Installation Guide

First InterComm ™ System Installation Guide
A29799 Page 7
November 2007
3.3 System Component Locations
WARNING
WHEN SELECTING LOCATIONS FOR FIRST INTERCOMM COMPONENTS, AVOID HIGH
FREQUENCY (HF) NOISE PRODUCERS AND DO NOT RUN DC POWER FEEDS TO
THE VCA100 PARALLEL TO IGNITION CIRCUITS, ELECTRONIC MODULES, OR
SIMILAR ITEMS. AVOID RUNNING POWER LEADS IN PARALLEL WITH VEHICLE
WIRING OVER LONG DISTANCES.
3.3.1 VCA100
The VCA100 has no operator interfaces other than an activity indicator. Also, the unit
has no fan; it is convection cooled and does not require any special ventilation.
However, it is not environmentally sealed and must be installed in a protected area (THE
ENGINE COMPARTMENT IS NOT ACCEPTABLE
). The optimum location is one in which the
VCA100 is out of the way, its face plate and cable connections protected as much as
possible, and there are at least six inches of space around the VCA100 to allow air
circulation.
Plan for cable management and strain relief loops for the cables. Cable ties and
mounts are needed to prevent cable movement and vibration.
3.3.2 WiFi Antenna
The WiFi antenna location has highest priority because the antenna’s relatively short
range has the greatest effect on system performance. Mount the antenna as high as
possible on the cab roof, and as close as possible to the vehicle’s centerline to provide
360-degree coverage. The antenna requires a metal ground plane to achieve its full
5dBi of gain.
We recommend keeping the antenna at least 12 inches away from any light bars or
other antennas
and MUST be installed so as to provide a separation distance of at least
18 inches (45 cm) from all persons. The maximum designed distance from the VCA100
to the WiFi antenna is 17 feet, the standard cable length that comes with the antenna.
Extensions may be added to the cable, but this will reduce the WiFi range.
Certain vehicles do not allow locating the antenna in the center or center-rear of the
roof. In this case, the next best antenna location is on the direct center of the trunk lid.
The mounting area under the antenna must be a flat, metallized ground plane. Be
aware, however, that this location will degrade the WiFi range.