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VPX and PPS manual updates for use of the B&C LR3C/D voltage regulator

cjensen

Well Known Member
Hi folks,

We just uploaded updated versions of both the VPX and PPS manuals to reflect a small change in wiring of the Vsense line from the B & C LR3C/D voltage regulator. The change came after a review with B & C Specialties over the last few weeks in which an inadvertent or accidental switch off of the PPS alternator reset switch, which would allow the VR to raise voltage to an unsafe level, which could damage the PPS. This was addressed in a previous manual update with a wiring and switch assignment change on the VPX, but this update eliminates the possibility of an accidental switch off of the alternator through the PPS preventing damage to the PPS by removing the Vsense connection to the VPX when using a PPS.

Please grab the latest version of both manuals, and if you have a PPS with VPX and an externally regulated alternator with the LR3C or D installed, please make the simple change in your wiring to ensure the possibility is removed.

Links to the manuals here, or they are available on the Documents page on the Vertical Power website.

https://verticalpower.com/media/att...-installation-and-operating-manual_rev-g1.pdf

https://verticalpower.com/media/att...-installation-and-operating-manual_rev-f1.pdf
 
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Chad,
Thanks for the update. Question: If I have a VPX and the B&C external regulator, but no PPS, does this apply? I just want to be clear.
 
Wiring Change PPS to VPX with BandC STBY Alt

Hello Chad, having changed the wiring as per the previous amendment, I do not understand the logic of the latest required change.
If switched of the regulated voltage sensed by the VPX is 0 apart from a possible residual voltage in the circuit, how therefore, can the PPS be damaged. The wiring change on a completed system is not particularly simple, particularly as it does not seem logical as explained in your post or the manuals. The VPX para that follows the diagram change does not reflect the diagram! It would be beneficial to understand what was the actual concern electrically with the previous wiring arrangement as this appeared logical?

Comments Please before I re-wire?
Mike
 
Hello Chad, having changed the wiring as per the previous amendment, I do not understand the logic of the latest required change.
If switched of the regulated voltage sensed by the VPX is 0 apart from a possible residual voltage in the circuit, how therefore, can the PPS be damaged. The wiring change on a completed system is not particularly simple, particularly as it does not seem logical as explained in your post or the manuals. The VPX para that follows the diagram change does not reflect the diagram! It would be beneficial to understand what was the actual concern electrically with the previous wiring arrangement as this appeared logical?

Comments Please before I re-wire?
Mike

Hi Mike,

I do need to correct my wording in my initial post to reflect the fact that this change is for the PPS alternator reset switch, not the field switch on the VPX. My apologies...I will change that.

These changes were made by request of the fine folks at B&C to protect the VP equipment correctly. The drawings and wording was an approved collaboration with them. Here is the explanation-

The change in wiring is to protect the alternator reset switch on the PPS (if used, tho even if it isn't used, one drawing was chosen to simplify things in either case). In Rev F, if that reset switch is used, and it is accidentally switched off, the alternator shuts down to reset, but the VR remains on (though the VPX). Wiring the Vsense to the 1A fuse allows the VR to detect no voltage, and will not attempt to raise voltage. If the Vsense were to remain wired to the VPX, per Rev F of the VPX manual, it would still sense voltage from the VPX, and attempt to raise voltage with the alternator shut down.
 
Has anyone installed the PPS and chosen to include the Main Battery Distribution reset and Alternator Distribution reset switches?

The PPS installation manual states the switch would need to "cycle to reset." We are trying to determine whether a simple NC momentary push button will suffice or if we need to use an "alternate action" switch (a switch that is "cycled" off and then on)?

Also, can the Main Battery Fault Lamp output and Alternator Fault Lamp output be wired as discrete inputs to the G3X to display the Main Battery or Alternator fault on the EFIS?
 
Those optional reset switched only remove a ground from the associated pins on the PPS circular connector. So I'd think a normally closed/momentary open switch would work. But, they might be hard to find. A normally-open/momentary closed switch will not work.

I opted not to install those switches. With pins 1 & 8 tied to ground, turning the master switch off and back on does the same thing. I'm running dual Dynon displays with battery back-ups.
 
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Those optional reset switched only remove a ground from the associated pins on the PPS circular connector. So I'd think a normally closed/momentary open switch would work. But, they might be hard to find. A normally-open/momentary closed switch will not work.
Sourcing a NC momentary switch is not an issue. Fortunately, Chad at Astronics replied directly and clarified "For the reset switches, they do need to be ON-OFF switches. Momentary switches won’t work for those functions."

He wasn't sure about connecting the Fault Lamp outputs to a G3X discrete input.

I opted not to install those switches. With pins 1 & 8 tied to ground, turning the master switch off and back on does the same thing.
Yes, that's stated in the manual. We're choosing to install dedicated reset switches.
 
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