22 S&C Instruction Sheet 1041-540
Switch Control Operation
(e) If the
Sectionalizer Reset and Extended Voltage Loss Time
timer expires
before the counter reaches the appropriate
Recloser Counts to Trip
value, the
switch control resets the counter to zero. Later voltage losses are considered
part of a different reclose sequence. However, if three-phase voltage is not
present when the timer expires, an
Extended Voltage Loss
condition exists
and the switch control opens the switch.
If the counter reaches the setpoint value before the timer expires, and the problem
was a load-side fault, the control trips open the switch.
Note:
When the
Fault Current Required Before First/All Voltage Loss(es)
mode
is set to the
All
setting, the switch will not trip open unless all voltage losses were pre-
ceded by fault current. However, it may still operate based on the
Recloser Counts to
Trip, Voltage Loss Only
setpoint. See the Setup Instruction Sheet 1041-530 for details.
If the counter reaches the setpoint value before the timer expires, and the problem
was a source-side fault, the control notes the events but does not trip open the switch.
To enable
Sectionalizing
mode:
STEP 1.
In the
Features Enabled
field on the
SETUP: Automatic Operation
screen,
select a combination that includes “Sectionalizing.”
STEP 2.
If desired, at the
SETUP: Automatic Operation
screen, set the S
uccessful
Reclose Reset Time
value to coordinate with the reclosers.
STEP 3.
Use either the faceplate automatic operation ENABLE/DISABLE switch or a
SCADA command to enable automatic operation of the switch control.
If the
Phase Loss Protection
feature is enabled, the switch control trips open the
switch in response to a persistent
Phase Imbalance
condition to prevent damage to
customer equipment.
When the
Phase Loss Protection
feature is enabled, the switch control uses the following
logic to determine when to trip open the switch:
(a) When the switch control detects a loss of voltage on one or two phases, it starts
the
Phase Loss Protection Time Threshold
timer.
(b) If the voltage loss persists, and true RMS current remains below the
Phase Loss
Protection Current Threshold
setpoint until the timer expires, the switch
control trips open the switch.
(c) If voltage returns before the timer expires, the switch control terminates the
timing operation.
(d) If voltage returns on one phase before the timer expires, but is then lost on
another phase, the switch control restarts the timer.
Complete the following steps to enable the
Phase Loss Protection
feature:
STEP 1.
In the
Features Enabled
field on the
SETUP: Automatic Operation
screen,
select a combination that includes “Phase Loss Protection.”
Phase Loss
Protection
