NFPA Journal - January/February 2020 - 41

CODES, STANDARDS
AND COMPLIANCE

for protection of all ESS, but currently
focuses on battery installations, which
are typically an arrangement of tightly
packed cells placed in modules that
are stacked vertically in racks. Since
these systems often consist of multiple
racks, a main objective of the standard
is to make sure, if a fire occurs, that it
is contained to a single rack. If the fire
is able to propagate from one rack to
the next, it could last for a considerable
length of time, potentially overwhelming the sprinkler system or taxing the
water supply.
To mitigate this risk, one of the
objectives of an ESS fire protection
system should be to contain the fire
to the rack of fire origin through the

installation of a sprinkler system and
the spacing of ESS groups. NFPA 855
addresses this by requiring that ESS
be protected by a sprinkler system
installed per NFPA 13, Standard for the
Installation of Sprinkler Systems, and
provides a specific design density and
design area. NFPA 855 also requires
ESS to be grouped into small segments
and spaced apart to prevent large and
lengthy fire events. One exemption to
the sprinkler and spacing requirements
in NFPA 855 is to allow for the use of
alternate means of fire protection and
spacing as long as it is proven to be
effective based on fire testing done in
accordance UL 9540A, Test Method for
Evaluating Thermal Runaway Fire
Propagation in Battery Energy Storage
Systems. This is allowed because there
is currently a lack of large-scale fire
test data; encouraging additional testing can help us understand the hazard
better and protect installations more
appropriately.
An example of determining protection requirements through testing is
illustrated in a recent Fire Protection
Research Foundation report, available
at nfpa.org/esssprinkler, which looks
at large-scale fire and sprinkler testing
for two different chemistries of lithiumion batteries in an ESS arrangement.
The main takeaways from the testing
are that the two chemistries had vastly
different heat release rates, and as a
result require different recommended
protection schemes. This highlights the
need for individual testing since the
chemistry and battery layout can alter
the amount of water and spacing that
would prevent an ESS fire from spreading to adjacent modules.
Ultimately, while NFPA 855 addresses
questions of how to protect ESS installations, the technology is evolving
rapidly, and additional testing will be
necessary to ensure that codes and
standards provide the optimal level of
safety for all stakeholders.
Brian O'Connor is a fire protection engineer at
NFPA. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA 13
at nfpa.org/13.

NFPA 101

Life safety in new
and existing structures

Stairwell and exit
enclosure penetrations,
and the balance between
security and life safety
By Jennifer Sisco
hile security measures

W

and life safety features
share the same goal of
protecting building occupants, the means to
achieve these forms of protection can
sometimes conflict. A number of provisions were added to the current edition
of NFPA 101®, Life Safety Code®, that
seek to strike a balance between security and life safety.
One issue that has become more
common is the need to allow wall
penetrations to accommodate the
installation of devices such as cameras
and card readers. While these are
important security features in a wide
variety of buildings, the presence of
penetrations through fire resistance
rated construction can theoretically
compromise the level of fire safety in
a structure. That's why the current
edition of NFPA 101 has addressed the
issue in the form of a provision permitting penetrations made for security
or communications systems, in metal
conduit, located in exit stairways and
other exit enclosures.
Recent events worldwide have
resulted in a heightened awareness
of the need for security-having accurate and timely information, such as
security camera footage, can be critical
in an emergency. Last year, a middle
school principal in Indiana was credited with saving the lives of students
and police during an active shooter
incident at his school after providing
911 dispatchers with live updates on
the shooter's location-updates based
N F PA . O R G / J O U R N A L * NFPA JOURNAL

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NFPA Journal - January/February 2020

Table of Contents for the Digital Edition of NFPA Journal - January/February 2020
