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Contents
| Introduction
| Symbols
Legend | Scheme
Book
Interlock Application
- Grounding Switch and Main Switch
Scheme # 4
To
prevent closing of grounding switch B when main switch
A is closed, and vice versa.

Main
switch A shown closed and grounding switch B shown open.
Key A-1 is held in main switch interlock.
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|
1.
2.
3.
4.
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Open main switch A.
Turn key A-1 in L-O interlock on main switch A to
lock open. Key A-1 is now free.
Insert Key A-1 in L-O interlock on grounding switch
B and turn to unlock. Key A-1 is now held.
Close grounding switch B. |
Reverse
sequence to restore service. |