January 20, 2020
© S&C Electric Company 1997-2020, all rights reserved
Instruction Sheet 681-510
Vista
®
Underground Distribution Switchgear
UnderCover™, Vault-Mounted, and Pad-Mounted Styles
Operation
Table of Contents
Section Page
Section Page
Introduction
Qualified Persons . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Read this Instruction Sheet . . . . . . . . . . . . . . . . . . . 2
Retain this Instruction Sheet. . . . . . . . . . . . . . . . . . . 2
Proper Application . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Safety Information
Understanding Safety-Alert Messages . . . . . . . . . . . 3
Following Safety Instructions . . . . . . . . . . . . . . . . . . 3
Replacement Instructions and Labels . . . . . . . . . . . 3
Location of Safety Labels . . . . . . . . . . . . . . . . . . . . . 4
Safety Precautions
. . . . . . . . . . . . . . . . . . . . . . . . . 5
Components
Overview of Components . . . . . . . . . . . . . . . . . . . . . 6
Understanding the Gas Pressure Gauge . . . . . . . . . 8
Gauge Needle Fluctuations from Rapid
Ambient Temperature Changes . . . . . . . . . . . . . . 8
Operation
Pre-Operation Checks . . . . . . . . . . . . . . . . . . . . . . . 9
Operating from Closed to Open Position . . . . . . . . .11
Operating from Open to Grounded Position . . . . . . .12
Operating from Grounded to Open Position . . . . . . .13
Operating from Open to Closed Position . . . . . . . . .14
Resetting a Fault Interrupter After
a Trip Operation . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Locking Out of Grounded Position . . . . . . . . . . . . . .16
Locking Out of the Closed Position . . . . . . . . . . . . .16
Locking In Closed, Open, or Grounded Position . . .16
Checking for Voltage Using Optional
VOLTAGE Indicator . . . . . . . . . . . . . . . . . . . . . . . .17
Low-Voltage Phasing Using Optional
VOLTAGE Indicator with Phasing . . . . . . . . . . . 20
Returning Equipment to Service . . . . . . . . . . . . . . . 22
Maintenance
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Enclosure Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Maintenance Recommendations in
Extremely Corrosive Environments . . . . . . . . . . . 24
Dielectric Testing
Routine Switchgear Testing . . . . . . . . . . . . . . . . . . 25
Cable Testing and Fault Locating . . . . . . . . . . . . . 25
Fault-Interrupter Testing . . . . . . . . . . . . . . . . . . . . . 26
Resistance Measurement . . . . . . . . . . . . . . . . . . . . 27
