I recently realized that I had short-shifted the installation of my VP-X electronic circuit breaker system in my previous posts about my winter panel upgrade. I’ll try to correct that here.

As a reminder, I chose to replace my original circuit breaker installation because it brought a bunch of wires into my cabin and made a clean interior installation very difficult. Of course, I chose to put them there rather than on the panel to try and simplify the wiring for panel removal to “just” the avionics wires which were already simple screw-on connectors on my Approach Fast Stack. So the VP-X is to the power wiring what the Approach is to the signal/avionics wiring.

I decided to take Andy’s concept of a full-width avionics tray instead of the half-width one I originally put in for my Blue Mountain EFIS. I used this tray for the primary and secondary EFIS bus fuseblocks as well as my relay decks, so it was very handy. This also keeps my power wiring off of the panel for ease of removal, but since the wires come in high on the canard bulkhead doesn’t interfere with the interior.

The main power connector to the VP-X main power lug gets a 6 or 8 AWG connection to the main aircraft power/battery bus with a ring terminal. The rest of the power connections out of the VP-X are via high-current plug terminals unique to the system. I chose to rent the special crimper required to make these connections since I shouldn’t have to do very many. It also requires a special pin removal tool, but that is provided in the installation kit. Also, the plug connectors have a special locking mechanism were you must click it one notch out before inserting or removing any terminals.

There are also 2 DSUB connections for serial input and output, trim control, switch connections, and flaps controls. I connected these to my overhead panel switches, and one of the cool features is that I can change what the switch controls in the VP-X software at anytime without changing any wiring. Also note that the VP-X has an Ethernet jack. This does not typically get used, it’s only for programming, so even though I have a hub installed on my canard for the GRT screens to to talk to each other, the VP-X talks to my Display Unit 1 via dedicated serial input and output wires.

The GRT needs bidirectional communication because not only does the VP-X give the GRT data on the status of each breaker and power user (ON/Off/Popped) but allows you to override a switch or reset the breaker on one of the engine display pages. VP-X design files attached at the bottom of this page.

VP-X controls on GRT “Engine” screen

Making the panel corner brace

Installing the avionics tray bracket

Canard Bulkhead Wire Opening

You can just see the Red VP-X Pro on the shelf in this picture

Again you can just see the VP-X and the tray extending across the fuselage

Another view of the avionics tray – The Gold box is the GRT dual AHRS unit


Pin Removal Tool

Connector Locking



Pin Insertion


VP-X Pro Box

Connector Layout

Posted By: Brett Ferrell
Tuesday August 30th, 2011 at 8:44 PM

Categories: VP-X Pro
Tags: Blue Mountain (BMA) Building EFIS Electrical GRT Vertical Power VP-X

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