, shots-to-lockout requested
In response to an automatic transfer command, or a SCADA or faceplate
Shots to
Lockout
command, the control closed the switch and started the
Shots to Lockout
timer.
Note:
If, before the timer expires, voltage is restored on any phase and then lost on
all three phases, the control will trip open the switch. If the
Overcurrent Required
before Shots-To-Lockout Operation
feature is enabled, the switch control also
detected overcurrent.
Lockout close complete with event after - OPEN executed
An operator requested a
Shots to Lockout
operation. The switch control detected the
appropriate number of three-phase voltage losses, within the specified shots-to-lockout
time interval, so it tripped open the switch. If the
Overcurrent Required before
Shots-To- Lockout Operation
feature is enabled, the switch control also detected
overcurrent. If the
Number of Shots Required for Lockout
value is set to 2, the
relationship between the detection of overcurrent and voltage losses follows the
Fault
Current Required before First/All Voltage Loss(es)
setpoint.
Persistent phase imbalance; OPEN executed
The switch control detected a loss of voltage on one or two phases, but not all three
phases. The imbalance continued for the full count of the
Phase Loss Protection Time
Threshold
timer. Because this loss occurred while the
Phase Loss Protection
feature
and automatic operation were both enabled, the switch control tripped open the switch.
