Mechanical Interlocking Three Sources (Open Transition To Standby System) - Siemens UL 489 Operating Instructions Manual

19.1.5 Mechanical interlocking three sources (open transition to standby system)

The standby system is mechanically interlocked with the two source circuit breakers to prevent paralleling the standby system with either or
both primary source(s).
Example
S
S
S
1
3
2
Description:
Two circuit breakers (S , S ) can be independently opened and closed, the third (S
1 3
If the third is closed, the other two cannot be closed.

Materials required:
Each circuit breaker has an interlocking module and a Bowden cable. A Bowden cable must be ordered separately.
 (page 19-6)
Order no.
Connections of Bowden cables:
1st Bowden cable: S A
1
2nd Bowden cable: S A
2
3rd Bowden cable: S A
2
4th Bowden cable: S A
3
19 – 6
Possible circuit breaker states
S
1
- S E
1 2 1
- S E
1 1 1
- S E
2 3 1
- S E
1 2 2
S
2
) being "Ready-to-close" only if the other two are open.
2
S
3