Siemens UL 489 - Mechanical Interlocking Source and Tie Circuit Breaker (Open Transition to Standby System)

19 – 7
19.1.6 Mechanical interlocking source and tie circuit breaker (open transition to standby system)
The standby system is mechanically interlocked with the tie circuit breaker to prevent paralleling with primary source.
Description:
One circuit breaker (S
1
) can be opened and closed independently of the two others. The two others cancel each other out, i.e. one can only
be closed if the other is open.

Materials required:
Two of the three circuit breakers (S
2
, S
3
) each have an interlocking module and a Bowden cable.
Order no.  (page 19-7)
Connections of Bowden cables:
Example Possible circuit breaker states
S
1
S
2
S
3
1st Bowden cable: S
2
A
1
- S
3
E
1
2nd Bowden cable: S
3
A
1
- S
2
E
1
S
1
S
2
S
3