S and C 665-510 Pad Mounted Gear Instruction Manual
- August 21, 2024
- S AND C
Table of Contents
- Introduction
- Warranty
- Safety Information
- Location of Safety Labels
- Safety Precautions
- Overview
- Enclosure Doors
- Switching with a Mini-Rutter® Switch
- Fuse Access—Opening
- Assembling the Fuse
- Installing the Fuse in the Mounting
- Closing the TransFuser Mounting
- Re-Fusing
- Fusing
- Dielectric Testing
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
**S and C 665-510 Pad Mounted Gear Instruction Manual
**
Introduction
Qualified Persons
WARNING
Only qualified persons knowledgeable in the installation, operation, and
maintenance of overhead and underground electric distribution equipment, along
with all associated hazards, may install, operate, and maintain the equipment
covered by this publication. A qualified person is someone 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, insulated 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 and all materials
included in the product’s instruction handbook before installing or operating
manual PME Pad-Mounted Gear. Become familiar with the Safety Information on
pages 4 and 5 and Safety Precautions on page 6. The latest version of this
publication is available online in PDF format at sandc.com/en/contact-us
/product-literature/.
Retain this Instruction Sheet
This instruction sheet is a permanent part of the manual PME Pad-Mounted
Gear. Designate a location where users can easily retrieve and refer to this
publication.
Proper Application
WARNING
The equipment in this publication is only intended for a specific application.
The application must be within the ratings furnished for the equipment.
Ratings for manual PME Pad-Mounted Gear are listed in the ratings table in S&C
Specification Bulletin 665-31. The ratings are also on the nameplate affixed
to the product.
Warranty
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 specification 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 fulfillment 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 specific 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 OBLIGATIONPROVIDED 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 Qualifications
The standard warranty contained in the seller’s standard conditions of sale
(as set forth in Price Sheet 150) does not apply to manual PME Pad-Mounted
Gear where fuse units, fuse-unit end fittings, holders, refill units, or
switch blades of other than S&C manufacture are used in conjunction with S&C
SME Mountings. Nor does it apply to manual PME Pad-Mounted Gear where other
than Fault Fitter® Electronic Power Fuses, S&C Switch Blades, or the current-
limiting fuses listed in Table 2 of S&C Information Bulletin 660-50 are used
in conjunction with Fault Fiter Electronic Power Fuse mountings and S&C
Holders designed therefore, or where the current-limiting fuses are applied
other than as set forth in the “Recommended Voltage Ratings” section of S&C
Information Bulletin 660-50.
Safety Information
Understanding Safety-Alert Messages
Several types of safety-alert messages may appear throughout this
instruction sheet and on labels and tags attached to the product. Become
familiar with these types of messages and the importance of these various
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.
Following Safety Instructions
If any portion of this instruction sheet is unclear and assistance is
needed, contact the nearest S&C Sales Office 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 manual
PME Pad-Mounted Gear.
Replacement Instructions and Labels
If additional copies of this instruction sheet are required, contact the
nearest S&C Sales Office, 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 the
nearest S&C Sales Office, S&C Authorized Distributor, S&C Headquarters, or S&C
Electric Canada Ltd.
Location of Safety Labels
Reorder Information for Safety Labels
Location | Safety Alert Message | Description | Part Number |
---|---|---|---|
A | WARNING | Keep Out. Hazardous voltage inside. | G-6398● |
B | DANGER | Hazardous Voltage – more than 4000 volts… | G-6503 |
C | DANGER | Keep Away. Hazardous voltage-more than 4000 volts…. |
G-6500
Safety Precautions
DANGER
Manual PME Pad-Mounted Gear 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.
-
QUALIFIED PERSONS. Access to pad-mounted gear must be restricted only to qualified persons.
See the “Qualified Persons” section on page 2. -
SAFETY PROCEDURES. Always follow safe operating procedures and rules.
-
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.
-
SAFETY LABELS. Do not remove or obscure any of the “CAUTION,” “WARNING,” or “DANGER” labels.
-
KEY INTERLOCKS.
-
If optional key interlocks were furnished, they must be in place.
-
Check the operating sequence of key interlocks to verify proper sequencing.
-
After the pad-mounted gear is installed, either:
(1) destroy the extra set of keys or (2) make them accessible only to qualified persons. This will maintain the integrity of the key-interlock scheme. -
Key interlocks are not security locks and are not substitutes for padlocks.
-
-
OPENING DOORS. Do not force doors open. Forcing a door open can damage the latching mechanism. If optional key interlocks are provided, correctly position the interlocks so the doors can be opened.
-
CLOSING AND LOCKING DOORS.
- Doors must be securely closed and latched, with padlocks in place at all times unless work is being performed inside the enclosure.
- Mini-Rupter Switches have switch operatingshaftaccess covers located on the sides of the pad-mounted gear enclosure. They must be closed and padlocked at all times unless the switches are being operated.
- Do not close a door on a TransFuser Mounting in the Open position with a fuse in the mounting. The door will strike the fuse pull-ring, which will interfere with door closing. The door may be closed if the fuse is removed from the mounting.
-
ENERGIZED TERMINALS. Always assume both sets of power terminals on any Mini-Rupter Switch or fuse are energized unless proved otherwise by test, by visual evidence of open-circuit conditions on both sets of terminals, or by observing that both sets of terminals are grounded.
-
BACKFEED. Mini-Rupter Switches and fuses may be energized by backfeed.
-
DE-ENERGIZING, TESTING, AND GROUNDING. Before touching any device that is to be inspected, replaced, serviced, or repaired in the high-voltage compartments, always disconnect Mini-Rupter Switches and fuses from all power sources (including backfeed), test for voltage, and properly ground.
-
TESTING. Test for voltage on both sets of power terminals of any Mini-Rupter Switch or fuse using proper high-voltage test equipment before touching any device that is to be inspected, replaced, serviced, or repaired in the high-voltage compartments.
-
GROUNDING.
- Make sure the pad-mounted gear enclosure is properly grounded to the station or facility ground.
- After the gear has been completely disconnected from all sources of power and tested for voltage, install suitable grounding cables in all compartments before touching any device that is to be inspected, replaced, serviced, or repaired in the high-voltage compartments.
-
SWITCH POSITION.
- Always confirm the Open/Close position of Mini-Rupter Switches by visually observing the position of the switch blades.
- Switches may be energized by backfeed.
- Switches may be energized in any position.
-
MAINTAINING PROPER CLEARANCE. Always maintain proper clearance from energized components.
-
FUSE STORAGE.
- Always store fuses in a clean, dry location.
- Do not store end-fittings, holders, interrupting modules, or fuses in termination compartments unless the unit is equipped with the optional Fuse Storage feature.
Instruction manuals regarding installation and operation of the pad-mounted gear are included in the “Installation and Operation Information Kit” provided with each unit of manual PME Pad-Mounted Gear. A catalog dimensional drawing showing cable-locating and anchor-bolt dimensions is also provided in the information kit. All personnel involved with installation and operation of the gear should be thoroughly familiar with the contents of the kit.
The following instructions cover operation of fuses and Mini-Rupter Switches in manual PME Pad-Mounted Gear. For installation instructions, refer to S&C Instruction Sheet 665-505.
Manual PME Pad-Mounted Gear, which is available in ratings of 14.4 kV and 25 kV, permits manual switching and provides fault protection for underground distribution systems. This gear features elbow-connected encased components and accommodates separable insulated connectors. See Figure 1 on page 8. Each unit contains the following:
- External handle-operated 600-ampere Mini-Rupter Switches for three-pole live switching of three-phase source circuits
- TransFuser Mountings—fuse-handling mechanisms with mechanical interlocks (Models available offer a choice of Type SME-20 and SME-4Z Power Fuses, Fault Fiter Electronic Power Fuses, or a variety of single-barrel current-limiting fuses.)
- Penta-Latch® Mechanisms on each door (right-hand door only for double-door models) for access control (The mechanisms provide automatic door latching and permit padlocking only when the doors are latched closed. The doors can be opened only with a pentahead socket wrench or tool.)
A variety of optional features are available for manual PME Pad-Mounted Gear. The catalog number stamped on the nameplate affixed to the enclosure door is suffixed with letter-number combinations applicable to the gear furnished. Refer to S&C Specification Bulletin 665-31 for descriptions of the optional features.
Overview
Figure 1. The manual Model PME-9 showing open-door views of fuse-termination
compartments (top) and switch termination compartments (bottom).
DANGER
When access to high-voltage compartments is required for inspection, service,
or repairs, always observe the precautions below. Failure to observe these
precautions may result in serious personal injury or death.
- Access to pad-mount gear must be restricted only to qualified persons. See the “Qualified Persons” section on page 2.
- Always follow safe operating procedures and rules.
- Before touching any device, always disconnect switches and fuses from all power sources (including backfeed), test for voltage, and properly ground.
- Always assume both sets of power terminals on any switch or fuse are energized unless proved otherwise by test, by visual evidence of opencircuit conditions on both sets of terminals, or by observing that both sets of terminals are grounded.
- Test for voltage on both sets of power terminals of any switch or fuse using proper high-voltage test equipment.
- After the gear has been completely disconnected from all sources of power and tested for voltage, install suitable grounding cables in all compartments.
- Make sure the enclosure is properly grounded to the station or facility ground. Do not return equipment to service unless such grounds are properly made.
Enclosure Doors
Opening and Closing the Doors
Complete the following steps to open the doors:
Step 1. To access a side of the enclosure, remove the padlock from the
doors.
Step 2. Insert a pentahead socket wrench or tool (a hexhead socket wrench
or tool when catalog number suffix “-B1” or “-B2” is specified) into the
latching mechanism. Rotate the wrench or tool 60° counterclockwise to unlatch
the doors.
See Figure 2.
NOTICE
Do not apply any undue force when attempting to open the doors. The use of
undue force may damage the latching mechanism.
Step 3. Disengage the left-door latching mechanism by turning the latch clockwise. See Figure 3.
Step 4. Open each door fully and latch the door holders. See Figure 4.
Step 5. To gain access to the other side of the enclosure, repeat Steps 1 through 4 to open the doors.
Figure 2. To unlock the doors, turn the pentahead socket wrench 60°
counterclockwise against spring resistance until a “click” is heard and the
wrench reaches its stop.
Figure 3. The left-door latching mechanism disengaged.
Figure 4. Using the door holder to hold the door open.
Complete the following steps to close and lock the doors:
Step 1. Lift the door holder up to allow the door to swing closed. See Figure 5. Make sure the door holder is placed back in the storage position to allow the door to be fully closed. See Figure 6.
Step 2. Repeat Step 1 for the other door.
Step 3. Engage the left-door latching mechanism. See Figure 7.
Step 4. The right-hand door of the unit is equipped with the Penta-Latch Mechanism, which latches automatically when the door is closed. To close a door equipped with the Penta-Latch Mechanism, place one hand at the midpoint of the door-front near the edge and firmly push the door closed. When the latch points are positively engaged, the spring mechanism will trip to latch the door.
Step 5. Insert the padlock shackle through the hole in padlock recess and lock the padlock. See Figure 8.
Step 6. Repeat Steps 1 through 5 for the doors on the other side of the enclosure (if open)
Figure 5. Lift the door holder to allow the door to swing closed.
Figure 6. The door holder placed in the storage position to allow the door to close.
Figure 7. The left-door latching mechanism engaged.
Figure 8. The enclosure doors padlocked.
Switching with a Mini-Rutter® Switch
The Mini-Rutter Switch is a three-pole, 600-A switch used to switch between power sources. The operating shaft used to control the switch is located on the same side of the enclosure with respect to the switch location. See Figure 9, Figure 10, and Figure 11
Operating the Mini-Rutter Switch
Complete the following steps to operate the Mini-Rutter Switch:
Step 1. Remove the padlock and open the switch-operating-shaft access cover.
Step 2. Remove the folding switch-operating handle from its storage pocket behind the access cover. Unfold the handle until it is latched and slide it onto the hex switch-operating shaft.
Note: the SWITCH POSITION indicator attached to the hex switch-operating shaft and that rests against a stop in either the Open or Closed position. Arrows indicate the Switch Open or Switch Closed position.
Step 3. Rotate the handle in the appropriate direction to open or close the switch, and check the SWITCH POSITION indicator to verify the switch is in the desired position.
Step 4. Follow the instructions in the “Opening and Closing the Doors” section on page 10 to open the enclosure doors.
Figure 9. The access cover padlock.
Figure 10. The access cover door is open.
Figure 11. The switch operating handle installed.
Step 5. Check the physical position of the switch by using the viewing window provided in the switch-termination compartment. See Figure 12.
WARNING
Always confirm the Open/Close position of the Mini-Rupter Switch by visually
observing the position of the switch blades. Failure to do so can result in
personal injury
Step 6. Remove and fold the switch-operating handle, and return the handle to its Storage position. Then, close and padlock the access cover.
CAUTION
Do not leave the switch-operating-shaft access cover unlocked if the gear is
left unattended. Failure to do so can result in equipment damage and personal
injury
Step 7. Follow the instructions in the “Opening and Closing the Doors” section on page 10 to close and lock the enclosure doors
Figure 12. (a) Shows the switch in the Open position, and (b) shows the switch in the Closed position.
Fuse Access—Opening
Manual PME Pad-Mounted Gear is equipped with the unique Trans Fuser Mounting—a fuse-handling mechanism that is interlocked with the load break elbow. First, the elbow is removed to interrupt any fuse load. Then, the mechanical interlock is actuated, allowing operation of the Trans Fuser Mounting mechanism. This permits access to the fuse for quick and easy replacement of blown fuses with a conventional shotgun stick. The fuse is accessible only when it is de-energized and isolated.
DANGER
The following procedures presuppose the user has supplied and installed load
break inserts and load break elbows.
Open the Mini-Rutter Switches before proceeding if dead break inserts and dead
break elbows are installed, or if company operating procedures and rules do
not permit switching with elbows. Failure to open the switches when daybreak
inserts and elbows are used
Opening the Transfuse™ Mounting
Complete the following steps to open a Transfuse Mounting:
Step 1. Open the appropriate fuse termination-compartment door and secure it with the door holder. See Figure 13. On double-door models, the adjacent door should be closed and latched to minimize exposure.
Figure 13. The termination compartment for fuses with elbows installed on 200-ampere inserts in the bushing wells.
Step 2. Using a shotgun stick, install a portable feedthru or standoff insulator on the parking stand directly above the cable guide of the elbow to be moved. This will ensure whenthe elbow is moved, the cable will not interfere with the TransFuser Mounting. Using the shotgun stick, and following the elbow manufacturer’s instructions for loadbreak operation, remove the 200-ampere loadbreak elbow (thus interrupting any load through the fuse to be removed), and move the elbow to the portable feedthru or standoff insulator. See Figure 14.
WARNING
When changing fuses, the 200-ampere interface need not be covered because it
will be exposed only temporarily. If company operating procedures and rules
require it, the interface may be covered with an insulating protective cap
without a drain wire. A cap with a drain wire must not be used. Operation
ofthe TransFuser mechanism will draw the grounded drain wire inside the
medium-voltage compartment close to energized parts, which can result in a
flashover and serious injury.
WARNING
If elbows are stored on feedthru or standoff insulators for an extended
periodof time, cover the 200-ampere interface with an insulating protective
cap with a drain wire and connect the drain wire to the ground bail. Failure
to connect the drain wire to the ground bail can result in a flashover,
injury, and equipment damage.
NOTICE
The insulated protective cap and drain wire must be removed before operating
the TransFuser mechanism. Failure to remove the cap and drain wire will
interfere with operation of the mechanism.
Figure 14. Removing the loadbreak elbow interrupts any load through the fuse to be removed.
Step 3. When the elbow has been moved and mounted on a feedthru or
standoff insulator, the TransFuser Mounting mechanism may be operated.
Using the shotgun stick, raise the mechanical interlock to unlock the
TransFuser Mounting.
See Figure 15. This interlock, which cannot be lifted to the unlocked position
until the elbow has been removed, guards against gaining access to the fuse
while it is carrying current.
Step 4. Secure the shotgun stick to the pull-ring at the lower end of the TransFuser Mounting. Be sure not to ratchet the shotgun stick all the way up when securing the pull-ring as it may hinder with the movement of the TransFuser Mounting. See Figure 16. With an outward pull, rotate the TransFuser Mounting end-for-end to expose the fuse in one motion.
Figure 15. Raising the mechanical interlock to unlock the Trans Fuser Mounting.
Figure 16. Unlatching (or latching) a TransFuser Mounting in the Closed position.
Make sure the mounting is latched before removing the shotgun stick. Then, disengage the shotgun stick from the pull-ring. Using the shotgun stick, push against the top of the mounting to verify it has securely latched. With the TransFuser Mounting latched in the Openposition, the fuse is de-energized, isolated from high voltage, and accessible for removal from the mounting using the shotgun stick. See Figure 17.
NOTICE
Do not close a door on a TransFuser Mounting in the Open position with a fuse
in the mounting. The door will strike the fuse pull-ring, which will interfere
with door closing. The door may be closed if the fuse is removed from the
mounting.
Figure 17. Latching (or unlatching) a TransFuser Mounting in the Open position.
Manual PME Pad-Mounted Gear is furnished with TransFuser Mountings that accommodate Type SME-20 Power Fuses, Type SME-4Z Power Fuses, or Fault Fiter Electronic Power Fuses. Fault Fiter Electronic Power Fuse Mountings also accommodate a variety of current-limiting fuses.
WARNING
When selecting current-limiting fuses, the voltage rating of the fuses must
conform to the recommendations in S&C Information Bulletin 660-50. Failure to
conform to these recommendations can result in a flashover, injury, and
equipment damage.
Assembling the Fuse
S &C Power Fuse
Install an SMU-20® Fuse Unit into each set of end fittings, an SM-4® Refill
Unit into each holder, or a Fault Fiter Interrupting Module and Control Module
into each holder in accordance with the instruction sheet furnished with the
fuse unit, refill unit, or interrupting module.
Current-Limiting Fuses
S&C Holders for current-limiting fuses are designed for use in pad-mounted
gear models that include mountings for Fault Fiter Electronic Power Fuses.
These holders will accommodate the current-limiting fuses listed in Table 2 of
S&C Information Bulletin 660-50.
For instructions on installing current-limiting fuses in current-limiting fuse
holders, refer to S&C Instruction Sheet 660-501.
Installing the Fuse in the Mounting
Fault Fiter Electronic Power Fuses rated 25 kV should be installed in their mountings by hand using suitable protective equipment. Install all other fuses as follows:
Step 1. Secure a shotgun stick tightly to the fuse pullring with the fuse positioned so the body of the fuse is below the stick. Grasp the shotgun stickwith both hands approximately 2 feet (61 cm) apart, placing one hand on the shotgun-stick latch mechanism.
Step 2. Lift the fuse and lower it into the cradle of the fuse mounting.
Step 3. With the fuse securely seated in the cradle, with one motion push the fuse forward to latch it in the Closed position. See Figure 18. Disengage the shotgun stick from the fuse.
Step 4. Verify the fuse is properly latched in the fuse mounting. While holding the shotgun stick, push against the fuse holder assembly and pull on the fuse assembly as shown in Figure 19 by locating the ring of the stick in the opening below the pull-ring.
Figure 18. A fuse lowered into the cradle in preparation for latching to a Transfuse Mounting.
Figure 19. Pull on the fuse assembly by locating the ring of the stick in the opening below the pull-ring.
Closing the TransFuser Mounting
After the fuse has been installed or replaced, close the TransFuser Mounting (to energize the fuse) as follows:
Step 1. Secure a shotgun stick to the pull-ring at the top of the TransFuser Mounting. Be sure not to ratchet the shotgun stick all the way up when securing the pull-ring as it may hinder the movement of the TransFuser Mounting. See Figure 17 on page 18. With an outward pull, rotate the TransFuser Mounting end for end to return the fuse to the medium-voltage compartment in one motion. Make sure the mounting latches in this position before removing the shotgun stick. Then, disengage the shotgun stick from the pull-ring. Using the shotgun stick, push against the bottom of the mounting to verify it has securely latched.
Step 2. Using the shotgun stick, lower the mechanical interlock to lock the Transfuse Mounting. See Figure 15 on page 17.
Step 3. If a protective cap was placed on the bushing interface, remove it with the shotgun stick.
Step 4. Using the shotgun stick, move the elbow from the portable feedthru or standoff insulator to the bushing in accordance with the elbow manufacturer’s instructions. Remove the portable feedthru or standoff insulator from the parking stand.
Step 5. Close and latch the enclosure doors. Pull outward on the Penta- Latch Mechanism cover to verify the door has latched securely and then padlock the door.
Re-Fusing
How to Detect a Blown Fuse
Open the appropriate fuse termination compartment door and secure it with the
door holder. On double-door models, the adjacent door should be closed and
latched to minimize exposure.
S &C Power Fuses
Observe the blown-fuse target through the viewing windows provided for that
purpose. See Figure 20 on page 23, for blown-fuse target locations for S&C
Power Fuses:
SME-20 Power Fuses or Fault Fiter Electronic Power Fuses
—A red blown-fuse target projects from the SME-20 Power Fuse end-fitting or
the Fault Fiter fuse holder when the fuse has operated, making it easy to
check the fuse condition with the fuse in the Closed position. The blown-fuse
target retracts when the blown fuse unit or interrupting module is replaced.
SME-4Z Power Fuses— A fluorescent-orange target in the translucent SME-4Z Holder moves to the Blown indicator window when the fuse operates, permitting a positive visual check of fuse condition without moving the fuse from its Closed position. The target fluoresces when illuminated.
Current-Limiting Fuses
Current-Limiting Fuses with Blown-Fuse Indicators—
To find a blown fuse, gain access to the fuses
following the instructions found in the “Fuse Access— Opening” section on
pages 14 through 18. A blown-fuse indicator appears at the trunnion end when
the fuse has blown.
Current-Limiting Fuses Without Blown-Fuse Indicators—
To find a blown fuse, remove each fuse from
its mounting following the instructions noted in the “Replacing a Blown Fuse”
section on page 24. Then, inspect the fuse per the current-limiting fuse
manufacturer’s recommendations to determine whether it has blown.
Figure 20. Blown-fuse target locations for S&C Power Fuses used in PME models of S&C Pad-Mounted Gear.
Fusing
Replacing a Blown Fuse
Complete the following steps when replacing a blown fuse:
Step 1. Gain access to the blown S&C Power Fuse or suspect current- limiting fuse following the instructions found in the “Fuse Access— Opening” section on pages 14 through 18.
Step 2. Fault Fiter Electronic Power Fuses rated 25 kV should be removed
from their mountings by hand using suitable protective equipment.
Remove all other fuses as follows:
(a) Grasp a shotgun stick with both hands approximately 2 feet (61 cm) apart,
placing one hand on the shotgun-stick latch mechanism.
(b) Secure the shotgun stick tightly to the fuse pull-ring. See Figure 21.
NOTICE
Do not permit the end-fitting of an SME-4Z Power Fuse to strike the ground
during the following removal process. The blown-fuse target may be damaged or
become impacted with dirt and may not operate properly
Figure 21. A shotgun stick secured to a fuse pull-ring in preparation for unlatching the fuse.
(c) Stand in a normal, upright position facing the shotgun stick. Unlatch the
fuse with a short, outward pull on the fuse pull-ring.
Then, remove the fuse from its mounting with an upward and outward lifting
motion. When the fuse has been removed from the mounting, the Mounting may be
left with the live parts in the termination compartment and the doors may be
closed.
Note: Take the blown fuse back to the service center for proper disposal.
NOTICE
Always store fuses in a clean, dry location. Do not store fuses in termination
compartments unless the unit is equipped with the optional Fuse Storage
feature.
This feature accommodates a number of complete fuse assemblies—three SME Power
Fuses, two Fault Fiter Electronic Power Fuses, or two current limiting
fuses—per switch-termination compartment.
For storage, position the fuse with the silencer or trunnion at the bottom,
and insert it into the bracket. Then, turn the fuse so the pull-ring is out of
the way of the cables.
Step 3. Install a new fuse unit, refill unit, interrupting module, or current-limiting fuse in the end-fittings or holder as follows:
_ For S &C Power Fuses: _Follow the instructions provided with each fuse unit, refill unit, or interrupting module for removal of blown SMU-20 Fuse Units, SM-4 Refill Units, or Fault Fiter Interrupting Modules, and for insertion of replacements in the end-fittings or holders.
_ For current-limiting fuses: _For instructions on replacing current- limiting fuses in current-limiting fuse holders, refer to S&C Instruction Sheet 660-501. These holders will accommodate the current-limiting fuses listed in Table 2 of S&C Information Bulletin 660-50.
Step 4. Install the fuse in its mounting following the instructions found in the “Fusing” section on page 20.
Components
No mechanical maintenance is required for manual PME Pad-Mounted Gear.
However, occasional inspection of the gear and exercising of the Mini-Rupter
Switches is recommended.
DANGER
When access to high-voltage compartments is required for inspection, service,
or repairs, always observe the following precautions. Failure to observe these
precautions will result in serious personal injury or death.
- Access to pad-mounted gear must be restricted only to qualified persons. See the “Qualified Persons” section on page 2.
- Always follow safe operating procedures and rules.
- Before touching any device, always disconnect switches and fuses from all power sources (including backfeed), test for voltage, and properly ground.
- Always assume both sets of power terminals on any switch or fuse are energized unlessproved otherwise by test, by visual evidence of open-circuit conditions on both sets of terminals, or by observing that both sets of terminals are grounded.
- Test for voltage on both sets of power terminals of any switch or fuse using proper high-voltage test equipment.
- After the gear has been completely disconnected from all sources of power and tested for voltage, install suitable grounding cables in all compartments.
- For maintenance of non-S&C equipment, follow the manufacturer’s instructions.
- Make sure the enclosure is properly grounded to the station or facility ground. Do not return equipment to service unless such grounds are properly made.
Returning Equipment to Service
When returning the equipment to service, the following procedures should be
observed:
Step 1. Make sure switch and fuse grounding means are removed (if external grounding was done).
Step 2. Make sure the Mini-Rupter Switches are in the correct positions (Open or Closed) as dictated by system requirements.
Step 3. Close each door and make sure the associated Penta-Latch Mechanisms are securely latched before energizing the circuit or operating any switching device.
Step 4. Padlock all doors and switch-operating-shaft access covers before leaving the installation site, even momentarily. Observe this procedure even in those cases where the gear is accessible only to qualified persons.
Enclosure Finish
The responsibility for ensuring a finish protects the enclosure lies with both
the manufacturer and the user. Manual PME Pad-Mounted Gear is finished with
the Ultrapure® II Outdoor Finish, which provides lasting protection for the
enclosure. To retain this protection, the user should take periodic corrective
action as follows:
Step 1. Touch up any penetration of the finish to bare metal, such as scratches and abrasions caused by shipping or vandalism, to maintain the original integrity. S&C touch-up finish and primer are available in aerosol spray cans. See S&C Specification Bulletin 665-31 for catalog number information used for ordering. No other finish or primer is approved. The area to be touched up should be cleaned to remove all oil and grease. Sand the area, removing any traces of rust that may be present, and make sure all edges are feathered before applying primer.
Step 2. Provide an occasional simple washdown, such as an automobile would be given, to remove surface contaminants. Use any ordinary mild household detergent solution.
In those cases where the enclosure must be refinished by the user before the finish has weathered—for example, to match other equipment—a special precaution must be taken. The entire surface must be sanded to provide a tooth to bond the new coat to the unusually tough and smooth Ultrapure II Outdoor Finish.
Dielectric Testing
For the convenience of users who normally perform electrical tests on system components such as pad-mounted gear, appropriate withstand test values are given in Table 1:
Table 1. Ratings and Insulation Test Values
Rating, kV | Withstand, kV |
---|---|
Nom. | Max① |
14.4 | 17.0 |
25 | 27● |
25 | 29■ |
-
Maximum voltage ratings are lower than the values listed when current-limiting fuses are used. Consult the appropriate current-limiting fuse manufacturer for complete fuse ratings.
-
Ac withstand tests made on this equipment after shipment by S&C should be conducted at no more than 0.75 times the values shown.
When making ac tests, the time duration for application of the test voltage should be limited to less than 10 seconds. -
The column headed “Dc” is given as a reference only for those making dc tests and represents values believed to be appropriate and approximately equivalent to the corresponding power-frequency withstand test values specified for components of this voltage class.
The presence of this column in no way implies any requirement for a dc withstand test on these components. -
Dc withstand tests made on this equipment after shipment by S&C should be conducted at no more than 0.75 times the values shown.
When making dc tests, the test voltage should be raised in discrete steps—one minute per step.
● With S&C SME-20 or SME-4Z Power Fuses.
■ With Fault Fiter Electronic Power Fuses or without fuses.
References
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