G & W Electric
ISO 9001: 2000 and 14001 Certified
Overview
Padmount Switchgear
Vault Switchgear
Overhead Switchgear
Reclosers
Automation Products
Current Limiting System Protection
Cable Accessories
Junction Bars
   
     

Typical Specifications
Trident Solid Dielectric Switchgear

This specification covers the requirements for solid dielectric, load break switches and fault interrupters for distribution systems through 38kV(27kV max. for multi-way switches). They shall be manufactured by G&W Electric Co. and designated as Trident™ Series. The manufacturer shall be ISO 9001:2000 and ISO 14001 certified.

A. APPLICATION
Switches shall be (select one):

   __ Padmount style with mild steel enclosure.

   __ Padmount style with stainless steel enclosure.

   __ Vault style, nonsubmersible control enclosures, if required.

   __ Vault style, submersible control enclosures, if required.

A1. Two-Way (using one module) shall consist of (select one only):

   __ Single phase, load break. 

   __ Single phase, fault interrupter.

   __ Three phase, load break. 

   __ Three phase, fault interrupter. 

A2. Multi-way (using two through six modules) shall consist of (select two through six total).

   __ (qty) Three phase, load break modules.

   __ (qty) Three phase, fault interrupter modules.

B. CONSTRUCTION 
Assembly shall be a deadfront design.The operating mechanism housing shall be stainless steel with a viewing window for verification of contact position.The housing shall be painted ANSI 70 light gray using corrosion-resistant epoxy paint. Operating handles shall be padlockable and adaptable to keylock schemes.The operating shaft shall be stainless steel providing maximum corrosion resistance. A double “O” ring shaft seal shall be used for a leak resistant, long life seal.  

Load Break Switches - The load break switch shall consist of vacuum bottle(s) encapsulated within solid dielectric epoxy modules with spring-assisted operating mechanism. For three phase switches the mechanism shall consist of three vacuum bottles mechanically linked to a single, spring-assisted operating mechanism. The operating mechanism shall be actuated from outside the mechanism housing. 

Fault Interrupters - The fault interrupter shall consist of vacuum bottle(s) and internal current transformer(s) encapsulated within solid dielectric epoxy modules with spring-assisted operating mechanism. For three phase interrupters, the mechanism shall consist of three vacuum bottles mechanically linked to a single spring-assisted operating mechanism. Electrical opening shall be by a solenoid that is activated from an interrupter relay. Closing (reset) of the interrupter shall be mechanical with the use of an operating mechanism actuated from outside the mechanism housing.The mechanical linkage assembly shall provide for a “trip-free”operation which allows the fault interrupter to operate independent of the operating handle.

Fused Load Break Switches - The fused load break switch shall consist of a load break switch (described above) with provisions for elbow mounted encapsulated fuses. Parking stands shall be available as an accessory.An optional interlock shall be available to prevent access to the fuses unless the switch is open. Fuses shall be current limiting with epoxy insulation and an integral 600A elbow (T body) connector for connection to the switch.The load side of the fuse shall be either a 200A deepwell or 600A apparatus ANSI/IEEE 386 separable connector interface.

C. RATINGS AND STANDARDS
Load Break Switches:
Shall be designed and tested per applicable sections of ANSI C37.71-1987, ANSI C37.72-1987, and the latest version of IEC 60265 standards. Certified test reports shall be provided.The switch shall be rated: (select column)

Maximum design voltage, kV
15.5
27.0
38.0*
Impulse level (BIL), kV
110
125
150
Continuous & load break current, A
630
630
630
One minute withstand (dry), AC kV Production test rating
34
40
50
15 minute withstand, DC kV
53
78
103
Momentary current, kA, ASYM
20
20
20
Fault-close current, kA, ASYM
20
20
20
One second current, kA, SYM
12.5
12.5
12.5
Mechanical endurance, operations
2000
2000
2000

* 27kV max. for multi-way switches.

Fault Interrupters:
Shall be designed and tested per applicable sections of ANSI C37.71-1987, C37.72-1987 and ANSI C37.60-1981 and the latest version of IEC 60265.The fault interrupter shall be rated: (select column)

Maximum design voltage, kV 15.5 27.0 38.0*
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
Symmetrical interrupting rating, kA 12.5** 12.5 12.5
Asym. interrupting rating, kA 20 20 20

* 27kV max. for multi-way switches.
** 16kA available.

Fuses:
Fuses are designed and tested to IEEE 386 and IEEE 592 standards.The fuses shall be rated: (select column)

Nominal Voltage, kV Gnd-Y

8.7/15

15/25

BIL Impulse, kV

95

125

Continuous Current, A

10-140

10-125

One Minute AC Withstand, kV

34

40

Fifteen Minute DC Withstand, kV

53

78

Interrupting, A rms sym.

50k

50k

D. ANSI C37.60 FAULT INTERRUPTING DUTY

15-20% 2,000 44
45-55% 6,000 56
90-100% 12,000 16

Total Number of Fault Interruptions: 116

E. BUSHINGS
E1. Two-Way (using one module):Bushings shall be integral to the switch module and designed and tested to ANSI/IEEE 386. Bushings shall be (check one bushing type for each location):

   Closest to operating mechanism:
     __ 600A            __200A

   Away from operating mechanism:
      __600A            __ 200A

Note: For fused switches, one 600A bushing is required to interface with the elbow mounted encapsulated fuses.

E2. Multi-way (two through six modules):Bushings shall be designed and tested to ANSI/IEEE 386. Bushings shall be one or more of the following (check one or both):

    __ 600A           __ 200A

F. FAULT INTERRUPTER RELAY
For fault interrupters, a relay shall monitor the current on each phase using the integral encapsulated current transformer(s).The relay shall compare currents on each phase of the load circuits with pre-selected time current curves and cause the fault interrupters to interrupt the current at the appropriate time.The relay shall be powered from the current transformers molded into the epoxy encapsulation.No external power source shall be required for protection.  

G. PADMOUNT ENCLOSURE (if applicable)
Enclosures shall be made of 12 gauge mild or stainless steel and manufactured to ANSI C37.72 and C57.12.28 standards.The enclosure shall be mounted independently to allow for easy removal for cable installation or future replacement. Enclosures shall be tamper-resistant incorporating hinged access door(s) with pentahead locking bolt(s) 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
Each assembly shall undergo a mechanical operations check, a one minute phase-to-phase, phase-to-ground and across the open contact AC hi-pot test. Circuit resistance shall be checked on all ways.Each module shall undergo an X-ray inspection and a partial discharge test to ensure void-free construction.

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

1) Welded stainless steel mechanism housing painted light gray with stainless steel and brass fasteners.

2) Lifting provisions.

3) Corrosion-resistant nameplates and line diagram.

4) Switch operating mechanism(s) with padlock provision and single keylock provision.

5) Mounting provisions.

6) Ground provisions (1/2-13 threaded boss).

7) For padmount switches:Padmount enclosure (see section G).

J. OPTIONS (included in catalog number) (check all that apply)
The following options shall be supplied:

 __ Auxiliary contacts installed on spring operating mechanism.

 __ Stationary mounted motor actuator with auxiliary contacts installed on spring operating mechanism.     

 __ Single way, stationary motor control.

 __ Multi-way, stationary motor control (not available on two way switches).

 __ Type 1 interrupter relay.

 __ Type 2 interrupter relay.

 __ Type 3 interrupter relay.

 __ Type 4 interrupter relay.

 __ Provision for Type 5 interrupter relay. 

  __ Type 6 interrupter relay.

  __ Type 7 interrupter relay.

K. ACCESSORIES (additional items) (check all that apply)
The following accessories shall be supplied:

 __ 4/0 brass ground lug(s).

  __ Portable motor control.

  __ Remote terminal units.

 __ Junction box for connection of remote power/remote trip or auxiliary contacts.

 __ Digital voltage sensors.

  __ Galvanized frame (24” high bushing height) 

  __ Laptop programming kit for Types 3, 4 and 7 relays.

 __ Parking stands for each phase.

 __ Type 5 oil fuse cutout interrupter relay.

 __ Removable operating handle.

 

 
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