VM1000 fuel totalizer

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jwx96
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Re: VM1000 fuel totalizer

Post by jwx96 »

Thanks Rich. I'll check into that. It would be nice that have all the VM 1000 functions working.
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blsewardjr
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Re: VM1000 fuel totalizer

Post by blsewardjr »

Rich- I have the same problem as John. I've searched the internet for the VM1000 installation manual but have not found a copy. Can you post a link or just Section 2.6? Thanks. Bernie
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KCHO Charlottesville, VA
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Rich
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Re: VM1000 fuel totalizer

Post by Rich »

VM1000 Fuel Computer Set Up

2.6 INITIAL SET UP OF THE FUEL COMPUTER
Your fuel computer features the capability of 'remembering' the SIZE of
your fuel tank. This is setup once after you receive your system, or if for
some reason the fuel computer memory has been lost. (NOTE: A
lithium battery module is located inside the DPU and will require
replacing about every 8 to 10 years.) Follow the steps below to
properly setup your fuel flow computer system:
Refer to ’FIGURE 7: VM1000 QUICK REFERENCE’.
STEP 1. With power OFF, press and hold 'BUTTON 4', then turn power
ON to the VM1000. Wait for the display test patterns to go off,
then for the 'HRS', 'REM', 'BRN', 'ADD' indicators to activate,
indicating that fuel tank setup mode has been activated.
STEP 2. You will program the tank size in whole units. Press 'BUTTON
3' for tens ('10.0') and 'BUTTON 5' for ones ('01.0') . If you
accidentally went too high, then just repeat pressing 'BUTTON
3' until the display resets back to '00.0' allowing you to start
over.
STEP 3. If you like the value displayed, then press 'BUTTON 4' to accept
the new maximum tank size, otherwise just leave everything
alone and after 20 seconds the setup mode will automatically
be canceled, leaving your previous tank size unchanged.
STEP 4. ADD fuel to your computer's memory according to 'Adding Fuel
to the Computer'.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
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blsewardjr
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Re: VM1000 fuel totalizer

Post by blsewardjr »

Rich- Thanks! I'll try to give it a try this week. Bernie
Bernie Seward, IR, AGI
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KCHO Charlottesville, VA
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perossichi
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Re: VM1000 fuel totalizer

Post by perossichi »

I’ve found very similar results to Rich. I keep track of accuracy of both gauges and totalizer. Totalizer is always conservative in that it indicates less fuel then actually available by about 1.5 -2 gallons. Fuel gauges are very accurate to within 1 gallon in each tank.

I got very paranoid about fuel after reading Mike Busch’s column about the fatal crash of a Lancair IV with inoperative fuel gauges and the very experienced pilot was relying on only fuel used computed by a totalizer. I check each fill on accuracy of both the gauges and the totalizer.
Sold 2002. Powerflo, Hartzell composite two blade, 530W/430, 345 transponder.
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blsewardjr
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Re: VM1000 fuel totalizer

Post by blsewardjr »

Thanks to Rich's fix, I was able to get the fuel totalizer to work today for the first time. It was useful because I was running at high power to break in a new cylinder and gulping down fuel. The amount remaining according to the totalizer was about 1-2 gallons less than the fuel tank indicators. It was hot and I was tired so I didn't refuel. It will be interesting to see which is closer to the actual when I get to it.
Bernie Seward, IR, AGI
2003 DA40 N377DS
KCHO Charlottesville, VA
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blsewardjr
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Re: VM1000 fuel totalizer

Post by blsewardjr »

Refueled today. As with Peter's experience the totalizer indicated a gallon less available then is probably there. Good to know.
Bernie Seward, IR, AGI
2003 DA40 N377DS
KCHO Charlottesville, VA
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Re: VM1000 fuel totalizer

Post by Lance Murray »

Working with a Garmin unit right now. You have to calibrate it by inputing a 'K-Factor". That is XXX,XXX pulses per minute. You may have to set a K-factor for these units also. No idea how to do it on a VMS-1000 though.
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Re: VM1000 fuel totalizer

Post by Robodog »

I have found the fuel gauges to be very unreliable. For the life of me, I can't understand why they installed gauges on 20 gallon tanks that only indicate a max of 17 gallons, but that's another story. The inaccuracy of the fuel gauges is the problem.

OTOH, the fuel computer on the VM1000 I have found to be very accurate and I never depart without having it properly set. BTW, I don't think it's correct to refer to it as a "totalizer". In my understanding, a totalizer adds the quantity of the two gauges and comes up with a total. The key word here is "gauges".

The VM1000 fuel computer works by the FUEL FLOW. It's simple math. You tell it how much is on board and then as soon as the computer detects FUEL FLOW, it starts to subtract based on that rate. If you have an accurate FUEL FLOW then you should have an accurate FUEL REM(aining). You should also have an accurate FUEL BURN. I have found it to be within 1 gallon after a couple hour flight.
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Re: VM1000 fuel totalizer

Post by Steve »

Roger:

Your aircraft seems to be the rare exception with respect to VM1000 fuel gauge accuracy. After more than 16 years on the various Diamond Forums, almost everyone reports a high degree of accuracy and repeatability with the VM1000 capacitive gauges. They do have the weird characteristic of not reading the outboard tank quantity (in the 40 gallon DA40s), but you will get used to that. My aircraft reads a maximum of 15 gallons per side (which is the actual capacity of the inboard tank). In my case, the gauges have never been off as much as one gallon per side in almost 18 years of ownership. Typically, they are off less than 0.5 gallons per side. I never fully trust the gauges (thanks to my primary flight instructor in the Navy), and crosscheck visually when possible, calculate fuel burn using the fuel flow numbers and book burn values, and in general, probably fly around with more fuel than I really need.

It is possible that your probes need to be recalibrated...

Steve
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