G3X Installation/Wiring

[Jimd]

I am searching for "backup" solutions for my new G3X. What I suspect as a typical failure is some alternator problem and a dead battery. Second might be some issue with the primary display and or ADAHRS and other systems connected to the EFIS. I do plan to fly IFR. For the near future I will have a single display and likely add a second screen next spring.

My initial search and thoughts are something like the GRT mini WITH the internal battery might provide a good solution. I might also consider a secondary backup battery.

I don't want to put a vac pump back into the picture.

What are some of the popular solutions?

Jim

[SMO]

I chose a GRT Mini-X with HSI, magnetometer and internal battery as a backup. I also have an SD-8, secondary alternator mounted to the vacuum pad.

Keep in mind that if your G3X display becomes inoperable the Mini will work fine for attitude and direction in the soup, but vertical guidance during an approach requires changing the screen. So during an approach you can either have attitude and directional guidance, or directional and vertical guidance but no attitude (not a good choice IMHO).

[redbaron]

I,m getting ready to install the GPS-20A box and was thinking of installing it to the back of the rear baggage bulkhead and installing the GA-35 ant. on the top tail area. Q: Can bus use for the GPS-20a to the ads-b in inst. pnl?

[Jimd]

I flew up to Airlake and picked up a GDU 460 and luckily it fit nearly perfectly into my panel where I had the 450. In some of my pictures above you can see the patch panel that came out to fit the larger screen.

GDU 450 small display with patch to allow large display.



My advice to anyone trying to decide between the small or large displays is get the big one! There are too many things that the small screen just does differently that the large screen does better.

One easy example, when you touch the autopilot control it pops up the full AP screen. On the small display, it covers up the PFD, on the large display, it splits the display and you still have a completely usable PFD with AP controls next to that.

My plan now is to move the rest of my engine probes over to the G3X EIS and then mount the smaller display where my current round gauges are.

I also got to see the MINI X while at SteinAir, it looked nice so I will be saving for that as my backup.

Jim

[Jimd]

Here is a preliminary layout for my upgrade.
Any changes or suggestions are welcome.
If you have a similar equipment layout I would love to see it.

Here is the panel now with the single large g3x.



And the first preliminary layout.



Jim

[deene]

Originally Posted by Jimd

I am searching for "backup" solutions for my new G3X. What I suspect as a typical failure is some alternator problem and a dead battery. Second might be some issue with the primary display and or ADAHRS and other systems connected to the EFIS. I do plan to fly IFR. For the near future I will have a single display and likely add a second screen next spring.

My initial search and thoughts are something like the GRT mini WITH the internal battery might provide a good solution. I might also consider a secondary backup battery.

I don't want to put a vac pump back into the picture.

What are some of the popular solutions?

Jim

I'm just finishing putting a G3X panel into Bobby Lucroy's RV8A. The panel was beautify built by Steinair and includes a GNC 625, dual COMS, TXP 23, A/P, audio panel and ADSB.

Our design solves the backup issue with a TCW 3AH lithium backup battery for the EFIS and associated modules and for COM1 (if desired by the pilot). Additionally a Dynon D2 is mounted to cover EFIS failures. This system should operate for 30-45 minutes after a battery, alternator or master contactor failure and also cover all electrical and panel single point failures...

[Jimd]

We are supposed to have a few nice days this week so I plan to migrate the rest of my engine sensors to the g3x. Does anyone have thoughts on the fuel level calibration process?

When I did this step for the vans analog gauges I think I used two 6 gal jugs that I have marked at 2 gal increments to check the indications. The gauges have worked fine and indicate properly, once you drop below the level where the float moves.

I am wondering if someone with a 6 (taildragger preferred, but tri gear might also provide useful info) has the "numbers" for the GEA 24 fuel level?

Otherwise, is there any new ideas for this step? I would love to have a new tank in the back of my pickup with a digital meter and electric pump, but I can see spending money on that for a one time deal.

More info. The senders are resistive and I don't recall recording any resistance values the first time around.


Jim

[SMO]

I did mine 1 gallon at a time. Was a bit time consuming but gives the most accurate result.

The G3X has two sets of parameters, one with the tail down and one for level flight, so each tank was done twice.

Mine's not a -6 so the numbers wouldn't help you.

[g3xpert]

Originally Posted by Jimd

We are supposed to have a few nice days this week so I plan to migrate the rest of my engine sensors to the g3x. Does anyone have thoughts on the fuel level calibration process?

When I did this step for the vans analog gauges I think I used two 6 gal jugs that I have marked at 2 gal increments to check the indications. The gauges have worked fine and indicate properly, once you drop below the level where the float moves.

I am wondering if someone with a 6 (taildragger preferred, but tri gear might also provide useful info) has the "numbers" for the GEA 24 fuel level?

Otherwise, is there any new ideas for this step? I would love to have a new tank in the back of my pickup with a digital meter and electric pump, but I can see spending money on that for a one time deal.

More info. The senders are resistive and I don't recall recording any resistance values the first time around.


Jim

Hi Jim,

If you have a self-serve fuel pump on your field, and a helper, it is pretty easy.

After installing a new G3X Touch system in our RV-7A last year, we calibrated the float (resistive) sensors every 2 gals. I sat in the plane and incremented each calibration point by 2 gals and captured the calibration value after the helper finished adding each 2 gal amount by watching the indication on the fuel pump.

Both of the floats topped out at about 16 gals (~21 gal tank), so be prepared to see the calibration curve go flat line on you there. You can stop calibrating when this happens.

Don't forget to save the calibration to the SD card for safe keeping after calibrating each tank. You can save both the in-air and on-ground calibrations for your -6 tail dragger. You can restore the calibration from the SD card any time you like.

One thing you might consider is to calibrate the in-air readings first, then the next time you burn off that fuel repeat the calibration at the pump to capture the on-ground readings (which are optional).

Let us know if you have questions, but the procedure is pretty straight forward.

Thanks,
Steve

[Jimd]

Minor update.

A good friend suggested we use the vans gauges to find data points for the g3x EIS. We used a power supply set to 14.5 volts and a potentiometer with a range that paralleled the SW senders. We recorded the settings of the pot (it has a large knob with a pointer and scale from 0 - 10 graduated in tenth's).

We recorded the major points and he created a table with 1/2 gal increments and pointer settings. Then at the hanger I plugged the potentiometer into the left tank pin 6 and ran the calibrate procedure for that tank. Then the right tank.

After all that I plugged the actual sender wires into the pins 6 and 9.

Haven't flown it yet, but I think it will be more than adequate and I plan to verify the quantities as I use fuel and top the tanks.

Jim

I will post another update as I verify the levels. What I really like about this method is that I didn't have to drain fuel or otherwise manage fuel in the hanger. If I had been doing this with a new airplane and empty tanks I would probably had the fbo bring the truck to the hanger and do the calibration 2 gal at a time. I also had the benefit of knowing how my original gauges worked, otherwise I wouldn't have been able to use them to gather the data points for this method.

Jim