The switch shall consist of manually operated fault interrupting, SF6 insulated, vacuum interrupters, electronically controlled. The switch manufacturer shall be ISO 9001 certified.

A. SWITCH CONFIGURATION
Switches shall be designed for front access to cables and operators. Each switch shall have:

_____ (Qty.) 3-phase vacuum interrupter tapped way(s) with gang linked operating handles (model VI).

_____ (Qty.) 3-phase vacuum interrupter tapped way(s) with single operating handle(s) (model FI, 15.5-27kV).

_____ (Qty.) single phase vacuum interrupter tapped way(s) with individual operating handles (model VI).

B. SWITCH CONSTRUCTION
All switch components and entrances shall be assembled in a totally welded mild steel tank. Entrances shall be internally connected by copper conductors capable of handling momentary and continuous current duty. The switch shall contain no electrically floating metallic parts or components. Construction shall be a deadfront design. Switch tanks shall be painted ASA70 light gray using a corrosion-resistant epoxy paint.

Vacuum Interrupters - The vacuum interrupter shall consist of vacuum bottles and a spring-assisted operating mechanism. The mechanism used shall be designated: (check)

____ Model VI for single or three phase operation. The interrupter shall consist of a single vacuum bottle mechanically linked to a spring-assisted operation mechanism. For three phase operation, the single phase mechanisms are mechanically linked externally with an operating handle assembly.

____ Model FI for three phase operation only. The interrupter shall consist of three vacuum bottles mechanically linked to a single spring-assisted mechanism.

The vacuum interrupter operating mechanism shall consist of the support assembly, linkage, spring latch mechanism, and solenoid utilized for electronic tripping. Maximum interrupting time shall be three cycles (50 msec). The movable contact shaft shall be flagged to indicate the contact position, open or closed. This contact position indicator shall be fully visible through viewing windows supplied in the switch tank.

Each tap phase is to be equipped with an individual 600A vacuum interrupter fully enclosed in an SF6 insulated switch tank. Electrical opening shall be by a solenoid that is activated from sources external to the switch tank. Closing (reset) of the vacuum interrupter shall be mechanical with the use of an external operating handle. The mechanical linkage assembly shall provide for a "trip-free" operation which allows the vacuum interrupter to interrupt independent of the operating lever.

C. DESIGN RATINGS AND STANDARDS
The vacuum interrupter shall be a non-reclosing, manual reset device incorporating vacuum bottles. It shall be designed, tested and built per application sections of ANSI C37.60-1981 and C37.71-1987. The vacuum interrupter assembly shall be rated: (select column)

* 38kV available in model VI only.

* 16kA available at 15kV.

Above tested to 50 fault interruptions at 12kA symmetrical.

Total Number of Fault Interruptions: 116

E. CABLE ENTRANCES
Cable entrances shall be tested to ANSI/IEEE 386 and be one or more of the following: (check)

____ 600 amp Quik-Change disconnectable apparatus bushing

____ 600 amp Apparatus bushing

____ 600 amp Universal bushing

____ 200 amp Deepwell bushing

____ 200 amp Deepwell bushingwith deadbreak insert

F. VACUUM INTERRUPTER ELECTRONIC CONTROL
An electronic assembly shall be provided to sense load and fault current on each phase of the load tap circuits. The electronic control shall be powered from the current transformers mounted inside the SF6 insulated switch tank. No external power source shall be required for overcurrent protection. The electronic control shall monitor the current on the individual phases of the load tap circuits using input from the internal current transformers. Electronic trip capability shall be selectable for each phase. Temperature range shall be -30C to +50C.

Minimum trip selection shall be accomplished with selector knobs inside the electronic enclosure. Trip time current characteristics (TCC) shall be field selectable using a dip switch. Maximum time for power up and ready-to-trip when closing on a circuit shall be ten percent of the trip time or 1/2 cycle, whichever is greater. Trip selection may be made with the load taps energized.

G. FACTORY PRODUCTION TESTS
The bulk SF6 gas supply and each individual switch shall be tested for moisture content. Each individual switch shall undergo a mechanical operation check and a leak test. The switch shall be factory filled with SF6 and AC hi-pot tested one minute phase-to-phase, phase-to-ground and across the open contacts. Circuit resistance shall be checked on all ways.

Switches will be shipped factory filled with SF6 gas. Tank shall be designed to withstand 15 psig internal pressure and an external pressure of 14 psig without affecting the performance of the switch.

H. STANDARD COMPONENTS
The following shall be included as standard:

- Welded steel tank painted light gray with stainless steel and brass fasteners.

- Lifting provisions.

- Gas pressure gauge and fill valve.

- Grounding provisions for switch tank and all cable entrances.

- Stainless steel three line diagram and corrosion-resistant nameplates.

- Parking stands.

- Switch operating handle(s) with padlock provision and end stops.

- For Model VI mechanism: Type 1 vacuum interrupter electronics package including a selector switch for single or 3-phase operation and individual phase trip levels. For Model FI mechanism: Type 2 electronics package including ground fault trip and time delay selector switches (three phase only).

I. OPTIONAL COMPONENTS (check)
The following options shall be supplied:

___ Stainless steel tank.

___ Low pressure warning device.

___ SF6 density switch for SCADA or remote indication of dielectric.

___ 4/0 brass ground lug(s).

___ 24VDC motor actuators.

___ Switch controllers.

___ Remote Terminal Units.

___ Digital voltage sensors.

___ Type 3 vacuum interrupter electronics package including programmable vacuum fluorescent display (VFD) and RS232/485 port.

___ 18kA symmetrical interrupting rating (model VI only).

___ Refill kit consisting of regulator, hose and 10 or 20 lb SF6 bottle.