S&C Loadbuster User manual
Instruction Sheet 811-510
Loadbuster®—The S&C Loadbreak Tool
Outdoor Distribution (14.4 kV, 27 kV, and 34.5 kV)
©S&C Electric Company 2016, all rights reserved
December 5, 2016
Inspection and Maintenance
Table of Contents
Section Page Section Page
Introduction
Qualified Persons ..............................2
Read this Instruction Sheet.......................2
Retain this Instruction Sheet......................2
Video........................................2
Proper Application..............................2
Warranty .....................................2
Safety Information
Understanding Safety Alert Messages ..............3
Following Safety Instructions .....................3
Replacement Labels and Instructions...............3
Location of Safety Labels ........................4
Before Starting ................................5
Disassembling the Loadbuster
Loadbreak Tool..............................6
Inspecting the Key Parts of
the Loadbuster Loadbreak Tool..............12
Assembling the Loadbuster
Loadbreak Tool.............................16
Replacement Parts
Table of Replacement Parts .....................24
Enhanced Operating Life Upgrade Kits ............26
2S&C Instruction Sheet 811-510
Qualified Persons WARNING
The equipment covered by this publication must be installed, operated, and maintained by
qualified persons who are knowledgeable in the installation, operation, and maintenance
of primary distribution fusing equipment along with associated hazards. A qualified
person is one 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 the 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.
Read this
Instruction Sheet NOTICE
Thoroughly and carefully read this instruction sheet before performing maintenance and
repair on your Loadbuster—The S&C Loadbreak Tool. Familiarize yourself with the Safety
Information on pages 3 and 4. The latest version of this publication is available online in
PDF format at sandc.com/Support/Product-Literature.asp
Retain this
Instruction Sheet
This instruction sheet should be available for reference whenever the Loadbuster
Loadbreak Tool is repaired. Designate a location where you can easily retrieve and refer to it.
Video A video of the procedures in this instruction sheet is available at sandc.box.com/v/
loadbuster
Proper Application WARNING
The equipment in this publication is only intended for specific switching applications.
When used with appropriately designed “hook-equipped” disconnects, cutouts, power
fuses, dropout reclosers, fuse limiters, and pad-mounted gear, the Loadbuster Load-
break Tool is suitable for the live-switching of single- or three-phase overhead distribution
circuits through 34.5 kV and underground distribution circuits through 25 kV. These appli-
cations must be within the ratings furnished for the equipment. Ratings for the Loadbuster
Loadbreak Tool are listed on the ratings table in Specification Bulletin 811-31. The ratings
are also on the S&C product labeling on the Loadbuster Loadbreak Tool’s chassis.
Warranty The warranty and/or obligations described in S&C’s standard conditions of sale, as set
forth in Price Sheet 150, plus any special warranty provisions, as set forth in the applicable
product-line specication 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 fulllment of all of the seller’s liability. In no event shall the seller’s liability
to the immediate purchaser or end user exceed the price of the specic 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, 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 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.
Introduction
S&C Instruction Sheet 811-510 3
Understanding
Safety-Alert
Messages
Several types of safety-alert messages may appear throughout this instruction sheet as well
as on labels attached to the crate, packing, and equipment. Familiarize yourself with these
types of messages and the importance of the various signal words, as explained below.
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.
Following Safety
Instructions
If you do not understand any portion of this instruction sheet and need assistance,
contact your nearest S&C Sales Office or S&C Authorized Distributor. Their tele-
phone numbers are listed on S&C’s website sandc.com,or call S&C Headquarters
at (773) 338-1000; in Canada, call S&C Electric Canada Ltd. at (416) 249-9171.
NOTICE
Read this instruction sheet thoroughly and carefully
before installing or operating your S&C Loadbuster Load-
break Tool.
Replacement
Instructions
and Labels
If you need additional copies of this instruction sheet, contact your nearest S&C Sales
Ofce, S&C Authorized Distributor, S&C Headquarters, or S&C Electric Canada Ltd.
It is important that any missing, damaged, or faded labels on the equipment be replaced
immediately. Replacement labels are available by contacting your nearest S&C Sales Office,
S&C Authorized Distributor, S&C Headquarters, or S&C Electric Canada Ltd.
Safety Information
4S&C Instruction Sheet 811-510
Safety Information
A A A
B B
B
Reorder Information for Safety Information
Location Safety Alert
Message Description Part Number
ANOTE To ensure resetting, depress telescoping tube until orange band . . . G-5840R1
BWARNING RESET AFTER EACH OPERATION—To check for proper
resetting . . .
G-4401 (for 5300R3)
G-4401 (for 5300R3-E)
G-4320 (for 5400R3)
Location of Safety Labels
S&C Instruction Sheet 811-510 5
Before Starting
Before performing maintenance on the Loadbuster
Loadbreak Tool, please make sure you have the necessary
tools and materials listed below:
• /-inch combination wrench
• (2) flat-head screwdrivers, (/-inch and /-inch
recommended)
• /-inch Allen key
• S&C spanner wrench (NA-1057) or a /-inch drift pin
• Vernier calipers
• Emery cloth
• Rubber mallet (8–16 oz.)
• DC-Moly-GY lubricant (Part no. 0352-407)
• Petroleum jelly lubricant
• Silicone oil lubricant, DOW Corning DC 200 (5 cSt
viscosity) or equivalent
Cleaning supplies:
• Soft cloth or lint-free towels
• Liquid abrasive-type household cleanser
• Degreasing dish soap
• Bottle brush
Four trigger screws and one set screw have integral nylon
gaskets that will need to be replaced with new hardware.
Make sure you have the replacement trigger assembly hard-
ware and socket head set screw before disassembling your
Loadbuster Loadbreak Tool. S&C also recommends having
on hand a new inner-tube seal, a moving contact, silicone oil
lubricant, and DC-Moly-GN lubricant. For a detailed view of
Loadbuster Loadbreak Tool parts, see Figure 51 on page 23.
Necessary replacement parts to have on hand:
• Socket head set screw (Part no. NA-1048)
• Trigger assembly hardware (Part no. NA-1050)
Suggested replacement parts to have on hand:
• Inner tube seal (Part no. NA-1023)
• Moving contact (Part no. NA-1068-1 or NA-1068-2)
6S&C Instruction Sheet 811-510
Disassembling the Loadbuster Loadbreak Tool
Step 1
Loosen the tube cover with a rubber mallet and remove
the tube cover by pulling it out. Unscrew the end cap. Pull
the end cap out until the Loadbuster Loadbreak Tool trips,
then push the end cap back until the contact tube is inside
the chassis. See Figures1 and 2.
CAUTION
Keep fingers clear of the end of the chassis when trip-
ping the Loadbuster Loadbreak Tool. The contact tube
is spring loaded and will move quickly toward the trig-
ger assembly. Failure to keep fingers clear could cause
minor injury.
Tube cover
Figure 1. Use a mallet to loosen the tube cover.
End cap
Contact tube
Figure 2. Unscrew the end cap and pull it out until the Load-
buster Tool trips. Push the end cap into the tube until the
contact tube is inside the chassis.
Step 2
To prevent spinning, use a /-inch combination wrench to
hold the locknut on the underside of the end cap steady.
Use an appropriately sized at-head screwdriver to loosen
and remove the set screw followed by the retaining screw.
Remove the end cap. See Figures 3 and 4.
NOTICE
DO NOT remove the locknut from the moving contact. End cap with set screw Hold but DO NOT
remove locknut
Figure 3. Hold the locknut steady and loosen and remove
the set screw.
Set screw End cap
Figure 4. Remove the set and retaining screws.
S&C Instruction Sheet 811-510 7
Disassembling the Loadbuster Loadbreak Tool
Step 3
NOTICE
Use a hand-driven screwdriver to loosen the four screws.
A power-driven screwdriver may damage the trigger
assembly.
Remove the four screws that fasten the trigger assembly to
the inner tube assembly, and withdraw the trigger assembly.
Discard the screws. See Figure 5.
Screws (4)
Trigger
assembly
Figure 5. Remove the four screws securing the trigger assem-
bly to the inner tube assembly. Remove the trigger assembly.
Step 4
Withdraw the moving contact assembly, and then slide off
the guide bearing. See Figure 6.
Guide bearing
Moving contact assembly
Figure 6. Remove the moving contact assembly and slide off
the guide bearing.
Step 5
Carefully withdraw the inner tube assembly from the
chassis. See Figure 7.
Inner tube assembly
Figure 7. Remove the inner tube assembly.
8S&C Instruction Sheet 811-510
Disassembling the Loadbuster Loadbreak Tool
Step 6
Unscrew and remove the silencer. See Figure 8.
Silencer
Figure 8. Remove the silencer.
Step 7
Use the mallet and a screwdriver or other pry tool to loosen
and remove the retaining ring securing the anchor assembly
to the inner tube assembly. See Figures 9, 10, and
Figure11 on page 9.
Inner tube assembly
Retaining ring
Figure 9. Use a hammer and screwdriver to loosen the ring.
Inner tube assembly
Retaining ring
Anchor
assembly
Figure 10. Pry the retaining ring until it comes off of the inner
tube assembly.
S&C Instruction Sheet 811-510 9
Disassembling the Loadbuster Loadbreak Tool
Step 8
Remove the anchor assembly. See Figure 11. Anchor
assembly
Retaining ring
Anchor
assembly
Figure 11. Remove the retaining ring and anchor assembly.
Step 9
Use a /-inch Allen key to remove the socket-head set
screw. Discard the set screw. See Figure 12.
Allen key in set screw
Figure 12. Remove and discard the set screw.
10 S&C Instruction Sheet 811-510
Disassembling the Loadbuster Loadbreak Tool
Step 10
Withdraw the stationary contact assembly from inside the
inner tube. See Figure 13.
Stationary contact
assembly
Inner tube
Figure 13. Remove the stationary contact.
Step 11
Remove the chassis cover by slightly prying the cover
equally on both sides and sliding off the chassis. See
Figure14.
Pull out using
both hands
Chassis cover
Figure 14. Remove the chassis cover.
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