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 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 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 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, 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 [phone]; in Canada, call S&C Electric Canada Ltd. at [phone].
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
Ofce, 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 Figures1 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
Figure11 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
Figure14.
Pull out using
both hands
Chassis cover
Figure 14. Remove the chassis cover.

S&C Instruction Sheet 811-510 11
Disassembling the Loadbuster Loadbreak Tool
Step 12
Unscrew and remove the bearing retainer from the chassis,
and remove the inner tube seal and the bearing. See
Figure15.
Bearing
retainer
Bearing
Bearing
retainer
Inner tube
seal
Chassis
Figure 15. Remove the bearing retainer from the chassis along
with the inner tube seal and the bearing.
Step 13
Use a drift pin or S&C spanner wrench (NA-1057) in the
wrenching hole to unscrew the contact tube from the
moving contact assembly. Remove the tube. See Figure16.
This concludes the Loadbuster tool disassembly.
Spanner
Contact tube
Moving contact assembly
Figure 16. Unscrew the contact tube from the moving contact.

12 S&C Instruction Sheet 811-510
Inspecting the Key Parts of the Loadbuster Loadbreak Tool
Step 14
Trigger assembly Inspection
Examine the trigger to make sure the spring is working
and the key is still secure and in place. Look for evidence
of excessive wear, a broken spring, or burning or pitting of
any part of the assembly. Replace entire trigger assembly
if necessary. See Figure 17.
Spring
Key
Figure 17. Inspect the trigger assembly.
Step 15
Moving contact assembly inspection Spring
Moving contact
Trailer
Blue dot
Flexible cable
Figure 18. Inspect the moving contact assembly.
Trailer
Figure 19. Measure the diameter of the trailer. Do not measure
the chamfered ends.
NOTICE
Do not soak any part of the Loadbuster Loadbreak Tool
in cleaning solution or water. The Loadbuster Loadbreak
Tool and its components are not designed for submer-
sion in water or solvent. Damage to the tool may result.
To inspect the moving contact assembly:
(a) Use water and a liquid abrasive-type household
cleanser to remove surface carbon deposits from the
trailer and the moving contact. Thoroughly rinse and
dry the assembly immediately after cleaning. DO NOT
submerge the moving contact assembly in water or
cleaning solution. See Figure 18.
(b) If necessary, use an Emery cloth to polish the moving
contact. Avoid heavy ling that would change the
dimensions.
(c) Pull either end of the assembly to extend the spring.
Examine the exible cable inside the spring for signs of
wear or fraying. Make sure the cable is securely
connected at both ends. See Figure 18.
(d) Using a micrometer, check the diameter of the trailer.
Note: Exercise care to avoid mechanical damage to the
trailer. See Figure 19.
If the trailer diameter is 0.650 inch (16.5 mm) or less at
any point other than the chamfered ends, or if the flexible
cable is frayed, replace the moving contact assembly and
inner tube assembly. S&C also recommends replacing the
stationary contact assembly, guide bearing, and the silencer
at the same time.
NOTICE
Loadbuster Tools with a red dot on the trailer (manufac-
tured before August 2002) can be operated 500 to 1,000
times before inspection and maintenance are required.
Tools with a blue dot on the trailer (manufactured during
or after August 2002) can be operated 1,500 to 2,000
times before inspection and maintenance are required.

S&C Instruction Sheet 811-510 13
Inspecting the Key Parts of the Loadbuster Loadbreak Tool
Step 16
Inner tube assembly Inspection
Do not replace the inner tube assembly unless the diameter
of the trailer is 0.650 inch (16.5 mm) or less, as described
in Step 15(d). If replacement is not required, use water and
an abrasive-type household cleanser applied with a bottle
brush to remove any surface carbon deposits from the liner
of the inner tube assembly. Thoroughly rinse and dry the
assembly immediately after cleaning. See Figure 20.
Minor scratches on the inner tube assembly are allow-
able. Tubes with rough scratches must be replaced because
the rough scratches may impede proper operation of the
Loadbuster Loadbreak Tool. DO NOT repaint the tube.
Check the length of the
inner tube for scratches
Figure 20. Inspect the inner tube assembly.
Step 17
Inner tube seal Inspection
Examine the inner tube seal. Replace the seal if it is cracked,
deformed, or damaged in any way. S&C recommends
replacing the inner tube seal when the inner tube assembly
is replaced. See Figure 21.
Check for cracks
in the seal
Figure 21. Inspect the inner tube seal.
Step 18
Stationary contact assembly inspection
Use water and an abrasive-type household cleanser to
remove any surface carbon deposits from the stationary
contact assembly. Thoroughly rinse and dry the assembly
immediately after cleaning. Examine the stationary contact
assembly for extreme pitting, erosion, or cracking. Light
polishing is permissible, but avoid heavy ling that would
change the dimensions. Replace the stationary contact if
the ring inside the contact is bent. Be careful not to drop
the contact assembly. See Figure 22.
Check surface for damage
Stationary
contact ring
Figure 22. Inspect the stationary contact assembly.

14 S&C Instruction Sheet 811-510
Inspecting the Key Parts of the Loadbuster Loadbreak Tool
Step 19
Anchor assembly inspection
Use an Emery cloth to polish the surface and remove pitting.
If the anchor assembly is severely pitted or burned, or if
the spring does not work, replace the anchor assembly.
See Figure 23.
Key
Springs
Figure 23. Inspect the anchor assembly.
Step 20
Resetting latch inspection
Examine the resetting latch and look for excessive wear on
the latching surface. The latching surface should be at. Pull
the latch and check the springs. Replace the resetting latch
if it is deformed or damaged. See Figure 24.
Resetting Latch
Check the condition
of the resetting latch
Detail view
Figure 24. Inspect the resetting latch.
Step 21
Hook frame attachment assembly inspection
Look for excessive burning or pitting on all contact surfaces
on the hook frame attachment assembly. Make sure the
pull ring hook is straight and the spring in the pivot contact
is working properly. The spring in the pivot should allow
movement in the same direction as the pivot contact. The
pivot also should move freely side to side. Replace the hook
frame attachment assembly if it is damaged. See Figure25. Pull-ring
hook
Pivot
contact
Pivot
Springs
Figure 25. Inspect the hook frame attachment assembly.

S&C Instruction Sheet 811-510 15
Inspecting the Key Parts of the Loadbuster Loadbreak Tool
Step 22
Chassis Inspection
Clean the chassis with a cloth and household detergent to
remove grease or dirt. DO NOT soak the chassis in water
or detergent solution. Replace the shunt strap if it is badly
burned. Check the hook frame assembly springs to make
sure they are in good condition and hold tension. Replace
the springs if necessary. The hook frame assembly should
move approximately 65° “in and out” and “side to side”
approximately 35° in each direction. Contact your local
S&C Sales Ofce if the chassis does not rotate properly.
Replace any missing or faded product labels. See Figure
26 and refer to page 4.
Chassis
Hook frame assembly
should open freely
Shunt strap
Hook frame assembly
should rotate freely
Figure 26. Inspect the chassis.
Step 23
Bearing and bearing retainer inspection
Examine the bearing and bearing retainer for evidence of
mechanical damage. See Figure 27. Replace as required.
Bearing Bearing retainer
Figure 27. Inspect the bearing and bearing retainer.
Step 24
Silencer Inspection
Check the silencer to make sure the snubber (gasket) is in
good condition. Also look inside and make sure there is no
corrosion and that the mesh is in good condition. Push the
pin that actuates the counter. The counter should advance
to the next “operation number.” Replace the silencer if there
is any evidence of damage. See Figure 28.
Mesh
Snubber
(gasket)
Figure 28. Inspect the silencer.

16 S&C Instruction Sheet 811-510
Assembling the Loadbuster Loadbreak Tool
Step 25
Install the stationary contact assembly in the inner tube
assembly. Use the /-inch Allen key to install a new socket
head set screw. Make sure that its point engages the locating
hole in the stationary contact assembly. Tighten the socket
head set screw rmly, but avoid overtightening that may
bend the stationary contact assembly. See Figure 29.
Align the holes
Set screw
Figure 29. Install the stationary contact assembly to the
inner tube assembly.
Step 26
To assemble the inner tube assembly: See Figure 30 and
Figure 31.
(a) Apply a thin coating of silicone oil to the surface of the
inner tube assembly.
(b) Slide the bearing retainer onto the inner tube assembly.
NOTICE
The inner tube seal will not perform properly unless it is
installed with its flared edge pointing toward the station-
ary contact end of the inner tube assembly.
(c) Slide the inner tube seal onto the assembly. If the seal is
difcult to put on the inner tube assembly, expand its
inner diameter somewhat by rotating it against a
thumbnail or other smooth object. Use care to avoid
damaging the seal. The seal material has a “memory”
and will soon return to its original shape. Immediately
place the ared edge of the inner tube seal squarely
against the metal insert on the lower end of the inner
tube assembly. Then, using a slight twisting motion,
work the inner tube seal onto the inner tube assembly,
taking care to avoid damaging or inverting the seal,
especially when sliding the seal past the at area on the
inner tube assembly.
(d) Slide the bearing onto the inner tube assembly.
Figure 30. Apply a layer of silicone oil.
Bearing
retainer
Inner tube
seal
Stationary
contact
Bearing
Flared end towards
stationary contact end
Inner tube seal detail
Figure 31. Assemble the inner tube assembly. Detail view of
inner seal. Make sure the flared end is pointing toward the
stationary contact end of the inner tube assembly.

S&C Instruction Sheet 811-510 17
Step 27
Insert the inner tube assembly into the chassis, lifting the
resetting latch to provide clearance for the inner tube. See
Figure 32.
Inner tube assembly
Chassis
Figure 32. Insert the inner tube assembly into the chassis.
Step 28
Thread the bearing retainer rmly onto the chassis. See
Figure 33.
ChassisBearing retainer
Figure 33. Thread the bearing retainer onto the chassis.
Step 29
Reinstall the chassis cover. See Figure 34.
Chassis cover
Figure 34. Install the chassis cover.
Step 30
Extend the inner tube assembly approximately two inches
(51 mm). See Figure 35.
2 inches
Inner tube assembly
Figure 35. Extend the inner tube assembly.
Assembling the Loadbuster Loadbreak Tool

18 S&C Instruction Sheet 811-510
Assembling the Loadbuster Loadbreak Tool
Step 31
Install the anchor assembly so the key on the anchor
assembly mates with a slot in the ferrule of the inner tube
assembly. See Figure 36.
Anchor assembly
Key
Slot
Figure 36. Install the anchor assembly so the key mates with
the slot on the inner tube assembly.
Step 32
Reinstall the retaining ring. Position the retaining ring so
the concave shape is toward the anchor assembly. Use a
hammer or mallet to secure the ring in place around the
inner tube assembly and the anchor assembly. See Figure 37.
Retaining ring
Figure 37. Reinstall the retaining ring. Make sure the ring is
bowed toward the surface of the anchor assembly.Tap it into
place with a mallet.
Step 33
Reinstall the silencer on the inner tube assembly. If
the silencer has metal threads, apply a light coating of
petroleum jelly to the threads. See Figure 38.
Silencer
Figure 38. Reinstall the silencer.

S&C Instruction Sheet 811-510 19
Assembling the Loadbuster Loadbreak Tool
Step 34
Screw the contact tube onto the moving contact assembly.
Use a drift pin or spanner wrench (NA-1057) in the
wrenching hole while tightening the threads. See Figure 39.
Contact tube
Moving contact
assembly
Figure 39. Install the contact tube onto the moving contact
assembly.
Step 35
Slide the guide bearing over the open end of the contact
tube. See Figure 40.
Guide bearing
Figure 40. Install the guide bearing.
Step 36
Apply a light coating of DC-MOLY-GN paste lubricant to the
trigger end of the moving contact assembly. See Figure 41.
Moving contact assembly
Figure 41. Apply lubricant to the trigger end of the moving
contact assembly.
Step 37
Insert the moving contact assembly into the inner tube
assembly, trailer end rst, making certain the guide bearing
is seated in the inner tube assembly. See Figure 42.
Figure 42. Insert the moving contact assembly into the inner
tube assembly.

20 S&C Instruction Sheet 811-510
Assembling the Loadbuster Loadbreak Tool
Step 38
Apply a light coating of DC-MOLY-GN paste lubricant to the
latching area of the trigger only. See Figure 43.
Figure 43. Apply lubricant to the latching area of the trigger.
Step 39
Insert the trigger into the inner tube assembly. Use a
screwdriver to depress the trigger latch and extend the
moving contact assembly through the trigger assembly.
See Figure 44.
Trigger
assembly
Figure 44. Insert the trigger into the inner tube assembly.
Depress the trigger to extend the moving contact assembly.
Step 40
Rotate the anchor assembly as required to center the
anchor with the pull-ring hook. Using 4 new screws, attach
the trigger assembly to the inner tube assembly, aligning
the guide pin on the trigger assembly with the slot in the
chassis. See Figure 45.
Rotate anchor
to center
Trigger Moving contact
assembly
Trigger assembly
(4) screws
Figure 45.With the moving contact extended, turn the anchor
to align the holes in the trigger with the holes in the inner
tube assembly. Attach the trigger assembly to the inner tube
assembly.