S&C VacuFuse II User guide

Instruction Sheet 466-501
January 24, 2022
© S&C Electric Company 2022, all rights reserved
VacuFuse®II Self-Resetting Interrupter—Quick Operation Guide
Outdoor Distribution (7.2 kV through 15 kV)
If Maintenance Is to Be Performed on the Transformer
STEP 1. Open the vacuum interrupter inside the VacuFuse II interrupter by pulling
down on the OPEN/CLOSE lever using the straight prong of the Talon™
Handling Tool or a distribution prong. See Figure 1.
STEP 2. Remove the VacuFuse II interrupter from its mounting after the vacuum
interrupter opens and drops out. If required by utility practice, follow the steps
in the “Removing the VacuFuse II Interrupter from the Cutout Mounting”
section. This creates a visible open gap showing the transformer is isolated
from the feeder. Depending on utility practice, additional grounds may be
required.
STEP 3. Follow your utility’s standard practice for transformer maintenance. After
maintenance is complete, install the VacuFuse II interrupter and close it into
the mounting as described in the “Installing a VacuFuse II Interrupter into the
Cutout Mounting” section.
Understanding the Closing Sequence
Note: The VacuFuse II Self-Resetting Interrupter is shipped from the factory with the
vacuum interrupter in the Open position.
When closing the VacuFuse II Self-Resetting Interrupter into the cutout mounting the
CHARGING LED will blink at a one-second interval as long as voltage is available at the
cutout and the vacuum interrupter is open. The READY TO CLOSE LED will steadily
illuminate when the VacuFuse II Self-Resetting Interrupter has harvested enough energy
to close the vacuum interrupter.
The VacuFuse II Self-Resetting Interrupter requires 45 seconds to harvest enough
energy to close the vacuum interrupter.
There are two ways to close the vacuum interrupter:
Option 1: Automatic Delay Close
Place the OPEN/CLOSE lever into the Close (up) position at any time (before or after
mounting the VacuFuse II interrupter into the cutout mounting). When closed into the
cutout mounting, the CHARGING LED will blink at a one-second interval as long as
voltage is available at the cutout and the vacuum interrupter is open. The VacuFuse II
interrupter will automatically close the vacuum interrupter after 45 ±10 seconds.
Option 2: Manual Close
Place the OPEN/CLOSE lever into the Open (down) position before mounting the
VacuFuse II interrupter into the cutout mounting or at any time before the 45-second
power up time elapses to the interrupter after closing it in to the cutout mounting.
For an intentional close on a precise timing, wait until the READY TO CLOSE LED illu-
minates and is solidly lit. At that time, the interrupter is ready to be closed manually by
moving the OPEN/CLOSE lever to the Close position. Three seconds after the lever is
moved to the Close position, the vacuum interrupter will close.
Always check the position of the vacuum interrupter by conrming the target at the base
of the interrupter is red before walking away. See Figure 2.
WARNING
VacuFuse II Self-Resetting Interrupters must be installed, operated, and maintained
by qualified persons knowledgeable in overhead electric power distribution equipment
and the associated hazards. This guide is not a replacement for adequate training
and experience in safety procedures for this product. Read S&C Instruction Sheet
465-510 thoroughly and carefully before installing or operating your VacuFuse II
Self-Resetting Interrupter.
DANGER
VacuFuse II Self-Resetting Interrupters may be energized from either side and in any
position. Always consider all parts live until de-energized, tested, and grounded.
If the VacuFuse Self-Resetting Interrupter Is Found Open
WARNING
The VacuFuse II Self-Resetting Interrupter is designed to protect distribution
transformers from internal and external fault current. A VacuFuse II interrupter found
in the Open and Drop Out position should not be closed using the OPEN/CLOSE
lever until the cause of the fault current has been determined and repaired. Closing
without repairing the fault could result in equipment damage, injury, or death.
WARNING
VacuFuse II Self-Resetting Interrupters must be dropped out from the cutout mounting
to be considered open.
VacuFuse II Self-Resetting Interrupters are different from other cutout-mounted
devices, including the VacuFuse® Self-Resetting Interrupter. VacuFuse II interrupters
have a voltage-harvesting power supply that allows up to 1 mA of current to go
through them, even when the vacuum interrupter is open.
Failure to consider the current through the VacuFuse II interrupter when the vacuum
interrupter is open may lead to serious injury or death.
After responding to an overcurrent event, the VacuFuse II interrupter’s vacuum inter-
rupter will open and the POSITION indicator will show a green target. If the overcurrent
event persists after the reclosing event, the interrupter will lock out and drop out from
the cutout mounting. Follow these steps if the VacuFuse II Self-Resetting Interrupter has
operated and is in the Open and Drop Out position:
STEP 1. Remove the VacuFuse II interrupter from its mounting, if required by utility
practice, following the steps in the “Removing the VacuFuse II Interrupter from
the Cutout Mounting” section.
STEP 2. Determine and resolve the cause of the fault.
STEP 3. After the fault has been resolved and repairs completed, install the
VacuFuse II interrupter and close it into the mounting as described in the
“Installing a VacuFuse II Interrupter into the Cutout Mounting” section.
Figure 1. A VacuFuse II Self-Resetting
Interrupter.
OPEN/
CLOSE
lever
Hinge-end
contact
Jaw-end
contact
Pull-ring
Trunnion
Figure 2. A VacuFuse II Self-Resetting
Interrupter (vacuum interrupter closed).
POSITION
indicator
LED
indicators
Opening and Closing the VacuFuse II Interrupter
WARNING
The VacuFuse II Self-Resetting Interrupter is designed to protect distribution
transformers from internal and external fault current. A VacuFuse II interrupter
found in the Open and Drop Out position (POSITION indicator displaying a green
target) should NOT be manually closed until the cause of the trip operation has been
determined and repaired. Manual closing without repairing the fault could result in
equipment damage, injury, or death.
The vacuum-interrupter inside the VacuFuse II interrupter can be opened using the yellow
OPEN/CLOSE lever on the side of the VacuFuse II interrupter, with or without power.
The interrupter must be powered for at least 45 seconds before the vacuum interrupter
can be closed by moving the lever to the Close position.
The VacuFuse II Self-Resetting Interrupter will drop out of the cutout mounting when
the vacuum interrupter is in the Open position and the VacuFuse II interrupter has
locked open.
To open: Pull the yellow OPEN/CLOSE lever down rmly using the straight prong of the
Talon tool or a distribution prong. Remove the tool right away. The vacuum interrupter
inside the VacuFuse II interrupter will open, and the POSITION indicator will show
the green target. See Figure 5. After one minute of the vacuum interrupter in the Open
position, the VacuFuse II interrupter will drop out.
To close: Push the pull-ring of the yellow OPEN/CLOSE lever up rmly using the
straight prong of the Talon tool or a distribution prong. The vacuum interrupter inside
the VacuFuse II interrupter will close after 45 seconds of the VacuFuse II interrupter
being powered, and the POSITION indicator will show the red target. See Figure 2.
If the VacuFuse II interrupter is inadvertently closed into a fault, the vacuum interrupter
will trip open independently of any force still applied to OPEN/CLOSE lever.
To reset the OPEN/CLOSE lever after manually closing into fault current: When
the VacuFuse II interrupter trips in response to a fault, the lever does not move, leaving
the lever in the Closed position when the vacuum interrupter is in the Open position. The
lever can be “reset” by operating it into the Open position while the vacuum interrupter
is in the Open position.

2 S&C Instruction Sheet 466-501
VacuFuse®II Self-Resetting Interrupter—Quick Operation Guide
Outdoor Distribution (7.2 kV through 15 kV)
WARNING
DO NOT attempt to open a VacuFuse II Self-Resetting Interrupter that is in the
Closed position without using a loadbreak tool, such as S&C’s Loadbuster tool. An
arc started by opening a VacuFuse II Self-Resetting Interrupter under load without
a loadbreak tool can cause equipment damage, serious injury, or death.
Instructions for using S&C’s Loadbuster tool can be found in S&C Instruction Sheet
465-510.
STEP 3. Remove the VacuFuse II Self-Resetting Interrupter from a 110-kV BIL-rated
or a 125/150-kV BIL-rated cutout mounting with gloved hands, as shown in
Figure 3.
Understanding the LED Indicators
Two LEDs are on the base of the VacuFuse II interrupter. See Figure 5.
The CHARGING LED is white and indicates the VacuFuse II interrupter is harvesting
energy to close the vacuum interrupter. When the VacuFuse II interrupter is powered,
the CHARGING LED will start flashing at one flash per second as long as voltage is in
the cutout mounting and the vacuum interrupter is open. When full charge is achieved,
the charging LED will continue flashing and the READY TO CLOSE LED will illuminate
and the CHARGING LED will continue blinking.
Note: Information on troubleshooting the VacuFuse II Self-Resetting Interrupter can
be found in S&C Instruction Sheet 465-510.
Installing a VacuFuse II Interrupter into the Cutout Mounting
WARNING
Provide training to line crews on the use of both a hotstick and an extendostick
before installing or operating the VacuFuse II Self-Resetting Interrupter. The
VacuFuse II interrupter is different from other cutout-mounted devices. Failure to
properly handle a VacuFuse II interrupter with a hotstick and/or an extendostick
may lead to serious injury or death.
For instructions on how to install a cutout mounting, see the “Installation” section of
S&C Instruction Sheet 465-510.
Installation using insulated gloves: With the OPEN/CLOSE lever in the Open position,
insert the VacuFuse II interrupter into a 110-kV or a 125/150-kV BIL-rated mounting with
gloved hands, as shown in Figure 3.
Closing the VacuFuse II Interrupter into the Cutout Mounting
NOTICE
Read the “Understanding the Closing Sequence” section before closing the
VacuFuse II interrupter into its cutout mounting.
STEP 1. Conrm the VacuFuse II interrupter is in the Open position by viewing its
POSITION indicator. Place the OPEN/CLOSE lever in the correct position for
the closing sequence desired.
STEP 2. Stand rmly in front of and in line with the cutout mounting. Do not operate
standing directly underneath the VacuFuse II interrupter. If using an
extendostick, stand from 6 to 10 feet (183 to 305 cm) away from the pole.
STEP 3. Insert the straight prong of a Talon tool or distribution prong into the pull-ring.
STEP 4. Swing the VacuFuse II interrupter to within approximately 45 degrees of the
fully Closed position. See Figure 4.
STEP 5. While rmly gripping the stick, drive the VacuFuse II interrupter closed with
forward force. Maintain the forward force until the interrupter properly closes
and latches into the cutout mounting.
STEP 6. Disengage the prong from the pull-ring, taking care to avoid pulling the
VacuFuse II interrupter open.
Removing the VacuFuse II Interrupter from the Cutout Mounting.
WARNING
DO NOT attempt to remove a VacuFuse II interrupter from its cutout mounting
with the vacuum interrupter in the Closed position. The vacuum interrupter is in
the Closed position when the POSITION indicator at the base of the VacuFuse
II interrupter displays a red target. Removing the VacuFuse II interrupter from its
cutout mounting with the vacuum interrupter in the Closed position may cause
arcing, equipment damage, serious injury, or death.
STEP 1. Open the vacuum interrupter by pulling down on the yellow OPEN/CLOSE
lever.Conrm thePOSITIONindicatoratthe baseoftheVacuFuseII interrupter
displays a green target. See Figure 5.
STEP 2. Wait about one minute until the VacuFuse II interrupter drops out.
If the VacuFuse II Self-Resetting Interrupter stays in its cutout mounting, confirm
the POSITION indicator at the base of the VacuFuse II interrupter displays a green
target. In this case, the VacuFuse II interrupter may not be powered and cannot drop
out. Attach a Talon Handling Tool or a distribution prong to a short hotstick. Using the
straight prong of the Talon tool or a distribution prong, pull the pull-ring forward until
the VacuFuse II interrupter disengages from the closed-into cutout position. A swift,
firm pull will be required.
If the VacuFuse II Self-Resetting Interrupter is in its cutout mounting with the vacuum
interrupter in the Closed position and operating the OPEN/CLOSE lever to the Open
position does not work, or the VacuFuse II interrupter is to be removed from its cutout
mounting in the Closed position for any other reason, follow the instructions in the
“Removing the VacuFuse II Interrupter from the Cutout Mounting using Loadbuster®—
The S&C Loadbreak Tool” section of S&C Instruction Sheet 465-510.
Figure 5. A VacuFuse II Self-Resetting Interrupter (vacuum
interrupter open).
CHARGING
LED
POSITION indicator
in the Open (green)
position
Figure 3. Guiding or removing the trunnion from
the hinge using gloved hands.
Trunnion
Figure 4. Guiding or removing the trunnion from the hinge
using a Talon Handling Tool.
45°
READY TO CLOSE
LED