The document discusses the installation of the EDM 900 engine monitoring instrument. It begins by stating that the EDM 900 comes in TSO'd and non-TSO'd versions, with the non-TSO'd version being $1000 less for experimental aircraft. It then provides details on installing the various components of the EDM 900, including orienting the screen, ensuring proper cable terminations and wire lengths, correct temperature probe polarity, crimping wire connections securely, and properly installing EGT probes, fuel flow senders, and fittings. It concludes by providing contact information for the manufacturer, J.P. Instruments.

1. EDM 900 comes in two versions – TSO’d and non-TSO’d (the latter version costs US
$1,000 less and is for use in experimental aircraft). Both are manufactured by the
California (U.S.A) based, J.P. Instruments – a pioneer in aftermarket flight
instruments.
The EDM-900 is basically an improved version of the EDM-800 with many
additional features. The reliability and ingenuity of many JPI products are secondto
none. The EDM-900 monitors
the aircraft engine conditions
four times per second and
includes instant warning if any
of the engine parameters fall
above or below the
programmed limit. Installation
too, is not too difficult and this
article covers it.

2. Installation of the EDM 900
To begin with, you need to sort out the various pieces and harnesses that are in the
EDM 900 box. The box also includes the EDM installation guide and the check-out
test report. The EDM installation guide has got the entire installation process in it.
So, in this article we shall cover things that are not specifically covered in the
installation guide.
1. Screen orientation:
The screen orientation can be changed from landscape i.e. horizontal to,
portrait i.e. vertical display. This can be achieved by holding the step button
for approximately 5 seconds. When you see the large arrow, push the lean fine
button to position the display the way you want it and then tap step to save.
The EDM will then reboot and change the display to the new orientation.
2. In our view, most of the post-installation problems relate topoor quality cable
terminations and insufficient wire lengths. For example, when cutting the
leads to the probes, ensure you leave enough slack in the wiring so the probe
may be interchanged to an adjacent cylinder (for testing).
3. Make sure the temperature probe is wired to the correct polarity.
4. When crimping wires, verify the quality of each crimp with a sharp tug on the
wire - when crimped correctly, the terminals should be impossible to pull off.
5. The star washer must be placed between the ring lugs - not against the nut
slide the sleeve.
6. Always push wires from the cabin through the firewall to the engine side and
try to use existing rubber grommets. When you've finished, use flame
retardant silicone to fill up any gaps along the wire route.

3. 7. When fixing EGT’s, be warned that they will fail if they get chafed so always
keep your wire routing clear of the hot spots.
8. The EGT Probe requires a 1/8 diameter hole 2 to 4 inches from the exhaust
flange. The probe should be inserted into the drilled hole so the tip of the probe
is in the centre of the exhaust stream.
9. The fuel flow sender must be installed using the supplied connectors and fire
jacket. Every fuel flow sender is a little bit different so before you being the
installation, write down the k-factor written on the side of your unit.
10.Finally, never use Teflon tape anywhere near fuel lines only use the supplied
steel fittings.
For more information on EDM 900, please visit:
https://www.jpinstruments.com/shop/edm-900-2/
JPI Sales:
1-800-345-4574
714-557-3805
FAX: 714-557-9840
sales@jpinstruments.com
JPI Technical Support:
1-800-345-4574
714-557-3805
support@jpinstruments.com