Vertical Power VP-X Pro User manual

Electronic Circuit Breaker System
VP-X Pro — VP-X Sport
Installation and Operating Manual
August 5, 2020
Rev. D
Current as of software version 1.6
VP-X Installation and Operating Manual Rev. D Copyright © 2020 Astronics

VP-X Installation and Operating Manual
Rev. D (August 5, 2020) Page 2
Important Notice
This manual contains important information that may affect the safety of your
aircraft. Do not y the aircraft until you fully understand the installation and
operating instructions, and all of the pre-ight checks have been successfully
completed.
Read the Limited Warranty document (Limited Warranty - Vertical Power Products)
available at www.verticalpower.com. There is information in the Limited Warranty that
may alter your decision to install this product. If you do not accept the terms of the
Limited Warranty, do not install this product. The product may be returned for a
refund if you do not accept the terms of the Limited Warranty.
Astronics is not liable or responsible for a pilot’s action or any situation that results in
personal injury, property damage, missed commitments, lack of use of an aircraft or
any expenses incurred due to: product failure, inaccuracy in displayed data or text les,
display or display format issues, software bugs or problems, upgrade or customization
issues, misinterpretation of the display, warning and/or limit settings, calibration
problems, installation issues (leaks, mis-wiring, obstructions, damage to aircraft or
components, incorrect installation of any parts, wrong parts, parts that don’t t, etc.) or
any other issues related to the installation or operation of this product. All of the above
are solely the pilot’s and/or installer’s responsibility.
The pilot must understand the operation of this product before ying the aircraft.
The pilot will not allow anyone to operate the aircraft that does not know the operation
of this product. The pilot will keep these Operating Instructions in the aircraft at all
times. The ability for this product to correctly control electronic components and detect
a problem is directly related to the pilot’s ability to properly install the system, and the
pilot’s interpretation and observation skills.
By installing this product, the aircraft owner/pilot and installer agree to hold Astronics
harmless and in no way responsible for monetary compensation, including punitive
damages for any incident, harm and/or damage associated with this product (including
but not limited to the ones listed above). If you do not agree to the above, DO NOT
INSTALL THIS PRODUCT. The pilot, aircraft owner and/or installer may want to obtain
an appropriate insurance policy before installing this product. If you do not have the
skills, knowledge, tools, equipment or facility, to perform and determine the installation
of this product is safe, reliable and accurate and to determine this product is operating
properly after installation, DO NOT INSTALL THIS PRODUCT. If the aircraft owner/pilot
and/or installer are unwilling to take the responsibility for the installation and operation
of this product, DO NOT INSTALL THIS PRODUCT. This product may be returned for
a refund by contacting Astronics.
It is possible for any system to fail thereby disabling electronic components or
displaying inaccurate high, low or jumpy readings. Therefore, you must be able to
recognize a system failure and you must be procient in operating your aircraft safely
in spite of a system failure. IT IS THE BUILDER AND/OR PILOT’S RESPONSIBILITY
TO DETERMINE THE APPROPRIATE LEVEL OF BACKUP AND REDUNDANT
SYSTEMS NEEDED FOR SAFE OPERATION OF THE AIRCRAFT. If you do not have
this knowledge or skill, contact the FAA, a certied aircraft mechanic, or a local ight
instructor for training prior to building or ying the aircraft with this system.
Before ying the aircraft verify the instrument markings displayed on the system are
accurate with your POH for every function displayed. Verify that each electrical device
is congured correctly and behaves appropriately. All data must be veried by the pilot
before it is used.
Before starting the installation, make sure that your planned installation will not interfere
with the proper operation of any controls. The installer should use current aircraft
standards and practices to install this product. Refer to AC 43.13-2A, Acceptable
Methods, Techniques, and Practices - Aircraft Alterations and AC 43.13-1B, Acceptable
Methods, Techniques, and Practices—Aircraft Inspection and Repair.
This is an experimental system limited to use in experimental aircraft or Light Sport
Aircraft. These products are not approved for use in aircraft with FAA or foreign type
certicates.
Limited Warranty
For warranty information, please refer to the Limited Warranty document (Limited
Warranty - Vertical Power Products) available at www.verticalpower.com.
Copyright Notice
Copyright ©2020 by Astronics. Astronics’ permission to copy and distribute this manual
is for the purchaser’s private use only and is conditioned upon purchaser’s use and
application with the hardware that was shipped with this manual. No commercial resale
or outside distribution rights are allowed by this notice. This material remains the
property of Astonics. All other rights reserved by Astronics.
Trademarks
Vertical Power is a registered trademark of Astronics. All other product names or
trademarks are property of their respective owners.
Astronics
The home of Vertical Power products
12950 Willows Road NE
Kirkland, WA 98034
Phone: [phone]
Email: [e-mail]

VP-X Installation and Operating Manual
Rev. D (August 5, 2020) Page 3
Contents
1. Introduction
1.1 Welcome to Vertical Power!..............................7
1.2 Vertical Power Terms ..................................7
1.3 Other Reference Documents.............................8
2. VP-X Overview
2.1 Installation Overview ...................................9
2.2 System Overview......................................9
2.3 Supported Bus Architecture..............................9
3. Electrical System Basics
3.1 Free Advice on Designing your Electrical System ............10
3.2 Introduction ......................................... 11
3.3 Alternator Operation .................................. 11
3.4 Wire Sizes and Circuit Protection ........................ 11
3.5 Grounding ..........................................12
3.6 Switch Nomenclature..................................12
3.7 Alternator Current Sensing (Shunt) .......................13
3.8 Bench Testing the VP-X................................13
4. Planning
4.1 EFIS...............................................14
4.2 How Switches Are Wired ...............................14
4.3 Wiring Harness ......................................15
4.4 Dual Bank Technology (VP-X Pro)........................15
4.5 Tools and Other Stuff ..................................17
4.6 VP-X Connectors.....................................17
4.7 Installing and Removing Power Connector Terminals .........18
4.7a Installing terminals ...............................18
4.7b Removing terminals ..............................19
4.7c Pin Removal Tool ................................20
4.8 Alternator and Voltage Regulator Considerations ............20
4.8a Over-voltage Planning.............................21
4.8b Low-voltage Planning .............................21
4.9 Landing Light Wig-Wag (Pulsing) Considerations ............21
4.10 HID Light Considerations..............................21
4.11 Electronic Ignition Considerations .......................21
4.12 Electric Motor Considerations ..........................22
4.13 VP-X Planner.......................................22
4.13a What if I run out of power pins? ....................23
4.13b What if I run out of switch inputs? ...................23
5. Installation
5.1 Pre-Installation Tasks..................................24
5.2 VP-X Installation .....................................24
5.3 Wiring Harness Construction ...........................26
5.4 Backbone Wiring .....................................26
5.5 Master Contactor Wiring ...............................27
5.6 Starter Switch and Contactor Wiring ......................27
5.7 Starter Annunciator Wiring..............................29
5.8 Other Contactor Wiring ................................29
5.9 Alternator Wiring .....................................30
5.9a Primary Alternator (B&C External Regulator) ...........30
5.9b Primary Alternator (Plane Power) ....................31
5.9c Backup Alternator (B&C 20 Amp) ....................31
5.9d Backup Alternator (B&C 8 Amp) .....................32
5.9e Backup Alternator (Plane Power 30 Amp)..............32
5.9f Alternator – Rotax, Jabiru, or UL Power engines .........33
5.10 Primary EFIS Wiring – Power and Data Connections ........34
5.11 Advanced Flight Systems EFIS Wiring ...................34
5.12 GRT EFIS Wiring ....................................34
5.13 MGL EFIS Wiring....................................34
5.14 Garmin G3X Wiring ..................................34
5.15 Dynon SkyView Wiring ...............................34
5.16 Items you don’t have to wire to the EFIS..................36
5.17 Ground Wiring ......................................36
5.18 General Power Wiring ................................36

VP-X Installation and Operating Manual
Rev. D (August 5, 2020) Page 4
5.19 Trim System Wiring ..................................37
5.19a Pitch Trim Wiring ................................38
5.19b Roll Trim Wiring.................................38
5.19c TruTrak Auto Trim Module .........................38
5.19d Co-Pilot Disconnect Switch ........................39
5.19e Wiring a third trim motor ..........................39
5.19f PH Aviation Trim.................................39
5.19g Garmin GSA 28 With Auto-Trim ....................39
5.19h Trio Auto Trim Module ............................39
5.20 Flap System Wiring ..................................40
5.20a Flaps System With Limit Switches ..................41
5.21 Panel Switches Wiring................................41
5.21a Standard switches...............................42
5.21b Wiring lighted switches ...........................42
5.21c Alternator switch ................................43
5.21d Boost pump switch ..............................43
5.21e Dual-Function Switch ............................44
5.21f Dimmer wiring ..................................44
5.21g Mag switch wiring ...............................44
5.22 P-Mag wiring .......................................44
5.23 Lightspeed Ignition wiring .............................45
5.24 Planning and Wiring Backup Circuits ....................45
5.24a Backup Circuit Considerations .....................46
5.24b Backup Method B ...............................47
5.24c Backup Method C ...............................47
5.24d Do not wire backups this way ......................48
5.24e Aft-mounted battery considerations..................48
5.25 TCW Integrated Back-Up Battery System .................49
5.25a TCW IBBS 2/4ah Wiring ..........................49
5.25b TCW IBBS 3/6ah Wiring ..........................50
5.26 Dual Battery/Single Bus Wiring .........................50
5.27 Aux Battery Wiring and Voltage Measurement .............52
5.28 AeroLEDs Wiring ....................................52
5.29 Strobe Light (non-LED) Wiring .........................52
5.30 Retractable Gear Wiring ..............................53
5.31 Testing Individual Circuits .............................53
6. Congure the System Settings
6.1 Conguring the AFS EFIS ..............................55
6.2 Conguring the GRT EFIS..............................55
6.3 Conguring the MGL EFIS..............................55
6.4 Conguring the Garmin G3X EFIS .......................56
6.5 Conguring the Dynon SkyView .........................56
6.6 Installing and using the VP-X Congurator .................56
6.7 Switch Input Verication ...............................56
6.8 Device Conguration (Starter, Avionics, Lights, etc.)..........57
6.9 Current Fault Detection ................................57
6.10 System Conguration (Over-voltage and Backup Alternator) ..57
6.11 Wig-Wag Conguration ...............................58
6.12 Trim Conguration ..................................58
6.13 Flaps Conguration ..................................59
6.14 Export Settings .....................................62
6.15 Import Settings .....................................62
7. Ground Test
7.1 Testing without engine running ..........................63
7.2 Testing while engine running ............................63
8. Flight Test
8.1 Notes about rst ight .................................64
8.2 VP-X system checkout ................................64
9. Troubleshooting
9.1 Flap Conguration ....................................65
9.2 Electrical Conguration ................................67
9.3 Trim faults ..........................................67
9.4 “Cannot Connect” error when using VP-X Congurator .......67
Contents (Continued)

VP-X Installation and Operating Manual
Rev. D (August 5, 2020) Page 5
10. VP-X System Operation
10.1 Power On and Off ...................................68
10.2 EFIS Electrical System Page...........................68
10.3 Other VP-X functions.................................68
10.4 Turning electrical devices on and off .....................68
10.5 Trim and ap operation ...............................68
10.5a Trim switch fault detection on startup ................69
10.5b Runaway trim and aps...........................69
10.5c Trim and ap operation with a faulty position sensor ....69
10.5d Max Flap Speed Functions ........................69
10.5e RV-10/RV-14 Flap Reex Operation .................69
10.5f Continuous Flaps ................................70
10.6 Landing Light Wig-Wag ...............................70
10.7 Circuit Faults .......................................70
10.8 Starter Disable......................................70
10.9 Low-Voltage Alarm...................................70
10.10 Over-Voltage Alarm .................................70
10.11 Battery Contactor Failure.............................70
10.12 Backup Circuits ....................................70
10.13 Data Comm Loss...................................71
10.14 Firmware Updates ..................................71
Contents (Continued) Appendix
Appendix A – Pinout Diagram . . . . . . . . . . . . . . . . . 72
Appendix A1 – J8, J10, J12 Connector Wiring . . . . . . . . . . 73
Appendix A2 – J1 Connector Wiring . . . . . . . . . . . . . . 74
Appendix A3 – J2 Connector Wiring . . . . . . . . . . . . . . 75
Appendix B – Wiring Harness Contents . . . . . . . . . . . . . 76
Appendix C – VP-X System Annunciators . . . . . . . . . . . . 77
Appendix D – VP-X Dimensions and Weight . . . . . . . . . . . 78
Appendix E – AeroLED Wiring Tips. . . . . . . . . . . . . . . 79
Appendix F – Ray Allen Stick Grip Wiring . . . . . . . . . . . . 80

VP-X Installation and Operating Manual
Rev. D (August 5, 2020) Page 6
Change Log
Change Date Revision Change
Aug 26, 2010 Initial public release
Oct 27, 2011 Added Rotax and Jabiru alternator section.
Nov 3, 2011 Added dimension drawings to Appendix.
Dec 13, 2011 Added pinout diagrams in Appendix.
Feb 6, 2012 Added more detail on EFIS data wiring. Added
strobe and AeroLED diagrams.
Feb 20, 2012 Fixed label on Option 2 dual battery diagram.
May 16, 2012 Added clarication about connecting serial data
line to GRT EFIS.
July 12, 2012 Updated dual battery drawings: moved
contactor diode placement.
Aug 20, 2012 Updated ap troubleshooting section. Updated
DualBuss Technology section.
Dec 1, 2012 Added RV-10 ap reex and continuous aps
features. Primary alternator disable feature. 1.4
rmware update.
Feb 27, 2012 Added Eagle EMS and updated IBBS section.
May 3, 2013 Added GSA 28, minor corrections.
May 15, 2013 Added section on advice for planning electrical
system.
June 24, 2013 Added guidance for HID lights.
July 24, 2013 Added note about ap circuit breaker value and
newer VP-X.
Sept 25, 2013 Added second option for wiring starter
annunciator.
Sept 26, 2013 Added more alternator switch wiring options.
Nov 22, 2013 Added section on dual-function switches.
Aug 28, 2014 B Added Trio Auto Trim, moved warranty to
separate document, updated style, minor
corrections.
May 18, 2017 C Added additional info about the TCW IBBS.
Phantom voltage info. Updated Installing
Terminals images. Removed Subaru and Viking
engine appendices.
Change Date Revision Change
Aug 5, 2020 D General manual update with multiple
corrections and additions. Added references to
the Vertical Power PPS.

Page 7
VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
1. Introduction
1.1 Welcome to Vertical Power!
The VP-X is an innovative way to intelligently control the electrical devices
on your aircraft using electronic circuit breakers (ECBs). The VP-X family
includes the VP-X Pro and the VP-X Sport models. This manual covers both
products. The physical installation for both products is identical, and setup
is nearly identical (the difference being that the VP-X Sport has eight fewer
circuits).
While the VP-X makes life a lot easier for the builder, it’s not simply a plug-
and-play solution. The builder must still run wires to electrically-powered
components and this wiring takes some careful planning. Please take the
time to read and understand this manual before proceeding.
This manual describes the installation steps and techniques necessary
to install the VP-X. It is also intended to provide the information you need
to know to capably wire your electrical system. Because many of the
features are controlled using the setup menus rather than with hard-wired
components, you can easily change things in the future.
This manual is updated as required, so check the Vertical Power web site for
updates during your build.
If you follow each of the ve steps outlined in this manual, you will have a
safe and full-featured electrical system.
1.2 Vertical Power Terms
VP-X VP-X is used by itself when the topic covers both the Pro
and Sport models. When the topic covers only a specic
product, then either “VP-X Pro” or “VP-X Sport” is used.
PPS The Vertical Power Primary Power System (PPS) is a
solid-state device that handles high-current primary power,
replacing electro-mechanical components.
Device A user of electrical power. It may be a light, radio, GPS
receiver, contactor, or EFIS, just to name a few. A device is
wired to a power pin on the VP-X.
Pin A pin refers to a physical pin on one of the VP-X connectors
that provides power to a device. Special-purpose pins
are provided for aps, trim, starter, and EFIS. Most pins,
however, are generic and can be congured to match the
type of load it is powering. Each pin has a maximum current
rating up to 15 amps.
State There are three states: on, off, or faulted. Faulted is
equivalent of a tripped circuit breaker.
Connector Two types of connectors are used throughout the system.
D-sub connectors are smaller and provide signal and
low power (less than 2 amps) connections. The VP-X
incorporates high quality, gold plated, machined-barrel
connectors. High-quality, Molex gold-plated connectors
are used to provide power (up to 15 amps) to high current
devices.
AWG American Wire Gauge – a standard that describes the size
of the wire.
Circuit breaker While the VP-X does not use conventional circuit breakers or
fuses, the term is very common and herein is used to mean
the maximum current a circuit will draw before faulting.
Fault The VP-X protects each circuit from short circuits, over-
current conditions, and current fault (open circuit) faults.
When a fault occurs, the VP-X turns the faulted device off,
and the EFIS displays an alarm message. You can then
reset or clear the fault from the EFIS screen, similar to
resetting a circuit breaker.
Backup circuit A backup circuit allows you to power a device directly from
the battery through an external switch (separate from the
VP-X). When the external switch is turned on, fused power is
provided directly from the battery to the device regardless of
whether or not the battery contactor is closed or the VP-X is
turned on. Wiring these circuits is optional.
B-lead This is the large wire that goes from the alternator to the
main electrical bus. It provides current from the alternator to
the battery and electrical bus.
p-lead This is the wire that goes from the mag switch to the
magneto. There is a p-lead for each magneto.

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VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
1.3 Other Reference Documents
We provide other documents that should be used in conjunction with this
manual to help you thoroughly plan a safe and effective electrical system
for the type of mission you y. The following documents are available on the
Documentation page of the Vertical Power web site (www.VerticalPower.
com), and should be reviewed in conjunction with planning your electrical
system.
Document Description
Contactor Wiring Overview of the different types of contactors
used in experimental aircraft, and step by step
instructions how to wire them properly.
Device Amps This document lists the electrical current draw of
many popular radios, GPS moving maps, EFIS
displays, lights, and other avionics. We maintain it,
but contributions come from builders.
Top 10 Wiring Mistakes A free, 12-page paper describing the most
common wiring mistakes and how to get started
wiring your aircraft.
Additional documentation may also be available on the web site.

Page 9
VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
2. VP-X Overview
Step 1: Planning
Complete the On-Line Planner
Step 2: Installation
Install the Vertical Power components and wiring
Step 3: Conguration
Congure Vertical Power system using setup menus
Step 4: Ground Test
Verify proper operation on the ground
Step 5: Flight Test
Verify proper operation in ight
2.1 Installation Overview
The installation of the VP-X is accomplished in ve main steps, and the
amount of work for each step is shown by the relative size of the boxes
shown above.
Following these steps will increase the likelihood of a trouble-free electrical
system. Each step is described in detail later in this manual. You can optionally
swap steps 2 and 3 and set everything up on the bench rst.
We recommend that you read through all ve steps so that you better
understand the system prior to beginning the planning step.
Taking the time up front to carefully plan your electrical system will pay big
dividends later on.
2.2 System Overview
The VP-X provides circuit protection, circuit switching, trim and ap control,
and a host of other functions. The electrical devices are controlled by
conventional switches that are wired into the VP-X. The VP-X integrates with
popular EFIS units, which display electrical system information. Trim and ap
position information from the VP-X is also displayed on the EFIS, and circuit
faults can be reset from the EFIS.
The VP-X system architecture with the PPS is shown below:
+
-Batt
VP-X
EFIS
Switches
Data
Avionics
Lights
Trim
Flaps
STARTER
Primary Power Supply (PPS)
The VP-X system architecture in a conventional system is shown below:
+
-
Batt
VP-X
EFIS
Starter
Contactor
Switches
Data
Avionics
Lights
Trim
Flaps
STARTER
Battery
Contactor
2.3 Supported Bus Architecture
The VP-X supports a single main aircraft electrical bus architecture, with
one or two alternators and one or two batteries. An additional independent
backup or ‘e-bus’ can be added as well for redundancy (described later in
this manual).
The Vertical Power PPS is
a solid-state replacement
for contactors. More
information can be found at
verticalpower.com

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VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
3. Electrical System Basics
This manual and the accompanying documentation on the Vertical Power
web site are intended to provide enough detail to understand overall
concepts and safely wire your aircraft. Should you want more information,
additional resources can be found in a variety of books and texts, a few of
which are shown here:
• FAA Advisory Circular AC 43.13, Acceptable Methods, Techniques,
and Practices - Aircraft Inspection and Repair available from www.
faa.gov
• FAA Advisory Circular AC 23.1311, Installation of Electronic Display
in Part 23 Airplanes,available from www.faa.gov
• EAA Hints for Homebuilders https://www.eaa.org/Videos/Hints-for-
Homebuilders
• AeroElectric Connection book, available from www.aeroelectric.com
• https://www.eaa.org/shop/SAW/SportAir_Workshops.aspx
• Aircraft Wiring Guide, by Mark Ausman, more info at https://www.
aircraftwiringguide.com/
3.1 Free Advice on Designing your Electrical System
Many builders are new to electrical wiring and nd it daunting. Even
experienced electrical engineers may not be familiar with good practices
specic to aircraft wiring. With that in mind, we’ve added lots of detail
throughout this manual. Before we dig into those details, this section will help
you to think about the big picture as you design your electrical system.
When designing your electrical system, there is a temptation to copy or
do things the same way as your buddy did them when he built his plane.
Avoid that temptation. Every experimental aircraft is different and is used
in different ways. It may end up that your plane, when nished, is similar
in certain ways to your friend’s plane, but that should be because your
requirements are similar and not because you blindly copied him.
We believe the most important free advice we can offer is the following:
CLARIFY YOUR MISSION
In this age of gadgets, it is all too tempting to add just one more
enhancement, then one more again, until we lose sight of how and why we
are building an airplane in the rst place. Think about the most basic things
rst. What will your plane be used for? What type of weather will you be
ying in? What do the worst-case scenarios look like?
The outcome of this decision drives not only how you wire your electrical
system, but also what avionics and other equipment you put in the aircraft.
If you clarify your mission like this, determining not only what it is but just as
importantly what it isn’t, you will be ready to adopt our next bit of free advice:
COMMIT YOUR ELECTRICAL SYSTEM TO PAPER
It is surprising to us how many builders, after relying on many pages of
detailed plans for their airframes, use little more than a napkin or a single
sheet of copy paper to draw out their electrical system. Planning and
researching your design and then committing every detail of that design to
hardcopy before you buy equipment and run wires will pay huge dividends
later on.
Whether you’re comfortable with either a pencil or a keyboard, write and
draw everything down, somewhere. Use whatever tools work best for you
— paper, PowerPoint, AutoCAD, or spreadsheets. We cannot design your
electrical system for you, but we can be a valuable sounding-board for your
thoughts. We even have an on-line planning tool at planner.verticalpower.
com that is a big step in the forward direction. After helping many different
customers with many different designs, we’ve learned that it’s much easier to
erase than to rewire. Much cheaper too.
While you commit your design to paper, erasing and redrawing as many
times as it takes to get it right, please keep in mind our last piece of free
advice:
KEEP IT SIMPLE
As a basic rule, the more complex something is the more likely it is to break.
For some reason, while most experimental airplanes are built as dependable
but simple vehicles, their builders are enticed to attach every electrical
bell and whistle they can nd in a catalog. By adding more relays, busses,
terminals, diodes, wires, and (let’s face it) toys, you are actually adding more
things that can fail and more things that make it harder to troubleshoot.
Before you delve into the details of designing your electrical system, please
consider these three bits of advice. If you do so, the end result will be an
electrical system and avionics package that meets your real needs when you
get your project in the air.

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VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
3.2 Introduction
An aircraft electrical system can be divided into three parts:
1. “Backbone” components: aircraft battery, alternator, voltage
regulator, the Vertical Power Primary Power System (PPS) and
associated wiring. This is called the primary power distribution
system. In place of the PPS, you can also use traditional contactors.
Contactors are just high-capacity relays that are energized by low
power signals but allow large amounts of power to pass through.
2. Busses, switches, smaller wiring, and circuit protection (fuses and/
or circuit breakers). This is called the secondary power distribution
system.
3. Users of power and the wiring to and from those users. Users may
be lights, instruments, avionics, pumps, etc. The term device or load
is used in this manual to generically describe all the users.
More on electrical system basics:
• The aircraft battery and alternator provide power to all electrically-
dependent systems. Normally, the battery powers systems before
and during starts and then the alternator takes over charging the
battery and providing power to the electrical devices. The Vertical
Power Primary Power System (PPS) connects (or disconnects)
the high-current wires between the battery and the main power
distribution bus. In place of the PPS, you can also use a traditional
battery contactor.
• Power typically runs from the battery/alternator to electrical busses
behind the panel where power is split and sent to individual devices
through circuit protection devices (fuses and circuit breakers) and
switches. The VP-X assumes the role of busses, circuit protection,
and a host of single-function modules. During construction, the VP-X
greatly simplies the task of wiring your aircraft.
• Wire sizes vary and the size of the wire to each device is determined
by the current load (amps) of that device as well as the distance the
current must travel. If a wire is too small for the load or distance,
it will heat up and possibly fail. If the wire is too big, it will certainly
carry the load but at the expense of added weight.
• To complete the electrical path, devices must have a ground. This
means connecting a ground wire to the metal aircraft structure or
ground plane (aircraft ground) or running a ground wire from the
device to a central location such as a rewall grounding point.
3.3 Alternator Operation
The alternator provides power to devices and also charges the aircraft
battery. The voltage regulator continuously monitors the bus voltage and
adjusts the output of the alternator. The regulator only works when it is
powered from a bus through a wire called the eld wire. Some alternators
are internally regulated (the regulator is built in), and others have external
regulators (a separate box located outside the alternator).
Today’s experimental aircraft are powered by either 14 volt or 28 volts
systems. Often you may hear 12 volt or 24 volt systems. Why the difference?
The reason is because the batteries are rated at either 12 or 24 volts. When
the engine is running and the alternator is turned on, the alternator generates
14 volts or 28 volts, slightly higher than the battery voltage so it will keep the
battery charged.
If you have a primary alternator and a secondary (backup) alternator only
one alternator (eld wire) should be powered on at a time. Therefore, we
refer to one alternator as the primary and the other as the secondary. If both
are on simultaneously, they do not equally “contribute” to powering the loads.
The one whose voltage regulator is set to the highest voltage will draw all
the current (sometimes called current hogging), possibly overloading the
alternator.
When planning your electrical system, assume the alternator provides 80% of
its rated output (in amperes), and therefore your total continuous load (don’t
worry about trim or aps or other transient loads) should not exceed 80% of
rated alternator capacity.
3.4 Wire Sizes and Circuit Protection
A table below shows wires sizes versus loads for a typical homebuilt-size
airplane. The wire size can be larger than necessary but should not be
smaller.
Circuit breakers (and fuses) protect the wiring, not the device. If the breaker
is too large, then the wire may overheat and fail. If too small, then the device
may fault (breaker trips) because it draws too much current.
Most kit aircraft companies and avionics companies provide
recommendations for sizing wires and breakers. You can use these
recommendations, or you can borrow or purchase an ammeter to measure
the current draw of each electrical device and then determine the sizes
yourself.

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When you know the current draw for each device, use the chart below to
size the power wires. For simplicity, the VP-X wiring harnesses (purchased
separately) use the four wire sizes in the table.
Up to (amps) Use wire size (AWG)
5A 20
10A 18
15A 14
Data signal 22
3.5 Grounding
Many people think that the power, or positive, wire is the most important wire
to provide electricity to a device. The electrical ground is just as important as
electricity must ow the entire path from the power source to the device and
back to the source. The ground wire must be the same wire gauge or a larger
diameter (smaller gauge number) as the wire that provides power to the
device, with the exception of VP-X ground wires from J12-4 and J10-9. See
section 5.17 for more information..
A ground loop is when electricity takes two different paths, and each path
has a different resistance. Ground loops are most noticeable in aircraft audio
equipment, and can produce a variety of problems, most notably unwanted
noise.
Grounding is as much of an art as it is a science. With that in mind, several
options for grounding your system are provided below. Choose the one that
best ts your needs. Keep in mind that more wiring means more weight
(although likely negligible). Also, note that in all the examples below the
avionics grounds are kept together.
• Option 1: Run a ground wire from each and every electrical device
back to a common grounding point, typically a ground bus on the
rewall.
• Option 2: Run ground wires from all the avionics to an intermediate
grounding point, then run a larger wire from the local ground bus
to the rewall ground. Run wires from all the other devices to the
rewall ground.
• Option 3: Run the ground wires from the avionics to the rewall
ground, and run the other ground wires to a local ground (a metal
part of the airframe located near the device).
3.6 Switch Nomenclature
The chart below shows the most common switch types. A parenthesis ( )
around a switch position indicates it is a momentary, spring-loaded position.
Switch Type Design Symbol Mechanism
Single Pole,
Single Throw SPST
OFF-ON
OFF-(ON)
OFF-(ON)
Single Pole,
Double Throw SPDT
ON-NONE-ON
ON-OFF-ON
(ON)-OFF-(ON)
ON-OFF-(ON)
Double Pole,
Single Throw DPST OFF-ON OFF-(ON)
Double Pole,
Double Throw DPDT
ON-NONE-ON
ON-OFF-ON
(ON)-OFF-(ON)
ON-OFF-(ON)

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Rev. D (August 5, 2020)
3.7 Alternator Current Sensing (Shunt)
If you are not using a Vertical Power PPS, you must consider whether to
wire an ammeter (usually a shunt or hall effect sensor provided with the
engine monitor) on the wire connecting the alternator(s) to the main bus. The
ammeters indicate the amount of current the alternator is providing.
A shunt is not required to tell if the alternator is working. It is very easy to tell
if the alternator is working correctly by simply looking at voltage. If you see
14 (or so) volts with the engine running then it is working. If you see 12 (or
so) volts it is not working or not turned on or the devices are drawing more
current than the alternator can provide (note, engine must be running). If you
set your low voltage alarm on the EFIS at 13 volts, then you will get a low
voltage alarm if the alternator fails.
Since the VP-X provides basically the same information as a shunt installed
on the alternator b-lead, our position is that adding a shunt gives you no
additional meaningful information.
A shunt on the alternator b-lead shows the amount of current the alternator is
providing to power the devices and charge the battery. The VP-X total current
reading shows the total amount of current the devices attached to the VP-X
are using. The delta between the two is the battery charging current, which
goes to (basically) zero after re-charging any loss from starting the engine or
charging a run-down battery.
If the battery charging current is important to you, then you should install
a shunt. If not, then simplify your wiring and don’t install it. Your call. And
of course each builder’s needs are different so there is no absolutely right
answer.
The EFIS displays a VP-X page which shows individual device current as
well as total current through the VP-X. The EFIS also has an ‘Amps’ gauge
that is used to show the readings from the shunt. In some cases the EFIS
‘Amps’ gauge can be used to display total system current from the VP-X.
Please check with your EFIS manufacturer for details.
If you don’t install the shunt then the shunt wires on the engine monitor/EFIS
are not used.
3.8 Bench Testing the VP-X
To test on the bench, connect the VP-X to a power supply and connect either
J10-9 or J12-4 to ground. Be aware that short circuit protection may not work
properly in this case. You must have the VP-X connected to a battery with at
least 8 AWG wire and good solid connectors.

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Rev. D (August 5, 2020)
4. Planning
It is a good idea to spend time on the planning stage whether you are
installing a simple or a complex aircraft electrical system. This section
discusses many items and considerations that should be incorporated into
your planning. At the end of the section, you will use the Vertical Power
Online Planner tool to document the design of your electrical system.
4.1 EFIS
We recommend purchasing the EFIS with its backup battery option. This
way, if there is a fault on the power circuit to the EFIS, the EFIS can still
communicate with the VP-X and reset the circuit breaker. Further, the battery
backup keeps the EFIS from rebooting during engine start.
4.2 How Switches Are Wired
Switches are wired a bit differently on the VP-X than they are using traditional
wiring. The main difference is that the switch does not carry the current of
the device or devices that are being switched. This means longer life for the
switch, and the ability to use almost any switch that you want since it does
not have to be rated to carry the current from the device. Further, the EFIS
can be used as a backup to turn devices on and off if the switch itself fails.
There are 10 switch inputs that can be used for things like avionics, boost
pump, lights, and other items on the aircraft. There are an additional 4
dedicated inputs for pitch and roll trim switch inputs and 2 more for ap
switch inputs.
Switch Input 1
Switch Input 2
Switch Input 3
Switch Input 4
Switch Input 5
Switch Input 6
Flap Up SwitchJ2-1
VP-X
J2-14
J2-15
J2-16
J2-17
J2-18
J2-19
J2-2
J2-3
J2-4
J2-5
J2-6
J2-7
J2-8
J2-9
J2-10
Flap Down Switch
Roll Left Switch
Roll Right Switch
Pitch Up Switch
Pitch Down Switch
Switch Input 7
Switch Input 8
Switch Input 9
Switch Input 10
VP-X Switch Inputs
(J2-1, for example, means connector J2 pin 1)
Each switch is wired to ground on one side, and the other side is wired to
one of the switch inputs as shown in the diagram below. You can use 20 or
22 AWG wire.
VP-X
SPST
Switch
To Gnd
Switches do not carry loads, they simply provide a ground to the
switch input pin, which then enables the VP-X to turn devices on and off.
Later on you will congure each power pin using the Online Planner, and
later, your laptop connected to the VP-X. Each pin can be congured for
a specic circuit breaker value, name and switch assignment. When the
specied switch input is grounded, the device or devices assigned to that
switch input turn on. When the specied switch input is not grounded, the
device or devices are off.
VP-X
SPST
Switch
(OFF) To Gnd
Power
In
Above, switch is open so lamp is off.

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VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
VP-X
SPST
Switch
(ON) To Gnd
Power
In
Above, switch is closed so lamp is on.
Here you can see that the light turns on when the switch is closed, and the
actual power switching is done inside the VP-X and not by the switch. The
switch simply tells the microprocessor to turn on the device(s) associated
with the switch.
Note that the starter circuit and master switch circuit are different and
explained elsewhere in this manual.
4.3 Wiring Harness
A VP-X wiring harness is available to simplify the installation of electrical
system. Appendix B at the end of this manual details the contents of the
wiring harness kit.
4.4 Dual Bank Technology (VP-X Pro)
The VP-X Pro includes our Dual Bank technology that has two independent
power banks in a single system, delivering unprecedented levels of
redundancy and safety. Builders can now easily divide avionics and other
electrical loads between two power banks, and should one bank controller
fail the other bank will continue to operate independently and be able to
provide power to the starter contactor. Each bank of circuits is powered by an
independent power supply and microprocessor.
Power
Supply A
ECB
Bank A
ECB
Bank B
Power
Supply B
Bank A
Power Circuits
Bank B
Power Circuits
Power In
Overview of Dual Bank Technology
The power pins associated with each bank are shown in Appendix A.
It is important to understand the following:
• Each switch input (1 through 10) can be read by either
microprocessor. Devices on both bank A and bank B can be
controlled by a single switch input. For example, the landing light
switch can control BOTH the left light (wired to bank A) and the right
light (wired to bank B).
• The two banks do not share common components on the circuit
board – each bank is isolated from the other outside of the main
power bus (input) and ground.
• Either bank (A or B) can power the starter circuit. Therefore if a bank
fails you can still start the engine.
• Pitch trim is controlled by both processors. Both processors must
agree to run the pitch trim before it can run. Therefore, if either bank
fails the pitch trim cannot operate.
• The roll trim is powered by bank A.
• The aps are controlled by bank B.
• The serial and Ethernet lines are connected to the bank A
microprocessor. If bank A fails then communications with the EFIS
are lost. In this case, bank B will continue to operate normally but
you will not receive status on the EFIS.
• Bank A provides the reference voltage to the trim and ap indictors.

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Rev. D (August 5, 2020)
Dual Bank technology should be used as a tool to mitigate risk in the case
of a system failure within the VP-X, and not as a tool to mitigate risk of
a larger system failure. Be sure to understand the failure modes you are
solving for. Dual Bank technology provides redundancy if a power supply or
microprocessor in the VP-X itself fails (an extremely rare event). It does not
solve the problem of a failed master switch, battery contactor, or contactor
(main bus) wiring. To solve for these failure modes, install a backup circuit
(Method B or C) as discussed later in this manual.
If you have redundant devices like radios, lights, or displays, then you can
divide those up between Bank A and Bank B so that each bank has one of
each type of device. That way if a VP-X bank fails, the redundant device on
the other bank still has power. Spend some time planning possible failure
modes and divide the devices between the two banks. For example, if you
have two comm radios, put one on each bank. If you have a taxi light and a
landing light, put one on each bank.
ECB
Bank A
ECB
Bank B
Left Landing
Light
Right Landing
Light
Power In
Redundant devices, one on each bank.
Some avionics have two power inputs but each is for a distinct function. Do
not split these power inputs between banks. For example, a Garmin 750
has a nav power and a comm power input. These should be wired to two
separate pins on the same bank.
ECB
Bank A
ECB
Bank B
G750
Power In
Comm Power
Nav Power
Two power inputs to a device should come from the same bank.
If a device has only a single power input, you should use backup Method B
(described later in this manual) to back up this circuit. Do not wire power from
both banks, as this does not provide backup in case of a failure of the battery
contactor or master switch.
ECB
Bank A
ECB
Bank B
Device
Power In
Power Input
Use backup Method B instead of this.
If an avionics device has dual redundant power inputs (most modern EFISs
do), you should use backup Method C (described later in this manual) to
back up this circuit. Do not wire power from both banks, as this does not
provide backup in case of a failure of the battery contactor or master switch.
ECB
Bank A
ECB
Bank B
EFIS
Power In
Primary Power
Backup Power
Use backup Method C instead of this.

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4.5 Tools and Other Stuff
This is a generic list of items to assist with planning. Some items may vary
depending on the requirements of your specic installation.
Things you will need
• Crimper - insulated terminals 10 to 22 AWG
• Crimper - d-sub machined barrel male
• Crimper – terminals for 2 to 8 AWG wire
• Stripper(s) – for wire 14 to 26 AWG
• Starter contactor (Optional, PPS Preferred)
• Battery contactor (Optional, PPS Preferred)
• Heavy gauge wire for “main” power runs
• Heavy gauge wire terminals (non-insulated)
• Alternator(s) and voltage regulator(s)
• Wires for data interconnects on avionics
• EFIS – for VP-X status and setup
• Ray Allen Co. POS-12 ap position sensor (optional)
• Momentary up and down (on)-off-(on) ap switch. All sticks can be
ordered or retrot with this switch type.
• Magneto/starter switch
• Switches
Be sure to use a momentary up and momentary down ap
switch (on)-off-(on). Most ap switches come standard in a
non-momentary up conguration on-off-(on).
Things you won’t need
• Battery contactor and starter contactor if using PPS (preferred)
• Flap Positioning System
• Flap Controller
• Flap over-speed module
• Trim Controller
• Trim speed controller
• Wig-wag module
• Trim or ap position indicators
• Trim relays
• Trim voltage regulator
• Avionics relay
• E-bus diode
• Circuit breakers/fuses (except for backup circuits)
• Shunts/hall effect sensor
• Over-voltage module
• Low-voltage alarm
4.6 VP-X Connectors
The photos below show the different connectors used in the VP-X, the big,
higher-amperage power connector on the left and the smaller, low-amperage
d-sub connector on the right.
Power Connector D-sub Connector
There are six connectors on VP-X Pro and ve on the VP-X Sport. Three of
these connectors, identied as J8, J10, J12 (corresponding with the number
of pins on the respective connector), carry high-current loads. J8 is not
installed on the VP-X Sport.
The two d-sub connectors, J1 & J2, are used for low-current purposes such
as trim motor operation, position feedback, serial data, and switch inputs.
J1 is the top connector. It is male. The connector on the wiring harness is
female. J2 is the bottom connector. It is female. The connector on the wiring
harness is male.
The top Ethernet connector is used to communicate with a Windows PC for
conguration and software updates. The bottom one is not used.

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VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
The VP-X connectors are shown in the diagrams below:
J10
J12
Power Lug
J8
Ethernet
J1 (top)
J2 (bottom)
Shown with mounting brackets installed.
A view of both ends is shown below.
J1
J2
J8
J10 J12
J1 is the top 25 pin d-sub connector and it is male. It mates with a female
connector that contains the wiring harness.
J2 is the bottom 25 pin d-sub connector and it is female. It mates with a male
connector that contains the wiring harness.
4.7 Installing and Removing Power Connector Terminals
The large (black) power connectors allow you to easily install and remove the
wire/terminal assembly.
4.7a Installing terminals
Step 1: Insert a small screwdriver (max width= 1/8 inch, about 3.0 mm) into
either pry point
Step 2: Using the housing as a pivot point gently pry out on the white insert,
until it reaches pre-lock position (5.0 mm travel)
Insert screwdriver Gently pop up white section
Before After
The white insert should never be removed.
If it is removed, discard the entire connector. Do not attempt to
re-assemble. Contact Vertical Power Support for information
regarding replacement connectors.

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Rev. D (August 5, 2020)
Step 3: With the white insert still in the ‘out’ position, align the terminal to
rear of connector. Align the orientation feature as shown and insert through
appropriate opening. If resistance is encountered, retract the terminal and
adjust the angle of insertion. Continue inserting the terminal until it stops with
an audible click. Give the wire a slight tug to make sure it is seated properly.
It should not come back out.
Orientation feature on terminal 90° mis-orientation
aligned with index on housing Not a straight entry
Troubleshooting:
The terminal should insert smoothly into the connector housing. If it does not,
the following are the most likely causes:
• The terminal is rotating while you are inserting it. The terminal must
remain aligned until it is fully inserted.
• The tangs on the insulation crimp may not be fully closed. Gently
squeeze the tangs closed around the insulation with a pair of pliers.
• The white insert may have closed. Open the insert.
Step 4: With the terminals fully installed, the white insert can be seated into
its nal lock position by applying an even force to both ends until it comes to
a stop, with an audible click. The white insert should move a distance of 5.0
mm (about ¼”).
4.7b Removing terminals
Steps 1 & 2: Follow these steps as shown above to raise the white part of
the connector.
Step 3: Using the pin removal tool, insert the tip into the terminal service hole
adjacent to the terminal to be serviced.
Step 4: Push down gently to release locking nger. You will hear a gently
click. Do not apply any lateral force, as this may damage the connector
or the terminal!
Step 5: With the white insert still in the ‘out’ position, gently pull on the wire to
release the terminal.
If the terminal resists, the service tool may not be fully engaged. Remove
the tool and re-try. Push the service tool further into the service opening to
ensure that it has fully disengaged the locking nger.
Insert Here
Do not insert the tool into the terminal opening!
Do not use excessive force, excessive force can damage the connector!
Step 6: The white insert can be seated into its nal lock position by applying
an even force to both ends until it comes to a stop, with an audible click. The
white insert should move a distance of 5.0 mm
(about ¼”).

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Rev. D (August 5, 2020)
4.7c Pin Removal Tool
A pin removal tool is included with the wiring harness or connector kit.
Pin Removal Tool
If the pin removal tool is not working as expected, use a Scotchbrite wheel to
grind the end of the pin removal tool as shown below.
Incorrect Correct
4.8 Alternator and Voltage Regulator Considerations
Choosing the correct alternator and voltage regulator is an important part of
planning your electrical system. The VP-X supports internally and externally
regulated alternators, as well as the B&C SD-8 permanent magnet alternator.
We do not take a position regarding which type or brand of alternator is best.
The VP-X does NOT replace the voltage regulator. Externally-regulated
alternators require a voltage regulator.
The typical automotive-style voltage regulator does simply that – regulates
the voltage to the eld wires on the alternator. Varying the eld voltage affects
the output capacity of the alternator. Higher voltage means a stronger eld to
generate current which means more output. An internally regulated alternator
provides the same function, but the regulator is housed in the alternator itself.
Certain internally regulated alternators provided by Plane Power, Ltd. (https://
planepower.aero/) have built in over-voltage protection. All alternators built by
Plane Power are compatible with the VP-X system.
Externally-regulated alternators have the regulator in a separate box outside
the alternator. Most voltage regulators provide only the voltage regulation
function, and some allow you to adjust the voltage level. The B&C LR-3C
(https://bandc.com/) external voltage regulator provides three functions: 1)
voltage regulation, 2) under-voltage alerting, and 3) overvoltage protection. It
is generally regarded as a high-quality product that has been through years
of eld experience. Note: B&C does not recommend the LR-3C be connected
to PTCs (Positive Temperature Coefcient thermistor) for circuit protection.
The VP-X does not use PTCs for the power circuits and is compatible with
B&C voltage regulators.
There is a long-standing and unresolved debate in the experimental
community about the benets of internally versus externally regulated
alternators. The table below shows some of the pros and cons of each type.
Some common backup alternators are the accessory-drive mounted SD-20
alternator and the SD-8 PM alternator, both available from B&C Specialty
Products. The one you choose is driven in large part by the size of the loads
you need the backup alternator to carry.
Pros Cons
Internally
Regulated
Alternator
Simple to wire
No external boxes
Certain failure modes
will cause over-voltage
condition that cannot be
stopped by removing
power from the eld wire*.
Externally
Regulated
Alternator
Separation of VR from
alternator, and each can
be serviced separately.
Removal of power from
regulator shuts down
alternator.
Extra box to install and
wire
Extra cost and weight