S&C VacuFuse II User manual

December 19, 2022
© S&C Electric Company 2022, all rights reserved Instruction Sheet 466-500
VacuFuse®II Self-Resetting Interrupter
Outdoor Distribution (12.47 kV through 27.0 kV)
For Overhead Distribution Transformer
Protection
Installation and Operation
Table of Contents
Introduction � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 2
Qualified Persons ........................... 2
Read this Instruction Sheet ................... 2
Retain this Instruction Sheet .................. 2
Proper Application .......................... 2
Operating Considerations..................... 3
Warranty .................................. 3
Warranty Qualifications ...................... 4
Application Note ............................ 4
Safety Information� � � � � � � � � � � � � � � � � � � � � � � � 5
Understanding Safety-Alert Messages........... 5
Following Safety Instructions .................. 5
Replacement Instructions and Labels ........... 5
Location of Safety Labels ..................... 6
Safety Precautions ������������������������� 7
Shipping and Handling � � � � � � � � � � � � � � � � � � � � 8
Inspection ................................. 8
Packing ................................... 8
Handling .................................. 8
Storage ................................... 8
Returning ................................. 8
Before Starting � � � � � � � � � � � � � � � � � � � � � � � � � � 9
VacuFuse II Interrupter Parts .................. 9
Understanding the Closing Sequence ...........10
Understanding the LED Indicators and
POSITION Indicator .......................10
Installation � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 12
Installing the Cutout Mounting .................12
Installing a VacuFuse II Interrupter into the
Cutout Mounting..........................13
Closing the VacuFuse II Interrupter into the
Cutout Mounting..........................14
Operation � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 15
If the VacuFuse II Self-Resetting Interrupter
Has Dropped Open .......................15
If Maintenance Is to Be Performed on the
Transformer .............................16
Opening and Closing the VacuFuse II Interrupter ...16
Removing the VacuFuse II Interrupter
from the Cutout Mounting...................18
Operation Using Loadbuster®—
The S&C Loadbreak Tool ...................19
Troubleshooting � � � � � � � � � � � � � � � � � � � � � � � � 23
Unable to Close a VacuFuse II Interrupter into its
Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
In Mounting With Contacts Open .............. 23
Vacuum Interrupter Cannot Be Closed.......... 23

2 S&C Instruction Sheet 466-500
Introduction
WARNING
Only qualified persons who are knowledgeable in the installation, operation, and maintenance
of distribution fusing equipment, along with all associated hazards, may install, operate, and
maintain the equipment covered by this publication. A qualified person is someone who is
trained and competent in:
• The skills and techniques necessary to distinguish exposed live parts from nonlive parts
of electrical equipment
• The skills and techniques necessary to determine the proper approach distances
corresponding to the voltages to which the qualified person will be exposed
• The proper use of special precautionary techniques, personal protective equipment,
insulating and shielding materials, and insulated tools for working on or near exposed
energized parts of electrical equipment
These instructions are intended ONLY for such qualified persons. They are not intended to
be a substitute for adequate training and experience in safety procedures for this type of
equipment.
NOTICE
Thoroughly and carefully read this instruction sheet before installing or operating a
VacuFuse II Self-Resetting Interrupter. Become familiar with the Safety Information and
Safety Precautions on pages 5 through 7. The latest version of this publication is available
online in PDF format at sandc�com/en/support/product-literature/.
This instruction sheet is a permanent part of the VacuFuse II Self-Resetting Interrupter. Designate
a location where users can easily retrieve and refer to this publication.
WARNING
The VacuFuse II Self-Resetting Interrupter is only intended for the protection of distribution
transformers. The application must be within the ratings furnished for the equipment. Ratings
for the VacuFuse II Self-Resetting Interrupter are listed in the ratings table in Specification
Bulletin 466-31. They are also etched on the body of the interrupter.
Qualified
Persons
Read this
Instruction
Sheet
Retain this
Instruction
Sheet
Proper
Application

S&C Instruction Sheet 466-500 3
Introduction
The warranty and/or obligations described in S&C’s Price Sheet 150 “Standard Conditions of Sale
– Immediate Purchasers in the United States” (or Price Sheet 153, “Standard Conditions of Sale –
Immediate Purchasers Outside the United States”), plus any special warranty provisions, as set
forth in the applicable product-line specication bulletin, are exclusive. The remedies provided
in the former for breach of these warranties shall constitute the immediate purchaser’s or end
user’s exclusive remedy and a fulllment of the seller’s entire liability. In no event shall the seller’s
liability to the immediate purchaser or end user exceed the price of the specic product that gives
rise to the immediate purchaser’s or end user’s claim. All other warranties, whether express or
implied or arising by operation of law, course of dealing, usage of trade or otherwise, are excluded.
The only warranties are those stated in Price Sheet 150 (or Price Sheet 153), and THERE ARE NO
EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. ANY EXPRESS WARRANTY OR OTHER OBLIGATION PROVIDED IN PRICE SHEET 150
(OR PRICE SHEET 153) IS GRANTED ONLY TO THE IMMEDIATE PURCHASER AND END USER,
AS DEFINED THEREIN. OTHER THAN AN END USER, NO REMOTE PURCHASER MAY RELY
ON ANY AFFIRMATION OF FACT OR PROMISE THAT RELATES TO THE GOODS DESCRIBED
HEREIN, ANY DESCRIPTION THAT RELATES TO THE GOODS, OR ANY REMEDIAL PROMISE
INCLUDED IN PRICE SHEET 150 (OR PRICE SHEET 153.)
Warranty
For VacuFuse II Self-Resetting Interrupters with the Reclose feature: The VacuFuse II
Self-Resetting Interrupter is factory-set with a TCC curve, an open interval between the initial
trip (TCC0) and the rst test (TCC1) of 45 ±10 seconds, as well as a sequence reset time (between
30 seconds and 15 minutes.)
The sequence of operation is as follows: The interrupter will open once in response to its TCC
curve and will have an open interval lasting 45 ±10 seconds. Then, it will close, and its TCC curve
will again become active.
If the fault is still on the line, the VacuFuse II Self-Resetting Interrupter will lock open and drop
out. If fault current is not still on the line, the Sequence Reset Time timer will begin timing. If
another fault occurs during this time, the VacuFuse II Self-Resetting Interrupter will lock open
and drop out. If this timer expires without the VacuFuse II interrupter detecting fault current, the
VacuFuse II interrupter will reset to TCC0. Unless it has been specifically requested at the time of
order, TCC0 is the same curve as TCC1.
For Non-Reclosing VacuFuse II Interrupters: Non-reclosing VacuFuse II interrupters are
factory-set with a single TCC curve. The sequence of operation is as follows: The interrupter will
open once in response to its TCC curve and lock open. When sufficient energy has built up in the
device (45 ±10 seconds), the unit will drop out.
Operating
Considerations

4 S&C Instruction Sheet 466-500
Introduction
The seller’s warranties do not apply to VacuFuse II interrupters installed in other than a present-
production (“-R10” or “-R11”) S&C-provided cutout mounting.
NOTICE
When retrofitting VacuFuse II interrupters in an existing cutout mounting: To
ensure proper performance, VacuFuse II interrupters must only be installed in a present-
production (“-R10” or “-R11”) S&C-provided cutout mounting. See the example in Figure 1. An
example of an earlier-production S&C cutout mounting is shown in Figure 2. The warranty set
forth in S&C Price Sheet 150 does not apply to a VacuFuse II interrupter retrofitted in other
than a present-production (“-R10” or “-R11”) S&C-provided cutout mounting.
VacuFuse II Self-Resetting Interrupters are expressly designed for protecting solidly grounded
single-phase overhead distribution transformers with primary voltages of 7.2 kV to 15.5 kV. These
voltages correspond to the line-to-neutral voltages of single-phase transformers on systems rated
12.47 kV to 27.0 kV.
Warranty
Qualifications
Application
Note
Figure 1� A present-production (“-R10” or
“-R11”) S&C-provided Type XS Fuse Cutout
mounting�
Figure 2� An earlier-production (“-R9”) S&C
Type XS Fuse Cutout mounting� “-R8” and
earlier versions have a similar upper contact�

Safety Information
S&C Instruction Sheet 466-500 5
Several types of safety-alert messages may appear throughout this instruction sheet and on
labels and tags attached to the VacuFuse II Self-Resetting Interrupter. Become familiar with
these messages and the importance of these signal words:
DANGER
“DANGER” identifies the most serious and immediate hazards that will likely result in serious
personal injury or death if instructions, including recommended precautions, are not followed.
WARNING
“WARNING” identifies hazards or unsafe practices that can result in serious personal injury
or death if instructions, including recommended precautions, are not followed.
CAUTION
“CAUTION” identifies hazards or unsafe practices that can result in minor personal injury if
instructions, including recommended precautions, are not followed.
NOTICE
“NOTICE” identifies important procedures or requirements that can result in product or
property damage if instructions are not followed.
If any portion of this instruction sheet is unclear and assistance is needed, contact the nearest
S&C Sales Ofce or S&C Authorized Distributor. Their telephone numbers are listed on S&C’s
website sandc.com, or call the S&C Global Support and Monitoring Center at 1-888-762-1100.
NOTICE
Read this instruction sheet thoroughly and carefully before
installing the VacuFuse II Self-Resetting Interrupter.
If additional copies of this instruction sheet are required, contact the nearest S&C Sales Ofce,
S&C Authorized Distributor, S&C Headquarters, or S&C Electric Canada Ltd. The latest version
is available online in PDF format at sandc.com/en/Support/Product-Literature/.
It is important that any missing, damaged, or faded labels on the equipment be replaced
immediately. Replacement labels are available by contacting the nearest S&C Sales Office, S&C
Authorized Distributor, S&C Headquarters, or S&C Electric Canada Ltd.
Understanding
Safety-Alert
Messages
Following
Safety
Instructions
Replacement
Instructions
andLabels

Safety Information
6 S&C Instruction Sheet 466-500
Reorder Information for Safety Labels
Location Safety Alert Message Description Part Number
A
WARNING A VacuFuse® II Self-Resetting Interrupter must be dropped out from the cutout
mounting to be considered OPEN and de-energized.
Device may be energized from either side…
G-9842
DANGER
BTCC Curve (Label displaying the VacuFuse II interrupter’s protection curve) ●
●Contact the nearest S&C Sales Office.
B
A
Location of Safety Labels

S&C Instruction Sheet 466-500 7
Safety Precautions
DANGER
The VacuFuse II Self-Resetting Interrupter operates at high voltage. Failure to
observe the precautions below will result in serious personal injury or death.
Some of these precautions may differ from your company’s operating procedures
and rules. Where a discrepancy exists, follow your company’s operating procedures
and rules.
1. QUALIFIED PERSONS� Access to the VacuFuse II
Self-Resetting Interrupter must be restricted only to
qualified persons. See the “Qualified Persons”
section on page 2.
2. SAFETY PROCEDURES� Always follow safe
operating procedures and rules.
3. PERSONAL PROTECTIVE EQUIPMENT� Always
use suitable protective equipment, such as rubber
gloves, rubber mats, hard hats, safety glasses, and
flash clothing, in accordance with safe operating
procedures and rules.
4. SAFETY LABELS� Do not remove or obscure any
of the “DANGER,” “WARNING,” “CAUTION,” or
“NOTICE” labels and tags. Remove tags ONLY if
instructed to do so.
5. ENERGIZED COMPONENTS� Always consider all
parts live until de-energized, tested, and grounded.
6. OPERATING TOOLS� To close a VacuFuse II Self-
Resetting Interrupter, use a conventional insulated
hotstick or S&C Universal Pole and Pole Extension
fitted with a Talon™ Handling Tool or distribution
prong. An extendostick also can be used after
proper training and practice. When energized or
installed near energized lines, contacts should be
considered live until tested and grounded. The
VacuFuse II interrupter can be operated using
Loadbuster®— The S&C Loadbreak Tool attached
to a conventional insulated hotstick or S&C
Universal Pole.
7. MAINTAINING PROPER CLEARANCE� Always
maintain proper clearance from energized
components.
8. DO NOT DISASSEMBLE the VacuFuse II Self-
Resetting Interrupter. There are no customer-
serviceable parts inside the VacuFuse II interrupter,
and disassembling the VacuFuse II interrupter will
void the warranty.
9. VACUUM INTERRUPTER POSITION� Always
confirm the Open/Closed position of the VacuFuse
II Self-Resetting Interrupter’s vacuum interrupter by
observing the POSITION indicator on the bottom of
the unit. The manual operating lever will not move
when the position of the vacuum interrupter
changes.

8 S&C Instruction Sheet 466-500
Shipping and Handling
Inspection
Examine the shipment for external evidence of damage as
soon after receipt as possible, preferably before removal
from the carrier’s conveyance. Check the bill of lading to
make sure the listed shipping skids, crates, and containers
are present. If there is visible loss or damage:
1. Notify the delivering carrier immediately.
2. Ask for a carrier inspection.
3. Note the condition of shipment on all copies of the
delivery receipt.
4. File a claim with the carrier.
If concealed damage is discovered:
1. Notify the delivering carrier within 15 days of receipt of
shipment.
2. Ask for a carrier inspection.
3. File a claim with the carrier.
Packing
A complete VacuFuse II Self-Resetting Interrupter consists
of the following components:
• The VacuFuse II Self-Resetting Interrupter
• A present-production (“-R10”) Type XS Cutout Mounting
and miscellaneous mounting hardware for securing the
cutout mounting to the pole, if specied
Handling
NOTICE
DO NOT DROP the VacuFuse II Self-Resetting
Interrupter or subject any of its parts to undue stress
during installation. Only remove a VacuFuse II Self-
Resetting Interrupter from the carton immediately
before installation.
Storage
VacuFuse II Self-Resetting Interrupters are shipped
on pallets banded with plastic wrap. This packaging
is designed to protect the VacuFuse II interrupters
from freight damage. This packaging is not suitable for
outdoor storage because it can pool water and damage
VacuFuse II interrupters. After receipt, VacuFuse II
interrupters should be stored indoors in their shipping
packaging. Storing VacuFuse II interrupters outdoors in
the shipping packaging will void the warranty.
Returning
When returning the VacuFuse II Self-Resetting Interrupter
for any reason, place the VacuFuse II interrupter in
the original shipping carton to prevent damage during
shipment. If additional shipping cartons are required,
contact the nearest S&C Sales Ofce, S&C Authorized
Distributor, or S&C Headquarters.

S&C Instruction Sheet 466-500 9
VacuFuse II Interrupter Parts
Become familiar with the parts of the VacuFuse II Self-
Resetting Interrupter. See Figure 3.
Figure 3� An overview of the VacuFuse II Self-Resetting Interrupter�
POSITION indicator
CHARGING LED
Manual operating
lever
Hinge-end contact
Jaw-end contact
Pull-ring
Before Starting
Trunnion
READY TO CLOSE LED

10 S&C Instruction Sheet 466-500
Before Starting
Understanding the Closing Sequence
Note: The VacuFuse II Self-Resetting Interrupter is
shipped from the factory with the vacuum interrupter in
the Open position.
After closing the VacuFuse II Self-Resetting Interrupter
into the cutout mounting, the CHARGING LED will blink
at a 1-second interval as long as there is sufcient voltage
present at the cutout mounting and the vacuum interrupter
is open.
The READY TO CLOSE LED will steadily illuminate
when the VacuFuse II Self-Resetting Interrupter has har-
vested enough energy to close the vacuum interrupter and
when the manual operating lever is in the Down position.
The VacuFuse II Self-Resetting Interrupter requires
45 ± 10 seconds to harvest enough energy to close the
vacuum interrupter.
There are two ways to close the vacuum interrupter:
Option 1 – Automatic Delayed Close
Place the manual operating lever into the Up position prior
to closing the unit into the cutout mounting, or less than
35 seconds after the CHARGING LED has begun blinking.
When closed into the cutout mounting in this state, the
CHARGING LED will blink at a 1-second interval if there
is sufcient voltage present at the cutout mounting and
the vacuum interrupter is open. The unit will automati-
cally close the vacuum interrupter after 45 ± 10 seconds.
Option 2 – Manual Close
Place the manual operating lever into the Down position
prior to closing the unit into the cutout mounting, or less
than 35 seconds after the CHARGING LED has begun
blinking.
Wait until the READY TO CLOSE LED is solidly lit. At
that time, the unit can be closed manually by moving the
manual operating lever to the Up position. Three seconds
after the lever is moved to the Up position, the vacuum
interrupter will close.
Understanding the LED Indicators and
POSITION Indicator
LED Indicators
There are two LEDs on the base of the VacuFuse II
interrupter. See Figure 4.
The CHARGING LED is white and indicates the
VacuFuse II interrupter is harvesting energy to close the
Figure 4� The LEDs on the base of the VacuFuse II
interrupter�
CHARGING
LED
READY TO
CLOSE LED