Installation Overview; Introduction; Wiring; Cooling Air - Garmin GMA 347 Installation Manual

2

INSTALLATION OVERVIEW

2.1

Introduction

This section provides hardware equipment information for installing the GMA 347 Audio Panel, related
hardware and suggestions relating to the marker beacon antenna. Installation of the GMA 347 should
meet the requirements of FAA Advisory Circulars AC 43.13-1B and AC 43.13-2A where applicable.
Cabling is fabricated by the installing agency to fit each particular aircraft.
2.2

Wiring

Use AWG #22 or larger wire for all connections unless otherwise specified in the interconnect diagrams
in Appendix C. The standard pin contacts supplied in the connector kit are compatible with up to AWG
#22 wire. In cases where some installations have more than one unit sharing a common circuit breaker,
sizing and wire gauge is based on aircraft circuit breaker layout, length of wiring, current draw of units,
and internal unit protection characteristics. Do not attempt to combine more than one unit on the same
circuit breaker unless it is specified on aircraft manufacturer approved drawings.
In some cases, a larger gauge wire such as AWG #18 or #16 may be needed for power connections.
Extended barrel contacts for AWG #16 and #18 wire are available from Garmin, if required. Special
thin-wall heat shrink tubing is also provided to insulate the extended barrels inside the backshell. If using
#16 or #18 barrel contacts, ensure that no two contacts are mounted directly adjacent to each other. This
minimizes the risk of contacts touching and shorting to adjacent pins and to ground.
Ensure that routing of the wiring does not come in contact with sources of heat, RF or EMI interference.
Check that there is ample space for the cabling and mating connectors. Avoid sharp bends in cabling and
routing near aircraft control cables.
2.3

Cooling Air

The GMA 347 does not have provisions for attaching cooling air and does not generate an excessive
amount of heat during typical operations, however the thermal characteristics of the installation should
always be assessed. An undesireable thermal condition could be created due to the unit's own internal
power dissipation combined with restricted ventilation, or due to heat generated by adjacent equipment.
Limiting thermal build up, by means of fan or natural convection is always a good practice and is
recommended to increase the product life.
GMA 347 Installation Manual
190-00325-01
Page 2-1
Revision A