GE Industrial Solutions Spectra RMS Molded Case - Manual (Page 13)

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GEH-702 Users Manual
All Spectra circuit breakers use the same auxiliary
switches, which are installed in the breaker’s right-
hand accessory compartment. Group mounted
Spectra breakers with an auxiliary switch that connects
to a junction box require a 1 “X” filler plate adjacent
to the breaker’s right-hand side to accommodate the
auxiliary switch wiring.
Communications
The Spectra microEntelliGuard TM breaker is available
with Modbus communications, which allows connection
to an external Modbus network and monitoring
platform. Connection to the network requires the
appropriate terminal board or junction box. Proper
operation of the circuit breaker’s protective functions is
not dependent on the communications network.
Spectra microEntelliGuard TM breakers are compatible
with EnerVista Viewpoint power system software
allowing for remote monitoring and control of the
breaker. Viewpoint Monitoring automatically detects
Spectra microEntelliGuard
TM breakers, generates
custom tailored monitoring screens, monitors power
quantities in real time (current, voltage, VARs, etc.), and
identifies the status of protected assets.
Reduced Energy Let-Through
Reduced energy let-through, or RELT, is an advanced
protective function that allows the trip unit to have
an alternate instantaneous pickup value. This
feature is intended to allow the user to set a lower
instantaneous pickup level and reduce the amount of
breaker let-through energy in the event of a fault . Trip
units optioned with the RELT function require either a
terminal board or junction box in order to wire the RELT
input and output signals. The RELT switch is enabled
via a 24V (AC or DC) signal across the input contacts or
via the Modbus communications network. This signal
can be derived from the power supply plate assembly
or it can be from a separate source. Trip units optioned
with the RELT function have dedicated input and output
contacts. The output contacts change state when the
RELT function is enabled. The output contacts are rated
1 amp, 60 Vac/Vdc. A RELT kit (catalog number GTURSK)
is available that provides an illuminated 3-position
selector switch allowing the user to select between
NORMAL, TEST, and ON positions. A typical wiring
diagram for the RELT connections is shown in Figure 3.
Figure 3. Typical RELT Wiring Diagram
Caution: Setting the RELT instantaneous pickup value
greater than the standard instantaneous pickup
value will result in higher breaker let-through energy
in the event of a fault . The factory default setting for
RELT instantaneous is 1.5 x sensor rating which is the
minimum setting value.
Zone Selective Interlock
Zone Selective Interlocking, or ZSI, is an advanced
protective function that allows one ZSI enabled trip
unit to communicate with another ZSI enabled trip
unit . The microEntelliGuard
TM trip unit is available
with ZSI signaling on the short time, ground fault,
and instantaneous functions. In the event of an
overcurrent pickup condition, the downstream ZSI trip
unit signals the upstream ZSI trip unit to temporarily
change the affected pickup settings to values that
allow the downstream trip unit/breaker to respond to
the overcurrent condition (and the upstream breaker to
remain closed and continue to service other loads).
Trip units optioned with the ZSI function require either
a terminal board or junction box in order to wire the
ZSI input and output signals and +24Vdc control power.
A ZSI module (catalog number TIM1) is available that
allows multiple ZSI enabled trip units to communicate
with one another for optimal system selectivity.