panel and 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. 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. [As an
alternate, detector circuits of the 2-wire type whereby the detector
operating power is transmitted over the initiating circuit are permitted,
provided the detectors used are approved by the control panel manufacturer
for use with the control panel provided and are UL listed or FM approved as
being compatible with the control panel (copies of the UL or FM listings
showing compatibility shall be submitted). When 2-wire smoke detectorsare
used, the total number of detectors on any detection circuit shall not
exceed 80 percent of the maximum number of detectors allowed by the control
panel manufacturer for that circuit and the standby current draw of the
entire system shall not exceed 80 percent of the rated output of the system
power supply module(s). Provide additional zones above those specified in
the paragraph entitled "Initiating Zones" if required to meet the above
requirements. Calculations showing compliance with the power consumption
limitation requirements specified above shall be submitted with the
calculations required by the paragraph entitled "Design Data." The data
submitted under the paragraph entitled "Test Reports" shall clearly
indicate the compatibility of the detectors with the control panel provided
and the maximum number of detectors permitted per zone.] Malfunction of
the electrical circuits to the detector or its control or power units shall
result in the operation of the system trouble signals. Equip each detector
with a visible indicator lamp that flashes when the detector is in the
normal standby mode and glows continuously when the detector is activated.
[Provide remote indicator lamps for each detector that is concealed from
view.] Provide plug-in type detectors with tab-lock or twist-lock, quick
disconnect head and separate base in which the detector base contains screw
terminals for making all wiring connections. Detector head shall be
removable from its base without disconnecting any wires. Removal of
detector head from its base shall cause activation of system trouble
signals. Provide each detector with an integral screen to prevent entrance
of insects into the detection chamber(s).
2.8.1
Ionization Detectors
Multiple chamber type which is responsive to both visible and invisible
particles of combustion. Detectors shall not be susceptible to operation
by changes in relative humidity.
2.8.2
Photoelectric Detectors
Operate on a multiple cell concept using an infra-red light-emitting diode
(LED) light source.
2.8.3
Detector Spacing and Location
NFPA 72, the manufacturer's recommendations and the requirements stated
herein, however, in no case shall spacing exceed 9 by 9 meters 30 by 30 feet
per detector, and 9 lineal meter 30 lineal feet per detector along
corridors. Detectors shall not be placed closer than [1] [1.50] meter [3]
[5] feet from any air discharge or return grille, nor closer than 305 mm 12
inches to any part of any lighting fixture.
SECTION 13956N
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