Northern Airborne Technology AA86 - Manual (Page 7)

AA86/87 Stereo Intercom Manual SM48 Rev. 4.00
Page 2-2 Nov 12, 2003
ENG-FORM: 805-0104.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.3 Installation Procedures
2.3.1 Warnings
Do not bundle any lines from this unit with transmitter coax lines. Do not bundle any
audio or DC power lines from this unit with 400 Hz synchro wiring or AC power lines. Do
not position this unit or wiring from this unit next to any device with a strong alternating
magnetic field such as an inverter, or significant audio interference will result.
2.3.2 Cautions
⇒ In all installations, connect exactly as shown and ground as indicated. Significant
ground loop and noise problems may result from not following these guidelines.
⇒ Do not connect the microphone and headphone shields together.
⇒ Use caution when routing microphone and ICS wiring as they use low level signals
prone to coupling from other sources.
⇒ Do not take a ground from the instrument panel or similar location that shares a
ground return with a turn and bank, horizon or other motor driven instrument. This
may cause the Intercom unit to pick up the sound of the motor as ground loop
interference.
⇒ The AA86/87 Intercom should not be connected through the avionics master
switch as it is generally desirable to have the intercom available at all times, even
when the avionics are off.
2.3.3
Cabling and Wiring
For shielded wire applications, use Tefzel Mil-M-27500 or Mil-M-81044 shielded wire
with solder sleeves (for shield terminations) to make the most compact and easy to
terminate interconnect. Follow the wiring diagrams in Section 2.6 as required.
Allow 3 inches from the end of the wire to the shield termination to allow easy
installation of the hood. Note that the hood is a ‘clamshell’ hood, and is installed after
the wiring is complete.
All wiring should be at least 22 AWG, except power and ground lines, which should be
at least 20 AWG. Ensure that all ground connections are clean and well secured.
To prevent system failure or inadequate equipment protection, supply power from a
separate 1.0 A breaker or fuse, not connected to any other source.