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Manual PMH Pad-Mounted GearOutdoor Distribution (14.4 kV and 25 kV)

December 9, 2019

© S&C Electric Company 1978-2019, all rights reserved Instruction Sheet 662-510

Operation

Table of Contents

Section Page Section Page

IntroductionQualified Persons . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Read this Instruction Sheet . . . . . . . . . . . . . . . . . . . 2Retain this Instruction Sheet. . . . . . . . . . . . . . . . . . . 2Proper Application . . . . . . . . . . . . . . . . . . . . . . . . . . 2Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Warranty Qualifications . . . . . . . . . . . . . . . . . . . . . . 3

Safety InformationUnderstanding Safety-Alert Messages . . . . . . . . . . . 4Following Safety Instructions . . . . . . . . . . . . . . . . . . 4Replacement Instructions and Labels . . . . . . . . . . . 4Location of Safety Labels . . . . . . . . . . . . . . . . . . . . . 5

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . 7

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Enclosure DoorsOpening and Closing the Doors . . . . . . . . . . . . . . . .10

Switching with Mini-Rupter® SwitchesOperating the Mini-Rupter Switch . . . . . . . . . . . . . .12Front Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

FusingAssembling the Fuse . . . . . . . . . . . . . . . . . . . . . . . .15Installing the Fuse in the Mounting . . . . . . . . . . . . . .15

Switching with Uni-Rupter® InterruptersInstalling and Closing the Fuse . . . . . . . . . . . . . . . .16A Note on Single-Pole Switching . . . . . . . . . . . . . . .19Opening and Removing the Fuse . . . . . . . . . . . . . . 20

Re-FusingHow to Detect and Replace a Blown Fuse . . . . . . . 23Installing the Fuse in the Mounting . . . . . . . . . . . . . 23

MaintenanceComponents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Returning Equipment to Service . . . . . . . . . . . . . . . 24Enclosure Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Appendix ADielectric Testing . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Appendix BRatings for S&C Mini-Rupter Switches . . . . . . . . . . 27Ratings for S&C Power Fuses with Uni-Rupter Interrupters . . . . . . . . . . . . . . . . . . . 27

Appendix COptional Features . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Appendix DCurrent-Limiting Fuses for Use in S&C PMH Pad-Mounted Gear . . . . . . . . . . . . . . 31Recommended Voltage Ratings . . . . . . . . . . . . . . . 32

2 S&C Instruction Sheet 662-510

Introduction

Qualified Persons WARNINGOnly qualified persons who are 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 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, 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 PMH Pad-Mounted Gear. Familiarize yourself with the Safety Information and Safety Precautions on pages 4 through 7. The latest version of this publication is available online in PDF format at sandc.com/en/support/product-literature/.

Retain this Instruction Sheet

This instruction sheet is a permanent part of Manual PMH Pad-Mounted Gear. Designate a location where you can easily retrieve and refer to this publication.

Proper Application WARNINGThe 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 PMH Pad-Mounted Gear are described in S&C Specification Bulletin 662A-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 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).

S&C Instruction Sheet 662-510 3

Introduction

Warranty Qualifications

The seller’s warranties do not apply if fuse units, fuse-unit end-�ttings, holders, re�ll units, or switch blades of other than S&C manufacture are used in conjunction with S&C SML Mountings. Nor do the seller’s warranties apply if other than Fault Fiter® Electronic Power Fuses, S&C Switch Blades, or selected current-limiting fuses are used in conjunction with S&C Fault Fiter Electronic Power Fuse Mountings and S&C Holders designed therefore, or if current-limiting fuses are applied other than as set forth under the “Current-Limiting Fuses for Use in S&C PMH Pad-Mounted Gear” section in Appendix D starting on page 31.


Safety Information

Understanding Safety-AlertMessages

Several types of safety-alert messages may appear throughout this instruction sheet and on labels and tags attached to Manual PMH Pad-Mounted Gear. Familiarize yourself 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 you do not understand any portion of this instruction sheet and need assistance, contact your 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 your Manual PMH Pad-Mounted Gear.

Replacement Instructions and Labels

If additional copies of this instruction sheet are needed, 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

A

AB

F F

C

E

C

D

D

Hazardous voltage—more than 4000 volts.Failure to follow these instructions will likely cause shock, burns, or death.• ALWAYS consider all circuits and component

parts live until completely de-energized, tested, grounded, and tagged or properly identified.

• Do not work on or near this equipment unless you:

(1) Know and obey your employer’s work rules and S&C’s instruction sheetsd (in Compartment 1); and

(2) Know the hazards involved with this high-voltage equipment.

• ALWAYS use proper personal protective equipment, protective devices, and tools suitable for the assigned task.

d Note: Additional instruction sheets are available free of charge from S&C by calling (773) 338-1000.

Ç DANGER

G-6503R1

DANGER

KEEP AWAY

Hazardous voltage—more than 4000 volts.Will shock, burn, or cause death.

•Qualifiedpersonsonly.

•Ifopen,immediatelycallelectriccompany.

G-6500

WARNINGDo not leave barrier in this position for more than one week.

Barrier damage could result which can cause flashover and injury.

G-6399

DR

AW

ING

NO

.

G-9137

DESCRIPTION DRAWING NO.

DUAL PURPOSE BARRIER LABEL AND CABLE TIE REMOVAL LABEL 15 & 25KV PMH

G-9137PROPRIETARY STATEMENT: THIS DOCUMENT AND ALL PREVIOUS ISSUES ARE THE SECRET AND CONFIDENTIAL PROPERTY OF S&C ELECTRIC COMPANY (“S&C”), 6601 NORTH RIDGE BOULEVARD, CHICAGO, ILLINOIS,AND NEITHER RECEIPT NOR POSSESSION THEREOF INFERS OR TRANSFERS ANY RIGHT IN OR LICENSE TO USE THIS DOCUMENT, THE SUBJECT MATTER THEREOF, OR ANY DESIGN OR TECHNICAL INFORMATIONSHOWN THEREON, OR ANY RIGHT TO REPRODUCE THIS DOCUMENT OR ANY PART THEREOF. NEITHER THIS DOCUMENT NOR ANY INFORMATION CONTAINED THEREIN MAY BE COPIED, REPRODUCED, OR OTHERWISEUSED OR DISCLOSED TO ANY OTHER PARTY WITHOUT FIRST OBTAINING THE EXPRESS WRITTEN PERMISSION OF S&C. THIS DOCUMENT IS PROVIDED UNDER THE EXPRESS CONDITION THAT IT WILL BE HELD INCONFIDENCE BY THE RECIPIENT, THAT IT IS SUBJECT TO RETURN UPON DEMAND, AND THAT IT WILL NOT BE USED IN ANY WAY DETRIMENTAL TO S&C.

SCALE MATERIAL:S&C SPEC. NO.DESCRIPTION

. 004 W H I T E V I N Y L W / . 0 0 1 M Y L A R L A M I N AT I O N A C R Y L I CB A S E A D H E S I V E . S & C S P E C , M S P - 0 0 8 3

REVISIONS

F U L L NO. DATE NOTICE NO.

DRAWN BY FINISH:S&C SPEC. NO.DESCRIPTION

O T H E R . S E E B E L O W000 1-17-05 84823

M N

CH. BY TYP. PMX MES EFH. OPTION PMH

UNLESS OTHERWISE SPECIFIED:

DECIMAL DIMS TO BE ! .031

APP. BY NEXTASSEMBLY

PRODUCTDESCRIPTION

FRACTIONAL DIMS TO BE !

A K ANGLES TO BE !

DATEUSED ON

WHEN CHECKED, BREAK ALL CORNERS g

1-17-05 WHEN CHECKED, REMOVE ALL BURRS g

s S&C ELECTRIC COMPANYG E N E R A L O F F I C E S • C H I C A G O

5.0

G-9137

.125 R. TYP

3.375

Specialists in Electric Power Switching and Protection

NOTICE1.0

HANG THIS DUAL PURPOSE BARRIERON THE SWITCH BARRIER MOUNTINGANGLE AND REMOVE THE CABLE TIESFROM THE INTERPHASE BARRIERSBEFORE ENGERGIZING THE SWITCH-GEAR.

WHITE CHARACTERS ON BLACK BACKGROUND

BLACK CHARACTERS ON WHITE BACKGROUND

Location of Safety Labels


Safety Information

Reorder Information for Safety Labels

Location Safety Alert Message Description Part Number

A DANGER Hazardous voltage —more than 400 volts . . . G-6503

B DANGER Storage and handling of spare fuses G-5147-2R1

C DANGER Switches may be energized . . . G-6501

D DANGER Keep away. . . G-6500

E WARNING Do not leave barrier in this position . . . G-6399

F NOTICE Hang this dual purpose barrier . . . G-9137

G WARNING Live switching with Uni-Rupter . . . G-6369

A

AG

G

C

CD

Hazardous voltage—more than 4000 volts.Failure to follow these instructions will likely cause shock, burns, or death.• ALWAYS consider all circuits and component

parts live until completely de-energized, tested, grounded, and tagged or properly identified.

• Do not work on or near this equipment unless you:

(1) Know and obey your employer’s work rules and S&C’s instruction sheetsd (in Compartment 1); and

(2) Know the hazards involved with this high-voltage equipment.

• ALWAYS use proper personal protective equipment, protective devices, and tools suitable for the assigned task.

d Note: Additional instruction sheets are available free of charge from S&C by calling (773) 338-1000.

Ç DANGER

G-6503R1

DANGER

KEEP AWAY

Hazardous voltage—more than 4000 volts.Will shock, burn, or cause death.

•Qualifiedpersonsonly.

•Ifopen,immediatelycallelectriccompany.

G-6500

E

WARNINGDo not leave barrier in this position for more than one week.

Barrier damage could result which can cause flashover and injury.

G-6399

Location of Safety Labels


Safety Precautions

DANGERPad-mounted gear contains high voltage. Failure to observe the precautions below will result in serious personal injury or death.

Some of these precautions may differ from company operating procedures and rules. Where a discrepancy exists, users should follow their company’s operating procedures and rules.

1. QUALIFIED PERSONS. Access to pad-mounted gear must be restricted only to qualified persons. See the “Qual ified Persons” section on page 2.

2. SAFETY PROCEDURES. Always follow safe operat ing 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 “CAUTION,” “WARNING,” or “DANGER” labels.

5. 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 accessi ble 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.

6. 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.

7. 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-operating-shaft access 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.

8. 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 ter minals are grounded.

9. BACKFEED. Mini-Rupter Switches and fuses may be energized by backfeed.

10. 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.

11. TESTING. Test for voltage on both sets of power ter minals 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.

12. 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 compart ments before touching any device to be inspected, replaced, serviced, or repaired in the high-voltage compartments.

13. 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.

14. MAINTAINING PROPER CLEARANCE. Always maintain proper clearance from energized compo nents.

15. 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 (catalog number suffix “-E1,” “-E2,” or “-E3”).


Overview

Figure 1. Fuse-side view of a Model PMH-9 with SML-20 Power Fuses in the right-hand compartment and Fault Fiter Elec tronic Power Fuses in the left-hand compartment. (This nonstandard combination of fuses is shown for comparison only.)

Dual-purpose front barriers guard against inadvertent contact with live parts when in a normal vertical position. Inserted into the open gap of a fuse, the barrier provides isola tion from bus and upper contacts.

Compartment-identification and phase-identification labels

Uni-Rupter InterrupterStorage rack holds up to six SM-4® Refill Units or three SMU-20® Fuse Units.

Ground studsInterphase and end barriers

Fault Fiter ElectronicPower Fuse with a Uni-Rupter Interrupter

Terminals accept a wide variety of field-assembled cable-terminating devices

SML-20 Power Fuse with a Uni-Rupter Interrupter

Grappler™ Handling Tool

Ground studsGround studsaccept a wide variety of field-assembled cable-terminating devices

Penta-Latch® Mechanism provides automatic three-point door latching—only after the actuator is secured can a padlock be installed.

three SMU-20® Fuse Units.

Storage rack Storage rack six SM-4® Refill Units or three SMU-20® Fuse Units.


Overview

Viewing window for visible verification of the switch position is removable for phasing. To remove the window, loosen the wing-head screws and lift the window off the alignment bolts.

Left-hand door retainer—Rotate the latch upward to open the door. To secure the left-hand door closed, rotate the latch downward over the stop mounted on outer edge of the door.

Ground pad on the inside at the bottom the door stile in each compartment accommodates con nectors for attachment of cable concentric-neutral ground leads and ground studs.

Main busDoor holder

Ground studs

Optional fuse-storage feature

Circuit diagram

Interphase and end-barriers for 14.4-kV gear; the end-barrier is provided with the optional fuse-storage feature only.

S&C Mini-Rupter Switch—Manually operated switches are furnished with a manual operating handle that folds for storage behind the switch operating-hub cover.

Dual-purpose front barrier guards against inadvertent contact with live parts when in a normal vertical position. Inserted into the open gap of a switch, the barrier provides isola tion from bus and upper contacts.

Instruction manual holder

Ground padGround pad on the inside at the bottom the door stile in each compartment accommodates con nectors for attachment of cable concentric-neutral ground leads and ground studs.

Optional mounting provisions foruser-supplied fault indicators Main bus

Figure 2. Switch-side view of a Model PMH-9.


Enclosure Doors

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.

1. Access to pad-mount gear must be restricted only to qualified persons. See the “Qualified Persons” section on page 2.

2. Always follow safe operating procedures and rules.

3. Before touching any device, always disconnect switches and fuses from all power sources (including backfeed), test for voltage, and properly ground.

4. Always assume both sets of power terminals on any 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.

5. Test for voltage on both sets of power terminals of any switch or fuse using proper high-voltage test equipment.

6. After the gear has been completely disconnected from all sources of power and tested for voltage, install suitable grounding cables in all compartments.

7. 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.

Opening and Closing the DoorsComplete 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 suf� x “-B1” or “-B2” is speci� ed) into the latching mechanism. Rotate the wrench or tool 60° counterclockwise to unlatch the doors. See Figure 3.

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 4.

STEP 4. Open each door fully and latch the door holders. See Figure 5.

STEP 5. To gain access to the other side of the enclosure, repeat Steps 1 through 4 to open the doors.

Figure 3. 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 4. The left-door latching mechanism disengaged.

Door-latching mechanism disengaged

Figure 5. Using the door holder to hold the door open.

Door holder (stored)

Door holder (latched)

(a)

(b)


Enclosure Doors

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 6. Make sure the door holder is placed back in the storage position to allow the door to be fully closed. See Figure 7.

STEP 2. Repeat Step 1 for the other door.

STEP 3. Engage the left-door latching mechanism. See Figure 8.

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 � rmly 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 9.

STEP 6. Repeat Steps 1 through 5 for the doors on the other side of the enclosure (if open).

Figure 8. The left-door latching mechanism engaged.

Figure 9. The enclosure doors padlocked.

Figure 7. The door holder placed in the storage position to allow the door to close.

Door holder (stored)

Figure 6. Lift the door holder to allow the door to swing closed.


Switching with Mini-Rupter® Switches

Operating the Mini-Rupter SwitchThe Mini-Rupter 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.

Before proceeding with the instructions on operating the Mini-Rupter Switch, refer to the “DANGER” message on page 7.

STEP 1. Remove the padlock and open the switch-operating-shaft access cover. See Figures 10(a), 10(b), and 10(c).

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 that is attached to the hex switch-operating shaft and rests against a stop in either the Open or Closed position.

STEP 3. Rotate the handle in the appropriate direction to open or close the switch, and check the switch-position indi cator to verify the switch is in the desired position.

STEP 4. Follow the instructions to open the enclosure doors on page 10.

STEP 5. Check the physical position of the switch by using the viewing window provided in the switch-termination compartment. See Figure 11.

WARNINGAlways confirm the Open/Close position of the Mini-Rupter Switch by visually observing the position of the switch blades.

STEP 6. Remove and fold the switch-operating handle, and return the handle to its storage position. Then, close and padlock the access cover.

CAUTIONDo not leave the switch-operating-shaft access cover unlocked if the gear is left unattended by qualified persons.

Folding switch-operating handle in operating position

Folding switch-operating handle in storage pocket

Access cover opened

Figure 10(a). The access cover padlock.

Hood shields padlock shackle

Access cover in padlocked position

Hexswitch-operating shaft

Figure 10(b). The access cover door is open.

C onn e c t ion diagram

(a) (b)

Figure 11. (a) Shows the switch in the Closed position, and (b) shows the switch in the Open position.

Figure 10(c). The switch operating handle installed.



Figure 12. Dual-purpose front barrier for switch in its nor-mal, suspended position.

Figure 13. A Grappler Handling Tool being used to lift the barrier. Note the door holder is in place and the adjacent door is latched closed to reduce exposure to high voltage.

Front BarriersBefore proceeding with the instructions on handling the front barriers, refer to the “DANGER” message on page 7.

S&C recommends the dual-purpose front barrier be inserted into the “Slide-in” position when the Mini-Rupter Switch is open. When the barrier is in the “Slide-in”position, the switch blades are isolated from the main contacts; moreover, the blades are blocked from closing if, for any reason, the Mini-Rupter Switch is operated.

WARNINGAlways use a Grappler Handling Tool attached to a suitable universal pole to insert, remove, or replace front barriers. No other tools are recommended.Failure to use the proper tools can result in damage to the equipment, flashover, and injury.

Grappler Handling Tool

Talon™ Handling Tool

Distribution prong

Station prong

WARNINGDual-purpose front barriers must be wiped clean before placing them in the “Slide-in” position. In addi tion, do not leave dual-purpose front barriers in the “Slide-in” position for more than one week. These bar riers are intended for temporary use only to isolate the blades of the Mini-Rupter Switch from the main con tacts while work is being performed. If the barriers are left in the “Slide-in” position for extended periods of time, there is the possibility of corona discharge to the barriers. Prolonged exposure to corona discharge may damage the barriers and result in a flashover and injury.

To insert the barrier in the “Slide-in” position, use an S&C Grappler Handling Tool, catalog number 4423R1, attached to and in line with a suitable universal pole●. Figures 13 and 14 through 15 on page 14 show the suggested insertion method. The Grappler tool’s prong is pointed upward when lifting the front barrier.

● Use a universal pole 1¼ inches (31.8 mm) in diameter and at least 6 feet (1829 mm) long (S&C catalog number 4452R2-E, or equal) for 14.4-kV gear; or at least 8 feet (2438 mm) long (S&C catalog number 4453R2-E, or equal) for 25-kV gear.

CAUTIONWhen ready to close the Mini-Rupter Switch, make sure that the dual-purpose front barrier is not in the “Slide-in” position.



Figure 14. The Grappler tool, after lifting and pivoting the barrier, is used to lower it into the “Slide-in” position. The image also shows the Grappler tool being used to return the barrier to its normal, sus pended position.

If the Mini-Rupter Switch is inadvertently closed with the front barrier in the “Slide-in” position, it will be neces-sary to unblock the blades. To do this, rotate the switch-operating handle all the way to the Open position. This will return the blades to the Open position.

To restore the dual-purpose front barrier to the normal suspended position, use a Grappler Handling Tool attached to a suitable universal pole. Slowly and carefully withdraw the barrier with the Grappler tool’s prong pointed upward, as shown in Figure 14, so that as it clears the “Slide-in” posi tion, the hooks on the gear settle into the holes in the bar rier. Then, lower the barrier to its normal, suspended position. (If, for any reason the barrier was completely removed from the enclosure, a suggested method of plac ing it in its normal, suspended position is shown in Figure 15. Note the barrier is supported on the Grappler tool and held there by engagement of the lifting ring with the Grappler tool’s cone. Place the barrier on the hooks of the gear, and lower the barrier to its suspended position.)

Figure 15. Alternate method for replacing the front barrier usinga Grappler tool: Place the barrier on the hooks of the gear and lower the barrier to its suspended position. The inset image shows a close-up of the Grappler tool in position to replace the barrier.


Fusing

Manual PMH Pad-Mounted Gear is furnished with S&C Fuse Mountings with Uni-Rupter Interrupters that accommodate Type SML-20 Power Fuses, Type SML-4Z Power Fuses, or Fault Fiter Electronic Power Fuses. Fault Fiter Electronic Power Fuse Mountings also accommo date a variety of current-limiting fuses.

WARNINGWhen selecting a current-limiting fuse, the voltage rating of the fuse must conform to the recommendations in Appendix D on page 31.

Assembling the Fuse

S&C Power FusesInstall an SMU-20 Fuse Unit into each set of end-�ttings, an SM-4 Refill Unit into each holder, or a Fault Fiter Inter rupting Module and Control Module into each holder, in accordance with the instruction sheet furnished with the fuse unit, re�ll unit, or interrupting module.

Current-Limiting FusesS&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 Appendix D on page 31. For instructions on installing current-limit ing fuses in current-limiting fuse holders, refer to S&C Instruction Sheet 660-500.

Installing the Fuse in the MountingFollow the instructions found in the “Installing and Closing the Fuse” section on pages 16 through 18.


Switching with Uni-Rupter® Interrupters

Storage rackfor S&C SMU-20 Fuse Units or SM-4 Refill Units

S&C Grappler tool in storage position

Door holder

Figure 16. Dual-purpose front barriers for fuses in their nor-mal, suspended positions. Note the door holder is in place.

Installing and Closing the Fuse●

Before proceeding with the instructions on installing and closing the fuse, refer to the “DANGER” message on page 7.

WARNINGAlways use a Grappler Handling Tool attached to a suitable universal pole to install, remove, open, or close a fuse. No other tools are recommended.Failure to use the proper tools can result in damage to the equipment, flashover, and injury.


Talon Handling Tool

Distribution prong

Station prong

Use a Grappler Handling Tool (S&C catalog number 4423R1) attached to and in line with a suitable universal pole■▲ to perform the following procedures:

STEP 1. Open the appropriate fuse-compartment door and secure it with the door holder. See Figure 16. On double-door models, the adjacent compartment door should be closed and latched to minimize exposure to high voltage.

STEP 2. If optional inner barrier panels (catalog number suf� x “-G7”) are furnished, loosen the pentahead bolts and remove the panel.

Then, remove only the dual-purpose front barrier asso ciated with the fuse mounting into which the fuse is to be installed. See Figure 17. Insert the barrier into the “Slide-in” position using the Grappler tool, as illustrated in Figure 18 on page 17. Note the barrier is supported on the Grappler tool’s prongs and held there by engagement of the lifting ring with the Grappler tool’s cone.

● Although the operations described in this section often refer sim ply to “fuses,” the procedures apply to Type SML-20 and SML-4Z Power Fuses, Fault Fiter Electronic Power Fuses, and current-limit ing fuses used in Fault Fiter Electronic Power Fuse Mountings with Uni-Rupter Interrupters.

■ Use a universal pole 1¼ inches (31.8 mm) in diameter and at least6 feet (1829 mm) long (S&C catalog number 4452R2-E, or equal) for 14.4-kV gear; or at least 8 feet (2438 mm) long (S&C catalog number 4453R2-E, or equal) for 25-kV gear.

▲ If the enclosure is furnished with an optional base spacer (or is attached to a higher-than-normal mounting pad), it may be desirable, for easier handling at the increased height, to reposition the Grappler tool on the universal pole at a favorable angle.

Figure 17. Removing or replacing the dual-purpose front barrier with the Grappler tool.



WARNINGDual-purpose front barriers must be wiped clean before placing them in the “Slide-in” position. In addition, do not leave dual-purpose front barriers in the “Slide-in” position for more than one week. These barriers are intended for temporary use only to iso late the fuse from the main contacts of the Uni-Rupter Interrupter while work is being performed. If the barri ers are left in the “Slide-in” position for extended periods of time, there is the possibility of corona discharge to the barriers. Prolonged exposure to corona discharge may damage the barriers and result in a flashover and injury.

STEP 3. For all fuses except 25-kV Fault Fiter Electronic Power Fuses: Install a fuse into its hinge as follows:

(a) Position the Grappler tool’s cone in the fuse pull-ring and cradle the fuse in the Grappler tool’s prongs. See inset of Figure 19.

(b) Grasp the universal pole with both hands (approxi mately 2 feet (610 mm) apart), with one hand at the opposite end of the pole from the Grappler tool.

(c) Lift the fuse and lower it into its hinge. See Figure 19. Make sure the fuse is securely seated in the hinge and then disengage the Grappler tool from the fuse. See Figure 20 on page 18.

DANGERMake sure the fuse is kept away from the con tacts of the Uni-Rupter Interrupter during installation of the fuse into its hinge to prevent reestablishment of the circuit. It is recommended that the associated dual-purpose front barrier be placed in the “Slide-in” position whenever a fuse is open or is being installed into or removed from its hinge.

STEP 4. For 25-kV Fault Fiter Electronic Power Fuses: De-energize, test, and properly ground the mounting in accordance with local operating practices, and then install the fuse in its mounting by hand using suitable personal protective equipment (PPE).

CAUTIONDo not close a compartment door when any of the associated fuses are in the Open position. If the door is closed, it will strike the fuse pull-ring. The door may be closed if the fuse is removed from its mounting.

Figure 18. Inserting the dual-purpose front barrier into the “Slide-in” position using a Grappler tool.

Figure 19. Installing a fuse using a Grappler Handling Tool. The inset image shows a close-up of a Grappler tool in position to install the fuse.



STEP 5. If a dual-purpose front barrier is in the “Slide-in” posi tion, use the Grappler tool to remove it. See Figure 21.

DANGERBecause there is always the possibility of closing the fuse into a faulted circuit, and because the closing operation is completely operator-dependent (with no assist from a quick-make mechanism), the clos ing operation must be accomplished with a swift, unhesitating stroke while turning one’s face away. When so operated, the Uni-Rupter Interrupter associated with the fuse is capable of closing into a fault current once or twice, as specified in Appendix B on page 27, remain ing operable and able to carry and interrupt rated current.

STEP 6. With the Grappler tool’s prong pointed downward (preferred), insert the prong into the pull-ring of the fuse. Rotate the hookstick clockwise slightly to ensure full and complete engagement of the Grappler tool’s prong with the pull-ring of the fuse. See inset of Figure 22 on page 19. Then, with one’s face turned away, close the fuse with a swift, unhesitating stroke. See Figure 22 on page 19.

If space is tight between the pull-ring of the fuse and an interphase or end barrier, it’s accept-able to attach the Grappler tool to the pull-ring with the prong pointed up. See lower inset of Figure 22 on page 19.

STEP 7. Remove the Grappler tool from the pull-ring.

STEP 8. After removing the Grappler tool from the pull-ring, make sure complete fuse closure was attained by pushing against the fuse, below the upper end-� tting, with the Grappler tool.

WARNING Fail ure to completely close the fuse may result in dam age to the Uni-Rupter Interrupter, flashover and injury.

STEP 9. Use the Grappler tool to hang the dual-purpose front bar rier in its normal, suspended position. See Figure 17 on page 16. Also install the optional inner barrier panel, if fur nished.

STEP 10. Close and latch the doors and install a padlock. Pull on the doors to verify they are securely latched.

Figure 20. A fuse installed in mounting in the Open position.

Figure 21. Removing dual-purpose front barrier from the “Slide-in” position using a Grappler tool.



CAUTION

Ferroresonant overvoltages may occur when switchingunloaded or lightly loaded three-phase transformers (or banks of three single-phase transformers) or single-phase transformers connected phase-to-phase. The excessive voltages caused by ferroresonance can damage transformers, cables, and secondary low-voltage loads. Ferroresonant overvoltages can also result in an external arc across the Uni-Rupter Interrupter when it is switched open, followed by a high-current fault with its associated arc-flash hazard.

To minimize the possibility that ferroresonant overvoltages will occur, only switch three-phase loads with the Uni-Rupter Interrupter where each phase is carrying 5% or more of the rated connected load current. Do not switch unloaded three-phase transformers with the Uni-Rupter Interrupter.

System Voltage Minimum Load Current to Prevent Ferroresonant Overvoltages, Amperes

Total Connected kVA Up to 600 kVA 750 kVA through 1250 kVA 1500 kVA through 2500 kVA

12 through 15 2 4 8

17 through 27 1 3 5

Figure 22. Closing the fuse with a swift, unhesitating stroke. The upper left inset shows a close-up of a Grappler tool in the preferred position to close the fuse. The upper right inset shows a close-up of a Grappler tool in an acceptable position to close the fuse. The lower right inset shows a close-up of a Uni-Rupter Interrupter with the fuse fully closed.

Uni-Rupter

Preferred Acceptable

A Note on Single-Pole Switching



Opening and Removing the Fuse Before proceeding with the instructions on opening and removing the fuse, refer to the “DANGER” message on page 7.

WARNINGAlways use a Grappler Handling Tool attached to a suitable universal pole to install, remove, open, or close a fuse. No other tools are recommended.Failure to use the proper tools can result in damage to the equipment, flashover, and injury.


Talon Handling Tool

Distribution prong

Station prong

Use Grappler Handling Tool (S&C catalog number 4423R1) attached to and in line with a suitable universal pole● to perform following procedures:

STEP 1. Open the appropriate fuse-compartment door and secure it with the door holder. See Figure 16 on page 16. On double-door models, the adjacent door should be closed and latched to minimize exposure to high voltage.

STEP 2. If optional inner barrier panels (catalog number suf� x “-G7”) are furnished, loosen the pentahead bolts and remove the panel.

Then, remove only the dual-purpose front barrier associated with the fuse to be opened using the Grappler tool for this purpose. See Figure 17 on page 16.

STEP 3. With the Grappler tool’s prong pointed downward (preferred), insert the prong into the pull-ring of the fuse. Rotate the hookstick clockwise slightly to ensure full and complete engagement of the Grappler tool’s prong with pull-ring of the fuse. See Figure 23.

If the space is tight between the pull-ring of the fuse and an interphase or end barrier, it’s acceptable to attach the Grappler tool to the pull-ring with the prong pointed up. See lower inset of Figure 23.

● Use a universal pole 1¼ inches (31.8 mm) in diameter and at least 6 feet (1829 mm) long (S&C catalog number 4452R2-E, or equal) for 14.4-kV gear; or at least 8 feet (2438 mm) long (S&C catalog number 4453R2-E, or equal) for 25-kV gear.

Figure 23. A Grappler tool, as positioned for an opening stroke.

Preferred

Acceptable


Figure 24. Opening the fuse.

Figure 25. Inserting dual-purpose front barrier into the “slide-in” position using a Grappler tool.


STEP 4. Pull the fuse vigorously through its full travel without hesitation at any point. See Figure 24. A downward force should be maintained on the universal pole through the fuse-opening operation to counteract any tendency the fuse may have to bounce toward the Closed position.

Note: The Uni-Rupter Interrupter is designed to require a hard pull to unlatch the fuse, thus reducing the possibility of an incomplete opening operation.

STEP 5. Remove the Grappler tool from the fuse pull-ring.

DANGERAlthough a fuse in the fully Open position provides visual evidence of an open circuit, it does not nec essarily mean the Uni-Rupter Interrupter, the load-side hinge, or the fuse is de-energized.

CAUTIONDo not close a compartment door when any of the associated fuses are in the Open position. If the door is closed, it will strike the fuse pull-ring. The door may be closed if the fuse is removed from its mounting.

STEP 6. S&C recommends the dual-purpose front barrier associated with the fuse to be removed be inserted into the “Slide-in” position. Use the Grappler tool for this, as illustrated in Figure 25. Note that the barrier is sup ported on the Grappler tool’s prongs and held there by engagement of the lifting ring with the Grappler tool’s cone.

STEP 7. For all fuses except 25-kV Fault Fiter Electronic Power Fuses: Remove the fuse from its hinge as fol lows:

(a) Grasp the universal pole with both hands (approxi mately 2 feet (610 mm) apart), with one hand at the opposite end of the pole from the Grappler tool.

(b) Position the Grappler tool’s cone in the fuse pull-ring and cradle the fuse in the Grappler tool’s prongs. See Figure 26 on page 22.

(c) Stand in a normal, upright position facing the uni versal pole. Move the pole forward until resistance between the Grappler tool and the fuse is felt, or approximately 2 inches (51 mm).

(d) Then, remove the fuse from its hinge with a forward and upward lifting motion. See Figure 27 on page 22.



DANGERMake sure the fuse is kept away from the con tacts of the Uni-Rupter Interrupter during removal of the fuse from its hinge to prevent reestablishment of the cir cuit. S&C recommends the associated dual-purpose front barrier be placed in the “Slide-in” position whenever a fuse is open or is being removed from or installed into its hinge.

STEP 8. For 25-kV Fault Fiter Electronic Power Fuses: De-energize, test, and properly ground the mounting in accordance with local operating practices, and then remove the fuse from its mounting by hand using suit able personal protective equipment (PPE).

STEP 9. Hang the dual-purpose front barrier in its normal, sus pended position using the Grappler tool. See Figure 17 on page 16. Also install the optional inner barrier panel, if furnished. Then, close and latch the doors, and padlock securely. Pull on the doors to verify they are securely latched.

WARNINGIf fuses are removed from the mountings, they should be stored in a clean, dry location. Do not store end-fit tings, holders, interrupting modules, or current-limit ing fuses in high-voltage compartments unless the unit is equipped with theoptional fuse-storage feature (cat alog number suffix “-E1,” “-E2,” or “-E3”) suitable for this purpose.

The optional Fuse Storage feature, if fur-nished, can accommodate three completely assembled spare Type SML Fuses, two spare Fault Fiter Interrupting Modules, one spare Fault Fiter Electronic Power Fuse Holder, or one spare current-limiting fuse holder in each switch com partment, as applicable. The Fuse Storage feature is mounted inside the enclo-sure, between the interrupter switch and the side wall of the enclosure. For storage, position the assembled fuses in the Fuse Storage fea-ture as shown on the label headed “STORAGE AND HANDLING OF SPARE FUSES” affixed to the inside of each applicable switch-compart-ment door.

DANGERDo not handle spare fuses unless the front barriers for the switches are in their normal, suspended positions to guard against inadvertent contact with live parts.

Figure 27. Removing a fuse from its hinge with a forward and upward lifting motion.

Figure 26. A Grappler tool positioned for fuse removal.


Re-Fusing

How to Detect and Replace a Blown FuseOpen the appropriate fuse-compartment door and secure it with the door holder. On double-door models, the adja-cent door should be closed and latched to minimize expo-sure to high voltage. Also remove the dual-purpose front barrier (using the Grappler tool) or inner barrier panel, if fur nished.

S&C Power FusesFrom a safe distance, observe the blown-fuse target for the fuse type furnished. Refer to Figure 28:

• SML-4Z Power Fuse—A � uorescent-orange target in the translucent SML-4Z Holder moves to the BLOWN indicator window when the fuse operates, permitting a positive visual check of fuse condition without remov-ing the fuse from its mounting. The target � uoresces when illuminated.

• SML-20 Power Fuse or Fault Fiter Electronic Power Fuse—A red blown-fuse target projects from the top of the SML-20 Power Fuse upper end-� tting or the Fault Fiter Holder when the fuse has operated . . . making it easy to check fuse condition with the fuse in the Closed position. The blown-fuse target retracts within the end-� tting or holder when the blown fuse unit or interrupt ing module is replaced.

Note On Handling: The present-design upper end-fitting for use in SML-20 Power Fuses and the Fault Fiter Holder use a free-floating blown-fuse target that can move (by force of gravity) into the Blown position should the

fuse be inverted during handling. The fuse condition can be veri fied by returning the fuse to the upright posi-tion. If the fuse is blown, the target will remain in the extended (projecting) position.

Remove the blown fuse from its mounting following the instructions found in the “Opening and Removing the Fuse” section on pages 20 through 22. Then, follow the instruc tions for replacing blown SM-4 Refill Units, SMU-20 Fuse Units, or Fault Fiter Interrupting Modules (as applicable) provided with each new refill unit, fuse unit, and interrupting module.

Current-Limiting FusesTo � nd the blown fuse(s), remove each fuse in turn from its mounting (the target cannot be seen while the fuse is in its mounting), following the instructions found in the “Opening and Removing the Fuse” section on pages 20 through 22. Then, inspect the fuse and check for a blown-fuse target.

Note: Following a two- or three-phase fault at a three-phase installation, any unblown fuses that carried the fault current should also be replaced. For instructions on replacing current-limiting fuses in S&C Holders, refer to S&C Instruction Sheet 660-500. S&C Holders will accommodate the current-limiting fuses listed in Appendix D starting on page 31.

Installing the Fuse in the MountingFollow the instructions found in the “Installing andClos ing the Fuse” section on pages 16 through 18.

Figure 28. Blown-fuse target locations for the fuse types used in PMH models of S&C Pad-Mounted Gear.

Fault Fiter Electronic Power Fuse

Red target projects from top of holder when fuse has operated

Fluorescent-orange target appears in the BLOWN indicator window when fuse has operated (visible through translucent holder)

SML-4Z Power Fuse

Red target projects from top of holder when fuse has operated

SML-20 Power Fuse


Components No mechanical maintenance is required for S&C Manual PMH Pad-Mounted Gear. However, occasional inspection of the gear and exercising of the Mini-Rupter Switches is recommended. In addition, inspection and cleaning—of insulators and cable terminators in particular—should be performed periodically, at intervals based on environ-mental conditions. Refer to S&C Instruction Sheet 662-590, “Inspection Recommendations.”

Before gaining access to high-voltage compartments, if required, refer to the “DANGER” message on page 7.

CAUTIONWhen, in the user’s judgment, cleaning is required, S&C recommends the pad-mounted gear be completely de-energized and properly grounded according to the user’s operating and safety procedures, and thoroughly cleaned by hand. If it is not possible to de-energize the gear, the use of pressure sprayed dry ice (solid CO2) is an acceptable alternative cleaning method. The use of pressure sprayed abrasives or solvents is specifically not recommended because such abrasives or solvents will damage switch and fuse components.

WARNINGDual-purpose front barriers for switch and fuse com partments should be inserted into the open gap of the Mini-Rupter Switch or fuse to provide physical isola tion for additional security in the event it is neces sary to work on the cables connected to the Mini-Rupter Switch or fuse.

Returning Equipment to Service When returning the equipment to service, observe the following procedures :

STEP 1. Make sure switch and fuse grounding means are removed and that dual-purpose front barriers are removed from the “Slide-in” position before closing the associated Mini-Rupter Switch or power fuses.

STEP 2. Make sure the Mini-Rupter Switches are in the correct positions (Open or Closed) as dictated by sys tem circumstances.

STEP 3. Close each door permitting access to high voltage 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 quali�ed per sons.

é These recommendations may differ from the user’s operating and safety procedures. Where a discrepancy exists, users should follow their procedures.

Maintenanceé


Maintenance

Enclosure FinishThe responsibility for ensuring that a finish protects the enclosure lies with both the manufacturer and the user. Manual PMH Pad-Mounted Gear is � nished with the Ultradur® II Outdoor Finish, which provides lasting protection for the enclosure. To retain this protection, the user should take periodic corrective action as fol lows:

STEP 1. Touch up any penetration of the � nish to bare metal—such as scratches and abrasions due to ship ping or vandalism—to maintain the original integrity. S&C touch-up � nish and primer are available in aerosol spray cans—order by catalog number: 9999-058 for olive green � nish, 9999-080 for light gray � nish, and 9999-061 for red-oxide primer. No other � nish 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 con taminants. Use any ordinary mild household detergent solution.

In those cases where the enclosure must be re� nished by the user before the � nish 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 Ultradur II Outdoor Finish.

Figure 29. Touch-up kit components


Appendix A

Table 1. Ratings and Insulation Test Values

Rating, kV Withstand, kV

Nom. Max① 60-Hz, RMS② Dc③④ Impulse (BIL)

14.42525

17.027●29■

366060

507070

95125125

① Maximum voltage ratings are lower than the values listed when cur-rent-limiting fuses are used. Consult the appropriate current-limiting fuse manufacturer for complete fuse ratings.

② 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 volt-age should be limited to less than 10 seconds.

③ The column headed “Dc” is given as a reference only for those making dc tests and represents values believed to be appropriate and approxi mately equivalent to the corresponding power-frequency with-

stand 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.

④ 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 fuses.

■ Without fuses.

Dielectric TestingFor the convenience of users who normally perform elec-trical tests on system components such as pad-mounted gear, appropriate withstand test values are given in Table 1.


Appendix B

Table 3. Ratings and Capabilities for S&C Power Fuses with Uni-Rupter Interrupters

Fuse Type

Voltage, kV Current, Amperes, RMS

Nom. Max BIL MaxInterr.(Sym.)

Live Switching

Load Splitting(Parallel or Loop

Switching)

LoadDropping

Duty-Cycle Fault-Closing

RMS, Sym.

SML-2014.4 17.0 95 200E or 200K 14 000 200 200 14 000●

25 27 125 200E or 200K 12 500 200 200 12 500■

SML-4Z14.4 17.0 95 200E 12 500 200 200 12 500●

25 27 125 200E 12 500▲ 200 200 12 500■

Fault Fiter14.4 17.0 95 200 14 000 200 200 14 000●

25 29 125 200 12 500 200 200 12 500■

● Three-time duty-cycle fault-closing capability

■ Two-time duty-cycle fault-closing capability

▲ Applicable to solidly ground-neutral systems only, with fuses connected by single-conductor, concentric-neutral-type cable to a transformer or transformers. Rating is 9,400 amperes, RMS, symmetrical for all other applications.

Table 2. Ratings for S&C Mini-Rupter SwitchesVoltage, kV Current, Amperes

Nom. Max BIL Cont.

Live Switching Three-Time Duty-Cycle Fault-Closing Short-Circuit

Load-Splitting (Parallel or

Loop Switching)

Load Dropping

Peak RMS, Sym.Peak

Withstand,Peak

One-Second Short Time Withstand,RMS, Sym.

14.4 17.5 95 600 600 600 36 400 14 000 36 400 14 000

25 29 125 600 600 600 32 500 12 500 32 500 12 500

Ratings for S&C Mini-Rupter SwitchesComplete ratings for Mini-Rupter Switches as applied in S&C Manual PMH Pad-Mounted Gear are shown in Table 2. In addition to the load-dropping ratings shown, Mini-Rupter Switches are capable of interrupting transformer magne tizing currents associated with the applicable loads, as well as line-charging and cable -charging currents typica l for distr ibution systems of these voltage ratings. For applications on

Ratings for S&C Power Fuses with Uni-Rupter InterruptersComplete ratings and capabilities of S&C Power Fuses with Uni-Rupter Interrupters as applied in S&C Manual PMH Pad-Mounted Gear are shown in Table 3. Uni-Rupter Interrupters are also capable of carrying and interrupting load currents up to and including the emergency peak-load capabilities of the associated SML Power Fuses. In addition to the load-dropping capabilities shown, Uni-Rupter Interrupters are capable of interrupting transformer magnetizing currents associated with the applicable

systems rated higher than 7.2 kV and involving load current with high harmonic content (such as recti�er load currents), refer to the nearest S&C Sales Of�ce. The three-time duty-cycle fault-closing ratings shown for Mini-Rupter Switches de�ne the ability to close the Mini-Rupter Switch three times against a three-phase fault with asym metrical current in at least one phase equal to the rated value, with the switch remaining operable and able to carry and interrupt rated current.

loads, as well as line-charging and cable-charging currents typical for distribution systems of these voltage ratings. The duty-cycle fault-closing capabil ities shown for S&C Power Fuses with Uni-Rupter Interrupters repre sent the fault-closing capabilities of the fuse with a Uni-Rupter Interrupter when the fuse is closed with a purposeful thrust without hesitation. Following the speci�ed number of such closings (two or three), the Uni-Rupter Interrupter will remain opera ble and able to carry and interrupt rated current.


Appendix C

Table 4. Optional Features

Item

Suffix to beAdded to

Pad-Mounted Gear

Catalog Number

Applicable to Models

Light gray outdoor Ultradur II Outdoor Finish instead of olive green -A2 All models

Equipment green outdoor finish (Toronto standard) instead of olive green -A3 All models

Seafoam green outdoor finish instead of olive green -A4 All models

Special color Ultradur II Outdoor Finish instead of olive green -A5 All models

Stainless steel enclosure①

With olive green Ultradur II Outdoor Finish -A10 All models

With light gray Ultradur II Outdoor Finish -A12 All models

With special color Ultradur II Outdoor Finish -A15 All models

Hexhead actuator for use in lieu of penta-head actuator on all Penta-Latch Mechanisms

For use except when catalog number suffix “-F2” is specified -B1●■ All models

For use when catalog number suffix “-F2” is also specified -B2▲■ All models except PMH-4

Copper bus② and copper switch terminals, fuse connector adapters, and bus terminals -B5 All models

Reinforced busUsed with standard aluminum bus -B6 15-kV models of PMH-6, -7, -8, -9,

-10, -11, 12, -13Used with optional copper bus -B7

Key interlocks to prevent paralleling of switches in Compartments 1 and 2③ -C1 PMH-6, -9, -10, -11, -13, -19

Key interlocks to prevent opening fuse-compartment doors unless all switches (series tap switch only in PMH-19) are locked open③ -C3◆ PMH-5, -6, -7, -9, -11, -12, -19

Key interlocks. Combines functions of options “-C1” and “-C3” listed above③ -C4◆ PMH-6, -9, -11, -19

Fuse Storage feature for three spare fuse assemblies per compartment④

Located in Compartment 1 -E1 PMH-5, -6, -7, -8, -9, -11, -19

Located in Compartment 2 -E2 PMH-6, -7, -9, -11, -12, -19

Located in Compartments 1 and 2 -E3 PMH-6, -7, -9, -11, -19

Mounting provisions for a fault indicator in each switch compartment (except series tap switch in PMH-19)Note: Accommodates three-phase indicator with single-phase sensors

Without viewing window in door -F1 All models except PMH-4

With viewing window in door -F2▼□ All models except PMH-4

Inner barrier panels—a panel inside the enclosure door for each compartment, secured by recessed pentahead bolt(s)⑤⑥ -G7□ All models

Copper ground stud for each switch, fuse, or bus terminal and ground pad⑦

In fuse compartments⑧ -H2 All models except PMH-3, -10, -13

In switch and bus compartments -J2 All models except PMH-4

① When this optional feature is specified, the entire exterior of the enclosure is fabricated from 11-gauge Type 304 stainless steel. When specifying optional hexhead actuators, provisions for fault indicators with viewing windows in doors, or base spacer, specify the correct suffix for use in gear with a stainless-steel enclosure.

② Copper bus measures ¼-in. (6 mm) × 2 in. (51 mm).

③ When specifying, furnish name of ultimate user, station, and location of gear.

④ Fuse assemblies (fuse holders or fuse units with end-fittings) are not included. For units equipped with Fault Fiter Electronic Power Fuse Mountings, two spare Fault Fiter Interrupting Modules, one spare Fault Fiter Electronic Power Fuse Holder, or one spare current-limiting fuse holder can be accommodated in each compartment.

⑤ Where the National Electrical Safety Code (ANSI Standard C2) app-lies, this optional feature may be included to meet the requirements of Section 381G.

⑥ Meets RUS’s requirements for “dead-front.”

⑦ Diameters of copper ground studs are as follows:Ground StudSwitchFuseBus TerminalGround Pad

Diameter, in inches (mm)¼ (6)

7/16 (11)7/16 (11)7/16 (11)

⑧ Including bus-compartment terminals in Model PMH-4.

● Specify catalog number suffix “-B11” for gear with stainless-steel enclosure.

■ Not available if UL listing (catalog number suffix “-X”) is specified.

▲ Specify catalog number suffix “-B12” for gear with stainless-steel enclosure.

◆ Must be specified if end user is not an electric utility and/or if Canadian Standards Association listing (catalog number suffix “-Z”) is specified.

▼ Specify catalog number suffix “-F12” for gear with stainless-steel enclosure.

□ Not available if Canadian Standards Association listing (catalog number suffix “-Z”) is specified.

TABLE CONTINUED ▶


Appendix C

Table 4. Optional Features—Continued

ItemSuffix to be Added to Pad-Mounted Gear

Catalog NumberApplicable to Models

Base spacer, compartmented to match enclosure, increases cable-termination height

Carbon steel

6 inches (152 mm) -K1 All models




Stainless steel





Base spacer, noncompartmented, increases cable-termination height

Carbon steel





Stainless steel





International crating① -L71 All models

Switch- and bus-terminal adapters—for connection of two cables (through 750 kc mil) per terminal②Note: Space limitations prevent use of these adapters where surge arresters are to be installed

-M1 All models

Cable guides, one at each terminal②③

In switch and bus compartments. For conductor sizes No. 2 through 1000 kc mil

-M2 All models

In fuse compartments. For conductor sizes No. 2 through 4/0 -M3

PMH-4, -5, -6, -11, -19

PMH-7, -8, -9

PMH-12

Polymer-housed metal-oxide surge arresters④, base-mounted, at switch terminals and bus terminals in compartments 1 and 2 (removed for shipment)

9 kV -N6● All models

10 kV -N7● All models

12 kV -N8 All models

15 kV -N9 All models

18 kV -N10■All models except PMH-19

Metal-oxide surge arresters④, base-mounted, at switch terminals and bus terminals in Compartments 1 and 2 (removed for shipment)

3 kV -N11▲ All models

6 kV -N12▲ All models

① Wood products used in the packaging are either hardwood or certified by the wood supplier as being “heat treated (kiln dried) to a core temperature of 133°F (56° Celsius) for a minimum of 30 minutes.”

② When catalog number suffix “-M1” or “-M2” is specified, cable-termination options (catalog number suffixes “-U2” and “-U3”) cannot be accommodated. In addition, when catalog number suffixes “-M1” and “-M2” are both specified, only one cable guide is pro vided at each switch terminal.

③ These devices extend below the base of the unit. Provide a cable pit or specify a base spacer that provides a 12-inch (305 mm) or greater increase in cable-termination height.

④ Surge arresters are base-mounted only (without isolators).

● Not applicable to 25-kV models.

■ Not applicable to 14.4-kV models.

▲ A supplemental label is provided for catalog number suffixes “-N11” and “-N12” indicating the voltage rating of the surge arresters furnished.


Appendix C

Table 5. Accessories

Item Catalog Number

Grounding jumpers, set of three, with eye-type clamps for installation with a standard shotgun clamp stick 3-ft (914-mm) cable length 4210

Shotgun clamp sticks for installation of grounding jumpers and for use with voltage testers

6-ft-5½-in (1969-mm) length 9933-150

8-ft-5½-in (2578-mm)length 9933-151

Storage bag, heavy canvas

For grounding jumpers 9933-149

For shotgun clamp stick6-ft-6-in (1981-mm) length 9933-152

8-ft-6-in (2591-mm)length 9933-153

Voltage Tester with audio and visual signals, includes voltage tester, batteries, adapter for shotgun clamp sticks, and storage case①

9931-072

Pentahead socket, for 1/2-inch drive 9931-074

① For ultimate users other than electric utilities, also specify a shotgun clamp stick of the appropriate length.

Table 6. Touch-Up Kit Components—Aerosol Coatings in 12-Ounce Cans

Item Catalog Number

S&C light gray outdoor finish 9999-080

S&C olive green (Munsell 7GY3.29/1.5) Outdoor Finish 9999-058

S&C red-oxide primer 9999-061

Table 4. Optional Features—Continued

ItemSuffix to be Added to Pad-Mounted Gear

Catalog NumberApplicable to Models

Mounting Provisions for Base-Mounted Surge Arresters①, at switch terminals and bus terminals in Compartments 1 and 2

9 kV, 10 kV, or 9/10 kV -P1● All models

12 kV -P3 All models

15 kV -P4 All models

18 kV -P5■ All models except PMH-19

Mounting Provisions for Porcelain Cable Terminators for single-conductor UD cable, at all cable-connected switch terminals and bus terminals

G&W PSC for No. 6 through 2/0▲, or G&W PAT for No. 4 through 250 kc mil copper or aluminum cable

-U2 All models

G&W PAT for 3/0 through 750 kc mil

copper or 500 kc mil aluminum cable▲-U3 All models

UL Listing. Includes “UL Listed” symbol on ratings label and nameplate -X◆▼ All 14.4 kV models

Canadian Standards Association Listing. Includes viewing window with tamper-resistant cover in switch compartment door(s), and hazard-alerting labels and nameplate per CSA specification

-Z□△◇◆

PMH-3, -5, -7, -12

PMH-6, -9

PMH-11, -13, -19

PMH-10

① These provisions accommodate Ohio Brass Type PDV (metal oxide), McGraw-Edison Type AZL19C (metal oxide), General Electric Tran-quell® (metal oxide), or McGraw-Edison Type ES (silicon carbide) dis-tribution-class surge arresters. Surge arresters must be base-mounted only (with out isolators).

● Not applicable to 25-kV models.

■ Not applicable to 14.4-kV models.

▲ These devices extend below the base of the unit. Provide a cable pit or specify a base spacer.

◆ UL Listing (catalog number suffix “-X”) cannot be furnished if Canadian Standards Association Listing (catalog number suffix “-Z”) is specified and vice versa.

▼ Not available if hexhead actuator for use in lieu of pentahead actua-tor on all Penta-Latch Mechanisms (catalog number suffix “-B1,” “-B2,” “-B11,” or “-B12”) is specified.

□ Key interlocks (catalog number suffix “-C3” or “-C4”) must be speci-fied on gear with fuse compartment(s).

△ Not available if mounting provisions for fault indicator with viewing window in switch compartment door(s) (catalog number suffix “-F2” or “-F12”) is specified.

◇ Not available if inner barrier panels (catalog number suffix “-G7) is specified.


Appendix D

Table 7. Current-Limiting Fuses—Types Accommodated and S&C Holders Required

For use in PMH Models

Rated, kV

Current-Limiting Fuse① S&C Holder③

Manufacturer TypeRating②

Catalog Number④Max, kV Max Amperes, RMS

14.4

Kearney

B 8.3 30—112 3142-A1

Q

8.3 8.315.515.515.5

6—3040—1006—3040—5065—100

3142-A33142-A13142-A23142-A13142

Cooper Power SystemsMcGraw-Edison NX®

8.3 8.315.515.5

1.5C—40C50C—100C1.5C—40C50C—100C

3142-A33142-A13142-A23142

RTE® ELX 8.315.5

3—503—50

3142-A33142-A2

Westinghouse CX 8.315.5

3.5C—40C4C—40C

3142-A33142-A2

Combined Technologies, Inc. X Limiter™

8.3 8.315.515.5

12—4050—14012—4050—100

3142-A33142-A13142-A23142

25

KearneyB 15.5

2230—10025—65

3143R1-A13143R1-A1

Q 15.515.5

6—3040—100

3143R1-A33143R1-A1

Cooper Power SystemsMcGraw-Edison NX®

15.515.523

1.5C—40C50C—100C6C—40C

3143R1-A33143R1-A13143R1-A3

RTE® ELX 15.523

3—503—40

3143R1-A33143R1-A3

WestinghouseCX 15.5 4C—40C 3143R1-A3

CXN 15.5 45C—60C 3143R1-A1

Combined Technologies, Inc. X Limiter™

15.515.523

12—4050—10012—40

3143R1-A33143R1-A13143R1-A3

① The single-barrel current-limiting fuses listed in this table are to be purchased from the appropriate current-limiting fuse manufacturer.

② The maximum voltage and maximum ampere ratings listed in this table apply when the corresponding current-limiting fuse is used. Con sult the appropriate current-limiting fuse manufacturer for complete fuse ratings.

③ S&C Holders for use in 14.4-kV models of PMH Pad-Mounted Gear are rated 14.4 kV nominal, 17.0 kV maximum, and 200 amperes maxi-mum. S&C Holders for use in 25-kV models of PMH Pad-Mounted Gear are rated 25 kV nominal, 29 kV maximum, and 200 amperes maximum.

④ Includes adapters when required.

Current-Limiting Fuses for Use in S&C PMH Pad-Mounted Gear

Types Accommodated and Adapters RequiredS&C Holders for current-limiting fuses are designed for use in pad-mounted gear models that include mountings for Fault Fiter Electronic Power Fuses. In PMH Pad-Mounted Gear, these holders will accommodate the single-barrel current-limiting fuses listed in Table 7 when the fuses

are equipped with ⅝-inch (16-mm) diameter mounting studs at both ends. Depending on the length and diameter of the current-limiting fuse to be used, adapters may be required in order to �t the fuse in the holder. Adapters, when required, are furnished with the S&C Holder and are signi�ed by a suf�x to the catalog number of the holder. For instructions on installing current-limit ing fuses in S&C Holders, refer to S&C Instruction Sheet 660-500.


Appendix D

Recommended Voltage RatingsIn general, current-limiting fuses should have a maximum voltage rating equal to, but not greater than 140% of, the system line-to-line voltage because, for most applications, the fuses can be exposed to full system line-to-line voltage in clearing faults. Although there may be economic or space-saving incentives for using current-limiting fuses with voltage ratings “appropriate for system line-to-ground voltage” (i.e., fuses with a voltage rating lower than line-to-line voltage but greater than or equal to maxi mum system line-to-ground voltage), S&C can only recom mend such use in the following applications:

• Protection of single-phase transformers serving single-phase loads

• Protection of three-phase lateral circuits fed by single-conductor shielded cable (provided each transformer on that lateral is individually fused so that the current-limiting fuse serving the lateral will not be required to clear secondary faults)

• Protection of single-phase lateral circuits fed by single-conductor shielded cable where the load is line-to-ground connected

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