VP-X Electronic Circuit Breaker System

When you’re flying an airplane, it’s critical to be able to monitor the status of your electrical system. If you have a glass cockpit, it’s even more critical. Only Vertical Power Electronic Circuit Breaker systems give you the level of detail and control you need for today’s electric aircraft.

The VP-X (the X is pronounced “ex”) integrates with many popular EFIS products enabling you to monitor and control your entire electrical system on the EFIS display. In addition using the EFIS for attitude, navigation, and engine information, you now can use the EFIS display to monitor the health of your electrical system, view and control the status of individual circuits, and respond to circuit faults.

Vertical Power systems provide these capabilities through the use of our patented electronic circuit breaker (ECB) technology that is at the core of all of our products. Of course, ECBs provide circuit protection like old-fashion thermal circuit breakers, but ECBs do a lot more than just detect circuit faults. ECBs are intelligent, configurable, and offer capabilities not otherwise available with old-style breakers. For example, ECBs can detect a burned-out landing light or disable the starter circuit while the engine is running.

ECBs greatly simplify wiring while at the same time provide advanced electrical system capabilities. Wiring is simplified because you don’t have to install circuit breakers, bus bars, relays, trim and flap modules, shunts, e-bus diodes, or other complex wiring right on the back side of the instrument panel. Switch wiring is simplified because you can use smaller-gauge wire and wire one side to ground and the other side to the the VP-X. The advanced electrical system capabilities include solid-state power switching and circuit protection, open circuit detection, automatic landing light wig-wag, pilot and co-pilot trim control, runaway trim protection with backup trim controls on EFIS, flap control with intermediate flap stops, starter disable when engine running, flap over-speed alarms, trim and flap position display, over-voltage protection, alternator control and more. These advanced features along with the wiring harness kit give you a “quick-build” wiring experience.

The VP-X works in conjunction with many popular EFIS products so you can monitor and control your entire electrical system on the EFIS display in addition to attitude, moving map, and engine gauge pages. View circuit faults, circuit status, and trim & flap position.

Electronic circuit breakers are fully configurable to match your specific aircraft. You can set the circuit breaker value for each ECB, and you can assign which switch controls the ECB. And you can use any type of switch you want for the avionics master, boost pump, landing lights and other functions.

The VP-X is built using the same field-proven hardware and software technology as our other products. It’s been proven in hundreds of experimental aircraft over thousands of flight hours. And you can easily wire backup circuits for critical avionics to eliminate any single point of failure concerns (see Designing Your Electrical System For Failures below).

A typical mechanical circuit breaker has a mean time between failure (MTBF) of 17,000 hours. A single electronic circuit breaker has an MTBF of about 1,000,000 hours. Further, a mechanical switch is rated for about 30,000 cycles. Our ECBs are rated for 2 billion cycles. As you can see, modern solid-state components offer significantly higher reliability.

The VP-X supports a single bus electrical architecture with a single or dual alternator configuration. It additionally supports the ability to measure the voltage on an aux battery. There are enough circuits to wire a typical RV (including the RV-10), Glastar, Lancair Legacy, Velocity, Cozy, or other 2 to 4 place aircraft. The differences between the VP-X Pro and VP-X Sport are shown in a table towards the bottom of this page.

The VP-X uses a third-party EFIS screen to display faults, flap and trim position, and individual electrical device status. You get the best of both worlds—ECBs are remotely mounted yet you can view their status and reset a fault from the EFIS screen. The VP-X is hidden from view and doesn’t take up any space on the panel. The screen below is an example of an electrical system display on the EFIS where you can view and control each electrical device.

Get started now with the free on-line planner.

Below are screenshots of the EFIS displays showing the VP-X page:

Click on image to see high resolution pictures.


VP-X Key Features for Builders of Modern Aircraft

The Vertical Power logo indicates features only available with Vertical Power systems.

Electrical System and Circuit Protection

Electrical fault alarming and resetting on EFIS. When a circuit breaker pops, you may or may not know it. When the VP-X detects a fault, an alarm is shown on the EFIS and also may flash a master warning light and sound an audio alarm in the your headset.

Short circuit alarm. When a short circuit is detected, the VP-X opens the circuit and generates a fault on the EFIS. You can then leave the circuit open or reset it manually from the EFIS screen.

Current fault alarm. When a device draws no current when turned on, the VP-X opens the circuit and generates an alarm on the EFIS. You know right away if a landing light is burned out, an avionics fan has stopped working, or the boost pump is inoperative, for example. The feature can be turned on or off for each individual circuit. You can then leave the circuit open or reset it manually from the EFIS screen.

Configurable panel switches. The switches on your instrument panel for avionics, landing lights, boost pump, and other items are wired directly to the VP-X.

DualBuss™ technology. Two independent power busses in a single system. Read more a few sections down.

Over-voltage protection. Disconnects the active alternator if an over-voltage condition is detected.

Backup power for critical avionics. You can wire backup circuits for critical avionics so in the event of a failure there is an alternate power source.


Land light wig-wag with auto turn on & off. When you turn the landing lights on they are steady on the ground and then automatically pulse (wig-wag) while in the air. When you come in for landing, the lights are pulsing, but then remain steady below a specified airspeed. You can also set a desired warm-up time before the lights begin to pulse (typically for HID lights).


The VP-X drives the electric pitch and roll trim on your airplane based on inputs from external trim switches. It supports standard trim switches on the stick such as those on the Ray Allen, Tosten, or Infinity sticks (Do not buy the sticks with embedded relays).

Solid-state, no relays The control circuitry is all solid-state, meaning there are no problematic mechanical relays to fail. For additional safety, each trim circuit has two solid-state control switches wired in series, and each switch is independently commanded (by two different command mechanisms) by the microprocessor.

Runaway trim protection and backup control. If your trim switch sticks or one of the switch wires shorts, you can stop the trim from running by pressing the opposite trim button. Holding the opposite button for three seconds will disable the trim switches. You can then control the trim from the soft keys on the EFIS as a backup.

Variable-speed trim. The pitch trim motor runs more slowly at higher airspeeds, making the trim switch less sensitive. While at slower airspeeds (in the pattern, for example) the pitch trim motor runs at full speed. For example, you can set the pitch trim motor to run at 60% speed above 120 knots and 100% speed below 120 knots.


The VP-X connects to standard (up)-off-(down) flap switches, the flap motor, and optionally a flap position sensor. The flap switch can be located on the stick, throttle, or on the panel. The pilot and co-pilot switches are both wired directly to the VP-X.

Solid-state, no relays or black boxes. The control circuitry is all solid-state, meaning there are no problematic mechanical relays to fail. For additional protection, the flap circuit has two solid-state control switches wired in series, and each switch is independently commanded (by two different command mechanisms) by the microprocessor.

Motor run-on protection. Some flap motors, like the one used by Van’s aircraft, have no internal limit switches and will run continuously if not controlled properly. You can specify the maximum motor run time, after which the motor will shut off and an alert displayed on the EFIS.

Intermediate stops. With the optional flap position sensor, you can set the top and bottom limits as well as up to two intermediate flap position stops. Simply bump the flap switch down to go to the next down position, and bump it up to go all the way up. You can stop the flaps anywhere along the way by bumping the flap switch in the opposite direction.

Backup flap control. If your flap switch becomes inoperative, you can control the flaps from the EFIS screen.

Flap switch disable above a certain airspeed. The flap down switch is automatically disabled above a specified airspeed. The flap up switch works at all times. No mechanical airspeed switch is required.

Flap reflex position for RV-10 and RV-14. Airspeed restrictions are lifted when moving flaps from the reflex to neutral position. When flaps are retracted, they retract to the neutral position and can be retracted to the reflex position with one more flap switch press.

Flap over-speed warning. The EFIS displays a flap over-speed warning on the screen if the flaps are down above a specified airspeed.


Automatic starter disable. If the engine in running, the starter circuit is disabled. This means you can install a starter switch on the stick or on the panel and not worry about hitting it accidentally during flight.

Starter annunciator. You see an annunciator on the EFIS whenever the starter contactor is closed. This is important as it can be difficult to detect a starter that is engaged once the engine is running.

DualBuss™ Technology

The Vertical Power VP-X Pro includes new DualBuss™ technology that has two independent power busses in a single system, delivering unprecedented levels of redundancy and safety. Builders can now easily divide avionics and other electrical loads between two power busses, and should one bus controller fail the other bus will continue to operate independently and be able to provide power to the starter contactor. Each bus controller is powered by an independent power supply and microprocessor.


Video of VP-X Interface on EFIS System


Video showing integration of VP-X with AFS, Dynon, Garmin, GRT, and MGL EFIS products. Video is 5:25 minutes.



Wiring With the VP-X

Wiring your airplane is a serious project. No one can make it easy, but we can make it a lot easier. We provide complete instructions, how-to guides, tool rentals, wiring harnesses and wiring diagrams to assist with your project. Download the wiring documents here.

Greatly simplified wiring yet powerful capabilities.


Rather than a mess of wiring behind the panel, you wire from the VP-X directly to each electrical device. Run a power wire from the VP-X to the landing light. Run a power wire to the EFIS. Run a power wire to the transponder. Run a bundle of five wires to a trim servo. Run two wires to the flap motor. And so on. Run a small wire from each trim switch, the flap switch, and panel switch to the VP-X.

Then use the setup menus in the EFIS to configure your system. You specify which power pin each device is connected to, what the circuit breaker values are, and which switch should turn each device (or group of devices) on or off.

You can use any type of switch you like to match your panel. Choose the style and type of switch you want.

There are two data wires between the VP-X and the EFIS. If this communications link should fail, the VP-X continues to operate autonomously and provides circuit protection and standard trim and flap operation.

The video below shows how to wire your aircraft using the VP-X. (Please note this video shows the original VP-X and not the VP-X Pro or Sport).


How it Works

The actual power switching and circuit protection is handled by the VP-X. The EFIS provides setup, annunciator, and status information to the pilot. Alarming is handled using the same alarming mechanism that is in the EFIS today for engine alarms. Status and manual control is provided on a new electrical system page in addition to the existing attitude, navigation, and engine monitoring pages.

The switches on your panel do not carry current and therefore can be any style of switch you prefer. Each switch simply tells the VP-X whether it is either on or off.

Let’s say you have a landing light switch. One side of the switch is wired to ground. The other side is wired to a switch input on the VP-X. When you turn on the switch, it grounds the switch input on the VP-X. The microprocessor then commands one or more Electronic Circuit Breakers to turn on. In this example, it will tell one ECB to turn on the left landing light, and the other to turn on the right landing light. Then, when you are above a specified airspeed, it will start to wig-wag the landing lights. This is all handled by the microprocessor, and does not add any weight, black boxes, or additional wiring to the aircraft.

If there is a fault, the VP-X reports the fault to the EFIS which displays an alert. You can ignore the fault or reset it, just like you can with an old-style circuit breaker. If the EFIS fails, the VP-X continues to operate normally but you don’t have a display of the faults.

Because the VP-X is microprocessor controlled (like all EFIS displays, moving maps, GPS receivers, AHRS units, weather receivers, and other new avionics in the airplane) you can configure it to match the specific configuration of your aircraft. For example, you can configure the speed at which the lights start to wig-wag, the flap over-speed limit, the landing light warm-up time, each circuit breaker value, and which devices each switch controls. You can turn features on and off based on your needs.

Below is a diagram of how a typical landing light wiring diagram might look. Remember, even with this simple wiring you have advanced features like burned out landing light detection, wig-wag, automatic wig-wag in the air, and lighting warm up prior to wig-wag.

Below is a diagram of a typical flap installation in an RV. The flap switch can be on the stick or on the panel. No outside relays or gizmos are needed. Even though the wiring is very simple, the functionality includes intermediate flap stops, flap position indicator on the EFIS, motor braking, motor run-on protection, flap over-speed warnings, and flap-down disable above flap extension speed.

Designing Your Electrical System For Failures

It’s important to design the various systems on your aircraft to be fault tolerant so that if there is a failure you can continue to fly safely. What if your EFIS, VP-X or magneto fails, for example? There are simple and proven ways to address this issue. Let’s look at the EFIS example first.

If you’re planning a single EFIS and your mission profile suggests that you need basic attitude, airspeed, and altitude information to fly safely, then you should design a backup EFIS into your instrument panel. So even though any single EFIS may fail, the overall design of the SYSTEM is fault tolerant and includes appropriate redundancy.

The same is true for your electrical system. The VP-X provides the main power distribution function and you can also wire backup circuits to provide power to critical avionics in case the VP-X fails. Viewed as a complete SYSTEM, the electrical system in your aircraft can be designed to have appropriate redundancies and backups to continue flight safely. More detail about wiring backup circuits is described in the Installation Manual.


VP-X Planner

Introducing the VP-X Planner – a new on-line to tool to help you plan your electrical system. The VP-X Planner can help you get started and easily make changes as you go. We do recommend reading the VP-X Installation manual to help get the full benefit from the VP-X planner. Get started here for free.


Cost Analysis

Below is a table showing the cost of various components for your aircraft to achieve a basic level of functionality to the VP-X. As you look at each component, consider the added complexity for the wiring, learning, troubleshooting, and mounting requirements for each one. We think you’ll find the cost and simplicity of the VP-X is very competitive.


Circuit breakers
Landing light wig-wag module
Trim controller w/ harness
Flap positioning system
Flap controller w/ harness
Flap over-speed warning module
Over-voltage module
Not Needed
Not Needed
E-Bus diode
Not Needed
Airspeed switch
Not Needed


The VP-X Sport costs $1,495 and the VP-X Pro costs $2,195.


What You Will Need What You Won’t Need

• Panel switches including master, mag and starter

• Trim switch(es) on panel or stick

• Flap switch on panel or stick

• Battery contactor

• Starter contactor

• VP-X Wiring Harness Kit (sold separately)

• Connector-Only Kit (sold separately)

• Flap position sensor (optional)

• Big wires between, starter and VP-X

• Circuit breakers/fuses (except for backup circuit)

• Shunt/hall effect sensor

• Over-voltage module

• Low-voltage alarm

• Flap positioning system

• Flap controller

• Flap over-speed module

• Mechanical airspeed switch

• Trim controller

• Trim speed controller

• Wig-wag module

• Trim or flap position indicators

• Trim relays

• Trim voltage regulator

• Avionics relay

• E-bus diode


Weight Analysis

The VP-X weighs about 2 pounds. Depending on the way your aircraft is outfitted, the VP-X can usually save a few pounds of weight.


VP-X Pro and VP-X Sport Comparison

VP-X Sport
VP-X Pro
2A Circuits*
3A Circuits*
5A Circuits*
10A Circuits*
15A Circuits*
Starter Contactor Circuit
Pitch Trim Motor Controller
Roll Trim Motor Controller
Reversible Flap Motor Control with Braking
Flap and Trim Position Sensor Inputs
Power Supplies
Flap and Trim Switch Inputs
Panel Switch Inputs
Aus Battery Voltage Measurement
Starter Annuciator
14v or 28v
Main Power Input from Battery Contactor
RS-232 Interface to EFIS
Ehternet Interface to PC


* Circuit breaker value can be set anywhere between 1 amp and the maximum value shown.


Start Your Planning Now!

Use the VP-X Load Planning Worksheet and Installation Manual to begin your electrical system planning here.


Software Updates and Setup

Software updating and system configuration are performed using a PC application that runs on Windows and connects to the VP-X via an Ethernet cable.

VP-X Configurator Application Demonstrates how to configure the VP-X using your laptop computer.


Shows how to configure your electrical system with the VP Configurator application.




The VP-X requires an EFIS for alarm and status display. The currently supported systems include:

Advanced Flight Systems 3400s, 3500s, 4500s, 5000 series

Grand Rapids Technologies HX and Sport SX, HXr

MGL Avionics Voyager GEN II/Odyssey Gen II/Xtreme/iEFIS

Garmin G3X

Dynon SkyView SV-D1000 & SV-D700 (plus $275 license fee charge by Dynon)



Power 6-32 volts DC, 70A max (Pro) / 50A max (Sport) continuous
Weight 2.0 lbs
Mounting Includes mounting bracket which attaches on side of VP-X. User can fabricate own mounting bracket as well.
Connectors Three power connectors, two 25 pin d-sub connectors
Operating Temperature -40 to +85 deg C
Certification The VP-X is for use only with experimental and light sport aircraft

Detailed dimension drawing here.