• Zone-selective interlocking with
downstream branch circuit breakers in the switchgear eliminates
the need for the maintenance
selector switch. Arc flash energies
can be permanently reduced with
Solution Group 2: Remove
Workers From Harm’s Way
De-energizing equipment does not
absolve the facility from the responsibility of performing an arc flash analysis or
providing the necessary personal protective equipment (PPE). The following arc
flash mitigation solutions remove a worker from the location of, or place a barrier
between, the workers and exposed energized parts.
Infrared Viewing Windows: Having infrared (IR) windows installed in electrical equipment panels enables IR
scans to be performed without exposing the worker to hazardous energy. Transparent to infrared rays, IR windows
allow hot spots to be registered by a thermographic camera.
They also facilitate permanent access for inspection of
electrical components without disturbing operations.
Online Temperature Monitoring: Online temperature
monitoring, via wireless sensors installed during a planned
outage, provides continual access to critical connection
points, where traditional thermography cannot be used. This
technology evaluates the equipment’s current condition
without exposing workers to energized
parts, since equipment covers do not have
to be removed.
Remote Racking System: A remote
racking system (RRS) allows circuit
breaker racking operations to be performed via a control panel located away
from the cell, removing the operator from
manual contact with the circuit breaker. If
the operator controlling the RRS is located
outside the arc flash boundary, the need
for PPE is eliminated.
Electrical hazards are a significant safe-
ty and financial risk for electrical workers
and their employers. OSHA mandates
that work on electrical equipment must be performed in a
manner that does not expose the worker to undue risk of
injury. Complying with the safe work practices dictated by
NFPA 70E and implementing arc flash mitigation strategies
through engineering controls will enhance workplace safety for
employees and reduce the financial risk for your company.
Antony Parsons, Ph.D., P.E. is a technical consultant in
Schneider Electric’s Power Systems Engineering group.
He is responsible for providing power system analysis,
troubleshooting and design consulting services for
Schneider Electric’s customers, as well as engineering
support for Schneider Electric’s field services operations.