EMS Fuel level alarms

[Rocketboy]

Hi,

Flew my fuel level into the red today but no alarm. How does the fuel level alarm system work?

Also, can you add a low fuel alarm based on fuel flow calculated quantity. This is much more accurate.

Better yet, how about do it like JPI FS-450 and add two alarms, one based on gallons remaining and one based on time remaining (E.G. :45 mins).

Bob

 

[dynonsupport]

Do you have the alarm turned on for the fuel level? You can have sensors with a red range, but if they cause an alarm is a separate setting.

Calculated quantity is only more accurate as long as you entered the right number the last time you filled up. Mess this up, and suddenly you have no alarm. Measured level is pretty darn accurate and doesn't require the pilot to interact at all.

Time remaining is a problem, since it's based on current fuel flow. Push the throttle in to climb when you are 1:45 from your destination and suddenly you get an alarm. This can get old fast.

 

[Rocketboy]

Hi, The alarm is "on" but your first sentence didn't make any sense. Can you clarify how the fuel level alarm works? When will it sound?
When the fuel level gets into the red of either tank? Or when it get to the total of all tanks?

The docs are quite deficient in this matter, and I must be missing something.

Thanks for help.

Bob

 

[Rocketboy]

What/where is a "separate setting" please?

Feeling lost here.

 

[dynonsupport]

Just because it falls into the red doesn't mean it causes an alarm. You need to have your alarms on as well. There's an "Alarm" setting in the fuel level sensor page, and it needs to be "Self-Clear" or "Latching" if you want it to cause an alarm. Page 5-12 of the D120 manual covers fuel settings and Page 5-2 covers alarm configs.

Alarms are per tank, when any one gets into the red. It does not take the whole fuel situation into account. This way you can't just let one tank run dry and watch the prop stop even though you still have 19 gallons on board.

 

[Rocketboy]

Ok so I'm still confused here.

I checked my fuel level page and the alarms are and were on "self clearing". So when does the alarm activate? I set my gauge to turn red at 3.5 gallons on each tank, but I know the alarm does not activate. I get the part that the gauge turns red below 3.5 gallons. SO where is the setting threshold for making that alarm go beep.

Is it at 3.5 gallons when the first tank hits red? Nope proved that.
Is it a when both are in the red?
Is there a secret page where I define total fuel when the alarm sounds?

I searched high and low for that secret settiting and can't find it so WHEN does the alarm activate and exactly how do I configure it?

Still not getting it obviously, though its begining to sound like I did everything right and my Dynon screwed up and didn't sound the alarm when it was supposed to.

Thanks, Bob

 

[dynonsupport]

The alarm should go off when any fuel tank gets into the red. As mentioned in the alarm section of the manual, alarms are always tied to the red threshold. Sorry if we didn't make this obvious in the previous posts. The only "separate setting" is if there is an alarm at all, not the threshold for the alarm.

We've got thousands of EMS units in the field, and I've personally been in airplanes with the fuel level alarm going off, so let's figure this out. The alarm does work.

What software version are you running? Never heard of this as a bug, but let's start there.

Second, when we talk about "alarm," there are three of them in the EMS. First is a red bar that shows up on the screen. Second is an output on the EMS that can light an external light. Third is an audio alarm that can be run to an intercom system. Are you getting any of these? Which one are you expecting? If it's anything but the internal alarm bar, let's check the output first. There are output test functions inside the EMS.

Maybe this is something you should check on the ground when it's easier to play around with. You could take your airplane with X amount of fuel on board, set the red alarm to just below that amount, and then drain a small amount of fuel, or maybe just tilt the aircraft if that works for your design.

Also, feel free to give us a call at 425-402-0433 someday when you are out at your plane and we can try and troubleshoot it that way.

 

[Rocketboy]

Hi,

I have all three though my bar is yellow not red at the bottom of the screen.

I will test this function again tomorrow. All other alarms work well.

Still testing, Thanks again for the help.

Bob

 

[dynonsupport]

We don't have a yellow alarm bar, so something isn't quite right.

Do you mean the fuel level is highlighted in yellow? If so, this is the yellow range, not the red, so you haven't triggered the alarm yet.

 

[Rocketboy]

** Problem Found ***

After a nice talk with Dynon Support, They/we figured it out. Basically there is a bug in the code that interferes with alarm function on (forgive spelling) amotonic tanks.

This means when my right hand tank was calibrated, the procedure ended with a "calibration failed/unsuccessful" type message, yet the fuel gauges indicate perfectly. As explained to me, some tank D/A values actually change in the wrong direction at upper and lower fill limits, causing math that the Dynon can't process so the calibration is flagged as failed.

Solution is wait for bug fix or attempt re-cal. Anyone who experienced a Fuel Level Calbration unsuccesful/failure better be darn careful of fuel levels in flight becuase you WON'T be getting a low fuel warning for that tank!


Thanks to all for the patience.

Bob