S&C PMH User manual

March 9, 2020
© S&C Electric Company 1983-2020, all rights reserved Instruction Sheet 662-505
Manual PMH Pad-Mounted Gear
Outdoor Distribution (14.4 kV and 25 kV)
Installation
Table of Contents
Section Page Section Page
Introduction
Qualified Persons ........................... 2
Read this Instruction Sheet ................... 2
Retain this Instruction Sheet. . . . . . . . . . . . . . . . . . . 2
Proper Application .......................... 2
Warranty .................................. 2
Safety Information
Understanding Safety-Alert Messages........... 3
Following Safety Instructions .................. 3
Replacement Instructions and Labels ........... 3
Safety Precautions ......................... 4
Shipping and Handling
Packing ................................... 5
Inspection ................................. 5
Handling .................................. 5
Overview................................... 6
Installation
Access to the Interior ........................ 7
Placement................................. 9
Cable Terminations..........................10
Fault Indicators .............................13
Completing the Installation ....................13
Dielectric Testing ...........................15

2 S&C Instruction Sheet 662-505
Qualified Persons WARNING
Only 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 your Manual
PMH Pad-Mounted Gear. Familiarize yourself with the Safety Information and
Safety Precautions on pages 3 and 4. 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 your Manual PMH Pad-Mounted Gear.
Designate a location where you 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.
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.)
Introduction

S&C Instruction Sheet 662-505 3
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 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 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.

4 S&C Instruction Sheet 662-505
Safety Precautions
DANGER
Manual PMH 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 company operating procedures and rules.
Where a discrepancy exists, follow your company’s operating procedures and rules.
1. QUALIFIED PERSONS. Access to S&C Manual PMH
Pad-Mounted Gear must be restricted only to qualified
persons. See the “Qualified Persons” section on
page 2.
2. SAFETY PROCEDURES. Always follow safe
operating procedures and rules.
3. PERSONAL PROTECTIVE EQUIPMENT. Always
use suitable protective equipment, such as rubber
gloves, rubber mats, hard hats, safety glasses, and
flash clothing, in accordance with safe operating
procedures and rules.
4. SAFETY LABELS. Do not remove or obscure any of
the “DANGER,” “WARNING,” “CAUTION,” or
“NOTICE” labels.
5. HIGH-VOLTAGE ISOLATION. Switch operators and
controls are isolated from high voltage in grounded,
metal-enclosed compartments. Access to these
components is controlled by padlockable covers,
which incorporate a nonrernovable manual handle.
Other low-voltage components, such as meters,
selector switches, toggle switches, etc., are similarly
isolated.
6. TEST FOR VOLTAGE. Test for voltage using proper
high-voltage test equipment before touching any
device to be inspected, serviced, or repaired in the
high-voltage compartments.
7. ENERGIZED COMPONENTS. Always consider all
parts live until de-energized, tested, and grounded.
Voltage levels can be as high as the peak line-to-
ground voltage last applied to the unit. Units energized
or installed near energized lines should be considered
live until tested and grounded.
8. GROUNDING. Manual PMH Pad-Mounted Gear
must be connected to a suitable earth ground at the
base of the utility pole, or to a suitable building ground
for testing, before energizing the switchgear, and at all
times when energized.
The ground wire(s) must be bonded to the system
neutral, if present. If the system neutral is not
present, proper precautions must be taken to
ensure the local earth ground, or building ground,
cannot be severed or removed.
9. MAINTAINING PROPER CLEARANCE. Always
maintain proper clearance from energized
components.
10. GROUNDING EQUIPMENT.
Install suitable
grounding equipment before touching any device to
be inspected, serviced, or repaired in the high-voltage
compartments.
11. PADLOCKS. Non-removable, manual handles in
high-voltage compartment doors and hinged-
padlockable covers, as well as hinged-bolted panels,
have provisions for padlocks which must be in place
and secured at all times unless work is being
performed inside the enclosure. Padlocks must be
installed and secured on manual switch operating
handles atall timesunless the switchis beingoperated.
12. KEY INTERLOCKS. Key interlocks (if applicable)
must be in place. Check the operating sequence of
key interlocks to verify proper sequencing. After the
switchgear is installed, destroy all duplicate keys or
make them accessible only to authorized persons so
the key interlock scheme will not be compromised.
Key interlocks are not security locks.
13. MECHANICAL CABLE INTERLOCKS. Mechanical
cable interlocks are provided to prevent access to
fuses unless the switch is open and to prevent
operation of stored-energy switch operators when the
enclosure door is open. Do not attempt to operate any
switch when the enclosure door is open. Periodically,
verify these interlocks are functional.
14. DO NOT APPLY UNDUE FORCE. Do not apply any
undue force when attempting to open a door. The use
of undue force may damage the door-latching
mechanism. If optional key interlocks are provided,
make certain the interlocks are in their correct
positions to allow door opening.
15. FUSES MUST BE DISCONNECTED. Make certain
fuses are disconnected from all power sources
(including backfeed) before being inspected or
replaced.

S&C Instruction Sheet 662-505 5
Shipping and Handling
Packing
Manual PMH Pad-Mounted Gear is fastened to a wood skid
for shipment. Any components specied, such as fuses,
rell units, fuse holders, end ttings, etc., are packed
separately and, insofar as practicable, are shipped within
the enclosure.
At the first opportunity, remove all packing materials
(cardboard, paper, foam padding, etc.) from the outside of
the gear. This will prevent the finish from being damaged
by rainwater absorbed by the packing materials and will
also prevent wind-induced abrasion from loose cardboard.
Inspection
Examine the shipment for external evidence of damage as
soon after receipt as possible, preferably before removal
from the carrier’s conveyance. Check the bill of lading to
make sure all listed shipping skids, crates, and containers
are present.
If there is visible loss and/or damage:
1. Notify the delivering carrier immediately.
2. Ask for a carrier inspection.
3. Note condition of shipment on all copies of the delivery
receipt.
4. File a claim with the carrier.
If concealed damage is discovered:
1. Notify the delivering carrier within 15 days of receipt of
shipment.
2. Ask for a carrier inspection.
3. File a claim with the carrier.
Also, notify S&C Electric Company in all instances of
loss or damage.
Handling
Follow these steps to avoid damaging this gear when
handling with an overhead hoist; observe standard lifting
practices as well:
STEP 1. Make sure the lifting tabs are securely bolted to
the enclosure before lifting the gear.
STEP 2. Use 6-foot (183-cm) or longer hoist slings
of equal length to prevent overstressing the
enclosure during lifting. (Four-foot (122-cm)
hoist slings are acceptable for two-compartment
pad-mounted gear models: PMH-3, -4, and -5.)
STEP 3. Arrange the hoist slings to distribute the lifting
forces equally between the lifting tabs. See
Figure 1.
STEP 4. Avoid sudden starts and stops.
Figure 1. Hoisting arrangements.

6 S&C Instruction Sheet 662-505
Overview
The following instructions cover installation of Manual
PMH Pad-Mounted Gear, which features directly operable
accessible components and is available in ratings of
14.4 kV and 25 kV. These units are equipped with external
handle-operated 600-ampere Mini-Rupter® Switches for
three-pole live switching of three-phase source circuits,
and 200- or 400-ampere hookstick-operated S&C Power
Fuses with a Uni-Rupter® Interrupter for single-pole live
switching of single-phase or three-phase load circuits.
Models available offer a choice of Type SML-20 and SML-4Z
Power Fuses, Fault Fiter® Electronic Power Fuses, or a
variety of single-barrel current-limiting fuses.
For operating instructions regarding Manual PMH
Mounted Gear, refer to S&C Instruction Sheet 662-510.
All personnel involved with the installation and operation
of the equipment should be thoroughly familiar with the
contents of the installation and operation instruction
sheets.
The catalog number stamped on the nameplates affixed
to the outside of the doors of the pad-mounted gear is
suffixed with letter-number combinations. These suffixes
indicate the inclusion of optional features, such as key
interlocks (catalog number suffix “-C1,” “-C3,” or “-C4”).
Refer to Specification Bulletin 662A-31 for a complete
listing of the available options for the gear.

S&C Instruction Sheet 662-505 7
Installation
Access to the Interior
CAUTION
Do not apply any undue force when attempting to
open a door. The use of undue force may damage
the latching mechanism. If optional key interlocks are
provided, be sure the interlocks are in their correct
positions to allow door opening.
Follow these steps to open the enclosure:
STEP 1. Access to the interior of Manual PMH
Pad-Mounted Gear is controlled by the
Penta-Latch® Mechanism, which must be
opened with a pentahead socket wrench or
tool except when hexhead actuators (catalog
number sufx “-B1” or “-B2”) are specied. The
latching mechanism is coordinated with the
provisions for padlocking so the mechanism
can be unlatched only after the padlock has
been removed. The padlock can be installed
only after the door has been securely closed and
completely latched.
(a) Use a pentahead socket wrench or tool
(a hexhead socket wrench or tool when
catalog number sufx “-Bl” or “-B2” is
specied) to unlatch the Penta-Latch
Mechanism by rotating the actuator
counterclockwise approximately 60°
against spring resistance until a distinct
“click” is heard and the actuator reaches its
stop. See Figure 2. This single motion
unlatches the mechanism and recharges the
latching spring for the subsequent closing
operation.
(b) Pull the door open and secure it with the
door holder. See Figure 3.
(c) For double-door models of pad-mounted
gear, the left-hand door is secured by a latch
and is overlapped by the right-hand door
equipped with the Penta-Latch Mechanism.
The left-hand door can be opened after (1)
opening the right-hand door, (2) removing
the tie wrap that secures it for shipment, and
(3) disengaging the latch by rotating the
latch upward. See Figure 4 on page 8.
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. Using the door holder to hold the door open.
Door holder (stored)
Door holder (latched)
(a)
(b)

8 S&C Instruction Sheet 662-505
Installation
STEP 2. Close the left-hand door, where applicable, and
secure it with the latch by rotating the latch
downward over the stop on the outer edge of the
door. See Figure 4.
(a) The right-hand door of double-door models
of pad-mounted gear 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.
(b) Pull outward on the cover of the Penta-Latch
Mechanism to verify the door has latched
securely. If it has not, use a pentahead (or
hexhead, when applicable) socket wrench or
tool to rotate the actuator counterclockwise
until a distinct “click” is heard and the
actuator reaches its stop.
(c) If the actuator will not rotate counter-
clockwise, the mechanism was already
charged for closing and was not closed
properly. Close the door again, making sure
that all latch points engage completely and
simultaneously.
When the door is securely latched, a
padlock may be inserted into the hasp.
Figure 4. Rotate the latch upward to disengage the left-hand
door, as shown above. To secure the left-hand door closed,
rotate the latch downward over the stop on the outer edge of
the door.
Door-latching
mechanism
disengaged

S&C Instruction Sheet 662-505 9
Installation
Placement
STEP 3. At the installation site, remove all separately
packaged components shipped in the pad-
mounted gear enclosure and set them aside in a
protected area.
(a) Unbolt the enclosure from its skid and lift the
unit onto the mounting pad, observing the
precautions given in the “Handling” section
on page 5.
(b) Open the doors to the interior of the gear and
secure them with the door holders. Refer to
the catalog dimensional drawing furnished
and verify the enclosure compartments are
positioned correctly and the unit is properly
aligned with respect to the anchor bolts (or
ush anchors).
(c) If excess lengths of direct-buried cable are in
place and it is desired to feed them into the
enclosure compartments as the unit is being
lowered, the doors must be opened (with
door holders in place) to allow any excess
cable to be fed over the door stiles.
(d) If switch interphase and end barriers (where
applicable) are removed to facilitate this
procedure, note their positioning to ensure
correct reinstallation later.
It should not be necessary to remove any
upper barriers. Refer to Step 4 in the “Cable
Terminations” section on page 10 for
instructions for removal of switch barriers.
(e) Level the pad-mounted gear enclosure using
metal shims as required between the
mounting pad and the enclosure.
(f) Shim the enclosure of four-compartment
units until the tops of the compartment
doors are even.
(g) For two-compartment units, shim the
enclosure until the top of each door is
parallel with the top of the gear.
(h) Secure the enclosure to the pad using the
anchor brackets provided (see anchor-bolt
detail on the catalog dimensional drawing).
Make sure all compartment doors open and
latch closed without binding. Binding
indicates enclosure distortion which must
be corrected by additional shimming.
Figure 5. Side view of the switch showing the interphase barrier attachment points, terminal-pad connections, and optional cable
guides.
Mounting angle and cable-
support bracket (furnished
with catalog number suffix
“-M2,” catalog number suffix
“-M3” is similar)
Barrier guide
Concentric-neutral
ground wires
Barrier-support angle
Wing-head screw
Switch interphase barrier
Connect terminator (or connector)
to two uppermost holes on switch
terminal pad when catalog number
suffix “-M2” is specified
Offset spade-type
compression terminal
Cable terminator
To Ground Bus
12-inch (30-cm) min. base spacer
or cable pit (required if catalog
number suffix “-M2” or “-M3” is
specified)
Cable terminator
Offset spade-type
Connect terminator (or connector)
Switch interphase barrier
Switch interphase barrier

10 S&C Instruction Sheet 662-505
Installation
Cable Terminations
STEP 4. To facilitate makeup and connection of cable
terminations to the switch terminals, switch
interphase and end barriers (where applicable)
can be removed by loosening the wing-head
screw that secures each barrier to the barrier-
support angle.
(a) Remove the tie wraps that secure the wing-
head screws for shipment. The screw will
remain attached to the barrier, which is
supported at the switch frame by the barrier
guide. See Figure 5 on page 9.
(b) Lift the barrier from the guide and place it in
a location where the barrier will not be
damaged.
STEP 5. Optional cable guides (catalog number sufx
“-M2”or “-M3”), if specied, include cable-
support brackets (packed separately) and
mounting angles (factory-installed when an
optional base spacer, 12-inch minimum, is
specied; packed separately otherwise).
(a) Using the hardware furnished, attach the
mounting angles (if packed separately) to
the tabs provided on the sidewalls of the
compartments and attach the cable-support
brackets to the angles. See Figure 5 on
page 9.
(b) Do not remove the protective sheet from the
saddle of the bracket or install the cable
wrap until instructed to do so in Step 6 on
page 12.

S&C Instruction Sheet 662-505 11
Installation
Figure 6. Minimum clearances that must be maintained when installing cable terminators.
Minimum clearance
from energized parts
to electrical ground:
6 inches (152 mm) for
14.4 kV; 7½inches
(191 mm) for 25 kV
Minimum clearance
from energized parts
to barriers:
1 inch (25 mm) for
14.4 kV; 2¼inches
(57 mm) for 25 kV
Minimum clearance
from energized parts
to barriers:
1 inch (25 mm) for
14.4 kV; 2¼inches
(57 mm) for 25 kV
Minimum clearance
from terminator skirts
to barriers:
½inch (13 mm) for
14.4 kV; 1¼inches
(32 mm) for 25 kV
Minimum clearance
from energized parts
to electrical ground:
6 inches (152 mm) for
14.4 kV; 7½inches
(191 mm) for 25 kV
Minimum clearance
from terminator skirts
to barriers:
½inch (13 mm) for
14.4 kV; 1¼inches
(32 mm) for 25 kV
Check clearances for both normal
and alternate positions of adapter

12 S&C Instruction Sheet 662-505
Installation
STEP 6. Make up cable terminations following the cable-
terminator manufacturer’s instructions.
WARNING
While the interior of Manual PMH Pad-Mounted Gear
is protected from direct exposure to the elements, it
is inherently an outdoor environment—and requires
selection and application of cable-terminating
devices accordingly. Terminations must incorporate
adequate leakage distance between the exposed
conductor and the stress-relief cone, across a surface
of non-tracking material (or surface rendered non-
tracking by properly taping with a suitable material).
Furthermore, to maintain the rated BIL, the following
minimum clearances are required. See Figure 6 on
page 11:
• From energized parts to electrical ground: 6 inches
(152 mm) at 14.4 kV; 7½inches (191 mm) at 25 kV.
• From energized parts to fiberglass-reinforced
polyester barriers: 1 inch (25 mm) at 14.4 kV;
2¼ inches (57 mm) at 25 kV
• From terminator skirts to fiberglass-reinforced
polyester barriers: ½inch (13 mm) at 14.4 kV;
1¼inch (32 mm) at 25 kV.
Two-position cable-terminator adapters are provided
at the fuse hinge assemblies. See Figure 7. These adapters
can be placed in their alternate positions when required
for increased clearance from energized parts to grounded
parts of the cable terminators.
Switch terminal pads are furnished with three mounting
holes. In general, cable terminators may be connected to
the two lower holes in the switch terminal pads. However,
if the pad-mounted gear includes optional cable guides
for switch terminals (catalog number suffix “-M2”), cable
terminators must be connected to the two uppermost holes
in the switch terminal pads. See Figure 5 on page 9.
CAUTION
When connecting cable terminators, avoid placing
any intentional strain on a switch or fuse terminal. It
is important each cable-terminator connector be flat
against the corresponding switch or fuse terminal
pad with the bolt holes in alignment. Do not use the
connecting bolts to pull the cables into alignment.
Figure 7. Fuse assembly showing alternate arrangement of two-
position cable-terminator adapters.
Normal position for
maximum cable-
terminating height
Alternate position for
use when required for
electrical clearance

S&C Instruction Sheet 662-505 13
Installation
Before connecting the cable terminators to
the aluminum terminal pads, thoroughly wire-
brush aluminum contact surfaces to remove
any dirt or foreign materials as well as natural
surface oxides. Immediately coat both contact
surfaces to one-half inch beyond the joint with
a uniform layer of Penetrox® A. Then, make the
connections as follows. See Figure 8.
(a) For aluminum connectors: Use ½-inch
aluminum or galvanized steel hardware
with two Belleville spring washers (not
furnished) as shown in Detail A of Figure 8.
Before tightening the connecting bolts,
complete the installation of optional cable
guides (where applicable) following the
cable-guide manufacturer’s instructions.
Torque aluminum bolts to the manu-
facturer’s specications. Torque steel bolts
to 50 foot-pounds or, in the absence of a
torque wrench, tighten each bolt until the
Belleville washers are at. Then, back off
one-half turn. Do not use lockwashers with
Belleville washers.
(b) For tinned copper or tinned bronze
connectors●: Use ½-inch galvanized steel
hardware with one Belleville spring washer
(not furnished) against the aluminum
terminal pad and one galvanized steel at
washer against the tinned connector as
shown in Detail B of Figure 8. Before
tightening the connecting bolts, complete
the installation of optional cable guides
(where applicable) following the cable-guide
manufacturer’s instructions. Torque the
bolts to 50 foot-pounds or, in the absence of
a torque wrench, tighten each bolt until the
Belleville washer is at. Then, back off one-
half turn. Do not use lockwashers with
Belleville washers.
STEP 7. Connect the cable concentric-neutral ground
wires and the ground pads inside the pad-
mounted gear enclosure to the system ground
facility in accordance with the user’s standard
grounding practice. Use the equivalent of 410
copper cable (or cable sized in accordance with
the user’s standard practice) in either a single or
multiple connection to realize the maximum
momentary rating of the gear. For a multiple
connection, cables smaller than 1/0 copper or
equivalent should not be used.
●The use of untinned copper or bronze connectors is not recommended.
Fault Indicators
STEP 8. Optional mounting provisions for fault
indicators (catalog number sufx “-F1” or “-F2”)
are available. Fault indicators are to be
furnished by the user and installed in
accordance with the manufacturer’s
instructions. If mounting provisions are
specied, mount the fault indicators on the
mounting brackets and attach the associated
sensors to the cables below the cable
terminators.
Completing the Installation
STEP 9. If applicable, install and connect surge
arresters in accordance with the manu-
facturer’s instructions.
STEP 10. If any switch barriers were removed to
facilitate cable termination, reinstall them at
this time. Make sure the clearances from the
barriers to energized parts and from the barriers
to terminator skirts conform to the minimum
dimensions specied in Step 6 on page 12.
Figure 8. Terminal-pad connections. See Step 6.
Aluminum
terminal pad
Belleville
spring washers
Aluminum
connector
Detail A
Aluminum
terminal pad
Galvanized steel
flat washer
Belleville
spring washer
Tinned copper or
tinned bronze
connector Detail B
Aluminum

14 S&C Instruction Sheet 662-505
Installation
STEP 11. Check functional operation of key interlocks, if
furnished.
CAUTION
When optional key interlocks are furnished,
duplicate keys are provided for use during
installation. To maintain the integrity of the
key-interlock scheme, duplicate keys must
be destroyed or made accessible only to
authorized persons.
Note: Key interlocks are not security locks
and are not a substitute for padlocks.
CAUTION
Use of undue force in an attempt to open
a door contrary to the correct sequence
dictated by the key-interlock scheme may
damage the door latching mechanism.
Be sure the interlocks are in their correct
positions to allow opening the door.
STEP 12. Be sure the doors open and close without
binding and the shimming of the pad-mounted
gear enclosure is adequate. A resilient closed-
cell gasket on the bottom ange of the
enclosure protects the nish from being
scratched during installation and isolates it
from the alkalinity of a concrete foundation.
This gasket also helps to seal the enclosure to
the foundation to guard against entry of
rodents, insects, or weeds, and to discourage
tampering.
In the event the gasket cannot compensate
for an uneven foundation, grout the bottom of
the enclosure as necessary. Any grout applied
should be recessed enough to permit caulking.
To complete the installation, caulk around the
bottom of the enclosure with a weatherproof
compound applied with a standard caulking
gun. A room-temperature vulcanizing (RTV)
silicon-rubber compound is recommended.
Apply a suitable compound to fill the spaces
between the cable and the conduit, and cap all
empty conduits to prevent the entry of rodents.
STEP 13. Before walking away:
(a) Remove the lifting tabs and replace the bolts
to plug the blind-tapped holes.
(b) Check the interior of the pad-mounted gear.
Remove all foreign materials and tools that
may have been mislaid, and sweep the
interior clear of debris.
(c) Remove the tie wraps that secure the dual-
purpose barriers to the inside of the door.
(d) Wipe barriers, insulators, switches, fuses,
and terminators clean with a mineral-spirits
solvent and dry with a clean cloth.
(e) Hang dual-purpose front barriers in their
normal, suspended positions. Also install
optional inner barrier panels, if furnished.
WARNING
Dual-purpose front barriers must be wiped
clean before placing them in the “slide-in”
position. In addition, do not leave any
dual-purpose front barriers in the “slide-in”
position for more than one week. These
barriers are intended for temporary use
only. 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 or injury.
(f) Store spare SMU-20 Fuse Units or SM-4
Rell Units (as applicable) in the fuse-
storage racks inside the fuse-compartment
doors. Storage for Fault Fiter Electronic
Power Fuses or current-limiting fuses
cannot be provided in these racks.
(g) Wipe down the exterior of the enclosure
with a clean, damp cloth. To preserve the
integrity of the surface, renish any
scratches or abrasions with S&C touch-up
paint and red-oxide primer which are
available in aerosol spray cans. Order
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 that all edges are feathered before
applying primer.
At completion of these installation instructions, refer
to S&C Instruction Sheet 662-510 for the operating
instructions.

S&C Instruction Sheet 662-505 15
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. Max①60-Hz, RMS②Dc③④ Impulse (BIL)
14.4
25
25
17.0
27●
29■
36
60
60
50
70
70
95
125
125
①Maximum 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.
②Ac 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.
③The 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 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.
④Dc 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.