Outdoor Air Switches

Selection on Basis of Insulation Level

Table 1 - Insulators

Available Insulators c Post

Ratings, kV

Insulator Technical Reference Number

Notes:

Post

Bolt Circle

Maximum Design

Nominal

BIL

For complete mechanical and electrical characteristics, contact the nearest sales representative.

Standard Strength

High Strength

3"

5"

8.3

7.2

95

202 205 208 210 214 216 286 288 291 304 312 324

222 225 227 231 267 278 287 289 295 308 316 368

8 8 8 8 8 8 8 8 8

8 8 8 8 8 8 8 8 8 8 8

15.5

14.4

110 150 200 250 350 550 650 750 900

27 38

23

d Technical Reference numbers not assigned by NEMA.

34.5

48.3 72.5 123 145 170 245 245 362 550 550 800

46 69

115 138 161 230 230 345 500 500 765

e Not available

e

1050 1300 1550 1800 2050

e e

d d e e

Switch open gap dimensions are selected to provide voltage withstand characteristics that exceed line-to-ground voltage withstand characteristics in order to protect personnel and equipment.

TABLE OF CONTENTS

PAGE

Table 2 - Switch Open Gaps

SELECTION AND APPLICATION Insulator Cantilever Strengths . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Insulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Switch Open Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Ground Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Phase Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Switch Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 INTERRUPTER ATTACHMENTS Arcing Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Arc Restrictor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Vacuum Interrupter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Summary of Devices and Ratings . . . . . . . . . . . . . . . . . . . . . . . 7 SWITCH OPERATING MECHANISMS MO-10 Motor Operator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10 Swing Handle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Worm Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Three-Pole Torsional Control . . . . . . . . . . . . . . . . . . . . . . . . . . .11 ACCESSORIES Grounding Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Cable Guides. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Auxiliary Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 EHV Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Min. (inches) Metal-to-Metal

Ratings, kV

Double Break One End

Single Break

Maximum Design

Nominal

BIL

8.3

7.2

95

7

NA NA NA

15.5

14.4

110 150 200 250 350 550 650 750 900

10 12 18 22 32 50 60 68 84

27 38

23

34.5

12 15 22 32 38 44 50 57 57 66

48.3 72.5 123 145 170 245 245 362 362

46 69

115 138 161 230 230 345 345

1050 1050 1300

104 104 120

Above 362 kV maximum design, switch open gap dimensions are dictated by expected maximum switching surge voltage levels.

2