GE Industrial Solutions Entellisys Low Voltage Switchgear - Manuel (Page 12)

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3-3 Front Compartment Area
The front enclosure of each section is divided into individual
compartments. These compartments typically house EntelliGuard E
low-voltage power circuit breakers or Entellisys instrumentation.
3-4 EntelliGuard Messenger
An EntelliGuard Messenger is mounted above each EntelliGuard E
breaker. The Messenger provides an interface between the breaker,
the compartment, and the central Entellisys system. See DEH-501
(Entellisys Low Voltage Switchgear System User’s Manual) for further
instructions.
Each Entellisys low voltage switchgear lineup contains standard
devices housed within the instrument compartments. Two CPUs
(Central Processing Units) provide the processing capability to
support all switchgear functions. At least one HMI (Human-Machine
Interface) provides user access to the Entellisys system. Network
switches provide communication links between the CPU, the HMI,
the EntelliGuard Messengers, and the external world. A pair of
uninterruptible power supplies (UPSs) and control power throwover
relays supply highly reliable control power to these system devices.
Fig. 3-3 EntelliGuard Messenger
3-5 Breaker Compartment
Closed-door drawout circuit breaker compartments, Fig. 3-4, are
standard construction with all Entellisys switchgear equipment. The
circuit breaker compartment doors remain closed and latched while
the breaker is racked out from the CONNECTED position, through
TEST, to the DISCONNECTED position.
Breaker compartment doors do not have any ventilation slots, thus
protecting operators from hot ionized gases which may be vented by
the breaker during circuit interruption. Additionally, the breaker
compartment, Fig. 3-5, is enclosed by grounded steel barriers on the
top, sides, bottom, and front. In the back, a flame-retardant, track
resistant, glass-filled polyester base minimizes the possibility of fault
communication between compartments or to the bus.