is activated all alarm sounders shall operate.] Power shall be 120 VAC,
obtained from a connection to a lighting circuit serving the room or suite
of rooms where the detector is located. Do not obtain power for detectors
in more than one room (or suite of rooms) from the same circuit. Connect
to the line side of all switches except the overcurrent device protecting
the circuit. Detector shall not be susceptible to loss of power by
tripping of a Ground Fault Circuit Interrupter (GFCI). Provide detectors
with 9-volt alkaline standby battery. Locate and install detector in
accordance with NFPA 72.
2.2.5
Duct Smoke Detectors
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NOTE: Shutdown of mechanical (HVAC) systems must be
carefully coordinated between this section and
mechanical sections. The designer must choose
whether to shut down all HVAC systems upon operation
of the alarm system or to shut down individual HVAC
units separately when smoke is detected in each
unit's ductwork. Shutdown of all HVAC systems upon
any alarm is desirable from a life safety
standpoint, but may not be practical in all cases.
Consult with the EFD/EFA Fire Protection Engineer
for guidance. To shut down all HVAC units from the
fire alarm control panel retain the reference to
HVAC equipment shutdown in paragraph titled
"Operation" and delete reference to shutdown in
paragraph titled "Duct Smoke Detectors". If it is
desired to shutdown systems on an individual unit
basis, delete the reference to HVAC equipment
shutdown in paragraph titled "Operation", and retain
the reference to shutdown in paragraph titled "Duct
Smoke Detectors".
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**************************************************************************
NOTE: Choose the type of smoke detector best suited
for application or design. Specify duct smoke
detectors as required by NFPA 90A. Specify separate
zones for duct detectors under paragraph titled
"Initiating Zones".
**************************************************************************
Provide detectors installed in ducts of the [ionization] [or]
[photoelectric] type and listed by UL or FM for duct installation. Control
and power modules required for operation shall be integral with the main
control panel. Detectors and associated modules shall be compatible with
the main control panel and shall be suitable for use in a supervised
circuit. Detector circuits shall be of the 4-wire type whereby the
detector operating power is transmitted over conductors separate from the
initiating circuit. Malfunction of the electrical circuits to the detector
or its control or power modules shall cause operation of the system trouble
signals. Provide a separate, fused power circuit for each smoke detection
initiating circuit (zone). Failure of the power circuit shall be indicated
as a trouble condition on the corresponding initiating circuit. Provide
duct detectors in accordance with NFPA 90A. Provide duct detectors with an
approved duct housing, mounted exterior to the duct, with perforated
sampling tubes extending across the width of the duct. Activation of duct
detectors shall cause [shutdown of the associated air handling unit,]
SECTION 13852N
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