Siemens 8BT2 Installation And Operating Instructions Manual page 77

Fig83. Steps to plug the low voltage connector into the circuit breaker's socket.
Fig84. The mechanical interlock between the low voltage connector and the high voltage door.
There is also the mechanical interlock between the low voltage connector and the high voltage
compartment door. If the connector is not plugged in, the door can not be closed. So, the
operation can not be started (Please see the photo in fig84).
Plug coding Although the circuit breaker's physical dimensions in the switchgear are same, the technical
parameters may be different. For example, in spite of the fact that the nominal current ratings
are different (1250A, 2000A or 2500A), the circuit breaker (rated 1250A) can be put into the
panel rated 2000A.
According to the technical differences, the coding system is applied on plug (Please see photos
in fig85 and 86).
Socket
Circuit breaker
Fig85. View of the socket on the circuit breaker
Pin-socket
Pin-socket
Fig86. View of different coded sockets
The pin-socket combination can let the right circuit breaker put into the related panel. So,
881-4027.9 * INSTALLATION AND OPERATING INSTRUCTIONS 8BT2 * Revision 04 77