Compensation for limited float range

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mlwynn
Posts: 18
Joined: Tue Jul 02, 2013 8:04 pm

Compensation for limited float range

Post by mlwynn »

Hi folks,

I am finishing up an RV 8. 21 Gallon tanks, EIS 4000 GRT Hx system. I calibrated the fuel tanks over the weekend. Started seeing float movement at about 1.5 gallons. Stopped moving about 17.5 gallons. I programmed per the GRT instructions and all is well except that it show full as 17 gallons. If I enter the capacity on the EFIS at 21 gallons, then the bar graph looks 3/4 full when the tanks are full. Someone on VAF said that they set this up so that the capacity is listed as 21 gallons. It indicates full until the float starts moving at 18 gallons. I clearly need to have the 21 gallons in the system to get the fuel totalizer to work properly, so this seemed like the right thing to do.

Anyway, anyone know how to do this? How to set up the HX or EIS to indicate full at 21 gallons until the float moves? Is there a better idea or how to program this?

Regards,

Michael Wynn
RV 8 Finishing
San Ramon, CA
Bobturner
Posts: 429
Joined: Mon Mar 11, 2013 6:34 pm

Re: Compensation for limited float range

Post by Bobturner »

Hi Mike,

I did it the other way around, e.g. On the -10 my float hits the tank top at 25 gal, tank holds 30 gal., I set the floats' bar graphs to show 25 max. They do not move until I've burned off the top 5 gal. The fuel flow programs independently, I set it to show full as 60 gal. It's true, the little symbol on the HX bar graphs shows a discrepancy between the FF and the float gauges until I've burned 5 gal off each tank; I just ignore it for the first hour of flight. I know that the float cannot measure anything between 25 and 30.

Bob
mlwynn
Posts: 18
Joined: Tue Jul 02, 2013 8:04 pm

Re: Compensation for limited float range

Post by mlwynn »

Makes sense. I will set the EFIS to indicate 17 gallons. Thanks for all your help with this. Hope to be joining you on the weekend fly-ins soon.

Michael Wynn
RV 8 Finishing
LVK
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