Page 45
VP-X Installation and Operating Manual
Rev. D (August 5, 2020)
3A CB
5
4
5
4
L P-Mag
3A CB
R P-Mag
VP-X
P-Lead
Switch
P-Lead
Switch
2. Wire the power to the p-mags, installing a switch in between the
p-mags and the VP-X. Set the pin on the VP-X to “Always On” (using
the configurator on your laptop).
3A CB
5
4
5
4
L P-Mag
3A CB
R P-Mag
VP-X
L P-Mag
Switch
R P-Mag
Switch
P-Lead
Switch
P-Lead
Switch
3. Wire power to the P-Mag using a direct power connection and
controlling it via a standard switch wired to a switch input.
3A CB
5
4
5
4
Switch Input
L P-Mag
3A CB
R P-Mag
VP-X
L P-Mag
Switch
Switch Input
R P-Mag
Switch
P-Lead
Switch
P-Lead
Switch
5.23
Lightspeed Ignition wiring
If you are wiring a single LSE ignition system (with a magneto on the other
side), we recommend wiring the LSE power wire directly to the VP-X and the
ground wire to ground.
If you are wiring a dual LSE ignition system, we recommend using two
batteries and wiring each ignition directly from each battery, similar to the
method suggested in the LSE installation manual. Please see the section in
this manual “Dual Battery/Single Bus Wiring.”
5.24
Planning and Wiring Backup Circuits
Backup circuits allow you to wire backup power directly from the battery,
through an external fuse and switch (separate from the VP-X), and then to
the device. Each circuit can provide backup power to a device regardless of
whether the VP-X is on or off.
Remember, as the aircraft builder, you are the systems engineer for the
electrical system design. So it is important to design the systems to support
the type of mission you expect to fly. Just because a friend built his plane a
certain way does not mean it is necessarily the right way for you to build your
plane. With that in mind, our goal here is to provide the information you need
to design a backup system that is right for you.
Take for example the EFIS. It’s important to consider what happens when it
fails. There’s nothing you can do to prevent it from failing at some point in the
future, but you can mitigate the risk when it does fail. You do that by installing
a separate backup EFIS with limited capability but one that can get you back
on the ground safely.