GE Entellisys 4.0 Application Manual page 9

Entellisys Low-Voltage Switchgear
Section 4. Minimizing Potential Exposure to Arc Flash Energy
This section addresses the ownership and operation
of Entellisys low-voltage switchgear for maximum
reliability and minimal arc flash risk.
Low-voltage switchgear can be expected to have
a long life within the facility's electrical power
distribution system. It can reasonably be expected
that, during that time, the equipment will need to
be operated and maintained, even modified and
expanded. Entellisys provides significant advantages
over more traditional technology for owning, operat-
ing, and maintaining the equipment. This section
describes some of Entellisys's inherent capabilities
and how to use them to improve the ownership
experience. The specific capabilities include:
• Complete control, monitoring, setting capability and
performing routine Entellisys system maintenance
from a remote location, reducing the need to
have personnel near live electrical equipment.
• Remote racking device to allow racking in or out
of circuit breakers by operators well outside the
flash protection boundary
increased by eliminating the need to stand near
the gear while racking circuit breakers into or
out from a live bus.
• Fully selective fast protection to lower arc-flash
energy in case of an arcing fault within the
equipment. The protection is fast enough to lower
PPE requirements and decrease the arc flash
protection boundary while maintaining complete
system selectivity.
• Reduced Energy Let Through (RELT) mode enables
an operator to easily change the circuit breaker
settings to more sensitive levels, potentially
reducing the hazard risk category, prior to working
near the equipment.
• A family of fused circuit breakers provide current-
limiting fuse performance across all circuit breaker
frame sizes. Full current-limiting performance for
all circuit breaker sizes provides optimum protection
at high-fault values.
• Fully insulated and isolated bus to minimize
potential bus faults. Minimizing live conductive
surfaces reduces the probability of internal
equipment faults due to contamination or
mechanical damage.
• Fully compartmentalized circuit breakers to min-
imize arc fault transmission within the equipment.
Grounded separation panels between circuit
breakers and barriers between the front breaker
1
Flash protection boundary as defined in Article 130 of NFPA 70E, "Standard for Electrical Safety in the Workplace." The distance at which the
2
incident energy equals 5 J/cm (1.2cal. cm
clearing time is 0.1 seconds or faster.
1 . Operator safety is
2
) for situations where clearing time is longer that 0.1 seconds or 6.24 J/cm
cubicles and the rear bus and cable compartments
minimizes the probability of transmission of an
arcing fault from one equipment area to another.
• Circuit breakers use monitoring to drive need/
use-based maintenance scheduling versus periodic
time-based maintenance.
• Self diagnostic features provide notification that
a device needs to be evaluated or changed.
• Flexible system design easily accommodates
added or changed functionality. Entellisys makes
it easy to modify installed equipment as the load
requirements change.
Below are general descriptions of how Entellisys
low-voltage switchgear provides more efficient and
safer operation and maintenance of your electrical
equipment. The specifics of some of the capabilities
are covered in other sections of this publication.
Remote Control, Monitoring, and Metering
The Entellisys system architecture makes remote
monitoring and control easy. The user interface to
the system is typically via a touchscreen Human
Machine Interface (HMI).
The Entellisys touchscreen (HMI) may be mounted
directly on the switchgear lineup and/or as a Near
Gear HMI either in a freestanding equipment stack or
wall mounted box. Another option is the Entellisys Near
Gear Control stack where the HMI, CPUs and UPSs
are located. The Near Gear modules may be locat-
ed up to 300 cable feet away from the equipment.
The HMI software can also be loaded on a remote
computer connected to a local- or wide-area net-
work, providing additional remote access to the
equipment for monitoring or control.
All control and protection settings (other than
long-time pickup) are made via the HMI software.
All metering, status monitoring, event monitoring,
and even waveform data can be viewed through
the HMI. Furthermore, to confirm that the circuit
breaker being viewed in the HMI screen is the same
one being checked in the physical equipment , the
Entellisys Messenger includes a blue LED light that
can be switched on from the HMI software to verify
circuit breaker location. Keep in mind that the pro-
tection, metering and control is provided by the
redundant CPUs and is independent of the HMI.
2
(1.5cal/ cm
2
) where fault
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