AirCell ST 3100, Руководство по установке

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5. To reduce EMI / RFI to an acceptable level, all signal and power lines require shielded cables.
Ground the to/from audio line shields at the Transceiver end only, (i.e., TX and RX signals).
Refer to the wiring diagrams in Section 10.0.
6. FAA-approved antenna coaxial cables are required for this installation. Part 25 aircraft must meet
FAR 25.1359 requirements, which does not allow for the use of PVC-type insulation. Refer to
Section 3.11 for coax recommendations.
7. Provide proper grounding of the equipment by isolating chassis, power return wires, and signal
grounds.
Note
Component Bonding
As with any communication equipment, bonding the equipment to airframe ground is essential for
optimum performance and lightning protection. Ensure that the equipment mounting provisions
are bonded to the shelf, and the shelf is bonded to airframe ground. Properly bonded, there
should be 2.5 milliohms or less between the Mounting Tray and airframe ground. Care in
bonding has been shown to eliminate erratic or poor system performance.
Additional Shield Drain information
As an option, up to four (4) 22 American Wire Gauge (AWG) 7” drains may be combined on a
single grounding strap and then routed to airframe chassis. The ground strap should be as short
as possible, but may be realized with a maximum of 24” of insulated (18 AWG or larger).
8. Size power wires to handle 5.0 amps @ 28 volts dc.
The Wiring Diagrams in Section 10.0 provide manufacturing instructions for the wire harnesses. Notes on
the wiring diagrams provide essential instructions that will save you needless rework during installation.
Note
When up to three (3) Handsets are wired in, individual Handset volume control via the Transceiver access
panel is possible. Additional handsets may be wired in parallel per handset circuit, but volume loading
will occur and volume adjustment at the ST 3100 Transceiver may be required. The wiring diagram in
Section 10.0 provides wiring definitions for the Audio Panel, Handsets, and RS-232 connections. Multiple
RS-232/Modem connectors are allowed, but only one (1) data appliance can be connected at a time, to
prevent appliance malfunction. The system also provides an Audio Panel interface for direct integration
into the aircraft communications system.
Good wiring practices can be obtained from FAA AC 43.13-1B and should be followed. Here are a few
reminders. Know the harness routing and equipment location before you begin fabricating the harness.
Measure and record the harness and coax lengths required and add a few feet for good measure. It is
easy to cut to fit, but hard to stretch the wires. Identify and mark the wires in accordance with AC
43.13-1B. Refer to Section 10.0., ICD 655-10680, for mating connector layouts. AirCell
®
strongly
recommends that you purchase coax assemblies from PIC, ECS, or EMTEQ, so that a test record
accompanies the installation data. This practice also minimizes those hard-to-track-down cabling
problems. Refer to Table 3.1. for coax recommendations.
3.11. Satellite Antenna Installation Cable Guide
Important
Refer at
AirCell
®
Antenna Installation Manual P/N 800-10355
for details on special Inmarsat
®
filtering,
Iridium to Inmarsat
®
, and other Antenna separation details.
When the installation requires cable lengths from the Transceiver to the Satellite Antenna greater than 60
feet
, please contact AirCell
®
Customer Service @ 1-888-286-9876 or your preferred cable Vendor.
The RF coaxial cable performance from the Transceiver to the Satellite Antenna is critical. Keep this
cable length as short as practical to enhance the satellite telephone performance. The total RF loss
Installation Procedures
Page 3-4
Section 3
800-10680-C, May 2007