Maintenance Technology May 2017 - 29

ELECTRICAL SAFETY

Available fault current is the amount
of current that may be present at any
point in the electrical system as a result
of a short or fault condition. If a fault
were to occur in the electrical system
as a result of equipment failure or
human error, the equipment affected
may not be rated to handle the fault
current and this could be catastrophic.
If an arc-flash risk assessment has
been performed, then the amount of
incident energy (typically expressed
in calories/cm2) must be observed
and personal-protective equipment
selected and put on before removing
equipment covers.
At this point, a decision must be
made, based on personnel risk, to open
or not open equipment and expose
energized conductors and circuit
parts. If it is determined that removing
equipment covers could expose
personnel to an unacceptable risk, the
equipment should be de-energized
before performing any type of preventive maintenance. An infrared scan
would be ineffective in this case.

Maintenance considerations
An effective preventive- and proactivemaintenance program should take
into consideration safety, the age of
the equipment, operating environment, and the criticality of the asset.
If infrared scanning is the only form
of preventive-maintenance approach
that's been employed, equipment reliability and safety have been compromised. That type of situation should
be of great concern to plant managers,
maintenance managers, technicians,
and other employees.
As outlined in NFPA 70B, several
available maintenance and testing
options are specific to the targeted
equipment. Take, for example, lowvoltage service-entrance equipment,
often referred to as switchgear. Some
of the maintenance recommendations outlined in NFPA 70B include
energized/de-energized inspection
and de-energized cleaning. While
the equipment is in a de-energized
state, all bolted connections and cable
MAY 2017

terminations should be torqued,
in accordance with manufacturer
specifications.
During de-energized maintenance,
molded-case/insulated case circuit
breakers should be exercised manually
to keep the contacts clean and help
the lubrication perform properly. This
simple maintenance procedure is often
overlooked, and breaker failure is a
common result. In addition, breaker
testing (primary and secondary
injection) and protective relay testing
are also recommended. These and
other factors must be considered when
determining what compliance means
and developing an electrical-safety
program that satisfies the OSHA and
NFPA requirements.
We've heard that, "an ounce of
prevention is worth a pound of cure."
This phrase should have significant
meaning when management is struggling with how to comply with the
latest regulations imposed by OSHA as
it relates to safety in the workplace.
Among the several elements that
make up an effective electrical-safety
program, electrical-equipment
maintenance is one that cannot be
ignored. When the decision is made
to have an arc-flash risk assessment
performed, consider the condition of
maintenance of the electrical equipment and the affect it will have on the
results of the risk assessment. This
will ensure that employees stay safe
and assure management that money
appropriated is well utilized. The result
of a well-administered electrical-safety
program will reduce life-safety risk, cut
business interruptions, and extend the
life of electrical equipment. MT
Jay Godfrey, CESCP, has more than 25
years of experience in the electricalcontracting industry and is a licensed
electrical contractor in Georgia. Godfrey
is OSHA trained, NFPA certified
and, for the past eight years, has been
working as a preventive-maintenance
and electrical-safety consultant
with Craft Electric & Maintenance
(craftelectricinc.com), Atlanta.

Maximize Uptime
and Enhance
Plant Safety



DAMAGED BELLOWS
OR WAY COVERS?

OPEN MACHINE PIT
CREATING A HAZARD?

BALL SCREW WORN-OUT
AND LOSING PRECISION?

We Can Help!
View Solutions @
Dynatect.com/MRO
* Replacement Bellows
* Telescopic Cover Repair
* Walk-on Roll-Up Pit Cover
* Ball Screw Repair/Rebuild

Global Leader in Protection for
Equipment and People
800-298-2066
sales@dynatect.com
MAINTENANCETECHNOLOGY.COM | 29

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Table of Contents for the Digital Edition of Maintenance Technology May 2017