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Waiex-B #21 Electrical System & Garmin G3X Touch Setup
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Waiex-B #21 Electrical System & Garmin G3X Touch Setup
by Spaceman » Fri Apr 10, 2020 1:08 am
I've been working from home lately and therefore making a bunch of progress designing my electrical system! I am chipping away at the details on this setup a little bit every day but I thought I'd start posting my progress. Since I got a lot of questions answered on my other thread about buses, I think I finally have my schematic respectable enough to post on the internet.
I'll be running an Aerovee Turbo, and I'm planning a Garmin G3X Touch panel/avionics setup. I'm sure I'm not the first Sonex guy to do a G3X setup, but I didn't find much content about this system on here so maybe this thread will help more people in the future. Seems like Garmin is a lot more popular with RV dudes, so I found a lot of useful info on their forum... most of their systems are a lot more complicated than what I'm planning though.
Anyway, I will continuously update this thread as I figure everything out and eventually start actually building it. Hopefully by the end it will be another coherent reference for future builders. Electrical stuff is not one of my strongest areas so I'm open to any and all feedback!! I am figuring all of this out as I go. I know the schematic still needs quite a few details filled in... Namely choosing wire gauges and specifying grounding info for a lot of items, and probably lots of other details I'm missing.
Files I'm attaching so far are:
1. Wiring schematic
2. Big picture Garmin data bus layout
3. List of components (just a barely organized brainstorm at this point)
4. List of electrical loads by item
Future items I'm working on but not ready to post yet:
5. Garmin pinout spreadsheet
6. Detailed Garmin connections diagram
7. Panel Layout Imagery
Sources I referred to and/or blatantly copied to come up with my system:
Noel Wade: http://sonexbuilders.net/viewtopic.php? ... ric#p26716
Frank Alvarez: http://sonexbuilders.net/viewtopic.php?f=6&t=1564
Ryan Roth: https://drive.google.com/file/d/0B4ApjY ... ZuYkU/view
Jeff Schultz: http://www.sonex604.com/misc/Sonex1374E ... 5Sep13.pdf
Bob Nuckolls figure Z-11 (or pretty much this: https://bandc.com/wp-content/uploads/20 ... le_alt.pdf)
B&C Crowbar OV Diagram: https://bandc.com/wp-content/uploads/20 ... 0_revJ.pdf
--------------
Some questions I'm pondering now are:
-Did I do the crowbar overvoltage protection correctly? Seemed like there were a couple different ways to do it based on the diagrams I've seen.
-Anyone know if the overvoltage/alternator OFF warning light that comes with the crowbar kit can be replaced with a discrete input of some kind on an EFIS? This might be a question for Garmin, but a popup annunciator on the PFD might be cleaner and better than the warning light.
-The voltage regulator that comes with the Aerovee appears to be grounded just by its hardware to the firewall. However the B&C crowbar diagram shows a negative lead from the regulator connected to the negative terminal of the filter capacitor, then a ground wire twisted with the positive lead until it reaches its ground point. How do you guys do that with our regulator? Just put them close together and run a wire from the capacitor negative to a ring terminal on one of the regulator mounting bolts?
-Anyone know the power required for the Sonex fuel level probe transducer? The instructions that came with it say it needs 12 volts, but Garmin's fuel level transducer power terminal on the GEA 24 is only 5 volts. I wonder if it would still work, or maybe I could connect it to a different pin on the GEA 24. If not I'll just power that transducer from the bus like what I have depicted.
-I have an FT-90 (gold cube) fuel flow sensor that I bought from Sonex, but I can't remember why I bought that over the FT-60 red cube. Now that I'm digging into the details more the FT-90 seems to be geared toward way higher fuel flow than an Aerovee... Does it work or should I see if I can swap it for an FT-60?
Other things that are not really questions but just things I'm considering:
-Adding a keyed switch in series with the starter button for security, or just go no keys at all
-Keeping the power stabilizer to enable avionics to be on during engine start, or look into a separate/backup power source as discussed in the other power distribution thread
I'll be running an Aerovee Turbo, and I'm planning a Garmin G3X Touch panel/avionics setup. I'm sure I'm not the first Sonex guy to do a G3X setup, but I didn't find much content about this system on here so maybe this thread will help more people in the future. Seems like Garmin is a lot more popular with RV dudes, so I found a lot of useful info on their forum... most of their systems are a lot more complicated than what I'm planning though.
Anyway, I will continuously update this thread as I figure everything out and eventually start actually building it. Hopefully by the end it will be another coherent reference for future builders. Electrical stuff is not one of my strongest areas so I'm open to any and all feedback!! I am figuring all of this out as I go. I know the schematic still needs quite a few details filled in... Namely choosing wire gauges and specifying grounding info for a lot of items, and probably lots of other details I'm missing.
Files I'm attaching so far are:
1. Wiring schematic
Electrical System rev 1.2.pdf- (425.53 KiB) Downloaded 347 times
2. Big picture Garmin data bus layout
- G3X Interconnect v1.1.pdf
- (101.05 KiB) Downloaded 322 times
3. List of components (just a barely organized brainstorm at this point)
- Electrical Components 2020-04-09.pdf
- (437.36 KiB) Downloaded 281 times
4. List of electrical loads by item
- Electrical Load Calcs 2020-04-09.pdf
- (410.47 KiB) Downloaded 287 times
Future items I'm working on but not ready to post yet:
5. Garmin pinout spreadsheet
6. Detailed Garmin connections diagram
7. Panel Layout Imagery
Sources I referred to and/or blatantly copied to come up with my system:
Noel Wade: http://sonexbuilders.net/viewtopic.php? ... ric#p26716
Frank Alvarez: http://sonexbuilders.net/viewtopic.php?f=6&t=1564
Ryan Roth: https://drive.google.com/file/d/0B4ApjY ... ZuYkU/view
Jeff Schultz: http://www.sonex604.com/misc/Sonex1374E ... 5Sep13.pdf
Bob Nuckolls figure Z-11 (or pretty much this: https://bandc.com/wp-content/uploads/20 ... le_alt.pdf)
B&C Crowbar OV Diagram: https://bandc.com/wp-content/uploads/20 ... 0_revJ.pdf
--------------
Some questions I'm pondering now are:
-Did I do the crowbar overvoltage protection correctly? Seemed like there were a couple different ways to do it based on the diagrams I've seen.
-Anyone know if the overvoltage/alternator OFF warning light that comes with the crowbar kit can be replaced with a discrete input of some kind on an EFIS? This might be a question for Garmin, but a popup annunciator on the PFD might be cleaner and better than the warning light.
-The voltage regulator that comes with the Aerovee appears to be grounded just by its hardware to the firewall. However the B&C crowbar diagram shows a negative lead from the regulator connected to the negative terminal of the filter capacitor, then a ground wire twisted with the positive lead until it reaches its ground point. How do you guys do that with our regulator? Just put them close together and run a wire from the capacitor negative to a ring terminal on one of the regulator mounting bolts?
-Anyone know the power required for the Sonex fuel level probe transducer? The instructions that came with it say it needs 12 volts, but Garmin's fuel level transducer power terminal on the GEA 24 is only 5 volts. I wonder if it would still work, or maybe I could connect it to a different pin on the GEA 24. If not I'll just power that transducer from the bus like what I have depicted.
-I have an FT-90 (gold cube) fuel flow sensor that I bought from Sonex, but I can't remember why I bought that over the FT-60 red cube. Now that I'm digging into the details more the FT-90 seems to be geared toward way higher fuel flow than an Aerovee... Does it work or should I see if I can swap it for an FT-60?
Other things that are not really questions but just things I'm considering:
-Adding a keyed switch in series with the starter button for security, or just go no keys at all
-Keeping the power stabilizer to enable avionics to be on during engine start, or look into a separate/backup power source as discussed in the other power distribution thread
-
Spaceman - Posts: 330
- Joined: Sat Jan 21, 2012 5:52 pm
- Location: Roseville, CA
Re: Waiex-B #21 Electrical System & Garmin G3X Touch Setup
by sonex1374 » Fri Apr 10, 2020 10:52 am
Chris,
A few comments on the system drawing ver 1.2:
- The crowbar module is routed thru a 2amp circuit breaker (CB) mounted next to the Bat-Alt switch. This 2a CB is probably a bit on the small side and might tend to trip randomly (nuisance trip), and should be a 5a. Also, just a bit further to the right you show a 10a fuse on that same line. This is redundant and can be eliminated. If you're using a fuse block to route power to the switch, I suggest making this fuse more robust so that it won't be stressed at all - say 15a. (During an overvoltage event the wire will temporarily see current flows higher than the CB's rating. You don't want that to hammer away at the fuse, building up accumulated cycles that might eventually cause the fuse to fail. Up-sizing a bit will hedge against this. It's for this very reason that convention discourages fuses and circuit breakers on the same line, unless they are vastly different ratings.)
- You asked is the light could be omited and instead displayed on the EFIS. Yes, this is possible. You'd need to configure an input with logic that says "activate warning if detected volts is > 9V (or something like that)". This is the condition that would normally light the warning lamp.
- Recent user experience suggests that the solenoid on the AeroVee starter may draw a pretty good load for a couple seconds. You might want to make that circuit from 14 AWG wire and protect with a 15a fuse. You also might want to change the diagram to show the fat starter supply wire (suggest 4 AWG) going to the starter rather than the solenoid portion of the picture. It's just a way of depicting that these wires have different purposes and connect to different places.
- Seat warmers will vary in amp draw, but mine use 5a each side when on high, 3a on low. Plan your wire and fuse sizes on 10 amps total draw.
- The aux power jack (I'm assuming this is a standard cigarette lighter plug outlet) should be wired for 7a. This is the rating that most plugs will support (some go up to 10a or even 15a, but that's overkill for our uses).
- The panel contains switches to energize the utility and comm buses, as well as CB's. However, every load that branches off those buses has it's own fuse to protect it. This makes the upstream CB redundant. The thing about redundant CB's is that they don't add any more safety - they actually decrease it (CB's are far less reliable than a single run of wire). What happens if that CB fails? The entire bus goes dark. What happens if a single load on the bus fails? That specific fuse pops and that circuit goes dark. Under what circumstances would the main CB trip? (e.g. when would it add value?) Only when there is a runaway short to ground in the main wire feeding that bus (how....chaffing? Bad luck?). How long is this feed wire and how likely is it to fail? (maybe a few inches???) Anyway, I'm just trying to provide a mental framework to think thru the value of these components.
- The voltage regulator can be grounded at any convenient place. The firewall typically is directly connected to the central ground point (especially if you use a 'forest of tabs" grounding block). You could also run a ground wire to the central ground point, but it usually isn't needed so long as you have good connectivity to the firewall. There's no need to run a ground wire to the capacitor.
- The 25a main circuit breaker (to the main bus) looks like it might be undersized. Worst case power draw on the main bus: secondary ignition (8a) + all lights (6a) + radios (5a) = 19a. Now add something unexpected like energize the starter solenoid (8a) or deploy flaps (3a) and you're really close to the 25a rating. Might not be a problem, but might be a good idea to re-look these loads and the CB rating. Again, I'd suggest that this CB might not even be a good idea. With one failed CB you'll go completely dark, and under what circumstances would it actually help you out? If you kept the wire feeding the main bus nice and large (8AWG) and short, it's unlikely to ever fail, and any sub-component of the main bus has it's own protection, so all you're protecting is the wire from the panel to the main bus. (Remember, the wire upstream of the panel CB is still subject to short circuit even after the CB has tripped!)
- I hope this helps, and gives you something to think about. Builders tend to think that adding components is the best way to improve safety, but that's not really the truth. A properly sized and constructed wire is by far the most reliable component, and we only add fuses and CB's when we absolutely need to. Only when the benefit they provide outweighs the risk we introduce by installing them are they appropriate.
Good work so far, and keep plugging away at it!
Jeff
A few comments on the system drawing ver 1.2:
- The crowbar module is routed thru a 2amp circuit breaker (CB) mounted next to the Bat-Alt switch. This 2a CB is probably a bit on the small side and might tend to trip randomly (nuisance trip), and should be a 5a. Also, just a bit further to the right you show a 10a fuse on that same line. This is redundant and can be eliminated. If you're using a fuse block to route power to the switch, I suggest making this fuse more robust so that it won't be stressed at all - say 15a. (During an overvoltage event the wire will temporarily see current flows higher than the CB's rating. You don't want that to hammer away at the fuse, building up accumulated cycles that might eventually cause the fuse to fail. Up-sizing a bit will hedge against this. It's for this very reason that convention discourages fuses and circuit breakers on the same line, unless they are vastly different ratings.)
- You asked is the light could be omited and instead displayed on the EFIS. Yes, this is possible. You'd need to configure an input with logic that says "activate warning if detected volts is > 9V (or something like that)". This is the condition that would normally light the warning lamp.
- Recent user experience suggests that the solenoid on the AeroVee starter may draw a pretty good load for a couple seconds. You might want to make that circuit from 14 AWG wire and protect with a 15a fuse. You also might want to change the diagram to show the fat starter supply wire (suggest 4 AWG) going to the starter rather than the solenoid portion of the picture. It's just a way of depicting that these wires have different purposes and connect to different places.
- Seat warmers will vary in amp draw, but mine use 5a each side when on high, 3a on low. Plan your wire and fuse sizes on 10 amps total draw.
- The aux power jack (I'm assuming this is a standard cigarette lighter plug outlet) should be wired for 7a. This is the rating that most plugs will support (some go up to 10a or even 15a, but that's overkill for our uses).
- The panel contains switches to energize the utility and comm buses, as well as CB's. However, every load that branches off those buses has it's own fuse to protect it. This makes the upstream CB redundant. The thing about redundant CB's is that they don't add any more safety - they actually decrease it (CB's are far less reliable than a single run of wire). What happens if that CB fails? The entire bus goes dark. What happens if a single load on the bus fails? That specific fuse pops and that circuit goes dark. Under what circumstances would the main CB trip? (e.g. when would it add value?) Only when there is a runaway short to ground in the main wire feeding that bus (how....chaffing? Bad luck?). How long is this feed wire and how likely is it to fail? (maybe a few inches???) Anyway, I'm just trying to provide a mental framework to think thru the value of these components.
- The voltage regulator can be grounded at any convenient place. The firewall typically is directly connected to the central ground point (especially if you use a 'forest of tabs" grounding block). You could also run a ground wire to the central ground point, but it usually isn't needed so long as you have good connectivity to the firewall. There's no need to run a ground wire to the capacitor.
- The 25a main circuit breaker (to the main bus) looks like it might be undersized. Worst case power draw on the main bus: secondary ignition (8a) + all lights (6a) + radios (5a) = 19a. Now add something unexpected like energize the starter solenoid (8a) or deploy flaps (3a) and you're really close to the 25a rating. Might not be a problem, but might be a good idea to re-look these loads and the CB rating. Again, I'd suggest that this CB might not even be a good idea. With one failed CB you'll go completely dark, and under what circumstances would it actually help you out? If you kept the wire feeding the main bus nice and large (8AWG) and short, it's unlikely to ever fail, and any sub-component of the main bus has it's own protection, so all you're protecting is the wire from the panel to the main bus. (Remember, the wire upstream of the panel CB is still subject to short circuit even after the CB has tripped!)
- I hope this helps, and gives you something to think about. Builders tend to think that adding components is the best way to improve safety, but that's not really the truth. A properly sized and constructed wire is by far the most reliable component, and we only add fuses and CB's when we absolutely need to. Only when the benefit they provide outweighs the risk we introduce by installing them are they appropriate.
Good work so far, and keep plugging away at it!
Jeff
- sonex1374
- Posts: 605
- Joined: Thu Mar 27, 2014 1:02 am
Re: Waiex-B #21 Electrical System & Garmin G3X Touch Setup
by Spaceman » Fri Apr 10, 2020 12:11 pm
Jeff,
Thanks for all the info!! All super helpful. Yeah the CB's upstream of fuse blocks was something I was wondering about too, like what is the point if everything downstream is on its own fuse? None I guess. I think I'm going to end up with only one CB for the alternator field circuit, which I think I've seen you recommend in other threads. Thanks for the help!!
Thanks for all the info!! All super helpful. Yeah the CB's upstream of fuse blocks was something I was wondering about too, like what is the point if everything downstream is on its own fuse? None I guess. I think I'm going to end up with only one CB for the alternator field circuit, which I think I've seen you recommend in other threads. Thanks for the help!!
-
Spaceman - Posts: 330
- Joined: Sat Jan 21, 2012 5:52 pm
- Location: Roseville, CA
Re: Waiex-B #21 Electrical System & Garmin G3X Touch Setup
by Spaceman » Sat Apr 18, 2020 3:11 pm
OK I finally made some more progress on this thing! New versions posted below.
Things I've changed:
-Updated wire/fuse/CB sizes per Jeff's suggestions.
-Moved the autopilot servos from the utility bus to avionics bus. Garmin says powering them down in flight will cause nuisance warnings so I'll just keep them powered with everything else.
-Removed engine sensor details to make some space, because I'm going to depict them on the G3X diagram.
Things yet to figure out:
-Exactly how to replace the crowbar/alternator OFF and the power stabilizer low voltage panel lights with Garmin discrete inputs.
-Several wire sizes yet to figure out.
-Trying to decide if I want to incorporate a keyed switch somewhere... I thought the simplest way would be to put one in series with the starter button, but I can't find any rated for more than 4 amps!
-Still need to add the turbo cooler stuff.
Latest Versions:
Overall wiring version 1.4:
Latest Component List:
Next, I think I have pretty much wrapped my head around the G3X wiring. I was initially pretty overwhelmed paging through the 900+ page installation manual, but after many hours of flipping pages I think I've extracted what's relevant to my installation. I'm still working out a few details, mostly with what to connect to the GEA 24 and how, but I think it's nearly figured out.
G3X Pinout List:
G3X Diagram:
Critiques welcome!!
Things I've changed:
-Updated wire/fuse/CB sizes per Jeff's suggestions.
-Moved the autopilot servos from the utility bus to avionics bus. Garmin says powering them down in flight will cause nuisance warnings so I'll just keep them powered with everything else.
-Removed engine sensor details to make some space, because I'm going to depict them on the G3X diagram.
Things yet to figure out:
-Exactly how to replace the crowbar/alternator OFF and the power stabilizer low voltage panel lights with Garmin discrete inputs.
-Several wire sizes yet to figure out.
-Trying to decide if I want to incorporate a keyed switch somewhere... I thought the simplest way would be to put one in series with the starter button, but I can't find any rated for more than 4 amps!
-Still need to add the turbo cooler stuff.
Latest Versions:
Overall wiring version 1.4:
- Electrical System rev 1.4.pdf
- (251.14 KiB) Downloaded 284 times
Latest Component List:
- Electrical Components 2020-04-18.pdf
- (442.67 KiB) Downloaded 282 times
Next, I think I have pretty much wrapped my head around the G3X wiring. I was initially pretty overwhelmed paging through the 900+ page installation manual, but after many hours of flipping pages I think I've extracted what's relevant to my installation. I'm still working out a few details, mostly with what to connect to the GEA 24 and how, but I think it's nearly figured out.
G3X Pinout List:
- G3X Pinout Lists 2020-04-17.pdf
- (475.54 KiB) Downloaded 287 times
G3X Diagram:
- G3X Pinout Diagram rev 1.2.pdf
- (34.88 KiB) Downloaded 278 times
Critiques welcome!!
-
Spaceman - Posts: 330
- Joined: Sat Jan 21, 2012 5:52 pm
- Location: Roseville, CA
Re: Waiex-B #21 Electrical System & Garmin G3X Touch Setup
by WilliamBatten » Wed May 11, 2022 1:52 pm
Chris,
Very nice work on the electrical system diagram. Can I ask you which CAD program you used?
Bill
Very nice work on the electrical system diagram. Can I ask you which CAD program you used?
Bill
Bill
N67WX - Reserved
Waiex-B Taildragger
Jabiru 3300
N67WX - Reserved
Waiex-B Taildragger
Jabiru 3300
-
WilliamBatten - Posts: 31
- Joined: Fri Mar 25, 2022 2:41 pm
Re: Waiex-B #21 Electrical System & Garmin G3X Touch Setup
by WilliamBatten » Wed May 11, 2022 1:59 pm
Chris,
One more question - Is your G3X the 7" or 10"?
Bill
One more question - Is your G3X the 7" or 10"?
Bill
Bill
N67WX - Reserved
Waiex-B Taildragger
Jabiru 3300
N67WX - Reserved
Waiex-B Taildragger
Jabiru 3300
-
WilliamBatten - Posts: 31
- Joined: Fri Mar 25, 2022 2:41 pm
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