NFPA Journal - Spring 2021 - 39

With buildings constantly changing and the ease with which modern
fire alarm systems can be modified,
the need for this reacceptance testing
is common. While routine inspection,
testing, and maintenance should catch
issues that arise and need to still be
performed in accordance with the rest
of Chapter 14 of NFPA 72, the correct
operation needs to be confirmed at the
time the changes are made, and that is
what the short but important requirements on reacceptance testing are
meant to accomplish.
Jonathan R. Hart, P.E. is technical lead, fire
protection engineering, at NFPA. NFPA members
and AHJs can use the Technical Questions tab to
post queries on NFPA 72 at nfpa.org/72. To follow
the progress on the upcoming edition of the code,
visit nfpa.org/72next

NFPA 70 + 70E

Electrical Safety

Understanding the what,
when, and why about NEC
listing requirements
By Derek Vigstol
oes electrical equip-

D

ment need to be listed?
This is a question that
stakeholders have
approached NFPA with
recently, and it's one that comes up on
a regular basis. In today's world, where
communication is dominated by social
media and online forum discussions,
people are having an increasingly difficult time determining what is required
to be listed and what is not.
Specifically, the most common bit
of misinformation floating around
online is that everything must be listed
to be installed. There have also been
statements made about how listed
equipment can be used in all sorts of
ways, based on the assumption that a
listed product is a safe product.
At the heart of these misconceptions
exists an important question: What
does it really mean for something to be
" listed " ?

Article 100 of NFPA 70®, National
Electrical Code® (NEC®), defines listing as " equipment, materials, or
services included in a list published by
an organization that is acceptable to
the authority having jurisdiction and
concerned with evaluation of products
or services, that maintains periodic
inspection of production of listed
equipment or materials or periodic
evaluation of services, and whose listing states that either the equipment,
material, or service meets appropriate designated standards or has been
tested and found suitable for a specified purpose. "
In other words, this equipment
has been evaluated by a third-party
agency that the AHJ trusts, and has
been stamped as being able to safely
do what the product is supposed to do.
This third-party then publishes a list
that includes the product in question,
and the AHJ can use this information
to help decide whether to approve an
installation.
This is beneficial in several ways
when it comes to electrical installations. Listing lets the AHJ know that
the product meets the applicable
industry consensus product standard, or that the evaluation body has
physically taken the product, or a
representative sample, and tested it
to make sure it is safe to use as advertised. This is what makes section
110.3(B) so important. This section
requires that listed equipment be
installed and used in accordance with
the instructions provided with the listing. One example of where this comes
into play is in wiring method fittings.
A fitting, such as a coupling or connector, gets a listing from a third-party
organization because it performs as
advertised with the wiring method
system it is designed for. Using this
fitting with a different wiring method
type might physically work, but the
fittings have not been evaluated to
work with the other wiring method-
meaning it may or may not operate
safely. There is no way to know without testing it, and the AHJ can
no longer use the listing to judge
compliance.

Being listed to an industry consensus product standard also allows the
NEC to require that only products that
have met these standards be installed,
if a product is required to be listed.
In addition to the benefit for judging
compliance, this allows standardization of products across manufacturers.
Using the example of wiring methods,
if a particular method and its associated fittings are required to be listed,
then we know those components will
work together, regardless if the fittings
are from a different manufacturer as
the wiring method.
This can also be a safety measure,
and appliances are a great example.
Section 422.6 requires that any appliance with a supply of 50V or more be
listed if it is to be installed in a jurisdiction covered by the NEC. This keeps
these appliances built to basic standards that incorporate certain safety
requirements such as the type of
conductor insulation that can be used,
and ensuring there are important
grounding and bonding connections
in place. This becomes increasingly
important considering that many appliance installations are not necessarily
inspected by an AHJ-homeowners, for
example, are unlikely to pull a permit
and schedule an inspection when they
replace a range. Having the appliance
listed helps ensure that it will at least
be built to a given standard.
Although the NEC doesn't require
that all electrical equipment be listed,
it is important that we understand the
importance for why certain equipment
is required to be listed. Additionally,
it is important that we understand
the impact a listing has on how equipment can be installed and used. If the
equipment is intended to be listed,
the NEC will specifically state a listing
requirement. Understanding the what,
when, and why about NEC listing
requirements helps us comply with
important requirements for safety and
keeps our world protected from electrical hazards.
Derek Vigstol is an NFPA technical lead, Electrical
Tech Services. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA 70 at
nfpa.org/70. To follow the progress on the upcoming
edition of the code, visit nfpa.org/70next.

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NFPA Journal - Spring 2021

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