NFPA Journal - Fall 2022 - 53

In Compliance
safety without altering any other
requirements is flawed and risky.
Jurisdictions need to rethink their
desire to amend a key component of
building fire protection and life safety
at the local level rather than through
the proven codes and standards development
process-the process that
created the Life Safety Code in the first
place. These kinds of changes need to
be proposed, evaluated, and ultimately
decided by the consensus process so
that additional building modifications
necessary for single-exit design can also
be considered. Through the consensus
code development process, we can
maintain the minimum level of safety
we have come to expect.
Valerie Ziavras is technical services engineer
at NFPA. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA
101 at nfpa.org/101. To follow the progress on the
upcoming edition of the code, visit
nfpa.org/101next.
types of comments from viewers who
may not understand how fire protection
and life safety systems operate.
The comment I saw the most was,
" Why isn't the fire alarm going off if
there is a fire? "
The answer is that the store's fire
alarm system might not have been
required to provide occupant notification
based on sprinkler actuation.
NFPA 72 permits up to a 100-second
delay between sprinkler waterflow and
occupant notification; it is likely that
the fire alarm did in fact notify the
occupants in that video, with notification
occurring after a delay of not more
than 100 seconds. It's possible the video
was taken before that delay was over.
The allowance for a 100-second delay
NFPA 72
Fire alarms, signaling,
and emergency communications
The time delay between
sprinkler actuation and
fire alarm notification
By Shawn Mahoney
I
n recent months,
fires have occurred in
mercantile occupancies
that have raised questions
on the timing of
sprinkler actuation and fire alarm
notification, a fundamental aspect of
NFPA 72®
Signaling Code®
, National Fire Alarm and
.
One example was captured in a
video-shot on a smart phone and
widely shared on social media-of a fire
that started in a retail store. The video
was taken by an occupant inside the
building prior to egressing and shows
sprinklers operating and controlling
the fire. The video was shared among
multiple social media platforms, and
everywhere I saw it I noticed the same
before the actuation of alarm notification
appliances is broken down into
two requirements. The first requirement
is related to the waterflow
initiating device and found in Section
17.13 of NFPA 72. Subsection 17.13.2
requires that the waterflow initiating
device activate within 90 seconds after
a flow occurs that is equal to or greater
than the flow from a single sprinkler of
the smallest orifice size. The 90-second
allowance exists to reduce the number
of nuisance alarms caused by water
flow that can occur from pressure
surges in the water supply system. The
delay provides added assurance that
the water flow in the sprinkler piping
is in fact sustained flow from a sprinkler,
and not just the result in a change
in pressure. This delay can be created
within the flow switch itself, or it can
be accomplished with the use of a
retarding device such as a retard chamber
when using a pressure switch.
The second part of this delay is
found in subsection 10.11.1. This section
requires that the actuation of alarm
notification appliances at the protected
premises occurs within 10 seconds after
the activation of the initiating device.
This requirement exists to ensure that
the operation of the notification appliances
occurs within a timely manner
after a fire has been detected. Between
those two requirements in subsections
17.13.2 and 10.11.1, NFPA 72 permits
up to a 100-second delay between the
initial waterflow from a sprinkler and
the actuation of the notification appliances
within the building.
In addition to this allowance
intended to reduce the number of
nuisance alarms, allowances exist to
delay the actuation of notification
appliances for other initiating devices
with the use of a presignal feature or
positive alarm sequence, though both
of these require a detailed response
plan and approval from the authority
having jurisdiction.
The next time someone asks you a
question about the timing of sprinkler
waterflow and fire alarm notification,
remember that NFPA 72 permits
the delay in the actuation of fire alarm
notification appliances. This timing is
engineered into the operation of the
systems, and it exists to ensure that they
function as effectively as possible.
Shawn Mahoney, P.E., is a technical services
engineer 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 25
ITM for water-based fire
protection systems
Automated testing
and inspection of
sprinkler systems
By Jonathan Hart
A
few years ago, remote
inspections and automated
testing were
trends that had been
gaining momentum in
codes and standards and field application.
Then, in the first half of 2020,
when the COVID-19 pandemic was in its
early stages and strict lockdowns were
being enforced, these practices took off,
propelled by the obvious possibilities
they held for the safety community. The
development of a proposed new standard,
NFPA 915, Standard on Remote
Inspections, also continued during this
NFPA .ORG/JOURNAL * NFPA JOURNAL | 53
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NFPA Journal - Fall 2022

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