Recloser Operation
The VXE recloser senses line current and automatically
interrupts the phase of the distribution circuit to which it is
connected when line current exceeds the minimum-trip
level. Next, it automatically recloses to restore service
and monitor the line to determine if the fault has been
cleared. If the fault is permanent, the recloser locks out
after one, two, three, or four preset trip operations. Once
locked out, the recloser must be manually reset to restore
service.
Note:
The recloser can be reset remotely if equipped with the
SCADA Input/Output accessory board, via the remote
close feature.
Should the fault clear before lockout, the recloser will
reset automatically for another sequence of operations.
The recloser can also be set for non-reclosing operation
(lockout after the first trip operation) with a manually
operated external non-reclosing lever. The recloser can
be remotely set for non-reclosing operation, if equipped
with the SCADA Input/Output accessory board, via the
remote non-reclosing feature. The trip operations of the
recloser can be all fast, all delayed, or any combination
of fast operations and delayed operations up to a maxi-
mum total of four. Fast operations clear temporary faults
before branch line fuses are weakened. Delayed opera-
tions allow time for fuses or other downline protective
devices to clear to limit permanent faults to the smallest
section of line.
The VXE recloser control uses solid-state electronics to
provide accuracy, reliability, and flexibility for overcurrent
sensing and trip timing. The electronic circuits are housed
in a separate weatherproof cabinet attached to the reclos-
er tank and connected to the recloser with a control cable.
Vacuum Interrupter
Arc interruption takes place within the sealed vacuum
interrupter. Oil is used for electrical insulation but is not
involved in arc interruption of load or fault current.
Tripping and Closing
The moving contact in the vacuum interrupter is driven
open by the release of an opening spring. A low-energy
actuator, operated by the electronic circuitry, releases the
opening spring when line current is sensed above the
preset minimum-trip level. Closing energy, as well as
energy to charge the opening spring, is supplied by a
high- or low-voltage closing solenoid momentarily con-
nected phase-to-ground through a high-voltage contactor.
Closing Solenoid
Selection of the closing solenoid voltage rating is based
on the phase-to-ground voltage of the system on which
the recloser is to be used. Low-voltage ac and dc closing
coils are also available for the closing solenoid (refer to
Table 6). Electrical power for low-voltage closing is sup-
plied through a 2-pin connector mounted on the recloser
head.
Closing Solenoid Operation
The closing operation is illustrated by considering the
recloser to be connected to the line, but locked out
(orange control lockout indicator target is displayed). To
close from lockout, the manual operating handle must be
pulled downward to the Open position and then raised to
the Closed position. This allows the closing solenoid con-
tactor to close the phase-to-ground connection, thereby
energizing the closing solenoid and imparting an upward
acceleration to the solenoid plunger.
Upward movement of the plunger causes the recloser
operating mechanism to effect the following actions:
1.
Opening spring is charged.
2.
Closing solenoid contactor opens.
3.
Closing spring is released, driving contact operating
rod downward to close the vacuum interrupter.
4.
Undervoltage lockout timer is reset.
Undervoltage Lockout
An undervoltage lockout feature is provided to protect the
high-voltage closing solenoid from thermal damage,
which could be caused by repeated closing attempts dur-
ing severe undervoltage conditions.
The undervoltage lockout system protects the closing
solenoid with a spring-biased hydraulic time-delay lock-
out linkage charged with the closing stroke of the closing
solenoid or by operating the yellow handle.
Each closing signal initiates a time-delayed lockout oper-
ation with the down stroke of the solenoid plunger. The
time-delay is 20 seconds. If sufficient voltage is present
and the oil is filled to the proper level, a closing operation
occurs and the undervoltage lockout linkage is reset. If
system voltage is too low to permit a closing operation or
if the oil level is low, the linkage will provide lockout fol-
lowing its time delay.
The undervoltage lockout feature also prevents unex-
pected recloser closing upon the return of line voltage, in
the event that a reclose operation is attempted without
sufficient line voltage.
If a closing operation is attempted by closing the manual
operating handle with a hotstick (or via remote close on
units equipped with the SCADA I/O board) and line volt-
age is below 85% of rated voltage, the recloser will lock
out and the manual operating handle will drop to the
Open position. The recloser can only be closed when line
voltage is within ± 15% of the rated voltage of the closing
solenoid.
Low-Energy Opening and Closing
Actuators
Low-energy actuators, which receive signals from the
electronic control, are utilized for both opening and clos-
ing functions. Each actuator consists of a permanent
magnet, a spring-biased armature, and a coil assembly.
Pre-charged reset springs are used to charge the arma-
ture of each actuator upon completion of mechanism
operation.
Type VXE Single-Phase Electronically Controlled Recloser Installation and Operation Instructions
4