3.1.1
Signal and Control Circuits Wiring
Signal and control circuits shall be installed in accordance with NFPA 70
and as indicated. The conductors shall be separated as recommended by the
equipment manufacturer.
3.1.2
Conduit, Cable Tray and Tubing Systems
Wiring shall be installed in rigid conduit, intermediate metal conduits,
cable trays, or electric metallic tubing as specified in Section 16402
INTERIOR DISTRIBUTION SYSTEM.
3.2
GROUNDING
The connection of interfacing components shall be accomplished through the
use of transformers and the tying of interconnecting lines to a unit ground
bus at one end only. The ground and distribution ground buses shall be
solid copper wire with insulating covering.
3.3
ACCEPTANCE TESTS
After installation has been completed, the Contractor shall conduct an
acceptance test, using the approved test plan, to demonstrate that the
equipment operates in accordance with specification requirements. The
Contractor shall notify the Contracting Officer [_____] days prior to the
performance of tests. In no case shall notice be given until after the
Contractor has received written approval of the test plans. The acceptance
tests shall include as a minimum the following test:
Operational Test: Test originating station-to-station, all call, and
page messages at each intercommunication station. Verify proper routing
and volume levels and that the system is free of noise and distortion.
Test available message path from each station on system.
Frequency Response Test: Determine frequency response of two
transmission paths, including all-call, and paging, by transmitting and
recording audio tones. Minimum acceptable performance is within 3dB from
150 to 2500 Hz.
Signal-to-Noise Ratio Test: Measure signal-to-noise ratio of
complete system at normal gain setting as follows:
a. Disconnect speaker microphone and replace it in the circuit with
a signal generator using a 1000 Hz signal. Measure signal-to-noise ratio
at paging speakers.
b. Repeat test for four speaker microphones and for each seperately
controlled zone of paging loudspeakers.
c.
Minimum acceptable ratio is 35 dB.
Distortion Test: Measure distortion at normal gain settings and
rated power. Feed signals at frequencies of 150, 200, 400, 1000, and 2500
Hz into each paging and all-call amplifier, and a minimum of 2 selected
intercommunication amplifiers. For each frequency, measure distortion in
the paging and all-call amplifier outputs. Maximum acceptable distortion
at any frequency is 5 percent total harmonics.
Acoustic Coverage Test: Feed pink noise into system using octaves
SECTION 16721
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