FAA Approved Installation Manual for the Report No 908
EDM-900 and EDM-930 Page 11 of 56 Rev I
Primary Engine Data Management System Date 1-18-2013
Be sure to verify that this matches your aircraft.
Note: If your EDM should ever have to be replaced with a different unit, the factory will reprogram it to match your
configuration. You should always retain your fuel quantity calibration records, as these may need to be manually re-
entered in a different or serviced unit.
7. Routing the Wiring Harnesses
Five connectors are protruding from the rear of the instrument. Connect the five wiring harnesses to the rear of the
instrument and run the cables through the firewall into the engine compartment. Allow sufficient service loop to
facilitate removal of the connectors for servicing. These wiring harnesses are labeled as follows:
Conn Harness PN
P1 790200 Power, Engine ground, MFD input, MFD output the following are optional and need
to be added : Oil temperature, Induction temperature, Carburetor temperature,
Outside air temperature, Turbine inlet temperature, Turbine inlet temperature 2,
P2 700700
700702
CHT, EGT 6 cylinder
CHT, EGT 4 cylinder
P3 790420 RPM, MAP, Oil pressure
P4 700708 Serial data to GPS, Serial data from GPS, Fuel flow transducer
P5 790749 Fuel Pressure, Fuel Level (Resistive and Capacitive ), Amps
RAD 790749 Category 5 jack and cable for RAD (Remote Alarm Display)
Route the wires from the connectors through the firewall using rubber grommets and flame retarding silicone. Use
an existing hole if possible. All wires must be routed away from high temperature areas (exhaust stacks,
turbochargers, etc.). Secure probe and sensor leads to a convenient location on the engine approximately 8 to 12
inches from the probe or sensor, being sure there is sufficient slack to absorb engine torque. It is essential in
routing the probe wire that this wire not be allowed to touch metal parts of the air-frame or engine since abrasion
will destroy this high temperature wire. Secure wires along the route to the indicator. Secure wire using original
clamps, tape or tie wrap if possible.
Note: The probe wires must not be tied in with ignition, alternator or engine cabin heater ignition wires or
transceiver coax cables because of potential induced interference with readings.
The temperature probe wiring harness is made of Chromel-Alumel alloy wires that must not be substituted or
extended with copper wire. Temperature probe leads must be spliced with the same type of wire (typically
Chromel-Alumel for JPI temp probes) using copper butt splices. The other signal and power wires are made from
normal copper and must meet MIL-W-32759/16 or equivalent.
CAUTION: Be sure the installation does not result in interference with any aircraft control movements.
When the installation is complete all wires should be secured using ties and carefully checked for interference,
rubbing or chafing with flight controls and associated cables or any other moving parts.
8. Power Connection
The EDM automatically adapts to either a 14 or 28-volt electrical system. Master Bus power wire to the EDM
should be 20ga copper connected directly to the master solenoid located at the battery to avoid a line drop when
cranking. A 5 amp circuit breaker is required. Connect the EDM ground wire to the engine block. The
instrument is designed to reset at less than 10vdc bus power, therefore the instrument may reset on engine start
(typical for 14vdc systems). For lighting, no connection to the aircraft dimmer system is required because the
instrument dims automatically with reductions in ambient light. Required power for 900 or 930 is 1.0 amp at 14vdc
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