S&C ELECTRIC COMPANY
INSTRUCTION SHEET
663-503
Page 1 of 35
August 14, 1995
Supersedes Instruction Sheet 663-503 dated 9-20-93
c
1995
s
S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT
®
Control
Outdoor Distribution (14.4 kv and 25 kv)
Section
Page Number
INTRODUCTION
Qualified Persons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
SAFETY INFORMATION
Understanding Safety-Alert Messages . . . . . . . . . . . . . . . . . . . . 3
Following Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Replacement Instructions and Labels . . . . . . . . . . . . . . . . . . . . 3
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
OPERATING DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MINI-RUPTER SWITCHES
Decoupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Automatic Switch Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Nonautomatic Switch Operation . . . . . . . . . . . . . . . . . . . . . . . . 11
Charging Operator (Nonelectrical) . . . . . . . . . . . . . . . . . . . . . . 11
Front Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
FUSING
Assembling the Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Installing the Fuse in the Mounting. . . . . . . . . . . . . . . . . . . . . . 15
Warranty Qualifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
SWITCHING WITH UNI-RUPTER
Installing and Closing the Fuse . . . . . . . . . . . . . . . . . . . . . . . . . 16
A Note on Single-Pole Switching . . . . . . . . . . . . . . . . . . . . . . . . 20
Opening and Removing the Fuse. . . . . . . . . . . . . . . . . . . . . . . . 20
INSTRUCTIONS
For Operation
Section
Page Number
RE-FUSING
How to Detect and Replace a Blown Fuse . . . . . . . . . . . . . . . . 23
Installing the Fuse in the Mounting. . . . . . . . . . . . . . . . . . . . . . 24
FINAL CHECKS BEFORE WALKING AWAY. . . . . . . . . . . . . . . . 25
IF OPERATOR STALLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
MAINTENANCE
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Returning Equipment to Service . . . . . . . . . . . . . . . . . . . . . . . . 28
Enclosure Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
APPENDIX A
Preliminary Tryout Before Gear Is Energized—Optional . . . 29
APPENDIX B
Dielectric Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
APPENDIX C
Ratings for S&C Mini-Rupter Switches. . . . . . . . . . . . . . . . . . . 29
Ratings for S&C Power Fuses with Uni-Rupter. . . . . . . . . . . . 30
APPENDIX D
Optional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
APPENDIX E
Current-Limiting Fuses for Use in
S&C PMH Pad-Mounted Gear . . . . . . . . . . . . . . . . . . . . . . . . . 34
TABLE OF CONTENTS
This publication contains instructions for operation of fuses and Mini-Rupter
®
Switches in S&C
Source-Transfer PMH Pad-Mounted Gear. For instructions regarding field programming and
operation of the S&C Micro-AT Source-Transfer Control, refer to S&C Instruction Sheet 515-500.
For operating instructions regarding the optional test-panel feature (Catalog Number Suffix “-Y5”),
if furnished, refer to S&C Instruction Sheet 515-505.
