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EFII Bus Manager with VP-X

clam

clam

Well Known Member
Have a VP-X Pro wired, and EFII ign system with their bus manager on the way.
Robert at EFII has given me some great considerations on wiring this combo up, but wanted to hear from some actual users. Did you integrate the 2 systems or keep separate, and how's it working? I'm considering either keeping the 2 systems completely separate, or having the VP-X power fed from the bus manager's "main buss" and all EI power fed from the BM's "essential buss".
Just looking to get some lessons learned on this integration.
Thanks again to Robert at EFII for his advice. Looking forward to this dual ECU/EI setup!
 
What's your overall power architecture like? Specifically, how many alternators/batteries, what size, how much load, etc.

Edit: also, your mission might help--how much redundancy are you looking for?
 
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I think I'm planning a similar setup using a Bus manager and VPX (sport or pro, not sure yet).

I plan to run all the engine stuff off the essential bus (aka Engine Bus), and use the main bus to feed the VPX. Everything other than engine stuff will run through the VPX. I would also run the secondary power source for the EFIS off the BusManager essential bus.

I have a schematic as a 'work in progress'

The only reason I would need the VPX "pro" would be to monitor the 2nd battery. I am not sure that is necessary.

Would be interested in feedback, and what considerations were given to you.

Subaru H6
2 aft mounted batteries
2 fuel pumps
1 alternator
Bus manager
VPX (sport/pro?)
GRT sport EFIS
EIS4000 engine monitor
SDS Engine control unit


Here is my schematic... If unreadable, I can send a PDF or the *.SCH by email.

MainBusCaplins.jpg


https://picasaweb.google.com/lh/photo/BncZRRGeEdVbCVe1fv6KodMTjNZETYmyPJy0liipFm0?feat=directlink
 
It's really the compatibility aspect...

lrgabriel said:
What's your overall power architecture like? Specifically, how many alternators/batteries, what size, how much load, etc.

Edit: also, your mission might help--how much redundancy are you looking for?
Click to expand...

... of these components I'm looking for. Vertical Power is unable to provide any recommendations or guidance since they have not done any testing with the EFII bus manager. I am comfortable with the level of redundancy I have, just trying to make a decision on whether to feed the VP-X from Altn (batt 1) or feed it thru the bus manager's main buss, as Jeff also discusses in post #3.

However, I will have
Single alternator
2x PC680 batteries
Dual EFII ignition with dual ECUs
EI redundancy very important (all engine related items and PFD will power off bus manager essential bus)
Occasional IFR (~non precision appr mins )
HXr with Dynon D6 backup PFD
 
Jeff,
My set up is a little different than yours... I'm going with dual ECUs, the mechanical fuel pump and a single electrical boost pump. For the wiring, I think I'm going to feed the VP-X from the ALT/BATT1 terminal of the bus manager. I will use the bus manager's main buss as VP-X backup (actually to bypass VP-X in case it fails) to a few circuits (landing light, pitot heat, boost pump, and engine monitor). These devices have single power inputs and VP-X method B backup will allow me to bypass the VP-X in case it fails somehow. All engine and primary PFD/AHRS will be fed from the bus manager's essential bus.

Send me an email if you want to discuss further, and keep in touch during your instal and we can exchange lessons learned on these similar configurations.
 
Bus Manager and VPX

I would consider two cases for the power distribution using the Bus Manager and VPX.

1. If the systems that will be powered from the VPX total less than 30 amps total current draw, the simplest configuration would be to power the VPX with the MAIN BUS output of the Bus Manager. This gives you one key switch attached to the Bus Manager to power up all systems. The Bus Manager ESSENTIAL BUS can provide the backup power to EFIS, GPS, etc. No other individual backup batteries necessary for these devices.

2. If you have lots of systems that will total more than 30 amps total draw, power the VPX off the main battery and use the Bus Manager soley for the ESSENTIAL BUS function and any of its other management functions that are appropriate for your engine electronics.

In either case above, the Bus Manager can provide the starter management, allowing the engine to be started off primary battery, secondary battery, or both batteries.

Robert
 
Recommend following Robert's #2 above, and wire the VP-X to a battery contactor then to a battery. The bus manager can be used for backups and engine functions.
 
Jeff (Clam): Your system seems quite a bit different than mine. I look forward to hearing how it goes.

Robert: I have an installation document for the Bus Manager that claims 40A max continuous load for the main bus (30A for Ebus). My understanding of the document is 40A main + 30A Essential, therefore a total 70A. Is this not correct?

Marc: Any reason you suggest against connecting to the Bus Manager?s main bus? I can live with a ?It?s from a different manufacturer and we haven?t tested it? answer, but if there is a technical reason, I would love to hear it.

Thanks,
 
Bus Manager limits notwithstanding, watch your wire limits--10 AWG wiring at higher amp loadings (anything greater than about 26 amps) requires conservative wire runs, temperatures, and bundle restrictions. Check out AC 43.13-1B Chg 1 Ch 11 for more.
 
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Bus breakout

Jeff,
Yes, you can run 40 amps through the Bus Manager MAIN BUS.
We just try not to run things at their maximum. Some planes have tons of systems and lighting and need more than one main bus to break things out.
Most two seaters can run everything through the Bus Manager.

Also, some people confuse breaker values with actual currents. It is important to dig into the technical info for every system you have and determine the actual current draw (not the breaker value). If you can't find a current draw value on a system, put 12 volts to it and measure the actual current with an ammeter.

Typically there are are two or three systems that are high current draw items like landing lights, strobes, pitot heat for example. If you are near the MAIN BUS current limits, these items can go on their own bus.

There is no problem supplying the VPX with the Bus Manager MAIN BUS output. The only items in this current path within the Bus Manager are a 40A relay and the key switch to activate it. If you need a MAIN BUS with a higher current capacity, you can break out some items as mentioned above, run the VPX off its own direct battery supply, or some combination.

The most important thing is to do your power consumption analysis first and then figure out the best way to supply the needed power.

Robert
 
Thanks for the clarification. Always appreciate it when a manufacturer answers our questions.
 
Robert,

What would the down sides be of using a VP-X Pro, and not using the buss manager at all?

Is it just:
1) Dual start battery selection not available
2) Automatic Fuel Pump monitoring not available

or are there other considerations?
 
Bus Manager

Hi Chuck,
The VPX products do not provide a protected bus. VPX will tell you not to run engine electronics off their product. This is the most important aspect of the Bus Manager. It gives you a protected source of 12 volts for the engine electronics.

Robert
 
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