D180 rebooting on climb out

[aj_richo]

Hello

My D180 went into a constant reboot cycle on climbout at my local airfield. During taxi and run ups checks it was fine.

With mechanical ASI it wasnt too much drama, so I left it on. After circling above the field for a few minutes it came up in the black and red screen, aquiring arhs (I think) then changed to the familiar normal display.

The week before I went on an interstate trip for nearly 9 hours so the internal battery should have received a decent charge.

I suspect its time to change the internal battery? It is a little old - I purchased the system in 2010  :-/

Cheers
Tony

 

[Robski]

Tony.

I have an EMS D120 fitted (and a D100 to install this autumn).
EMS worked OK to start with but then had random rebooting after a few hours. After a wander around this forum I found a suggestion to change the Oil Pressure sender.

Figured it was worth a punt as the sender was a second hand VDO type one that came with the used EMS from my friend. Swapped it out for a new Kavlico from Dynon to match the fuel pressure Kav under the cowling. (My friend's plane was injected so I had to install a carb ranged FP sender.)

Rebooting problem went away, so I assume the VDO type sender was faulty.

Fitting the new Kavlico oil pressure sender:
It is mechanically a straight swap (1/8 NPT).
It has 3 wires, needing a power wire from the D100/180 (5v?) and a dedicated ground (again from the main unit). I already had them ahead of the firewall as feeds to the manifold pressure sender and Kav FP sender.
You need to change the sender type in the D180-EMS setup screen. If it doesn't appear in the list then you'll need a software update. I was lucky and it was already there!

Given the age of your installation I'm guessing you have VDO type senders. There is a reason Dynon switched to Kavs!

If you have more than one VDO type pressure sender then you'll have to take best guess, or maybe disconnect them in turn to identify the faulty one!

A new sender is cheaper than a new internal battery! 
There is an option in the EFIS to display the 3 supply voltages (main, secondary and internal). The manual has info on what constitutes good internal battery condition (16v?).

I'm reasonably certain of my memory but check the Dynon installation manuals: they are very good!

Hope this helps!

Rob.

 

[aj_richo]

Thanks Rob

I'd have never suspected an oil sender, but will check it out. Mine is a VDO unit, supplied with the Jab engine. It is actually mounted on the oil cooler, monitoring outlet pressure and the mech guage is mounted at the pump outlet. Disconnecting the VDO sender wouldn't be an issue to check if the problem goes away.

I did find the additional voltage monitor setup for the main screen in the manual, but with the bad weather of late at my location I haven't been out to do any tinkering or flying.
Also downloaded the latest 5.6.1 update, so thats on the todo list as well.

Thanks again, will advise what I find in due course.
Cheers
Tony

 

[Robski]

Does seem odd, doesn't it?

Have to admit I didn't test - just swapped out the sender. I was always skeptical of the condition of my original, second-hand sender.
I would test by disconnecting it (and fuel pressure, if you have it) in your situation, though, seeing as it has been fine up to now. Remember to insulate the disconnected end! 
Hope this diagnoses / fixes it.

At home now so checked the paperwork that came with the Kavlico sender. (Rev C, October 2015)
Dynon software 5.4.2 onward has the options for Kav senders.

I have 5.6.1 to install on the D120 too. Needs to match my new D100 so they will play nicely together.

Rob

 

[Dynon]

So a few things here: We wouldn't expect that a faulty sender would cause your system to reboot. Even if the sensor was shorting to ground, you'd only get a spurious reading, not a full system reset. A disruption or erratic power supply could cause issues, or or possibly a voltage level that was right at the lower threshold to power the D180. But you also said you have the backup battery, and even if it weren't well-charged, it would still buffer against an issue like this. It could conceivably be something within the unit itself. Are there any other readings, particular the unit voltage, that are misbehaving when the unit is in normal operation?

 

[aj_richo]

Update:

Rather than change a couple of things at once, like disconnect the oil pressure sender etc. I decided to just monitor the behaviour of the unit and fly for at least an hour with the voltage readings displayed on the primary screen.

I began by updating the firmware to 5.6.1

I had a CTEC charger on the Odyssey PC625 battery during the update. The unit was on for probably 20 minutes before the update was started, (by the time I had sorted the correct serial port and reloaded the USB serial driver)

Approximately 10 minutes after the update had completed, the system started the reboot cycle.

I powered it down with the DC buss still energised and left it for about 10-15 minutes while I preflighted the aircraft.

Powered the unit back up no problem and set the display to show the voltage parameters for the DC buss and internal battery. Prior to engine startup.
Main 12.8 VDC - maybe a bit low
Internal 16.2 VDC

Airborne at cruise power
Main 14.4 VDC - maybe a little high but the Jabiru regulator is not known for its stable and clean output
Internal 16.3 VDC

Pretty much stayed that way for a total 90 minute flight out and return to base.

No rebooting of the unit during the flight, alll other parameters stable and within in their normal ranges.

The only thing other I can think of is moisture in the internals of the unit?? If the unit is on long enough it dries out and stabilises?

The temperature in the hangar has been around 5C° most nights, and the humidity has been high inside due to the carpet covered dirt floor. It has been a very wet winter here.

Being a polished all metal aircraft there is spot corrosion under the belly and lower wings. As the temperature drops overnight, there would be moisture gathering on cold metal, and perhaps accumulating inside the D180?? Enough to upset it?
Dunno - haven't seen inside one but I imagine it is well protected against this sort of problem.


Cheers
Tony

 

[Robski]

We wouldn't expect that a faulty sender would cause your system to reboot

I do agree with you, it was most unexpected.
Nevertheless it was my experience, and that of somebody else on the forum. That was where I got the (frankly quite odd) idea that it might be the cause of my D120 rebooting problem.
I have looked but I can't find the posting now! :-?

Main 14.4 VDC - maybe a little high but the Jabiru regulator is not known for its stable and clean output

14.4V is about what one would expect. I think it's the nominal 'book figure' most often used for aircraft/vehicle wiring.