Northern Airborne Technology PIA01-001 - Manual (Page 12)

PIA01-001 Passenger Intercom Amplifier
SM78 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 1 Page 2-3
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.4.3 Mounting
The PIA01 can be bulkhead mounted in any orientation using four 10-32 screws. No shock or vibration
isolators are required.
The PIA01 must be mounted to a clean metal surface which is electrically bonded to the aircraft ground
plane. The unit is finished with a coating which prevents corrosion. This film is electrically conductive and
should not be removed for electrical bonding.
2.4.4 Cabling and Wiring
All wire shall be selected in accordance with the original aircraft manufacturer's Maintenance Instructions
or AC43.13-1B Change 1, Paragraphs 11-76 through 11-78. Unshielded wire types shall qualify to
MIL-W-22759 as specified in AC43.13-1B Change 1, Paragraphs 11-85, 11-86, and listed in Table 11-11.
For shielded wire applications, use Tefzel MIL-C-27500 shielded wire with solder sleeves (for shield
terminations) to make the most compact and easily terminated interconnect. Follow the connector map in
Section 2.7 as required.
Allow 3" from the end of the shielded wiring to the shield termination to allow the connector hood to be
easily installed. Reference the interconnect drawing in Section 2.7 for shield termination details.
Note that
the hood is a 'clamshell' hood, and is installed after the wiring is complete.
Maintain wire segregation and route wiring in accordance with the original aircraft manufacturers
Maintenance Instructions.
Unless otherwise noted, all wiring shall be a minimum of 22 AWG, except power and ground lines, which
shall be a minimum of 20 AWG. Reference the Interconnect drawing for additional specifications. Check
that the ground connection is clean and well secured, and that it shares no path with any electrically noisy
aircraft accessories such as blowers, turn and bank instruments or similar loads. Power to this unit must
be supplied from a separate circuit breaker or fuse (fast blow), and not attached to any other circuit
breaker without additional protection. Verify that the selected circuit breaker size and wire gauge are
adequate for the installation using the techniques specified in AC43.13-1B Change 1, Paragraphs 11-47
through 11-51 and 11-66 through 11-69.
2.4.4.1 Interconnect Discretes
2.4.4.1.1 Intercom Volume Input (VOLUME INC / VOLUME DEC)
The PIA01 has two Intercom Volume Inputs for adjusting the Intercom Audio Level at the headphone
outputs. Each activation of the volume switch causes one volume level change of 2 dB. On power-up the
volume level defaults to maximum.
These inputs are only active when the PIA01 is operating in analog mode. In digital mode the PIA01
Intercom Volume level is controlled by data on the Digital ICS Tieline.