S&C Metal-Enclosed Custom Switchgear
34.5 kv - Manual
Indoor and Outdoor Distribution
Two lineups of 34.5-kv, manual, S&C Metal-Enclosed
Custom Switchgear provide switching and protection for
the power distribution circuits serving the printing facilities of a major magazine publisher. An olive green, threebay, outdoor switchgear assembly serves as the serviceentrance switching center and includes a switch-only
entrance bay, a bay with metering provisions, and a fused
feeder bay with future bus extension for anticipated system growth-another bay to serve a second facility is
planned. This feeder bay provides power by underground
cable to the light gray, four-bay, indoor switchgear assembly that serves as the switching center for the new facility.
The four-bay lineup consists of an entrance bay that
switches the cable to a bus serving three feeder bays. Each
feeder bay provides switching and protection for one
three-phase load circuit, which includes a 2000 kva,
27.6 kv/480 v, epoxy-cast coil power transformer having a
fan-cooled capability to 3000 kva. A system diagram is
shown on page 4.
For all switching duties, the 34.5-kv (150 kv BIL),
600-ampere, three-pole, group-operated, indoor S&C
Alduti-Rupter ® Switch is provided. Main-contact-at-
bottom style switches are furnished in the entrance bays,
and main-contact-at-top style switches are furnished in
feeder bays.
For fault protection, S&C Type SM-5S Power Fuses
rated 34.5 kv nominal (200 kv BIL) and 300E amperes
maximum are furnished in all feeder bays. These power
fuses like all SM power fuses, have the superior performance characteristics and reliability required to provide
two-fold protection-protection for the system upstream,
and protection for downstream equipment such as the
transformers and cables.
For surge protection, entrance bays are equipped with
30-kv intermediate class arresters. Ground studs are provided on the source side of switches, and on the load side
and source side of fuses. Convenience features include a
two-pole breaker (120 volts, 20 amperes per pole) for the
strip heater circuit, and a duplex receptacle outlet on the
entrance bay of the outdoor assembly. An ammeter with
selector switch, utilizing three current transformers rated
300/5 amperes for sensing, is furnished on the entrance
bay of the indoor assembly.
The outdoor service-entrance switching center at left is connected by underground cable to the four-bay indoor switching center
at right.
PHOTO SHEET
621-853
Page 1 of 4
October 31, 1983
S&C Metal-Enclosed Custom Switchgear
34.5 kv - Manual
Indoor and Outdoor Distribution
Interior views of entrance bays showing the manually operated, 34.5-kv, 150 kv BIL, 600-ampere S&C Alduti-Rupter Switches with
ground studs and 30-kv intermediate class surge arresters on the source side. At left is the entrance bay for the service-entrance
switching center showing the interrupter switch with barriers installed, an externally accessible two-pole circuit-breaker (behind
bolted cover) for the strip-heater circuit, and a duplex receptacle outlet mounted in the stile below the switch operating handle.
The entrance bay for the other switching center (shown at right) illustrates the interrupter switch with barriers removed, and
shows the current transformers which provide sensing for the ammeter.
621-853
Page 2 of 4
October 31, 1983
PHOTO SHEET
Interior views of feeder bays showing the S&C Alduti-Rupter Switch with Type SM-5S Power Fuses. Barriers are shown installed in
the feeder bay of the service-entrance switching center (at left) and removed in the feeder bay of the other switching center (at
right). Ground studs are provided on the source and load side of each fuse.
PHOTO SHEET
621-853
Page 3 of 4
October 31, 1983
S&C Metal-Enclosed Custom Switchgear
Indoor and Outdoor Distribution
34.5 kv - Manual
The customer’s in-plant power distribution system, with the addition of future service-entrance feeder bays, will consist of
multiple radial circuits serving segmented blocks of load. This simple and direct circuit arrangement facilitates quick location and
repair of faulted circuits. By segmenting the toad, the power fuses protecting each transformer wilt clear and isolate any faults
associated with the transformer and continuous service can stiff be provided to the remaining loads on the system.
621-853
Page 4 of 4
October 31, 1983
PHOTO SHEET