TruTrak EMS BU (8300-065) - Manual (Page 16)

TruTrak Flight Systems 14 EMS Installation Manual
JUNE 2009 8300-065 Rev D
Outside Air Temperature Sensor (8250-042)
It is important that the OAT probe be mounted somewhere on the skin of the
airplane where it will not be affected by heat sources (sun, engine, airplane interior,
etc). The ideal location would receive no heat from the aircraft engine or any other
source in the airplane body. While this may be impractical, it is a good idea to
mount the probe as far away from heat sources as possible. Generally, avoid these
locations:
Engine exhaust paths
The engine itself
Where the sensor will be in direct sunlight
Where the sensor mounting is exposed to a heated cabin
Transducer Installation
After the mounting location has been determined, drill a 5/16” hole in the skin at the desired location.
Install the OAT probe through the skin make sure that the flange nut is on the outside of the skin. Then
tighten the two nuts with the lock washer on the inside of the skin in place against the skin. Use some
Loctite around the threads of the OAT probe. Twist the nuts onto the threads of the OAT probe and
tighten. Once you have physically mounted the OAT probe, route the attached wires to the EDM. Connect
one of the white wires to ground, at a supplied connection on the 37-pin harness. The other white wire on
the OAT probe to the OAT input on the 37-pin connector pin 25.
Carburetor Air Temperature Sensor
TruTrak can accommodate an additional air temperature sensor for the carburetor or manifold. Westgate
makes carburetor air temperature probes for the different carburetors on an engine. The sensor must be a
399S9 resistive type. Use the TruTrak OAT Sensor (8250-042) if there is room in the manifold plenum
for a Manifold sensor. This sensor MUST be installed in pin 7 of J2 and the CARB must be ON to
function. The selection of the CARB will not allow a second resistive type CHT sensor.