Instruction Sheet 663-503 [English, 329 KB, 8/14/1995]

S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
INSTRUCTIONS
For Operation
This publication contains instructions for operation of fuses and Mini-Rupter® Switches in S&C
Source-Transfer PMH Pad-Mounted Gear. For instructions regarding field programming and
operation of the S&C Micro-AT Source-Transfer Control, refer to S&C Instruction Sheet 515-500.
For operating instructions regarding the optional test-panel feature (Catalog Number Suffix “-Y5”),
if furnished, refer to S&C Instruction Sheet 515-505.
TABLE OF CONTENTS
Section
Page Number
INTRODUCTION
Qualified Persons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
SAFETY INFORMATION
Understanding Safety-Alert Messages . . . . . . . . . . . . . . . . . . . . 3
Following Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Replacement Instructions and Labels . . . . . . . . . . . . . . . . . . . . 3
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
OPERATING DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MINI-RUPTER SWITCHES
Decoupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Automatic Switch Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Nonautomatic Switch Operation . . . . . . . . . . . . . . . . . . . . . . . . 11
Charging Operator (Nonelectrical) . . . . . . . . . . . . . . . . . . . . . . 11
Front Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
FUSING
Assembling the Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Installing the Fuse in the Mounting. . . . . . . . . . . . . . . . . . . . . . 15
Warranty Qualifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
SWITCHING WITH UNI-RUPTER
Installing and Closing the Fuse . . . . . . . . . . . . . . . . . . . . . . . . . 16
A Note on Single-Pole Switching . . . . . . . . . . . . . . . . . . . . . . . . 20
Opening and Removing the Fuse. . . . . . . . . . . . . . . . . . . . . . . . 20
Supersedes Instruction Sheet 663-503 dated 9-20-93
Section
S&C ELECTRIC COMPANY
23
24
25
26
27
28
28
29
29
29
30
31
33
34
c1995
INSTRUCTION SHEET
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Page Number
RE-FUSING
How to Detect and Replace a Blown Fuse. . . . . . . . . . . . . . . .
Installing the Fuse in the Mounting. . . . . . . . . . . . . . . . . . . . . .
FINAL CHECKS BEFORE WALKING AWAY. . . . . . . . . . . . . . . .
IF OPERATOR STALLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Returning Equipment to Service . . . . . . . . . . . . . . . . . . . . . . . .
Enclosure Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX A
Preliminary Tryout Before Gear Is Energized—Optional . . .
APPENDIX B
Dielectric Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX C
Ratings for S&C Mini-Rupter Switches. . . . . . . . . . . . . . . . . . .
Ratings for S&C Power Fuses with Uni-Rupter. . . . . . . . . . . .
APPENDIX D
Optional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX E
Current-Limiting Fuses for Use in
S&C PMH Pad-Mounted Gear . . . . . . . . . . . . . . . . . . . . . . . . .
663-503
Page 1 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
INTRODUCTION
Qualified Persons
Ç WARNING
The equipment covered by this publication must be installed, operated, and maintained by qualified persons
who are knowledgeable in the installation, operation,
and maintenance of underground electric power distribution equipment along with the associated hazards. A
qualified person is one who is trained and competent in:
• The skills and techniques necessary to distinguish
exposed live parts from non-live parts of electrical
equipment.
• The skills and techniques necessary to determine
the proper approach distances corresponding to the
voltages to which the qualified person will be
exposed.
• The proper use of the special precautionary techniques, personal protective equipment, insulating
and shielding materials, and insulated tools for
working on or near exposed energized parts of electrical equipment.
These instructions are intended only for such qualified persons. They are not intended to be a substitute
for adequate training and experience in safety procedures for this type of equipment.
Ç CAUTION
The equipment in this publication must be selected for a
specific application. The application must be within the
ratings furnished for the equipment. Ratings for this gear
are listed on a ratings label on the interior of the doors
(right-hand doors only for double-door models).
General
Each unit of S&C Source-Transfer PMH Pad-Mounted
Gear is provided with an “Installation and Operation
Information Kit” located in the holder inside the PentaLatch-equipped door of the low-voltage control compartment. The information kit includes applicable instruction
sheets covering installation of the gear and operation of
components, plus wiring diagrams and a catalog dimensional drawing showing cable-locating and anchor-bolt
dimensions. All personnel involved with installation and
operation of the gear should be thoroughly familiar with
the contents of the kit.
These instructions are for operation of fuses and MiniRupter Switches in S&C Pad-Mounted Gear, Source-Transfer PMH Models equipped with the S&C Micro-AT Source-
663-503
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August 14, 1995
Transfer Control. For instructions regarding field programming and operation of the Micro-AT control, refer to
S&C Instruction Sheet 515-500.
Source-Transfer PMH Pad-Mounted Gear is a totally
self-contained switching and protection package that provides fault protection and fully automatic two-way source
transfer for critical loads requiring a high degree of service continuity. This gear contains the following:
• Switch-operator-driven 600-ampere S&C Mini-Rupter
Switches for three-pole live switching of three-phase
source circuits.
• Stored-energy operators to provide high-speed power
operation of the Mini-Rupter Switches. The operators
automatically charge when voltage is present on the
associated source.
• S&C Micro-AT Source-Transfer Control for programmed control of all switching functions associated
with automatic source transfer.
• S&C Voltage Sensors to provide three-phase sensing
for automatic source transfer and control power for
the Micro-AT control. The voltage sensors also provide
supply power for motor charging of the stored-energy
operators and capacitor charging for solenoid tripping
of the operators.
• Decouplers to permit exercising of the stored-energy
operators without affecting the position of the MiniRupter Switches.
• 200- or 400-ampere hookstick-operated S&C Power
Fuses with Uni-Rupter for single-pole live switching of
single-phase or three-phase load circuits. Models available offer a choice of S&C Type SML-20 or SML-4Z
Power Fuses, S&C Fault Fiter® Electronic Power
Fuses, or a variety of current-limiting fuses.
• Penta-Latch Mechanism on each set of doors for
access control. Mechanism provides automatic door
latching and permits padlocking only when the door is
latched closed. Doors can be opened only with a pentahead socket wrench or tool except when hexhead actuators (Catalog Number Suffix “-B1” or “-B2”) are
specified.
A variety of optional features are available for S&C
Source-Transfer PMH Pad-Mounted Gear. The catalog
number stamped on the nameplate affixed to the enclosure door is suffixed with letter-number combinations
applicable to the gear furnished. Refer to Appendix D for
descriptions of the optional features.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
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SAFETY INFORMATION
Understanding Safety-Alert Messages
There are several types of safety-alert messages which
may appear throughout this instruction sheet as well as
on labels affixed to the S&C Source-Transfer PMH PadMounted Gear. Familiarize yourself with these types of
messages and the importance of the various signal words,
as explained below.
Ç DANGER
“DANGER” identifies the most serious and immediate
hazards which will likely result in serious personal injury or death if instructions, including recommended
precautions, are not followed.
Ç WARNING
“WARNING” identifies hazards or unsafe practices
which can result in serious personal injury or death if
instructions, including recommended precautions, are
not followed.
Ç CAUTION
“CAUTION” identifies hazards or unsafe practices
which can result in minor personal injury or product or
property damage if instructions, including recommended precautions, are not followed.
Following Safety Instructions
Ç NOTICE
Thoroughly and carefully
read this instruction sheet
before operating your S&C
Pad-Mounted Gear.
If you do not understand any portion of this instruction
sheet and need assistance, contact your nearest S&C
Sales Office or S&C Authorized Distributor, or call S&C
Headquarters at (312) 338-1000, Monday through Friday
between 8:30 AM and 5:00 PM Central Standard Time. (In
Canada, call S&C Electric Canada at (416) 249-9171.)
Replacement Instructions and Labels
If you need additional copies of this instruction sheet,
contact your nearest S&C Sales Office or S&C Authorized
Distributor, or call S&C Headquarters.
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 Canada.
Ç NOTICE
“NOTICE” identifies important procedures or requirements that, if not followed, can result in product or
property damage if instructions are not followed.
INSTRUCTION SHEET
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S&C ELECTRIC COMPANY
663-503
Page 3 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
SAFETY PRECAUTIONS
Ç DANGER
Pad-mounted gear contains high voltage. Failure to observe the precautions
below will result in serious 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 “Qualified Persons” 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 “CAUTION,” “WARNING,” or “DANGER” labels.
5. KEY INTERLOCKS.
v If optional key interlocks were furnished, they must
be in place.
v Check the operating sequence of key interlocks to
verify proper sequencing.
v After the pad-mounted gear is installed, either: (1)
destroy the extra set of keys or (2) make them accessible only to qualified persons. This will maintain the
integrity of the key-interlock scheme.
v Key interlocks are not security locks and are not
substitutes for padlocks.
6. MECHANICAL CABLE INTERLOCKS. If optional
mechanical cable interlocks were furnished, periodically verify that these interlocks are functional. These
interlocks prevent operation of the Mini-Rupter Switch
when the associated switch-compartment door is open.
7. OPENING DOORS. Do not force doors open. Forcing
a door open can damage the latching mechanism. If
optional key interlocks are furnished, correctly position the interlocks so the doors can be opened.
8. CLOSING AND LOCKING DOORS.
v Doors must be securely closed and latched, with
padlocks in place at all times unless work is being
performed inside the enclosure.
v Do not close a door on a fuse in the open position.
The door will strike the fuse pull ring which will
interfere with door closing. The door may be closed if
the fuse is removed from the mounting.
9. ENERGIZED TERMINALS. Always assume that
both sets of power terminals on any Mini-Rupter
Switch or fuse are energized unless proved otherwise by test, by visual evidence of open-circuit conditions on both sets of terminals, or by observing that
both sets of terminals are grounded.
10. BACKFEED. Mini-Rupter Switches, switch terminals, fuses, and fuse mountings (Uni-Rupter, load-side
hinge, and terminals) may be energized by backfeed.
11. DE-ENERGIZING. Before touching any device that
is to be inspected, replaced, serviced, or repaired in
the high-voltage compartments, always disconnect
Mini-Rupter Switches, fuses, and other devices such
as voltage sensors from all power sources (including
backfeed) and control sources, test for voltage, and
properly ground.
12. TESTING. Test for voltage on both sets of power terminals of any Mini-Rupter Switch or fuse using
proper high-voltage test equipment before touching
any device that is to be inspected, replaced, serviced,
or repaired in the high-voltage compartments.
13. GROUNDING.
v Make sure that the pad-mounted gear enclosure is
properly grounded to the station or facility ground.
v After the gear has been completely disconnected
from all sources of power and tested for voltage,
install suitable grounding cables in all compartments
before touching any device that is to be inspected,
replaced, serviced, or repaired in the high-voltage
compartments.
14. SWITCH POSITION.
v Always confirm the open/close position of the
Mini-Rupter Switches by visually observing the position of the switch blades.
v Switches and switch terminals may be energized
by backfeed.
v Switches and switch terminals may be energized in
any position.
15. FUSE POSITION. Fuses and fuse mountings (UniRupter, load-side hinge, and terminals) may be
energized by backfeed even when the fuse is in the
fully open position.
CONTINUED
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August 14, 1995
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INSTRUCTION SHEET
S&C ELECTRIC COMPANY
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SAFETY PRECAUTIONS — Continued
Ç DANGER — Continued
Pad-mounted gear contains high voltage. Failure to observe the precautions
below will result in serious 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.
16. S&C GRAPPLER.
v The Grappler (Catalog Number 4423) is the S&C
fuse-handling fitting supplied with each unit equipped
for fuses.
v The Grappler improves grip, balance, and control
of fuses during handling.
v Always use the S&C Grappler attached to a suitable universal pole (1¹⁄₄ diameter) to handle barriers
and to install, remove, open, or close fuses. The universal pole must be at least 4 feet long (S&C Catalog
Number 4451R2-E, or equal) for 14.4-kv gear or at
least 6 feet long (S&C Catalog Number 4452R2-E, or
equal) for 25-kv gear.
17. MAINTAINING PROPER CLEARANCE.
v When working in the high-voltage compartments,
always maintain proper clearance from energized
components.
v When handling barriers or when installing, removing, opening, or closing fuses, always use an S&C
Grappler attached to a suitable universal pole (see 16
above).
v Switch Side: These barriers are intended for temporary use to isolate the blades of the Mini-Rupter
Switch from the main contacts while work is being
performed.
v Fuse Side: These barriers are intended for temporary use to isolate the fuse from the contacts of UniRupter while work is being performed.
19. CLOSING FUSES. Closing a fuse into a faulted circuit will cause a loud noise, a flash of light at the UniRupter contacts, and the fuse to blow. Closing a fuse
into a faulted circuit is always a possibility. When
closing a fuse, always turn your face away then use a
swift, unhesitating thrust since the closing operation
is completely operator dependent. With Uni-Rupter,
a fuse can be closed into a fault current once or
twice as specified in Appendix C, and the Uni-Rupter
will remain operable and able to carry and interrupt
rated current.
18. FRONT BARRIERS.
v Always use an S&C Grappler attached to a suitable
universal pole to handle barriers in the high-voltage
compartments.
v Do not leave dual-purpose front barriers in the
“slide-in” position for more than one week. If the barriers are left in the “slide-in” position for an extended
period of time, there is the possibility of corona discharge to the barriers. Prolonged exposure to corona
discharge can damage the barriers and result in a
flashover, injury, and equipment damage.
OPERATING DESCRIPTION
Refer to S&C Instruction Sheet 515-500 for an operating
description of the Micro-AT Source-Transfer Control.
Remote Indication
The optional remote-indication feature (Catalog Number
Suffix “-Y4”) includes isolated contacts wired to a terminal block for user’s external connection to remote indicating devices. Isolated contacts are provided for remotely
monitoring the presence of source voltages; the position
of the manual/automatic operation selector switch; and
the status of the “ready” indicating lamp, “event” indicating lamp, and overcurrent-lockout circuit (if furnished).
Remote indicating devices and their control power are to
be provided by the user and installed in accordance with
the manufacturer’s instructions.
INSTRUCTION SHEET
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S&C ELECTRIC COMPANY
663-503
Page 5 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
COMPONENTS
Figures 1 through 4 which follow illustrate many of the
basic components and features of S&C Source-Transfer
Pad-Mounted Gear. Before proceeding with the remainder
of the instructions, it is recommended that these figures
be reviewed to gain familiarity with the various components and locations.
Operator target indicates whether stored-energy
operator is in switch-open or switch-closed
position and whether quick-make quick-break
mechanism is charged or discharged
Open/close
pushbuttons
Emergency-trip access cover
Charging shaft
Remote-control receptacle
(Catalog Number Suffix “-C11”)
Dual-purpose
manual handle
Decoupler
handle
Switch-position
target
Operation
counter
Operation
selector
Micro-AT
Source-Transfer Control
Terminal-block
compartment
Decoupler indicator
Bolted cover provides access to
input plug and shorting receptacle
for Micro-AT control
Figure 1. Low-voltage control compartment.
663-503
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August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
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COMPONENTS — Continued
Left source voltage
indicating lamp
Automatic-transfer
“ready” indicating lamp
Overcurrent-lockout
indicating lamp and reset key
(furnished with optional overcurrentlockout feature, Catalog Number
Suffix “-Y2”)
Right source voltage
indicating lamp
Manual/automatic operation
selector switch. When in
“MANUAL,” prevents an
automatic source transfer
while permitting manual
operation using open/close
pushbuttons
Two-line 24-character backlit
liquid-crystal display (LCD)
Menu keys
Last and next
item keys
Test keys for simulating
overcurrent and loss of
voltage on left source
Test keys for simulating
overcurrent and loss of
voltage on right source
Keypad
Figure 2. S&C Micro-AT Source-Transfer Control.
INSTRUCTION SHEET
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S&C ELECTRIC COMPANY
663-503
Page 7 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
COMPONENTS — Continued
Remote-indication wiring
provided with optional remoteindication feature (Catalog
Number Suffix “-Y4”), leads
to a terminal block for user’s
connections
Supervisory control wiring
(not shown) provided with
optional supervisory-control
feature (Catalog Number Suffix
“-Y6”), also leads to a terminal
block for user’s connections
Voltage limiters
Input plug (signal-voltage,
control-voltage, and currentsensing input circuits)
Input receptacle
Shorting receptacle
Figure 3. Access panel removed showing input plug, input receptacle, and shorting receptacle of S&C Micro-AT SourceTransfer Control.
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August 14, 1995
INSTRUCTION SHEET
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COMPONENTS — Continued
Left-hand door retainer—rotate latch
upward to open door. To secure left-hand
door closed, rotate latch downward over
stop mounted on outer edge of door
Dual-purpose
front barriers
S&C Uni-Rupter
Viewing window for visible verification of switch position is removable
for phasing. To remove window,
loosen wing-head screws and lift
window off alignment bolts
S&C Mini-Rupter Switch
Interphase
and end
barriers
S&C Power Fuse
(Fault Fiter Electronic
Power Fuse shown)
S&C Voltage
Sensor
Ground studs
Current sensors furnished for attachment to each entrance cable when
optional overcurrent-lockout feature
(Catalog Number Suffix “-Y2”) is
included
Figure 4. Switch and fuse compartments.
INSTRUCTION SHEET
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S&C ELECTRIC COMPANY
663-503
Page 9 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
MINI-RUPTER SWITCHES
Ç WARNING
1. To prevent an automatic operation when decoupling
or coupling an operator to a switch, during manual
charging of an operator, or when manually operating a switch, place the manual/automatic operation
selector switch located on the faceplate of the
Micro-AT Source-Transfer Control in “MANUAL.”
2. Do not perform any switching operations if the
source-transfer control is in the lockout mode as
indicated by illumination of the “LOCKOUT” lamp.
See Figure 2. For such cases, see “OvercurrentLockout Condition” under the “OPERATING
DESCRIPTION” in S&C Instruction Sheet 515-500.
3. If the gear is energized and paralleling of sources is
not permitted, decouple both stored-energy operators (see “Decoupling” below) to avoid temporary
service interruptions when manually operating
the gear. Switching operations will result in temporary service interruptions if stored-energy operators are coupled.
4. Due to operating errors, the stored-energy operator’s quick-make quick-break mechanism may stall
in a partially discharged state. The conditions which
will cause this mechanism to stall, as well as
instructions for restoring the operator to the normal
latched-open condition after a stall, are listed under
“IF OPERATOR STALLS . . .” on page 26.
5. Do not assume that the operator position necessarily indicates the open or closed position of the
Mini-Rupter Switch. Upon completion of an opening or closing operation, check to be sure that the
following conditions exist:
• The operator target (see Figure 1) signals “OPERATOR IN SWITCH-OPEN POSITION” or “OPERATOR IN SWITCH-CLOSED POSITION” to
indicate that the switch operator has moved
through a complete operation.
• The switch-position target (see Figure 1) which
signals “SWITCH OPEN” or “SWITCH CLOSED,”
is in agreement with the operator target.
• The switch position, as verified by visual check
of the switch-blade position, is in agreement with
the switch-position target. A viewing window is
provided in the switch compartment to allow
positive visual verification of switch-blade position (see Figure 4).
• The operator target (see Figure 1) signals
“OPERATOR CHARGED” to indicate that the
operator is ready for the next operation.
6. To prevent all electrical and mechanical operations,
padlock the operation selector in the “LOCK POSITION.” This will also prevent motor charging of the
stored-energy operator if system operating procedures require that the quick-make quick-break
mechanism remain discharged—and source voltage
is present.
Decoupling
Coupling
Decoupling is accomplished using the decoupler handle.
See Figure 5. When decoupled, the stored-energy operator
may be operated without affecting the position of the
associated Mini-Rupter Switch. Moreover, when decoupled, the Mini-Rupter Switch is prevented from moving by
a mechanical device which locks the switch drive-shaft.
To decouple the stored-energy operators, first place
the manual/automatic operation selector switch on the
faceplate of the S&C Micro-AT Source-Transfer Control
in “MANUAL.” For each stored-energy operator, grasp
the decoupler handle and press down on the coupledposition latch to release the handle. Then move the
handle upward to the “DECOUPLED” position. Make
sure that the handle is fully latched in the decoupled
position. While an operator is decoupled, the automatictransfer “ready” indicating lamp on the faceplate of the
Micro-AT control will not light—a reminder of the decoupled condition. See Figure 2.
To couple the stored-energy operators, first place the
manual/automatic operation selector switch on the faceplate of the Micro-AT control in ”MANUAL.” Then make
sure that the stored-energy operators are in the same
position (open or closed) as their associated MiniRupter Switches by observing the switch-position and
operator targets. See Figure 1. If required, use the
open/close pushbuttons (provided control power is available) to reposition the operator(s).
For each operator, grasp the decoupler handle and
press down on the decoupled-position latch to release the
handle. Then move the handle downward to the “COUPLED” position. Make sure that the handle is fully latched
in the coupled position. An attempt to operate a switch
that is not completely coupled (or decoupled) will cause
the operator mechanism to stall.
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August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
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MINI-RUPTER SWITCHES — Continued
Automatic Switch Operation
High-speed quick-make quick-break operation is provided
by stored-energy operators which, when solenoid tripped
in response to control signals from the S&C Micro-AT
Source-Transfer Control, automatically open and close
the Mini-Rupter Switches. After each trip operation, the
operators automatically charge when voltage is present
on the associated source—ready for the next operation.
For automatic switch operation, the manual/automatic
operation selector switch on the Micro-AT control must
be in “AUTOMATIC.” See Figure 2. The Micro-AT control
will not function automatically if one operator is coupled
and the other is decoupled. Field programming and operation of the Micro-AT control is covered in S&C Instruction
Sheet 515-500.
Nonautomatic Switch Operation
If Control Power Is Available: To manually operate the
stored-energy operator’s quick-make quick-break mechanism—and (if coupled) to open or close a Mini-Rupter
Switch—place the manual/automatic operation selector
switch in “MANUAL” and press the associated open/close
pushbutton. See Figure 1. After each trip operation, the
quick-make quick-break mechanism automatically charges
Figure 5. Decoupler handle being
moved upward to decouple switch
from associated switch operator.
when voltage is present on the associated source. The
charging operation takes approximately 25 seconds.
If Control Power Is Lost and Operator Is Charged:
To manually operate the stored-energy operator’s quickmake quick-break mechanism—and (if coupled) to open
or close a Mini-Rupter Switch—insert the small keyed end
of the dual-purpose manual handle into the groove of the
tripping shaft, behind the cover labeled “EMERGENCY
TRIP,” and turn in the direction indicated to effect desired
operation. See Figure 6.
If Control Power Is Lost and Operator Is Discharged:
Manually charge the stored-energy operator’s quick-make
quick-break mechanism as described under “Charging
Operator (Nonelectrical)” below. Then proceed as just
described under “If Control Power Is Lost and Operator Is
Charged.”
Charging Operator (Nonelectrical)
The dual-purpose manual handle is used to manually
charge the stored-energy operator’s quick-make quickbreak mechanism (required only in the event that control
power has been lost). See Figure 7. Keep the chargingshaft access port open by holding the operation selector
in the “CHARGING POSITION.” While the operation
Figure 6. Dual-purpose manual
handle inserted in groove of shaft
for emergency manual switching if
control power is lost.
Figure 7. Dual-purpose manual
handle on the charging shaft.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 11 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
MINI-RUPTER SWITCHES — Continued
selector is in the “CHARGING POSITION,” the control
circuit is disconnected to prevent manual or automatic
electrical operation (charging or tripping) in the event
that control power is restored; and the emergency-trip
port is mechanically blocked to prevent a manual
mechanical trip operation.
While holding the port open, insert the large notched
end (with recessed bolt) of the dual-purpose manual
handle and secure it to the end of the charging shaft by
turning the knurled knob clockwise 8 to 9 turns until firm
resistance is felt. To charge the mechanism, grasp the
tubular portion of the handle and, while pivoting the
handle a few degrees, push in to engage the charging
shaft. At the same time, rotate the handle as far as it will
go (approximately 120°) in the appropriate direction. The
“OPERATOR CHARGED” target will appear in the indicator window.
After the charging operation, loosen the knurled knob
and remove the handle. The operation selector will springreturn to the “OPERATING POSITION.”
Front Barriers
Before proceeding with the instructions on handling the
front barriers, refer to the “DANGER” on pages 4 and 5,
and the “WARNING” on page 10.
Figure 8. Dual-purpose front barrier for switch in its normal, suspended position.
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August 14, 1995
Ç DANGER
When working in the high-voltage compartments,
always maintain proper clearance from energized
components. Failure to maintain proper clearance will result in serious injury or death.
Always use an S&C Grappler (Catalog Number
4423) attached to a suitable universal pole (1 ¹⁄₄ inches
in diameter) to handle barriers and to install, remove,
open, or close fuses. The universal pole must be at
least 4 feet long (S&C Catalog Number 4451R2-E, or
equal) for 14.4-kv gear or at least 6 feet long (S&C Catalog Number 4452R2-E, or equal) for 25-kv gear.
Place the dual-purpose front barrier in the “slide-in”
position whenever the Mini-Rupter Switch is open. When
the barrier is in the “slide-in” position, the switch blades
are isolated from the main contacts. This also keeps the
blades from closing if, for any reason, the Mini-Rupter
Switch is operated.
To insert the barrier in the “slide-in” position, use an
S&C Grappler™ attached to and in line with a suitable
universal pole. Figures 8 through 10 show the suggested
insertion method. The Grappler prongs are pointed
upward when lifting the front barrier.
Figure 9. Grappler being used to lift barrier. Note that door
holder is in place and adjacent door is bolted closed to
reduce exposure to high voltage.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
MINI-RUPTER SWITCHES — Continued
Ç WARNING
Do not leave dual-purpose front barriers in the “slide-in”
position for more than one week. These barriers are intended for temporary use to isolate the blades of the
Mini-Rupter Switch from the main contacts while work
is being performed. If the barriers are left in the “slidein” position for an extended period of time, there is the
possibility of corona discharge to the barriers. Prolonged exposure to corona discharge can damage
the barriers and result in a flashover, injury, and
equipment damage.
Ç NOTICE
Before closing a Mini-Rupter Switch, remove the dualpurpose front barrier from the “slide-in” position.
Closing a switch on the barrier will block the
switch blades and result in a stalled condition.
If the Mini-Rupter Switch is closed with the front barrier in the “slide-in” position, the switch blades will be
blocked and the stored-energy operator will stall in a partially closed position. To correct this condition, follow the
directions under “IF OPERATOR STALLS . . .” on page 26.
To restore the dual-purpose front barrier to the normal
suspended position, use an S&C Grappler attached to a
suitable universal pole. Slowly and carefully withdraw the
barrier with the Grappler prongs pointed upward (as
shown in Figure 10) so that, as it clears the “slide-in” position, the holes in the barrier catch on the hooks on the
gear. 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 placing it in its normal, suspended position is shown in Figure
11. Note that the barrier is supported on the Grappler
prongs and held there by engagement of the lifting ring
with the Grappler cone. Place the barrier on the hooks of
the gear, and lower the barrier to its suspended position.)
Figure 10. Grappler, after lifting and pivoting the barrier, is
used to lower it into the “slide-in” position. Also shows
Grappler being used to return the barrier to its normal,
suspended position.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 13 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
MINI-RUPTER SWITCHES — Continued
Figure 11. Alternate method of replacing front barrier using
Grappler. Inset shows barrier being supported on Grappler
prongs.
663-503
Page 14 of 35
August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
FUSING
S&C Source-Transfer PMH Pad-Mounted Gear is furnished with S&C Fuse Mountings with Uni-Rupter that
accommodate S&C Type SML-20 Power Fuses, S&C Type
SML-4Z Power Fuses, or S&C Fault Fiter Electronic
Power Fuses. Fault Fiter Electronic Power Fuse Mountings also accommodate a variety of current-limiting fuses.
Ç WARNING
When selecting current-limiting fuses, the voltage rating
of the fuses must conform to the recommendations in
Appendix E. Failure to conform to these recommendations can result in a flashover, injury, and
equipment damage.
Assembling the Fuse
S&C Power Fuses
Install an SMU-20 Fuse Unit into each set of end fittings,
an SM-4 Refill Unit into each holder, or a Fault Fiter Interrupting Module and Control Module into each holder, in
accordance with the instruction sheet furnished with the
fuse unit, refill unit, or interrupting module.
Installing the Fuse in the Mounting
Follow the instructions found under “Installing and Closing the Fuse” on pages 16 through 19.
Warranty Qualifications
The standard warranty contained in seller’s standard conditions of sale (as set forth in Price Sheet 150) does not
apply to S&C Source-Transfer PMH Pad-Mounted Gear
where fuse units, fuse-unit end fittings, holders, refill
units, or switch blades of other than S&C manufacture are
used in conjunction with S&C SML Mountings. Nor does it
apply to S&C Source-Transfer PMH Pad-Mounted Gear
where other than Fault Fiter Electronic Power Fuses,
S&C Switch Blades, or the current-limiting fuses listed in
Appendix E are used in conjunction with Fault Fiter Electronic Power Fuse Mountings and S&C Holders designed
therefor, or when current-limiting fuses are applied other
than as set forth under “Recommended Voltage Ratings”
for current-limiting fuses in Appendix E.
Current-Limiting Fuses
S&C Holders for current-limiting fuses are designed for
use in pad-mounted gear models that include mountings
for Fault Fiter Electronic Power Fuses. These holders will
accommodate the current-limiting fuses listed in Appendix E. For instructions on installing current-limiting fuses
in current-limiting fuse holders, refer to S&C Instruction
Sheet 660-500.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 15 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
SWITCHING WITH UNI-RUPTER
Installing and Closing the Fuse
Before proceeding with the instructions on installing
and closing the fuse,d refer to the “DANGER” on pages
4 and 5.
Ç DANGER
When working in the high-voltage compartments,
always maintain proper clearance from energized
components. Failure to maintain proper clearance will result in serious injury or death.
Always use an S&C Grappler (Catalog Number
4423) attached to a suitable universal pole (1 ¹⁄₄ inches
in diameter) to handle barriers and to install, remove,
open, or close fuses. The universal pole must be at
least 4 feet long (S&C Catalog Number 4451R2-E, or
equal) for 14.4-kv gear or at least 6 feet long (S&C Catalog Number 4452R2-E, or equal) for 25-kv gear.
Use an S&C Grappler attached to and in line with a
suitable universal polel to perform the procedures listed
below:
1. Open the appropriate fuse-compartment door and
secure it with the door holder. See Figure 12. The adjacent compartment door should be closed and latched
to minimize exposure to high voltage.
2. If optional inner barrier panels (Catalog Number Suffix
“-G7”) are furnished, loosen the pentahead bolts and
remove the panel.
Door holder
Then remove only the dual-purpose front barrier
associated with the fuse mounting into which the fuse
is to be installed. See Figure 13. Insert the barrier into
the “slide-in” position using the Grappler as illustrated
in Figure 14. Note that the barrier is supported on the
Grappler prongs and held there by engagement of the
lifting ring with the Grappler cone.
Ç WARNING
Do not leave dual-purpose front barriers in the “slide-in”
position for more than one week. These barriers are intended for temporary use to isolate the fuse from the
contacts of the Uni-Rupter while work is being performed. If the barriers are left in the “slide-in” position
for an extended period of time, there is the possibility
of corona discharge to the barriers. Prolonged exposure to corona discharge can damage the barriers
and result in a flashover, injury, and equipment
damage.
d Although the operations as described in this section often refer simply to “fuses,” the procedures apply to S&C Type SML-20 and SML-4Z
Power Fuses, S&C Fault Fiter Electronic Power Fuses, and current-limiting fuses used in Fault Fiter Electronic Power Fuse Mountings with UniRupter.
l 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 on the
universal pole at a favorable angle.
S&C Grappler in
storage position
Storage rack for S&C
SMU-20 Fuse Units or
SM-4 Refill Units
Figure 12. Dual-purpose front barriers for fuses in their
normal, suspended positions. Note that door holder is in
place.
663-503
Page 16 of 35
August 14, 1995
Figure 13. Removing or replacing dual-purpose front
barrier with the S&C Grappler.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
SWITCHING WITH UNI-RUPTER — Continued
3. For all fuses except 25-kv Fault Fiter Electronic
Power Fuses, install a fuse into its hinge as follows:
(a) Position the Grappler cone in the fuse pull ring and
cradle the fuse in the Grappler prongs. See inset of
Figure 15.
(b) Grasp the universal pole with both hands (approximately 2 feet apart), with one hand at the opposite
end of the pole from the Grappler.
(c) Lift the fuse and lower it into its hinge. See Figure
15. Make sure that the fuse is securely seated in the
hinge; then disengage the Grappler from the fuse.
See Figure 16.
4. For 25-kv Fault Fiter Electronic Power Fuses, deenergize, test, and properly ground the mounting in
accordance with safe operating procedures and rules,
and then install the fuse into its mounting by hand
using suitable protective equipment.
Ç NOTICE
Do not close a door on a fuse in the open position. The
door will strike the fuse pull ring which will interfere with door closing. The door may be closed if the
fuse is removed from its mounting.
Ç DANGER
Keep the fuse away from the Uni-Rupter contacts
when installing the fuse into its hinge. Touching the
contacts will close the circuit which can cause a
flashover and serious injury. Always place the
dual-purpose front barrier in the “slide-in” position
whenever a fuse is open or is being removed from or
installed into its hinge.
Figure 14. Inserting dual-purpose front barrier into the
“slide-in” position using Grappler.
Figure 15. Installing fuse using the Grappler. Inset shows
close-up of Grappler in position to install the fuse.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 17 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
SWITCHING WITH UNI-RUPTER — Continued
5. Use the Grappler to remove the dual-purpose front barrier from the “slide-in” position. See Figure 17.
Ç DANGER
Closing a fuse into a faulted circuit will cause a
loud noise, a flash of light at the Uni-Rupter contacts, and the fuse to blow. Closing a fuse into a
faulted circuit is always a possibility. When closing a
fuse, always turn your face away then use a swift, unhesitating thrust since the closing operation is completely operator dependent. With Uni-Rupter, a fuse
can be closed into a fault current once or twice as
specified in Appendix C, and the Uni-Rupter will remain operable and able to carry and interrupt rated
current.
Figure 16. Fuse installed in mounting in the open position.
663-503
Page 18 of 35
August 14, 1995
6. With the Grappler prongs pointed downward, insert the
longer prong into the pull ring of the fuse. See inset of
Figure 18. Then with one’s face turned away, close the
fuse with a swift, unhesitating thrust. See Figure 18.
Remove the Grappler from the pull ring.
Ç NOTICE
After removing the Grappler from the pull ring, make
sure that complete fuse closure was attained by pushing
against the fuse with the Grappler. Failure to completely close the fuse can result in damage to the
Uni-Rupter.
7. Use the Grappler to hang the dual-purpose front barrier in its normal, suspended position. See Figure 13.
Also install the optional inner barrier panel, if furnished.
8. Close and latch the doors and install a padlock. Pull on
the doors to verify that they are securely latched.
Figure 17. Removing dual-purpose front barrier from the
“slide-in” position using Grappler.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
SWITCHING WITH UNI-RUPTER — Continued
Figure 18. Closing the fuse. Inset on right shows close-up of Grappler in position to close the fuse.
Top inset shows close-up of Uni-Rupter with the fuse fully closed.
INSTRUCTION SHEET
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S&C ELECTRIC COMPANY
663-503
Page 19 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
SWITCHING WITH UNI-RUPTER — Continued
Ç WARNING
A Note on Single-Pole Switching
In single-pole switching of ungrounded-primary threephase transformers or banks (or single-phase transformers connected line-to-line), circuit connections or
parameters may, in some cases, produce excessive
overvoltages. In particular, for the following applications above 22 kv, single-pole switching by any
means—including Uni-Rupter—should be performed
only under the conditions stated in italics:
• Switching unloaded or lightly loaded delta-connected or ungrounded-primary wye-wye connected
three-phase transformers or banks (or line-to-line
connected single-phase transformers), rated 150 kva
or less three-phase, or 50 kva or less singlephase—or of any kva rating when combined with
unloaded cables or lines—where maximum system
Opening and Removing the Fuse
Before proceeding with the instructions on opening and
removing the fuse, refer to the “DANGER” on pages 4
and 5.
operating voltage exceeds 22 kv. Single-pole switching should be performed only if each phase is carrying 5% load or more, or if the transformer or
bank is temporarily grounded at the primary neutral during switching.
• Switching loaded or unloaded ungrounded-primary
wye-delta connected three-phase transformers or
banks—alone or combined with unloaded cables or
lines—where maximum system operating voltage
exceeds 22 kv. Single-pole switching should be performed only if each phase is carrying 5% load or
more and if the lighting-load phase is always
switched open first (or switched closed last); or if
the transformer or bank is temporarily grounded
at the primary neutral during switching.
3. With the Grappler prongs pointed downward, insert
the longer prong into the pull ring of the fuse. See
Figure 19.
Ç DANGER
When working in the high-voltage compartments,
always maintain proper clearance from energized
components. Failure to maintain proper clearance will result in serious injury or death.
Always use an S&C Grappler (Catalog Number
4423) attached to a suitable universal pole (1 ¹⁄₄ inches
in diameter) to handle barriers and to install, remove,
open, or close fuses. The universal pole must be at
least 4 feet long (S&C Catalog Number 4451R2-E, or
equal) for 14.4-kv gear or at least 6 feet long (S&C Catalog Number 4452R2-E, or equal) for 25-kv gear.
Use an S&C Grappler attached to and in line with a
suitable universal pole to perform the procedures listed
below:
1. Open the appropriate fuse-compartment door and
secure it with the door holder. See Figure 12. The adjacent door should be closed and latched to minimize
exposure to high voltage.
2. If optional inner barrier panels (Catalog Number Suffix
“-G7”) are furnished, loosen the pentahead bolts and
remove the panel.
Then remove only the barrier associated with the
fuse to be opened, using the Grappler for this purpose.
See Figure 13.
663-503
Page 20 of 35
August 14, 1995
Figure 19. Grappler, as positioned for opening stroke, with
longer prong inserted in the fuse pull ring.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
SWITCHING WITH UNI-RUPTER — Continued
4. Pull the fuse vigorously through its full travel without
hesitation at any point. See Figure 20. 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 is designed to require a hard
pull to unlatch the fuse, thus reducing the possibility of
an incomplete opening operation.
5. Remove the Grappler from the fuse pull ring.
Ç DANGER
The fuse and fuse mounting (Uni-Rupter, load-side
hinge, and terminals) may be energized by backfeed
even when the fuse is in the fully open position. Always
assume that both terminals of a fuse are energized unless proved otherwise by test, by visual evidence of
open-circuit conditions on both terminals, or by observing that both terminals are grounded. Failure to
follow these precautions can result in serious
injury or death.
Figure 20. Opening the fuse.
Ç NOTICE
Do not close a door on a fuse in the open position. The
door will strike the fuse pull ring which will interfere with door closing. The door may be closed if the
fuse is removed from its mounting.
6. Place the dual-purpose front barrier associated with
the fuse to be removed in the “slide-in” position. Use
the Grappler for this, as illustrated in Figure 21. Note
that the barrier is supported on the Grappler prongs
and held there by engagement of the lifting ring with
the Grappler cone.
Ç WARNING
Do not leave dual-purpose front barriers in the “slidein” position for more than one week. These barriers are
intended for temporary use to isolate the fuse from the
contacts of the Uni-Rupter while work is being performed. If the barriers are left in the “slide-in” position
for an extended period of time, there is the possibility
of corona discharge to the barriers. Prolonged exposure to corona discharge can damage the barriers
and result in a flashover, injury, and equipment
damage.
Figure 21. Inserting dual-purpose front barrier into the
“slide-in” position using Grappler.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 21 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
SWITCHING WITH UNI-RUPTER — Continued
7. For all fuses except 25-kv Fault Fiter Electronic Power
Fuses, remove the fuse from its hinge as follows:
(a) Grasp the universal pole with both hands (approximately 2 feet apart), with one hand at the opposite
end of the pole from the Grappler.
(b) Position the Grappler cone in the fuse pull ring
and cradle the fuse in the Grappler prongs. See
Figure 22.
(c) Stand in a normal, upright position facing the universal pole. Move the pole forward until resistance
between the Grappler and the fuse is felt (approximately 2 inches). Then remove the fuse from its
hinge with a forward and upward lifting motion.
See Figure 23.
Ç DANGER
8. For 25-kv Fault Fiter Electronic Power Fuses, deenergize, test, and properly ground the mounting in
accordance with safe operating procedures and rules,
and then remove the fuse from its mounting by hand
using suitable protective equipment.
9. Hang the dual-purpose front barrier in its normal, suspended position using the Grappler. See Figure 13. Also
install the optional inner barrier panel, if furnished.
Then close and latch the doors, and padlock securely.
Pull on the doors to verify that they are securely
latched.
Ç WARNING
Always store fuses in a clean, dry location. Do not store
end fittings, holders, interruping modules, or currentlimiting fuses in the enclosure.
Keep the fuse away from the Uni-Rupter contacts
when removing the fuse from its hinge. Touching the
contacts will close the circuit which can cause a
flashover and serious injury. Always place the
dual-purpose front barrier in the “slide-in” position
whenever a fuse is open or is being removed from or
installed into its hinge.
Figure 22. Grappler positioned for fuse removal.
663-503
Page 22 of 35
August 14, 1995
Figure 23. Removing fuse using the Grappler.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
RE-FUSING
How to Detect and
Replace a Blown Fuse
Open the appropriate fuse-compartment door and secure
it with the door holder.
Ç WARNING
To minimize exposure to high voltage, close and latch
the adjacent door.
Also remove the dual-purpose front barrier (using the
Grappler) or inner barrier panel, if furnished.
Ç DANGER
When working in high-voltage compartments, always
maintain proper clearance from energized components.
Failure to maintain proper clearance will result in
serious injury or death.
S&C Power Fuses
From a safe distance, observe the blown-fuse target for
the fuse type furnished (refer to Figure 24):
• 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 fitting or the Fault
Fiter Holder when the fuse has operated . . . making it
easy to check the fuse condition with the fuse in the
closed position. The blown-fuse target retracts within
the end fitting or holder when the blown fuse unit or
interrupting module is replaced.
• SML-4Z Power Fuse—A fluorescent 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 removing the fuse from its mounting. The target fluoresces
when illuminated.
NOTE ON HANDLING: The current-design upper
end fitting for use in SML-20 Power Fuses, and the
Fault Fiter Holder employ a free-floating blown-fuse
target which can move (by force of gravity) into the
“BLOWN” position should the fuse be inverted during
handling. Fuse condition can be verified by returning
the fuse to the upright position. 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 under “Opening and Removing the
Fuse” on pages 20 through 22. Then follow the instructions for replacing blown SMU-20 Fuse Units, SM-4 Refill
Units, or Fault Fiter Interrupting Modules (as applicable)
that are provided with each new fuse unit, refill unit, or
interrupting module.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 23 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
RE-FUSING — Continued
Current-Limiting Fuses
To find the blown fuses, remove each fuse in turn from its
mounting (the target cannot be seen while the fuse is in its
mounting), following the instructions found under “Opening and Removing the Fuse” 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 E.
Installing the Fuse in the Mounting
Follow the instructions found under “Installing and Closing the Fuse” on pages 16 through 19.
Red target projects from top of upper
end fitting when fuse has operated
Red target projects from top of holder
when fuse has operated
Fluorescent-orange target
appears in “BLOWN” indicator window when fuse
has operated (visible
through translucent holder)
SML-20 Power Fuse
SML-4Z Power Fuse
Fault Fiter
Electronic Power Fuse
Figure 24. Blown-fuse target locations for the fuse types used in PMH models of S&C Pad-Mounted Gear.
663-503
Page 24 of 35
August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
FINAL CHECKS BEFORE WALKING AWAY . . .
So that the S&C Micro-AT Source-Transfer Control is
ready for automatic operation, make sure that both
source voltage indicating lamps and the automatic-transfer “ready” indicating lamp are illuminated. If the
“READY” lamp is not lighted, refer to the liquid-crystal
display on the faceplate of the Micro-AT control. When
not being used to show menu information, this display
shows messages explaining why the lamp is not lighted.
NOTE: A lighted “READY” lamp indicates that the
status of associated components is normal, but an
absence of illumination does not necessarily mean that
the control is inoperative. For example, when transfer
to the alternate source occurs, the lamp extinguishes
but the control is ready for any subsequent programmed automatic operation required by a change in
source conditions. Likewise, if the stored-energy operators are decoupled, the “READY” lamp is extinguished—and the switches will not operate—but the
control is fully operative.
Close and padlock the access doors to the low-voltage
control compartment and high-voltage compartments.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 25 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
IF OPERATOR STALLS . . .
The stored-energy operator’s quick-make quick-break
mechanism will stall in a partially discharged state if the
operator is inadvertently tripped while its associated
Mini-Rupter Switch is prevented from closing by any of
the following conditions:
• Switch not completely coupled (or decoupled) to
switch operator.
• Switch blocked open by mechanical cable interlock
(applicable when that option, Catalog Number Suffix
“-C6,” is included).
• Switch blocked open by mechanical antiparalleling
(applicable when that option, Catalog Number Suffix
“-C7,” is included).
• Switch locked open by key interlock (applicable when
that option, Catalog Number Suffix “-C5,” is included).
• Switch blades blocked by insertion of the dual-purpose
front barrier in its “slide-in” position.
To determine if the quick-make quick-break mechanism has stalled, observe the switch-position indicator
target. If the words “SWITCH OPEN” on the target appear
slightly off-center and one or more letters are partially
hidden from view in the target opening, then the mechanism is in a stalled condition. See Figure 25.
Normal
Page 26 of 35
August 14, 1995
Ç WARNING
To guard against handle kickback during performance
of this step, do not release grip on handle until latching
has occurred.
2. Place the large notched end (with recessed bolt) of the
dual-purpose manual handle in the center of the decoupler. See Figure 26. (The handle’s knurled knob performs no function in this application.) While pivoting
the handle, push it in to engage the reverse-drive hub.
Then rotate the handle counterclockwise for the lefthand switch (clockwise for the right-hand switch) to
back drive the switch and the quick-make quick-break
mechanism—against the tension of the stored-energy
spring—until the mechanism latches in its open position. A slight click may be heard when the mechanism
latches.
3. Verify that the latched-open condition has been
achieved by observing that the switch-position target
reads “SWITCH OPEN” and the operator targets read
“OPERATOR IN SWITCH-OPEN POSITION” and
“OPERATOR CHARGED.”
Stalled
Figure 25. Switch-position indicator target appears slightly
off-center if mechanism is stalled.
663-503
Restore the stored-energy operator to a normal
latched-open condition after such an occurrence as
follows:
1. Make sure that the manual/automatic operation
selector switch is in “MANUAL.”
Figure 26. Dual-purpose manual handle reverse-driving the
Mini-Rupter Switch and operator’s quick-make quick-break
mechanism to recover from a stalled condition.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
MAINTENANCEa
Components
No routine maintenance is required for the S&C Micro-AT
Source-Transfer Control. However, operational testing
once per year in accordance with S&C Instruction Sheet
663-590 is recommended to verify proper functioning of
the system.
No mechanical maintenance is required for S&C PadMounted 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 environmental conditions.
Ç WARNING
Before cleaning, completely de-energize, test, and
ground the pad-mounted gear. Never use pressuresprayed abrasives to clean pad-mounted gear. Pressure-sprayed abrasives will damage switch and
fuse components.
The stored-energy operators should be given an exercising consisting of five or more operations at least once
every year, unless normal operating duty provides equal
or greater exercise. With the switches decoupled from the
operators, exercising can be accomplished at any convenient time without requiring that the switches themselves
be operated and, therefore, without requiring an interruption of service.
The nominal operating life of the stored-energy operators is 1500 operations (complete close-open cycles), provided that no more than 500 of such operations are
performed while decoupled.
Place dual-purpose front barriers for switch and fuse
compartments into the “slide-in” position. See Figures 10
and 14. This will provide physical isolation for additional
security if it is necessary to work on the cables connected
to the Mini-Rupter Switch or fuse.
Ç DANGER
When access to high-voltage compartments is required
for inspection, service, or repairs, always observe the
precautions below. Failure to observe these precautions will result in serious injury or death.
1. Access to pad-mounted gear must be restricted only
to qualified persons. See “Qualified Persons” on
page 2.
2. Always follow safe operating procedures and rules.
3. Before touching any device, alway disconnect
switches, fuses, and other devices from all power
sources (including backfeed) and control sources,
test for voltage, and properly ground.
4. When external voltage is used to test any secondaryside wiring or devices, disconnect all voltage sensors to avoid energizing the high-voltage conductors
through the voltage sensors. To disconnect the voltage sensors, transfer the input plug from the input
receptacle to the shorting receptacle. See Figure 3.
5. Always assume that 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.
6. Test for voltage on both sets of power terminals of
any switch or fuse using proper high-voltage test
equipment.
7. After the gear has been completely disconnected
from all sources of power and tested for voltage,
install suitable grounding cables in all compartments.
8. For maintenance of non-S&C equipment, follow the
manufacturer’s instructions.
9. Make certain the enclosure is properly grounded to
the station or facility ground. Do not return equipment to service unless such grounds are properly
made.
NOTE: Occasionally, low-voltage components may
require maintenance. The maintenance of other lowvoltage components isolated from high-voltage compartments may be performed under the safety rules for
equipment rated 600 volts or less. If maintenance is to
be performed on devices connected to the secondary
of a voltage sensor, short-circuit the secondary connections. A separate drawing will be provided with the
replacement part explaining how to properly short-circuit the secondary connections.
a These recommendations may differ from company operating procedures and rules. Where a discrepancy exists, users should follow their
company’s operating procedures and rules.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 27 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
MAINTENANCE — Continued
Returning Equipment to Service
Enclosure Finish
When returning the equipment to service, the following
procedures should be observed:
1. Make sure that 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.
2. Make certain that the Mini-Rupter Switches are in the
correct position (open or closed) as dictated by system
circumstances.
3. Close each door permitting access to high voltage.
Make sure that the associated Penta-Latch Mechanisms
are securely latched and padlocked before energizing
the circuit or operating any switching device.
4. Make certain that the input plug is on the input
receptacle.
5. Refer to “FINAL CHECKS BEFORE WALKING AWAY . . .”
on page 25.
6. Close both low-voltage compartment doors and make
sure that the associated Penta-Latch Mechanism is
completely latched and padlocked.
7. Padlock all doors before leaving the installation site,
even momentarily. Observe this procedure even in
those cases where the gear is accessible only to qualified persons.
The responsibility for ensuring that a finish protects the
enclosure lies with both the manufacturer and the user.
S&C Source-Transfer PMH Pad-Mounted Gear is finished
with the S&C Ultradur™ Finishing System, which provides lasting protection for the enclosure. To retain this
protection, the user should take periodic corrective
action as follows:
1. Touch up any penetration of the finish to bare
metal—such as scratches and abrasions due to shipping or vandalism—to maintain the original integrity.
S&C touch-up finish and primer are available in aerosol
spray cans—order by Catalog Number: 9999-058 for
olive green finish, 9999-080 for light gray finish, and
9999-061 for red-oxide primer. No other finish or
primer is approved. The area to be touched up should
be cleaned to remove all oil and grease. Sand the area,
removing any traces of rust that may be present, and
make sure all edges are feathered before applying
primer.
2. Provide an occasional simple washdown—such as an
automobile would be given—to remove surface contaminants. Use any ordinary mild household detergent
solution.
In those cases where the enclosure must be refinished
by the user before the finish has weathered—for example,
to match other equipment—a special precaution must be
taken. The entire surface must be sanded to provide a
tooth to bond the new coat to the unusually tough and
smooth S&C Ultradur Finish.
663-503
Page 28 of 35
August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
APPENDIX A
Preliminary Tryout Before Gear Is
Energized—Optional
To expedite full service once high voltage is available, the
user may wish to perform a preliminary checkout of the
Micro-AT Source-Transfer Control before the gear is energized. For this purpose an S&C Test Accessory, Catalog
Number TA-1316, is available to permit checkout of the
source-transfer operation using an external single-phase
120-volt ac source.
If a preliminary checkout is to be performed, special
instructions must be followed to ensure correct operation
of the Micro-AT control. These instructions are set forth in
S&C Instruction Sheet 515-510, furnished with the test
accessory. The programming and testing described under
“FIELD ADJUSTMENT AND PROGRAMMING” and
“OPERATIONAL TESTING” in S&C Instruction Sheet
515-500 can be completed during the preliminary
checkout.
When the test accessory is used, the control power
available to supply the charging motors of the storedenergy operators and to maintain the charge on the solenoid-tripping capacitors is less than that available during
normal three-phase operation. As a result, the time
required for the motors to charge the stored-energy operators will be longer than normal. Furthermore, it may
take as long as two minutes after the stored-energy operators are charged for the solenoid-tripping capacitors to
become fully charged. Therefore, wait at least two minutes after the stored-energy operators are charged before
initiating a transfer operation.
APPENDIX B
Dielectric Testing
When high-voltage dielectric tests are to be performed on
S&C Source-Transfer PMH Pad-Mounted Gear, special
precautions should be taken to prevent damage to the
voltage sensors and voltage limiters. Refer to S&C Instruction Sheet 591-500.
APPENDIX C
Ratings for S&C Mini-Rupter Switches
Complete ratings for Mini-Rupters as applied in S&C
Source-Transfer PMH Pad-Mounted Gear are shown in the
table below. In addition to the load-dropping ratings
shown, Mini-Rupter is capable of interrupting transformer
magnetizing currents associated with the applicable
loads, as well as line-charging and cable-charging currents
typical for distribution systems of these voltage ratings.
For applications on systems rated higher than 7.2 kv and
involving load current with high harmonic content (such
as rectifier load currents), refer to the nearest S&C Sales
Office. The two-time duty-cycle fault-closing ratings
shown for Mini-Rupters define the ability to close the
Mini-Rupter twice against a three-phase fault with asymmetrical current in at least one phase equal to the rated
value, with the switch remaining operable and able to
carry and interrupt rated current.
RATINGS FOR S&C MINI-RUPTER SWITCHES
Kv
Amperes, Rms
Live Switching
Momentary
(Asym.)
1-Second
(Sym.)
22 400
22 400
14 000
22 400
22 400
14 000
Nom.
Max
BIL
Cont.
Load Splitting
(Parallel or
Loop Switching)
Load
Dropping
Duty-Cycle
Fault-Closing,
Two-Time (Asym.)
14.4
17.0
95
600
600
600
25
29
125
600
600
400
14,000 amperes rms symmetrical, 35,000 amperes peak.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 29 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
APPENDIX C — Continued
Ratings for S&C Power Fuses
with Uni-Rupter
Complete ratings and capabilities of S&C Power Fuses
with Uni-Rupter as applied in S&C Source-Transfer PMH
Pad-Mounted Gear are shown in the table below. UniRupter is also capable of carrying and interrupting load
currents up to and including the emergency peak-load
capabilities of the associated SML Power Fuses, or up to
400 amperes at 14.4 kv and 200 amperes at 25 kv when
used with Fault Fiter Electronic Power Fuses. In addition
to the load-dropping capabilities shown, Uni-Rupter is
capable of interrupting transformer magnetizing currents
associated with the applicable loads, as well as line-charging and cable-charging currents typical for distribution
systems of these voltage ratings. The duty-cycle fault-closing capabilities shown for S&C Power Fuses with UniRupter represent the fault-closing capabilities of the fuse
with Uni-Rupter when the fuse is closed with a purposeful
thrust without hesitation. Following the specified number
of such closings (one or two), Uni-Rupter will remain
operable and able to carry and interrupt rated current.
RATINGS AND CAPABILITIES FOR S&C POWER FUSES WITH UNI-RUPTER
Ratings
Live Switching Capabilities, Amperes, Rms
Kv
Fuse Type
Nom.
Max
14.4
17.0
25
27
14.4
17.0
25
27
14.4
17.0
25
29
Amperes, Rms
Load
Dropping
Duty-Cycle Fault-Closing
(Asym.)
Load Splitting
(Parallel or
Loop Switching)
One-Time
Two-Time
BIL
Max
Interrupting
(Sym.)
95
200E or
200K
14 000
200
200
22 400
13 000
125
200E or
200K
12 500
200
200
20 000
13 000
95
200E
12 500
200
200
20 000
13 000
125
200E
12 500f
200
200
20 000
13 000
95
400
14 000
400
400
22 400
13 000
125
200
12 500
200
200
20 000
13 000
SML-20
SML-4Z
Fault Fiter
f Applicable to solidly grounded-neutral systems only, with fuses con-
nected by single-conductor, concentric-neutral-type cable to a transformer or transformers. Rating is 9,400 amperes rms symmetrical for all
other applications.
663-503
Page 30 of 35
August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
APPENDIX D
OPTIONAL FEATURES
Suffix Added to
Pad-Mounted Gear
Catalog Number
Item
Light Gray Outdoor Ultradur Finish instead of olive green
Stainless-Steel Enclosure1
Hexhead Actuator for use in lieu of pentahead actuator
on all Penta-Latch Mechanisms
-A2
With olive green finish
-A10
With light gray finish
-A12
For use except when option suffix “-F2”
is specified
-B1d
For use when option suffix “-F2”
is specified
-B2d
Key Interlocks to prevent opening fuse-compartment doors unless both switches are locked open
-C5d
Mechanical Cable Interlocks to prevent operation of switch when associated switch-compartment
door is open
-C6d
Mechanical Antiparalleling to prevent paralleling two sources
-C7d
Auxiliary Switches, 4-PST, one coupled to each switch
-C9d
Auxiliary Switches, 4-PST, one coupled to each stored-energy operator
-C10d
Remote-Control Receptacle for each stored-energy operator to permit open/close operations from an
adjacent location using the remote-control station (not included; see “ACCESSORIES” on page 33)
-C11
Mounting Provisions for a Fault Indicator in each switch
compartment
Note: Accommodates three-phase indicator with singlephase sensors
Applicable to
Models
Without viewing window in door
-F1
With viewing window in door
-F2d
Inner Barrier Panels—a panel inside the enclosure door for each compartment, secured by recessed
pentahead bolt(s)23
-G7
6 inches
-K1
12 inches
-K2
18 inches
-K3
24 inches
-K4
All models
Carbon steel
Base Spacer, compartmented to match enclosure,
increases cable-termination height
6 inches
-K11
12 inches
-K12
18 inches
-K13
24 inches
-K14
Stainless steel
6 inches
-K7
12 inches
-K8
18 inches
-K9
24 inches
-K10
Carbon steel
Base Spacer, noncompartmented, increases cabletermination height
6 inches
-K17
12 inches
-K18
18 inches
-K19
24 inches
-K20
Stainless steel
1 When this optional feature is specified, the entire exterior of the
3 Meets REA’s requirements for “dead-front.”
enclosure is fabricated from 11-gauge Type 304 stainless steel.
d When optional feature “-B1,” “-B2,” “-C5” through “-C10,” or “-F2” is
2 Where the National Electrical Safety Code (ANSI Standard C2)
ordered for use with a stainless-steel enclosure, the suffix designation is
increased by 10; for example, “-B11” is specified instead of “-B1.”
applies, this optional feature may be included to meet the requirements of
Section 381G.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 31 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
APPENDIX D — Continued
OPTIONAL FEATURES—Continued
Suffix Added to
Pad-Mounted Gear
Catalog Number
Item
Switch-Terminal Adapters—for connection of two cables (through 750 kc mil) per terminal 1
Note: Space limitations prevent use of these adapters where surge arresters are to be installed
Cable Guides, one at each terminal12
-M1
In switch compartments. For conductor sizes
No. 2 through 1000 kc mil
-M2
In fuse compartments. For conductor sizes
No. 2 through 4/0
-M3
Polymer-Housed Metal-Oxide Surge Arresters,3 base-mounted, at all switch terminals
(removed for shipment)
9 kv
-N6f
10 kv
-N7f
12 kv
-N8
15 kv
-N9
18 kv
-N10l
9 kv, 10 kv,
or 9/10 kv
Mounting Provisions for Base-Mounted Surge Arresters,4 at all switch terminals
Mounting Provisions for Porcelain Cable Terminators for
single-conductor UD cable, at all switch terminals
Applicable to
Models
-P1f
12 kv
-P3
15 kv
-P4
18 kv
-P5l
Joslyn PSC for No. 6 through 2/0,d or G&W
PAT for No. 4 through 250 kc mil copper or
aluminum cable
-U2
G&W PAT for 3/0 through 750 kc mil copper or
500 kc mil aluminum cabled
-U3
Overcurrent Lockout. Prevents an automatic source transfer that would close a switch into a fault. Includes
field adjustable lockout level and lockout-reset time delay, lockout-indicating lamp, manual-reset key,
facilities for external reset, and six current sensors (one per phase for each switch)5678
-Y2
Remote Indication. Includes provisions for remote monitoring of presence or absence of source voltages,
manual or automatic operating mode, and status of “ready” indicator, “event” indicator, and overcurrent
lockout (if furnished)9
-Y4
Test panel. Permits the use of an external, adjustable three-phase source to verify, through independent
measurement, the response of the control to loss-of-source, phase-unbalance, and overcurrent-lockout
(if furnished) conditions0⁄
-Y5
Supervisory Control. Permits switch operation from a remote location9
-Y6
Communications Card. Permits local uploading of “events” and settings from the Micro-AT control to a userfurnished personal computer, as well as downloading of the user’s standard operating parameters¤‹
-Y8
All models
1 When optional feature “-M1” or “-M2” is specified, cable-termination
8 Current sensors must not be installed on unshielded cables or on
options (suffixes “-U2” and “-U3”) cannot be accommodated. In addition,
when optional features “-M1” and “-M2” are both specified, only one cable
guide is provided at each switch terminal.
2 These devices extend below the base of the unit. A cable pit or
optional base spacer that provides a 12-inch or greater increase in cabletermination height is required.
3 Surge arresters are base-mounted only (without isolators).
4 These provisions accommodate Ohio Brass Type PDV (metal oxide),
McGraw-Edison Type AZL19C (metal oxide), General Electric Tranquell®
(metal oxide), or McGraw-Edison Type ES (silicon carbide) distributionclass surge arresters. Surge arresters must be base-mounted only (without isolators).
5 The current sensors furnished cannot be used with the switch-terminal adapter option (suffix “-M1”) for applications involving two source
conductors per phase. For such applications, refer to the nearest S&C
Sales Office.
6 For applications where pad-mounted gear load feeders are connected
to transformers with wye-grounded primary windings, refer to the nearest
S&C Sales Office.
7 S&C Closed-Gap Current Sensors, Catalog Number TA-1758, are
furnished. Each current sensor accommodates a single conductor up
to 2¹⁄₂ inches in diameter.
cables where the insulation is exposed but ungrounded (for example,
where dielectric tape or heat-shrink tubing is used). These sensors are
intended for application at ground potential and may be damaged by the
voltage gradient between the cable insulation and ground.
9 Includes a terminal block for user’s connections.
0 If a three-phase test source is not available, limited testing may be
performed using an external, adjustable single-phase source.
⁄ In instances where a three-phase test source is to be used, an S&C
Voltage Limiter—Three-Phase Catalog Number TA-1741 must be furnished for the test circuit.
¤ Requires an IBM PC AT or compatible computer using Intel’s 80386
microprocessor, or higher. The computer must have a minimum of
2MB of memory, one 3.5-inch 1.44-MB floppy disk drive, and a hard
disk drive with at least 2MB of free space. The computer must operate
under Microsoft Windows™, Version 3.1.
‹ Requires S&C Maintenance Cable Catalog Number TA-2320 or
TA-2321. See “ACCESSORIES” on page 33.
d These devices extend below the base of the unit. A cable pit or
optional base spacer is required.
f Not applicable to 25-kv models.
l Not applicable to 14.4-kv models.
663-503
Page 32 of 35
August 14, 1995
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
APPENDIX D — Continued
ACCESSORIES
Item
Catalog Number
S&C Test Accessory, permits preliminary checkout of source-transfer control using single-phase 120-volt ac source (before
medium-voltage connections are made to the pad-mounted gear) to expedite full service once medium voltage is available. The test
accessory isolates the S&C Voltage Sensor during testing and eliminates the possibility of backfeed during test procedures
TA-1316
Portable Remote-Control Station with 50-foot cord, connects to one remote-control receptacle (not included; see optional feature
“-C11” on page 31) to permit open/close operations from an adjacent location
Maintenance Cable, for connecting Micro-AT control communications card (see optional
feature “-Y8” on page 32) to user-furnished personal computer
Grounding Jumpers, set of three, with eye-type clamps for installation with a standard
shotgun clamp stick
Shotgun Clamp Sticks for installation of grounding jumpers and for use with voltage
testers
5294
For personal computers having 25-pin
serial communication port
TA-2320
For personal computers having 9-pin
serial communication port
TA-2321
3 cable length
4210
65¹⁄₂ length
9933-150
85¹⁄₂ length
9933-151
For grounding jumpers
Storage Bag, heavy canvas
For shotgun
clamp stick
9933-149
66 length
9933-152
86 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.
INSTRUCTION SHEET
s
S&C ELECTRIC COMPANY
663-503
Page 33 of 35
August 14, 1995
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT® Control
Outdoor Distribution (14.4 kv and 25 kv)
APPENDIX E
Current-Limiting Fuses for Use in
S&C PMH Pad-Mounted Gear
Types Accommodated and Adapters Required
S&C Holders for current-limiting fuses are designed for
use in pad-mounted gear models that include mountings
for Fault Fiter Electronic Power Fuses. In PMH PadMounted Gear, these holders will accommodate the
single-barrel current-limiting fuses listed in the table
below when the fuses are equipped with ⁵⁄₈-inch 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 fit the fuse in the holder.
Adapters, when required, are furnished with the S&C
Holder and are signified by a suffix to the catalog number
of the holder. For instructions on installing current-limiting fuses in S&C Holders, refer to S&C Instruction Sheet
660-500.
CURRENT-LIMITING FUSES—Types Accommodated and S&C Holders Required
For use in
PMH Models
Rated, Kv
Current-Limiting Fuse1
Manufacturer
Type
Combined
Technologies, Inc.
Max Amperes, Rms
Catalog Number4
8.3
30—112
3142-A1
Q
8.3
8.3
15.5
15.5
15.5
6—30
40—100
6—30
40—50
65—100
3142-A3
3142-A1
3142-A2
3142-A1
3142
McGraw-Edison
NX®
8.3
8.3
15.5
15.5
1.5C—40C
50C—100C
1.5C—40C
1.5C—100C
3142-A3
3142-A1
3142-A2
3142
RTE® ELX
8.3
15.5
3—50
3—50
3142-A3
3142-A2
CX
8.3
15.5
3.5C—40C
4C—40C
3142-A3
3142-A2
X Limiter™
8.3
8.3
15.5
15.5
12—40
50—140
12—40
50—100
3142-A3
3142-A1
3142-A2
3142
B
15.5
22
30—100
25—65
3143R1-A1
3143R1-A1
Q
15.5
15.5
6—30
40—100
3143R1-A3
3143R1-A1
McGraw-Edison
NX®
15.5
15.5
23
1.5C—40C
50C—100C
6C—40C
3143R1-A3
3143R1-A1
3143R1-A3
RTE® ELX
15.5
23
3—50
3—40
3143R1-A3
3143R1-A3
Cooper Power Systems
Westinghouse
Max, Kv
B
Kearney
14.4
S&C Holder3
Rating2
Kearney
Cooper Power Systems
25
CX
15.5
4C—40C
3143R1-A3
CXN
15.5
45C—60C
3143R1-A1
X Limiter™
15.5
15.5
23
12—40
50—100
12—40
3143R1-A3
3143R1-A1
3143R1-A3
Westinghouse
Combined
Technologies, Inc.
1 The single-barrel current-limiting fuses listed in this table are to be
3 S&C Holders for use in 14.4-kv models of PMH Pad-Mounted Gear are
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. Consult the appropriate current-limiting fuse manufacturer for complete fuse
ratings.
rated 14.4 kv nominal, 17.0 kv maximum, and 200 amperes maximum.
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.
663-503
Page 34 of 35
August 14, 1995
4 Includes adapters when required.
INSTRUCTION SHEET
S&C ELECTRIC COMPANY
s
APPENDIX E — Continued
Recommended Voltage Ratings
• Protection of single-phase transformers serving single-
In general, current-limiting fuses should have a maximum
voltage rating equal to, but not greater than 140% of, the
system line-to-line voltage since, 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-toground voltage” (i.e., fuses with a voltage rating lower
than line-to-line voltage but greater than or equal to maximum system line-to-ground voltage), S&C can only recommend such use in the following applications:
phase loads.
• Protection of three-phase lateral circuits fed by singleconductor shielded cable (provided each transformer
on that lateral is individually fused so that the currentlimiting fuse serving the lateral will not be required to
clear secondary faults).
• Protection of single-phase lateral circuits fed by singleconductor shielded cable where the load is line-toground connected.
INSTRUCTION SHEET
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S&C ELECTRIC COMPANY
663-503
Page 35 of 35
August 14, 1995