PPRuNe Forums - EDM700 systems

As with all avionics work, make sure the firm has done it before.

There is a lot of thermocouple cables to wire up, and it needs to be done neatly, and away from exhaust pipes, properly tied to any engine support tubes but in a way so as to enable flexing under engine vibration, with the connectors not hanging in the air but having both sides firmly tied down (so they can't come loose), all metal filings behind the instrument panel (from the hole cutting) hoovered up and not just left in there (how do I know this? :) ) etc.

Always go for the extra probe option. I went for the oil temperature, so I now have two oil temp sensors. I would have dearly liked to have two oil pressure sensors but that is considerably more complicated.

Make sure you can download the data into your laptop. The EDM product has a long history of bugs, corrupting the data and generally being unable to download the data. So make sure you have the current firmware (email JPI to check what this should be) and check with the installation firm that that is what you will get. Make sure that you have their download software installed and (before you hand over the money) that you can download the data and successfully decompress it into .CSV or .XLS files.

There is a particular issue with downloads which are done infrequently, so the circular queue in the EDM has wrapped around (overflowed). This will obviously result in one incomplete flight being recorded, but the remaining ones should be retrievable. This doesn't work in older units (if one is corrupted in this way, you have to email the .DAT file to JPI for recovery) and I don't know if they have fixed it. Their tech support is responsive but not exactly clued-up and like a lot of firms they can't read English very well. I make sure I download frequently enough (the memory is enough for about 30 hours, depending on the recording period) but sometimes I forget.

Get the data download connector fitted somewhere neat, not bang in the middle of the dash where one day you may want to fit something else. You won't be downloading the data while flying an ILS, after all :)

It is because of these little problems that I would also consider the EI alternative

http://www.buy-ei.com/

They claim to have better quality EGT probes (I have had 2 fail in 4 years).

http://www.buy-ei.com/EI_vs_JPI_Probe_Chart.htm

Personally I never use any of the fancy features like "lean find"; it's trivial to lean until the EGTs peak and then a tiny bit more. I never touch the buttons on the unit during flight; no need to.

Hope this helps.