2.2.3
Access
Switches and other controls shall not be accessible without the use of a
key. Access to controls shall be by unlocking and opening a panel or door.
2.2.4
Mounting
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NOTE: Choose the type of mounting most suited for
application of design.
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Interface housings shall be designed for universal mounting on walls,
poles, or pedestals. Mounting shall utilize either lag bolts, anchor
bolts, stainless steel banding, mounting brackets, or a shackle/bolt
combination, as applicable to the specific installation.
2.2.5
Inputs/Outputs
Each interface panel shall provide, as a minimum, the number of alarm
circuit inputs and outputs indicated. Each input circuit shall be arranged
so that the alarm signals shall override the trouble signals.
2.3
RADIO FIRE ALARM MONITORING BASE STATION
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NOTE: Radio link supervision may be by periodic
reporting of radio fire alarm transmitters or by
periodic polling of all transmitters by the radio
fire alarm receiver. The total number of
transmitters on any one frequency and the polling
rate of the transmitters in a two-way system must be
determined and checked to ensure code compliance.
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2.3.1
Receiver (Transceiver) System
[Two identical] [One] master radio fire alarm receiving (transceiver)
system compatible with transmitter frequency shall be provided. The system
shall be completely assembled, wired, tested at the factory, and delivered
ready for installation and operation. Transceivers shall be solid-state
design and shall use frequency modulation. The transceiver can be a single
integrated unit, or it may consist of separate transmitter and receiver
modules with a common power supply, amplifier, and control unit.
2.3.1.1
Transmitter Section
Transmitter shall operate
on a frequency of [_____] MHz. Frequency
stability shall be within
0.00025 percent over the operating temperature
range. Transmitter shall
be designed to work into a 50-ohm load.
Frequency deviation shall
be less than or equal to 5 kHz. Audio response
shall be within plus 1 dB
and minus 3 dB over the 300 Hz to 3,000 Hz range.
2.3.1.2
Receiver Section
Receiver antenna input impedance shall be 50 ohms. Receiver shall be tuned
to a frequency assignment of [_____] mHz. Receiver shall have no more than
5 percent audio distortion measured at 1,000 Hz. Receiver shall have a
noise level not greater than minus 50 dB below the signal level. Receiver
SECTION 13852A
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