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VP-X Pro ALT FIELD "always on" question

pazmanyflyer

pazmanyflyer

Well Known Member
With OSH travels this weekend and all next week I know the VP boys and girls will be busy. So I turn to other VP-X users here in search of ideas and explanations.

I have my VP-X setup that the alt field is "always on" yet when I did my first engine start we noticed the alt field was not on in the efis menu and I manually have to select it. Is this correct? My understanding is that the "always on" alt field will be on anytime the VP-X is powered up.
 
pazmanyflyer said:
With OSH travels this weekend and all next week I know the VP boys and girls will be busy. So I turn to other VP-X users here in search of ideas and explanations.

I have my VP-X setup that the alt field is "always on" yet when I did my first engine start we noticed the alt field was not on in the efis menu and I manually have to select it. Is this correct? My understanding is that the "always on" alt field will be on anytime the VP-X is powered up.
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Look in the literature, but if I remember right, I have a 3 way switch for Primary, Off, or Backup alternator switch. So, if I turn on just the master, the VPX will energize the ALT Field at a few Amps (when the Alt switch is on Primary). When I turn on the master to load the G3X, I get in to the EFIS and shut off the Alt. field circuit to save the Amps while updating the databases.
 
The way mine is set up (not flying yet though) is the Alt Field Circuit comes from pin 6 ("Bus") of my B&C LR3 type voltage regulator to Pin 11 on J12 of the VP-X. The CB is 5A, and it is mapped to a switch labeled "ALT".

I have split masters labeled BATT & ALT.

I just had Chad at VP review both my "planner" and my primary electrical wiring diagram and he said it was good to go.
 
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I have yet to install the VP-X into my build so i have no direct hand on experience, but from reading the manual it sounds like you are always supposed to have a physical switch input mapped to the primary alternator. When you say it's configured to "always on" i assume you don't have that switch. Also don't put the switch between the VPX power output and the alternator since VPX wants to be able to switch off the alternator on over-current events
 
"always on" should work as you expect.

From the install manual:
The VP-X provides bus voltage (positive) power to the alternator field input
or voltage regulator from J12 pin 11. This pin is configurable and you set its
circuit breaker value up to 5 amps and assign it to be controlled by any of the
switch inputs (or be always on).

Recommend you connect the configurator and verify it is set to 'always on'. If that's not it, check w Chad next week after OSH. ;-)
 
Finally got back out with my laptop to check VP-X settings in the plane. As Marc mentioned, I found the issue. My config file on my laptop says "always on" but it wasn't set like that on the actual box. Changed the setting, updated and done. All good now.

PXL_20230729_133217392.jpg
 
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