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Interlock Application - Prevent Paralleling of Lines

Scheme # 16
To prevent paralleling of lines A, B, and C. Three loads, fed from any source (two tie-breakers).

Breaker A is closed to supply load M. Breaker B is closed to supply load N. Breaker C is closed to supply load P. Keys A-1, B-1, and C-1 are held in L-O interlocks of breakers A, B, and C. Tie-breakers D and E are locked open. Tie-breaker D interlock has a master or apartment lock and can be unlocked for operation with either keys A-1 or B-1. Tie-breaker E has a master or apartment lock and can be unlocked for operation with either keys B-1 or C-1.

To transfer load M from Breaker A to breaker B:

Reverse sequence to restore service through breaker A.

To transfer load M and N from breakers A and B to breaker C:

Reverse sequence to restore service (M and N through breakers A and B).

Any of the loads M, N, or P can be transferred from its own supply to any adjacent supply.

Scheme # 25
Scheme # 26
Scheme # 27 Scheme # 28
Scheme # 29
Scheme # 30
Scheme # 31
Scheme # 32
Scheme # 33 Scheme # 34
Scheme # 35
Scheme # 35A
Scheme # 36