How do I get electrical experience?

In the past few months I've been working hard on learning about electricity so that I can make informed decisions about how to design and implement an electrical system into my RV-8. I've watched all the related Hints for Homebuilders videos, I went to the Sport Air workshop on electricity, I've read Bob's book twice and have done my best to learn from other builders through discussions here and on other forums.

I posted my design a few weeks ago and got a lot of great feedback. However, some of that feedback is troubling to me, and frankly has shaken my confidence in my ability to design and install my own system.

I'm sure electrical work is like any other area of building a plane -- there are some definite right and wrong ways to do things, and lots of ways to accomplish things that are right, and even more ways to accomplish things that are wrong!

I experienced this same sort of conflict when I began metal construction. One builder would recommend one thing, another would say to avoid that and do it another way. At that point in my project, following the plans gave me the experience I needed to form my own opinion with respect to metal work.

My trouble with electrical work is there aren't detailed plans for me to follow to gain experience so that I can form my own opinions. I have no idea if fuses are better than CBs, but that's a decision I have to make up front so I can design my system around that decision. For this particular item, I read Bob's book where he laid out an argument for fuses. I thought about it and agreed with him on it in principle, even though I don't have my own experience. That one was relatively easy, but there are hundreds of similar electrical decisions to be made that aren't so easy.

I don't want to do something because someone said to do it, no matter if he's Bob, a guy on the internet with an opinion, or one of the Wright Brothers. I want to learn why people recommend a certain thing so I can understand the problem and solutions and then be able to pick the one that represents the best option for me.

So my question to those who have gone before, how did you educate yourself well enough to be able to make your own decisions? I was feeling pretty confident in my abilities to design and install my system, but now I'm not sure.

Grateful for any insight you could offer.

Thanks,
Rob

Nihon_Ni said:

In the past few months I've been working hard on learning about electricity so that I can make informed decisions about how to design and implement an electrical system into my RV-8. I've watched all the related Hints for Homebuilders videos, I went to the Sport Air workshop on electricity, I've read Bob's book twice and have done my best to learn from other builders through discussions here and on other forums.

I posted my design a few weeks ago and got a lot of great feedback. However, some of that feedback is troubling to me, and frankly has shaken my confidence in my ability to design and install my own system.

I'm sure electrical work is like any other area of building a plane -- there are some definite right and wrong ways to do things, and lots of ways to accomplish things that are right, and even more ways to accomplish things that are wrong!

I experienced this same sort of conflict when I began metal construction. One builder would recommend one thing, another would say to avoid that and do it another way. At that point in my project, following the plans gave me the experience I needed to form my own opinion with respect to metal work.

My trouble with electrical work is there aren't detailed plans for me to follow to gain experience so that I can form my own opinions. I have no idea if fuses are better than CBs, but that's a decision I have to make up front so I can design my system around that decision. For this particular item, I read Bob's book where he laid out an argument for fuses. I thought about it and agreed with him on it in principle, even though I don't have my own experience. That one was relatively easy, but there are hundreds of similar electrical decisions to be made that aren't so easy.

I don't want to do something because someone said to do it, no matter if he's Bob, a guy on the internet with an opinion, or one of the Wright Brothers. I want to learn why people recommend a certain thing so I can understand the problem and solutions and then be able to pick the one that represents the best option one for me.

So my question to those who have gone before, how did you educate yourself well enough to be able to make your own decisions? I was feeling pretty confident in my abilities to design and install my system, but now I'm not sure.

Grateful for any insight you could offer.

Thanks,
Rob

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Rob:

You are asking the right questions on for the decisions that you will need to make.

Asking on the Internet, you will get lots of opinions for FREE. Since you paid nothing for them, some of them will be worth nothing.

It has been my experience to divide and conquer. Break the decision down to as small of parts as you can. List the Pros and Cons.

You are correct in that you must make the decision. Gain as much info as you can on the subject and reason it out.

I wanted to learn more about electricity when I was young. I went to College and got a degree in Electrical Engineering. I got a Ham Radio license, I built kit built electronics, I helped wire a house, I had a job repairing electronics, I had a job building interface cables, etc. Yes there is a lot of learning by doing AND making mistakes. We do not like to make mistakes with our airplanes.

I am not saying you should do everything I did to get experience but you can see that I am one person that learns by doing. Yes I have done things that I did not like, ripped it out out, and did it all over. That is part of the learning experience. It costs money and time. We homebuilt aircraft builders have time and most of us do not have a lot of money.

Here is an example of using pros and cons for one of your electrical questions.

Do I use Fuse or Circuit Breaker?

1st, what is the purpose of the fuse or circuit breaker (CB)?

The purpose is to protect the wire.

Pro and Con

Fuse Pro
Light Weight
Inexpensive

Fuse Con
Requires switch
Must have replacement when it blows
May not be replaceable in fight

CB Pro
Easy to reset / reusable in flight
CB Switch eliminates switch and one piece of wire (2 connections)

CB Con
Heavier than fuse
More Expensive
Can cause distraction while flying when necessary to reset


Unfortunately there are a lot of decisions like this that must be made. EVERY choice is a compromise.

I designed my aircraft electrical system while I was working a job in Japan. That was in the mid 90's. Airplane made first fight in 1997.

With my background, my own ideas and design were very similar to Bob Nuckolls. There were a few things I did that Bob did not recommend but there were things I wanted.

IF you can find someone that is doing electrical work, ask if them if you can look over their shoulder and help them. If you are like me, you will learn from watching and doing. If you were close to me, you could watch the questions I am asking myself about the installation of APRS Transmitter in my aircraft, location of APRS antenna, can I use one G5 RS232 for my APRS GPS source and my second G5 RS232 as serial altitude encoder data to a future ADS-B Transponder? What Wire size? What fuse size? What way will I route my wire?

The way the wire is routed in the electrical system can be important. My old steam gauge panel with compass mounted in the panel, had to have electrical wire kept away from the compass as electrical current creates an electrical field that will cause errors in the compass. After the installation of the two G5s and GMU11, the compass is redundant and no longer necessary but back in 1997 when the aircraft first flew, I did not want compass errors caused by my electrical system.

Rob, do not be discouraged. Your latest schematic is looking pretty good. Just a few more minor changes and it will look exactly like Bob N's. Seriously though, you will not go wrong by using Bob's Z-13/8. Many have tried to improve upon his architecture, but few have succeeded. Keep it simple and there will be less to go wrong. There is more than one way to skin a cat. Sometimes it is not a matter of the right way or the wrong way, just different ways, either of which is acceptable. Fuses versus circuit breakers is one example. It is a matter of personal preference. Being able to reset a circuit breaker in flight is not an advantage. It is a disadvantage because the pilot might be tempted to reset it, which could result in a fire. Wait until safely on the ground before troubleshooting an electrical problem. There should not be any device that is critical to safe flight. For each device, ask yourself what the backup plan is if this device fails.
To answer your question, the way to get electrical experience is by making mistakes.

Educate. Design. Decide. Install.

Lots of verbs there, and, IMHO, the right ones, except for one:

Educate, design, critique, decide, install.

Remember, you are not just the work force here, you are the project manager. You need to move a bit toward the management side for a bit.

So, as a worker, you gained an education in electrical systems, you designed one based on that education, and you asked for critique.

Now, as a manager, you need to draw upon your earlier education, supplement it with some more, evaluate the critique given, and decide. There is no perfect decision, but there is a best one, right now, given all you know. You can live with that decision. Really, you can.

Then you transition back to being a worker, and start to install. And when the worker finds something the manager missed, you start the process all over again, albeit on a much smaller scale.

Just wait for the fun that awaits you in post-production field modifications!

And as I re-read what the others have replied, all I really am doing is piling on, so much for being a sage. Still gonna post, though.

Hi Rob. My learning curve was pretty steep too. I can’t provide a recommendation for a source of learning but perhaps a philosophy might help you decide how much you need to know.

A comment another builder made to me that in retrospect was very prescient was to ignore the overly complex electrical systems many other builders use that just aren’t necessary for the vast majority of (especially VFR) RVs. In fact it is MUCH better to design and use a simple design that you FULLY understand than a more complex one that you do not. In an emergency a lot may ride on your full understanding.

FWIW, I followed a combination of Vans electrical design and bob nuckolls most simple design. Going simple made the learning curve much less steep. By the time I installed their designs I knew a far greater bit about electricity than I understood before starting.

Hope this helps just a bit.

You have done all the right things and studied the right sources to gain the knowledge you didn't have before. It sounds like you don't have a lot of piloting experience (not a criticism, I don't have very much either, and it's almost all in my Cessna 150 with a very basic panel). So to further fill in the gaps in my knowledge, I was fortunate in getting a great tutorial from Gary (since retired) at Aerotronics and having a flight instructor who is a former airline pilot. I'd suggest Aerotronics, SteinAir or a similar company for you to deal with and also perhaps find an instructor with airline experience.

I'm at the same stage you are at and have felt the same feelings of despair. I think that designing your own system is imperative to understanding what to do if failures pop up but it's a bit of a leap to get from a zero knowledge state to putting something on paper. What I've found tremendously helpful is to look at what other builders have done. Many are forthcoming with their schematics if you ask, while others protect their designs like it was the secret Coke formula. By looking at other's ideas in addition to Bob's Z-diagrams and Ausman's book, you see commonalities that consolidate standard practices and lead to greater understanding. You also get to see different solutions to the same problem which gives a larger repertoire to choose from when designing your own.

Rob,

To me, there are two learning "experiences" in wiring your plane: 1. the design, in which you have immersed yourself. 2. The mechanical implementation of your design. Of all the sources you quoted for information, if I had to choose one and just go with it, it would be Bob Nuckolls. He does a great job of addressing both areas. You can't go wrong by just implementing one of his designs!

Wiring a plane is like writing software. Lots and lots of ways to accomplish a single goal. I went with the VPX, and am happy with it, but I also use some fuses for my battery bus. CBs are a proven and reliable alternative. That's why certified planes have them. All are good alternatives. Pick one or a mix and get on with it. Your goal here is to build a plane, not an electrical system. Have your watched SteinAir's videos on Youtube? Great stuff there!

While I haven't been through your scheme like others have, it sure looks complicated. The more complicated the design, the more wire, the more frustration, etc. Why not take a clean sheet of paper and see how simple you can make it this time? I mean bare bones. I'll bet it looks like one of Bob's diagrams when you finish! These are little homebuilt planes, not airliners, and you can't fly them the same way in the same conditions. Every once in a while, when there's weather across the country, I'll go out to flightaware.com and search for RVs...rarely do I see anyone on a trip, and there's a good reason. They are not great planes for IMC, especially long stretches in the clouds or in turbulence, rain, etc. The plane's wiring, avionics as well as how you fly the plane need to reflect that reality.

Mark Dickens said:

Rob,

To me, there are two learning "experiences" in wiring your plane: 1. the design, in which you have immersed yourself. 2. The mechanical implementation of your design. Of all the sources you quoted for information, if I had to choose one and just go with it, it would be Bob Nuckolls. He does a great job of addressing both areas. You can't go wrong by just implementing one of his designs!

Wiring a plane is like writing software. Lots and lots of ways to accomplish a single goal. I went with the VPX, and am happy with it, but I also use some fuses for my battery bus. CBs are a proven and reliable alternative. That's why certified planes have them. All are good alternatives. Pick one or a mix and get on with it. Your goal here is to build a plane, not an electrical system. Have your watched SteinAir's videos on Youtube? Great stuff there!

While I haven't been through your scheme like others have, it sure looks complicated. The more complicated the design, the more wire, the more frustration, etc. Why not take a clean sheet of paper and see how simple you can make it this time? I mean bare bones. I'll bet it looks like one of Bob's diagrams when you finish! These are little homebuilt planes, not airliners, and you can't fly them the same way in the same conditions. Every once in a while, when there's weather across the country, I'll go out to flightaware.com and search for RVs...rarely do I see anyone on a trip, and there's a good reason. They are not great planes for IMC, especially long stretches in the clouds or in turbulence, rain, etc. The plane's wiring, avionics as well as how you fly the plane need to reflect that reality.

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I pretty much agree with everything Mark wrote here, and would only add a couple of thoughts. First - Bob Nuckoll?s isn?t just another homebuilder. He is a professional GA aircraft electrical systems designer who does this for major names in teh the certified airplane world. They bet their liability and business future on his work, so he has to meet pretty high standards. And his designs(and lifetime of experience) are there for you to use. SOmethign to think about!

Second, you get practical experince the same way we all do - by trying stuff, making mistakes, doing better the next time, and eventually reaching a level of competence. Practice making crimps and testing them. Practice lacing bundles. Practic running wires and be prepared to redo them. Don?t expect shortcuts to help you.

Simple is better, as simple as possible (but no simpler) is best.

Paul

Nihon_Ni said:

I don't want to do something because someone said to do it.... I want to learn why people recommend a certain thing ...

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Keep asking why, and you'll do fine.

I was feeling pretty confident in my abilities to design and install my system, but now I'm not sure.

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An observation:

Builders select an airplane kit because most don't feel confident in their ability to design their own, or build from scratch. Even pro structural and aero engineers buy kits, because the end result, in their professional judgment, is as good as anything they could design.

Most builders buy an engine, because they don't feel confident about building up their own, be it Lycoming, Subaru, or other.

A high percentage buy a complete plug and play panel, same reasons.

So why is it that so many feel they must jump in the deep end and design a world-beater electrical system, when it's possible to wire 90% of the RV's straight from a Nuckolls diagram, with no variations at all?

It's not a criticism Rob. I'll suggest you're demonstrating good judgement by questioning your design and ability.

True story. When I was five, I asked my grandfather, a career bridgeman, "Grandpa, why aren't you scared of heights?" He looked down at me, and said "Son, I am scared of heights. That's what keeps me alive".

Ironflight said:

Simple is better, as simple as possible (but no simpler) is best.

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+2

One of the most useful suggestions I followed in my electrical design was to just keep it simple. Break it all down into circuits for each item that needs to be powered, and do one at a time. The grander design will then follow from what you plan to equip your airplane with. For example, if you have IFR requirements, then figure out your emergency buss needs, or if you have electronic fuel injection, how are you going to keep the electrons flowing to make the engine run if a battery goes dead.

I built up a spread sheet for every wire. Source to destination. Power to switch. Switch to component. Component to ground. Lather, rinse, repeat.

I used the Vertical Power unit, and their manual was great to follow for the basic "systems" power - starter, alternator, shunt, etc. Think of it as a power supply with different outputs of varying amperage, and some logic that allows you to switch these circuits on/off -- just like a fuse or circuit breaker.

I have sections on the spreadsheet for the following:
Switches
Starter/Ignition/Mags
Flaps
Trim
Fuel pump
Seat Heaters
EFIS
EMS (includes things like fuel levels, EGT/CHT, MP, RPM, volts/amps, oil/fuel pressures, oil temp, canopy open micro-switches etc.)
ADAHRS
Strobe/POS lighting
Landing lighting
Panel lighting
GPS
XPNDR
ADS-B
APRS
Comm Radio
Intercom/headphones/microphones
ELT
Hobbs
Aux power outlets

There are HUNDREDS of wires involved, but breaking it down into smaller "systems" will go a long way to making it more manageable to wire up and get working.

Once I had it mostly figured out, I bought what I needed for wires/connectors/antennas/etc. and after that, it all went together in a couple of weeks of wiring work. The hard part is really in the planning/design (which took months).

Thanks for all the input. It's helpful to me to read about how others went about the learning process. I wish there was a like button in VAF, I would have clicked it on every one of the above posts! It's really comforting to know that I'm not the only one who has struggled with this part of the project, and everyone's comments have helped restore my confidence.

Many of you mentioned the simple theme, so I did go back and compare my schematic to Bob's Z-13/8T that I based it on. I think mine looks more complicated because I include all the switches and appliances, and Bob's doesn't. Otherwise, I've made very few changes to his original design:

• I've added six CBs where he uses fuses for everything except the main alternator field (I added AP & Servos CBs because I felt the need to be able to disconnect power in the event of a trim runaway; Com 2 & Transponder CBs as a means of additional load shed without designing away the option to use either of these devices; L & R P-mag CBs because the manufacture recommends CBs even though Bob's design has a fuse for his one P-mag.) Because of these CBs, I had to split the Main and E-Bus in two: bus 1 is a fuse block, and bus 2 is a series of three or four CBs.
• I've incorporated his design for an avionics master switch (because I'm in the "gotta have one camp").
• I went with dual P-mags instead of one P-mag & one E-mag.
• I used Hall effect sensors instead of shunts -- both are listed as options for the G3X.
• I eliminated the battery bus, because I didn't have anything to put on it except the E-Bus feed (no dome light, clock, hobbs meter, and no E-mag).
• I upgraded the main alternator controller from the Z-12 design instead of the generic Ford regulator in the Z-13 design. When I did, Bob told me to remove the crowbar on the master switch because the LRC3 has one built in.
• I added an Aux Alt Warn light proposed by the SD-8 manufacturer, and incorporated a Starter Engaged alert into my G3X because it's an available feature of the starter contactor.

Actually, now that I look at the above list I'm not sure why I've been so fearful of my design. I think I was feeling that it was overly complex too, but it's really a Z-13/8 at heart that includes every switch and appliance that uses power all on one sheet.

The biggest thing that has given me pause is how to feed power to the E-Bus 2 and Main Bus 2, but that's a discussion for the other thread.

I do have some good electricians in our chapter, and I'll make sure to lean on them when I start wiring to make sure I'm using good techniques.

Thanks again for everyone's input!

Rob

bruceh said:

Once I had it mostly figured out, I bought what I needed for wires/connectors/antennas/etc. and after that, it all went together in a couple of weeks of wiring work. The hard part is really in the planning/design (which took months).

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That's great to hear, because I've been stuck on the design phase for months!

BTW, I don't know if you recall Bruce, but you were kind enough to let me steal two hours of your build time back in 2011. I was stationed in Japan at the time and had a week of duty in San Diego and you invited me over to your workshop one evening. You were one of eight builders I visited that week, and that time was incredibly valuable to my journey as an airplane builder. Thanks again for that!!