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S&C Circuit-Switcher Mark VI
S&C Circuit-Switcher Mark VI
Outdoor Transmission (69 kV through 138 kV)
Construction Guide
Data Bulletin 712-60
July 21, 2008� S&C Electric Company
Section
Page
Section
Page
Installation on a
User-Furnished Support Structure
Checklist for Required Installation Materials . . . . . . . . . 2
Loadings for Support Structures . . . . . . . . . . . . . . . . . . 2
How to Determine Total Bending Moments
and Total Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Foundation Loading Data for
S&C Mounting Pedestals . . . . . . . . . . . . . . . . . . .
5
Terminal-Pad Loading Limits . . . . . . . . . . . . . . . . .
7
Battery and Wiring Requirements . . . . . . . . . . . . .
8
Table of Contents
This publication sets forth the data required for the user
to design a support structure or pedestals for a Mark VI
Circuit-Switcher; the data required to properly construct
foundations for a Mark VI Circuit-Switcher on S&C Mounting
Pedestals; the maximum-continuous and permissible-peak
terminal pad loading limits for a Mark VI Circuit-Switcher;
pole-unit wiring requirements; and external wiring and
battery requirements. 2 S&C Data Bulletin 712-60
S&C Circuit-Switcher Mark VI
Installation on a
User-Furnished Support Structure
Checklist for Required Installation Materials
The following items are included with the Mark VI Circuit-
Switcher:
Three interrupters
Three interrupter charging motors
Three vertical-break disconnectsa
Hardware to attach the interrupters to the disconnects
Hardware to attach the charging motors to the inter-
rupters
One drive-train gearbox (double offset)
Interphase operating shaft sections, cut to lengtha
Vertical operating shaft sections, cut to lengtha
Drive-train couplings and associated hardware
Mark VI CS-1A Switch Operator.
The following items are not included and must be fur-
nished by the user:
Mounting brackets and hardware to attach the Mark VI
CS-1A Switch Operator to the structure
Mounting brackets and hardware to attach the power-
train gearbox to the structure
Hardware to attach the conduit to the structure
Conduit and wiring to electrically connect pole-units to
operator.
All of the above items are included when S&C
Mounting Pedestals are furnished.
Loadings for Support Structures
The high operating speed of the vertical-break disconnect
(1.5-second total travel time on closing) brings about high
acceleration and deceleration rates, which result in high
dynamic forces transferred to the support structure and
the adjoining bus. The support structure must be designed
to withstand apparatus loads, dead-weight loads, wind
loads, and ice loads. Structures should be designed to limit
deflections as follows:
Horizontal deflections of the structural section to which
a pole-unit is attached should not exceed C\, inch in any
direction.
Horizontal deflections of the structural section under
static wind load should not exceed one inch.
The total of the rotational deflections of the switch
operator and the gearbox support in resisting the switch
operator locked-rotor torque of 21,500 inch-pounds (2429
Newton-meters) should not exceed 5�.
Pole-units must be mounted vertically upright, at 90�
�15�.
For purposes of supporting-structure design, it is
assumed that dynamic forces and static wind loads do not
occur simultaneously. Generally, the bending moments
produced by dynamic forces will dictate the design of the
structure and the foundation. Forces produced by wind
loads must be considered in the case of high structures,
as these static bending moments may exceed the dynamic
moments.
In these loading diagrams, no attempt has been made to
indicate a specific arrangement of the supporting structure,
since there are many ways in which it can be executed.
However, the values shown provide complete loading data.
(Steel pedestals are available from S&C which meet the
requirements outlined herein.)
For further information on the arrangement of the
components for a specific installation, refer to the catalog
drawing supplied by S&C.
a A drawing or specification detailing the configuration of the user-
furnished structure must be made available to S&C Electric Company at
the time of order . Vertical and interphase pipe is cut to length and mount-
ing holes on the pole-unit base may need to be customized to the user-
furnished structure .
S&C Data Bulletin 712-60

3
S&C Circuit-Switcher Mark VI
How to Determine Total Bending Moments
and Total Forces
M
wt
and M
wl
are the wind moments in the transverse
and longitudinal directions, respectively, at each
Circuit-Switcher pole-unit. F
wt
and F
wl
are the wind forces
in the transverse and longitudinal directions, respectively,
at each Circuit-Switcher pole-unit. For individual pole-units
mounted on independent structures of height B, the
maximum bending moment at the foundation may be found
as follows:
Transverse: M
wt
+ (F
wt
3 B)+ (Bending moment from
wind acting on structure)
Longitudinal: M
wl
+ (F
wl
3 B) + (Bending moment from
wind acting on structure)
F
c
and F
o
appear as forces at the Circuit-Switcher termi-
nal pads accompanying closing and opening operations. F
c

is a direct compression force resulting from closing of the
Circuit-Switcher. F
o
is a shear force parallel to the pole-unit
base. M
o
is a turning moment tending to rotate the pole-unit
in a counterclockwise direction as viewed in the elevation
drawings. Limiting deflections of the Circuit-Switcher
supporting members to recommended values will ensure
that these forces will be absorbed by the structures and
not transferred to adjoining bus or other apparatus (e.g.,
bushings). Use of expansion joints at Circuit-Switcher ter-
minal pads will compensate for inherent insulator-column
deflection.
LEGEND:
A = Moment arm of force F
o
B = Height of pedestal or supporting structure
F
c
= Dynamic force accompanying closing
operation
F
o
= Dynamic force accompanying opening
operation
F
wl
= Static wind force, longitudinal
F
wt
= Static wind force, transverse
M
o
= Dynamic bending moment (= F
o
3 A)
M
wl
= Static wind bending moment, longitudinal
M
wt
= Static wind bending moment, transverse
T
1
= Switch operator locked-rotor torque
T
2
= Torque delivered to interphase shaft
W
1
= Weight of one Circuit-Switcher pole-unit
W
2
= Weight of switch operator
X = Horizontal distance from the centerline of
rotating insulator stack to center of gravity
Y = Vertical distance from center of gravity to
bottom of base
15 (381)
3 (76)
9 (229)
34 (864)
Switch operator mounting-hole
spacing, inches (mm)
F
c
W
2
F
wl
M
wl
F
o
F
wl
F
wl
M
o
M
wl
W
1
CENTER OF
GRAVITY
X
F
o
Y
A
Dimensions in Inches (mm) 4 S&C Data Bulletin 712-60
S&C Circuit-Switcher Mark VI
MAXIMUM LOADING DATAPer pole-unit1
Rating,
kV
Fc, lbs.
(New-
tons)
2
Fo, lbs.
(New-
tons)
2
Fwl, lbs.
(New-
tons)
2
Fwt, lbs.
(New-
tons)
2
Mo,
in.-lbs.
(Newton-
meters)
2
Mwl,
in.-lbs.
(Newton-
meters)
2
M
wt
,
in.-lbs.
(Newton-
meters)
2
T1,
in.-lbs.
(Newton-
meters)
T2,
in.-lbs.
(Newton-
meters)
W1,
lbs.
(kg)
23
W2,
lbs.
(kg)
A,
in.
(mm)
X,
in.
(mm)
Y,
in.
(mm)
69
225
(1001)
200
(890)
410
(1824)
425
(1890)
17,400
(1966)
7,500
(847)
9,000
(1017)
21,500
(2429)
20,000
(2260)
730
(329)
350
(158)
87
(2210)
5 .5
(140)
22
(559)
115
350
(1557)
275
(1223)
530
(2358)
580
(2580)
31,400
(3548)
16,500
(1864)
18,200
(2056)
21,500
(2429)
20,000
(2260)
1040
(468)
350
(158)
114
(2896)
15
(381)
30
(762)
138
450
(2002)
350
(1557)
560
(2491)
625
(2780)
45,200
(5107)
20,500
(2316)
22,000
(2486)
21,500
(2429)
20,000
(2260)
1120
(504)
350
(158)
129
(3277)
19
(483)
34 .5
(876)
1
Values shown assume 100-mph (160-kmph) wind velocity .
2
Per Circuit-Switcher pole-unit .
3
For Pre-insertion Inductors Option -P6, add 240 lbs . (109 kg) per
pole-unit (W1 ) . For Pre-insertion Inductors Option -P61, add 215 lbs .
(97 kg) per pole-unit .
F
wt
T
2
T
1
M
wt
F
wt
Gearbox support may be installed as indicated,
at the end of the phases or at opposite side
To base of
mounting structure
B
S&C Data Bulletin 712-60

5
S&C Circuit-Switcher Mark VI
Foundation Loading Data
for S&C Mounting Pedestals
The following tables provide the loading data necessary to
properly construct foundations for Mark VI Circuit-Switcher
pole-units installed on S&C Mounting Pedestals. This
loading data is based on the most-adverse combination of
maximum terminal-pad loading limits and accounts for the
dead-weight contribution of the Mark VI Circuit-Switcher,
Mark VI CS-1A Switch Operator, and S&C Mounting
Pedestal(s), along with wind loading of 100 miles (160
kilometers) per hour.
Mark VI Circuit-Switcher, when installed with the recom-
mended S&C anchor bolts and with flexible-conductor con-
nections at all six terminal pads, is capable of withstanding
seismic loading of