FAA Approved Installation Manual for the EDM-960 system
Report No 909
Primary Engine Data Management System
Page 18 of 45 Rev C
Date 12-12-12
24. Fuel Level Interface Installation
The EDM-960 has the capability to interface to 4 tanks in the aircraft’s fuel level system. This is done by connecting
the DAU directly to the senders or in some cases to the aircraft’s fuel sender signal conditioner, for example the
Pennycap system which converts capacitance (frequency) to a voltage output, typically found in Cessna Twins. The
DAU has the capability to process signals from two types of sender signals: Resistive output, Voltage output. JPI
provides the appropriate interface hardware (the P5 harness and any associated signal conditioners) based on
information you provided when your order was placed. Once installation is completed, you will perform a fuel level
calibration. The EDM-960 stores this calibration internally. NOTE: The fuel quantity function will not be available
until this calibration has been performed successfully.
Note: All Twin Aircraft are considered resistive even thought the sensor it self is capacitance. The Gull or
Pennycap system converts the frequency to resistive values.
24.1 Resistive Output Type Sender System
Locate the wires that run between the existing ships fuel gauges and the senders and disconnect them at the
senders. For tanks that have more than one sender, the wiring between the senders must be retained. Make sure
the senders do not have voltage on them before connecting to the EDM. Connect the EDM to the senders using the
wire pairs coming from the signal conditioner (PN 790802) P7 as shown below. Note that one pair is for MAIN and
the other is for AUX. Connect the ‘SIG’ wire to the senders signal terminal (typically the center stud) and the ‘GND’
wire to the closest ground terminal near or on that sender.
