SECTION 16330
MEDIUM-VOLTAGE METAL-ENCLOSED LOAD INTERRUPTER
PART 1 - GENERAL
1.01
SUMMARY
A.
Provisions of Division 01 apply to this section
B.
Section Includes:
C.
1.02
1.
Medium voltage load interrupter metal enclosed switchgear, single or
multiple section line-ups as described and as indicted on Drawings and
specified herein.
2.
Equipment shall be manufactured and tested in accordance with IEEE
C37.20.3 IEEE standard for metal-enclosed interrupter switchgear (ANSI),
and NEMA SG6 power switching equipment. Equipment shall comply
with California Electrical Code.
Related Sections:
1.
Section 16125: Medium-Voltage Cables, Splices and Terminations.
2.
Section 16275: Medium-Voltage Transformers.
3.
Section 16360: Unit Substations.
SUBMITTALS
A.
Provide in accordance with Division 01.
B.
Shop Drawings: Shop Drawings shall include a front elevation, dimensions, make,
and electrical ratings of all components.
C.
Installation Instructions: Submit approved manufacturer's written installation
instructions, including recommendations for handling, storage and protection.
PART 2 - PRODUCTS
2.01
LOAD INTERRUPTER SWITCHGEAR
A.
Switches shall be quick-make, quick-break, 3-pole, 2-position with a stored
energy spring mechanism to provide quick switch operation independent of the
PROJECT NAME
SCHOOL NAME
4/7/2006
MEDIUM-VOLTAGE METAL-ENCLOSED
LOAD INTERRUPTER
16330-1
handle speed. A viewing window shall be installed in switch enclosure and
located to enable visible inspection of switch poles from outside enclosure.
B.
Complete metal enclosed switchgear shall be rated as indicated on Drawings with
fault close, momentary ratings capable of withstanding short-circuit stresses.
C.
High-voltage fuses and non-disconnecting fuse mountings shall be accessible only
through a separate door mechanically interlocked with load break switch, to insure
the switch is in open position when fuses are accessible. A key interlocking
system shall also be provided to prevent fuse access door from being opened
unless switch is open, and to prevent switch from being closed unless fuse access
door is closed. Switch designs with full height fuse access doors shall have a solid
barrier covering area of main cross bus and/or line side of switch. Metal screen
barriers are not permitted. Energized parts shall not be within normal reach of
opened doorway. Four single full length inter-phase barriers shall isolate three
phases of the switch from each other and from enclosures. Fuses shall be current
limiting type of self contained design to limit available fault current stresses on
system. Fuses shall be affixed in position with provisions for removal and
replacement from front of gear without use of special tools. Provisions for
padlocking in open and closed position shall be provided.
D.
Utility company metering section shall be furnished with mounting and wiring
instrument transformers and meters, as required by the serving utility company.
E.
Enclosure frame and internal barriers shall be fabricated of code gage and finished
with 2 coats of medium gray, ANSI No. 451, paint applied over a rust-inhibiting
phosphate primer.
2.02
SWITCHGEAR CONSTRUCTION
A.
Switch bays shall be separately constructed cubicles assembled to form rigid
freestanding units. Adjacent bays shall be securely bolted together to form an
integrated rigid structure. Top and rear covers shall be removable. Individual
units shall be braced to prevent distortion. Installation shall adhere to zone 4
Seismic Requirements.
B.
Provisions shall be furnished to allow for convenient extension of both main bus
and ground bus to adjacent bays, which may be added in future. Main crossover
bus is to be furnished and supported from top of enclosure on NEMA glass
polyester insulators. Ground bus shall run continuously through entire line-up and
shall be securely fastened to the steel frame of each bay.
C.
Metal enclosed gear shall be fully assembled and tested at factory prior to
shipment. Large line-ups shall be split to permit normal shipping and handling as
well as for ease of installation at the Project site.
PROJECT NAME
SCHOOL NAME
4/7/2006
MEDIUM-VOLTAGE METAL-ENCLOSED
LOAD INTERRUPTER
16330-2
D.
Outdoor units shall be furnished in NEMA 3R enclosures designed with sloped
drip-proof roofs. Cubicles shall be furnished with door-in-door construction.
Outer doors shall open to normal switch doors and operating handles. Switchoperating handles shall not be exposed to weather and will be operable regardless
of weather conditions. Furnish the front with a bulkhead type door along with 3point latch and vault type handle with provisions for padlocking. Cubicles are to
be designed to allow front and rear access and do not require routing of line side
or load side connections in front of switch/fuse compartment. Padlocks shall be
furnished for doors and keyed to Corbin No. 60 keys.
PART 3
EXECUTION
3.01
INSTALLATION
A.
Cable terminations shall be as indicated in Section 16125: Medium-Voltage
Cables, Splices, and Terminations.
B.
Furnish Spare Fuses: One spare fuse shall be furnished for each fusible switch
installed. Spare fuse shall be of type and rating as those installed.
C.
Where free-standing equipment is installed at exterior locations or in locations
below grade, concrete pads shall be provided as described under Section 03300:
Cast-In-Place Concrete. Anchor bolts for freestanding equipment shall be
designed to meet code seismic requirements. Equipment shall be anchored to new
slabs with four 1/2 inch x 3-1/2 inch expansion bolts per section; 1/2 inch
anchored bolts shall be tested to withstand 100 foot-pounds of torque.
D.
Follow manufacturer's instructions for receiving, handling, storage and installation
of switchgears.
E.
Provide two sets of manufacture’s recommended service and maintenance
documents.
3.02
PROTECTION
A.
3.03
Protect the Work of this section until Substantial Completion.
CLEANUP
A.
Remove rubbish, debris, and waste materials and legally dispose of off the Project
site.
END OF SECTION
PROJECT NAME
SCHOOL NAME
4/7/2006
MEDIUM-VOLTAGE METAL-ENCLOSED
LOAD INTERRUPTER
16330-3