Communication-capable Circuit Breakers
Breaker Status Sensor (BSS)
BSS stands for “breaker status
sensor.” All microswitches that
contain information on the state
of the circuit breaker are either
installed directly to the BSS or
connected to it. The BSS makes
this digital information available
on the
Cubicle
BUS
.
If the status of the circuit breaker
in the switchgear is to be displayed
or read via communications, the
BSS module and the appropriate
signaling switch must be installed
(if they are not already). The circuit
breaker must be installed with an
electronic trip unit of type ETU745
or higher.
The BSS can also be field installed.
The BSS indicates the following
information:
• Closing spring
(charged/discharged)
• Position of the main contacts
(open/closed)
• Ready-to-close signal
• Bell Alarm switch on the trip unit
(connected to the red mechanical
trip indicator)
• Signaling switch on the first
shunt trip
• Signaling switch on the second
shunt trip
The BSS is included when you order
the communications option with
with the assembled circuit breaker.
If a BSS is required without
communication (e.g. for operating
the BDA), it can be ordered
separately.
2/12
WL Circuit Breaker
This picture shows the BSS signaling contacts and how they have to be connected.
The BSS is factory installed when the communications option is ordered with the
assembled breaker.
Figure
2-3
WL PROFIBUS Communication and Electronic Accessories • July 2004
