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Typical Specifications
Triad Series 1, Rotary Puffer, Padmount Switchgear
Three Position

The switch shall consist of manually operated load interrupting, SF6 insulated, 600A rotary puffer three position switches and manually operated vacuum interrupter fault interrupting tap switches, electronically controlled. The switches shall be designated G&W Triad Series 1 (TVI style) (TFI style) incorporating internal ground switches for the load break switch ways. The switch manufacturer shall be ISO 9001:2000 and 14001 certified.

A. SWITCH CONFIGURATION
Each switch shall have:

_____ (Qty.) 3-phase load switch ways with integral ground position.

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

_____ (Qty.) Single phase vacuum interrupter tapped way(s) with individual operating handles (TVI style).

_____ (Qty.) 3-phase vacuum interrupter tapped way(s) with internal three phase mechanism and one operating handle (TFI style).

Switches shall be designed for: (check)

____ Front access to cables and operators.

____ Front/back access to cables and operators (four ways max.).

B. SWITCH CONSTRUCTION
Switch contacts and cable entrance terminations shall be contained in a single welded mild steel tank with entrances internally connected by copper conductors. Construction shall be a deadfront design. Switches shall be shipped factory filled with SF6 gas conforming to ASTM D-2472. Switch tanks shall be painted ASA70 light gray using a corrosion-resistant epoxy paint.

Load break Puffer Switch - Each switching way is to be equipped with an internally mounted operating mechanism capable of providing quick-make, quick-break operation in either switching direction. The mechanism must be capable of delivering sufficient torque and shall be provided with latches for each position to assure load interrupting, fault closing and momentary ratings. All switch positions are to be clearly identified, padlockable and adaptable to keylock schemes. The operating mechanism shall be actuated from outside the switch tank with an operating handle. The operating shaft shall be made of stainless steel providing maximum corrosion resistance. A double "O" ring type operating shaft seal shall be used for a leak resistant, long life seal.

Switch contacts shall be of a rotary puffer design made with copper alloy contacts with silver plating to assure permanent, low contact resistance. Each rotating contact simultaneously disengages from two fixed contacts, thus providing two break points per phase giving improved interrupting capability compared to single break contact systems. Contact travel shall be 60 degrees to assure efficient arc extinction and a wide open contact gap. Arcing is confined away from the main contact surfaces. The stationary contacts shall be supported independent of the cable entrance bushings, eliminating possible misalignment. Auxiliary blades used for load interruption are not acceptable.

Vacuum Interrupters - The vacuum interrupter shall consist of vacuum bottles and a spring-assisted operating mechanism.

For TVI style switches: The mechanism used shall be designated "Model VI" for single phase or three phase operation. The mechanism shall consist of a single vacuum bottle mechanically linked to single spring-assisted operating mechanism. For three phase operation, the single phase mechanisms are mechanically linked externally with an operating handle assembly.

For TFI style switches: The mechanism used shall be designated "Model FI" for three phase operation. The mechanism shall consist of three vacuum bottles mechanically linked to a single spring-assisted operating mechanism.

For all styles: 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. Reset or closing 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 handle.

C. DESIGN RATINGS AND STANDARDS
Load break Puffer Switches:
Switches shall be designed, tested and built per ANSI C37.72-1987 and IEC 265 standards. Certified test reports shall be provided. The switch shall be rated: (select column)

Voltage class, kV 15 25 35
Impulse level (BIL), kV 110 125 150
Continuous & load break current, A 630 630 630
One minute withstand (dry), AC kV 35 60 70
One minute withstand (dry), AC kV Production test rating 34 40 50
15 minute withstand, DC kV 53 78 103
Momentary current, kA, ASYM 25 25 25
Fault-close current, kA, ASYM
(3 times)
25 25 25
One second current, kA, SYM 16 16 16
Mechanical endurance, operations 2000 2000 2000

Vacuum Interrupters:
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 C37.72-1987. The vacuum interrupter assembly shall be rated: (select column and model)

For TVI style switches:
Voltage class, kV 15 25 35
Impulse level (BIL), kV 95 125 150
Continuous & load break current, A 630 630 630
One minute withstand (dry), AC kV 35 60 70
One minute withstand (dry), AC kV Production test rating 34 40 50
Symmetrical interrupting rating, kA* 12 12 12
Asym. interrupting rating, kA 19.2 19.2 19.2

* 18kA optional.

For TFI style switches:
Voltage class, kV 15 25
Impulse level (BIL), kV 95 125
Continuous & load break current, A 630 630
One minute withstand (dry), AC kV 35 60
One minute withstand (dry), AC kV
Production test rating
34 40
Symmetrical interrupting rating, kA 12* 12
Asym. interrupting rating, kA 19.2 19.2

*16kA available at 15kV.

D. ANSI C37.60 FAULT INTERRUPTING DUTY

15-20% 44
45-55% 56
90-100% 16

Total Number of Fault Interruptions: 116

E. CABLE ENTRANCES
Load break Puffer Switches:
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

Vacuum Interrupters:
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

____ 200 amp Deepwell bushing

F. VACUUM INTERRUPTER TRIP MODULE
Trip modules shall be provided to sense load and fault current on each phase of the load tap circuits. The trip modules 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 trip modules 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 -40 degrees C to +65 degrees C.

Trip characteristics (TCC curves) shall be user selectable.  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.  Trip modules shall not require a computer or other external device for programming trip settings or other operational parameters.

G. ENCLOSURE
Enclosures shall be made of 12 gauge mild steel and manufactured to ANSI C37.72 and C57.12.28 standards. The enclosure shall be mounted independent of the switch allowing removal for ease of cable installation or future replacement if required. Enclosures shall be tamper-resistant incorporating hinged access doors with pentahead locking bolts and provisions for padlocking. The enclosure shall be provided with lifting provisions and painted with a Munsell 7.0GY3.29/1.5 green finish.

H. 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.

I. 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.

- Switch operating handle(s) with padlock provision.

- 12 gauge mild steel padmount enclosure painted Munsell green with stainless steel hinges and pentahead locking mechanisms.

- Type 1 vacuum interrupter trip module.

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

___ Stainless steel tank.

___ Stainless steel enclosure.

___ Low pressure warning device.

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

___ 4/0 brass ground lug(s).

___ Parking stands.

___ Keylock provisions.

___ Current transformers (600:5) (500:1) (1000:1) on load break ways for current monitoring on automation schemes.

___ Automatic transfer control package for a maximum 5 seconds per mechanical switching operation.

___ 24VDC motor actuators.

___ Switch controllers.

___ Remote Terminal Units.

___ Auxiliary switches.

___ Analog voltage sensors.

___ Digital voltage sensors.

___ Type 2 trip modules including ground fault trip and time delay selector switches (three phase only).

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

 


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