VP-X ECB's vs CB's

[jimevison]

As an early adopter, I'm drawn to technology that offers advancement, but before installing a new piece of technology in my plane, there have to be clear cut advantages together with improved reliability over existing devices - it's a safety issue.

From the perspective of risk assessment, you can rank each device in an aircraft in a hierarchical structure. Failure of some elements are catastrophic, while others are merely undesirable. The integrity of your bus structure tends toward the first category. It's hard to improve on the simplicity of the series circuit connecting your switch, breaker and load. Wiring the Vertical Power VP-X system requires the same wiring tasks as a conventional system with breakers. Switches are connected to the control box then loads are connected to that same box. No savings in installation time or wire there. Breakers are controlled by a processor and susceptible to malfunction due to power supply faults, processor failure and coding errors. In other words, the MTBF will almost certainly be shorter than stand-alone breakers. Quoting MTBF figures for individual components such as ECB's are not useful numbers in isolation. The only meaningful number is the "system MTBF". This takes into account the weaker links in the chain.

The VP-X system offers the ability to monitor current in each circuit though this is of limited value. Currents vary according to the mode of operation of each device, such as between transmit and receive on a radio for instance. Unless we have a record of this data, analyzing each value in flight to determine whether it is outside predefined parameters is impossible. Do you know what current your radio should draw when you press PTT? In the event your EFIS fails, you also lose your monitor and control functions and the option of resetting breakers. Something I'd like to keep within my control.

The one thing that is essential in any wiring design is that when prescribed current limits are reached, power is removed and a traditional set of circuit breakers perform this task admirably at low cost.


Jim

[Bob'sRV6A]

I was looking forward to VP-X integration with Skyview, until I really dug into the manual, asked some questions, and thought about it. If you loose an alternator, you must manually drop equipment off line to adjust max loads on the one bus. The automatic load adjustments come with another $4K worth of equipment. Also, one of the "advantages" to VP-X is integrated wig wag, flap control, and trim control. That all sounds good but what do you do if one of these features stops working? Down the Aircraft, send in the unit and wait to fly again when you get the trim/wig-wag/flap controls back? I think this is placing too many eggs in one basket.
This is just me. I bet most others are very happy with the VP systems and I would never dispute their requirements or needs.
I have decided to stick with a proven Z13/8 architecture, put up with the increased difficulty in wiring and move on.
Who knows, in a year or so, when I really need to start wiring, I many change back. I seem to have a habit of bouncing back and forth on these kinds of decisions. Especially after seeing how this will work on Skyview--I bet it will be awsome.
Bob

[RV7Guy]

You guys are seeking a solution for a problem that doesn't exist. So you put your Dynon Skyview in that has everything in one box, yet you are concerned about the VPX? Doesn't make sense. I think you have considerable misinformation. Are you aware the VPX pro has two busses? I'd contact Marc Ausmann at Vertical Power with your questions and concerns. Failure rate of modern electronics is very rare.

If something breaks, you're going to be down till it is fixed regardless of what caused it. To my knowledge, there have been no failures of the VPX.

Regarding the work load to wire, I will respectfully but highly disagree with you. My neighbor, Chris Sands whose incredible RV7 was featured here a few weeks ago wired that very extensive panel with conventional breakers. It took him several days to mount the breakers and complete the wiring. It turned out beautiful. (The VPX wasn't available when he was wiring)

Fast forward. Chris is completing another guys 7 with an equally extensive panel. This plane has the VPX. ALL of the wiring was completed in 4 hours including mounting the brain box!!! Doesn't get any quicker or easier.

Chris said he will not build another plane without consideration of using the VPX system.

Don't over think this stuff. You'll never complete your plane and you'll be nutty when you do.

[SmilingJack]

I installed a VP100, would have done the VPX, but it wasn't available when I built.

I have to say I am very happy with this decision. Yes, I am out there testing the new technology and yes it could fail. But, I did opt for the EFIS options and the GPS options with XM weather, onboard charts, etc... and that to has exposure.

Just recently I had an issue with my GPS, not a big one, but a software issue. I was able to troubleshoot this in seconds because of my VP100.

The GPS was cycling like it was getting intermittent power, I switch over to my VP100 and displayed that device on the screen and watched the power draw - steady as a rock!

One call to the GPS manufacturer, downloaded a little data and problem solved.

on a related note, my friend was doing his annual and while cleaning and lubing his tailwheel he dropped the little centering spring - yup! grounded him. yes, some would fly without it and yes he really wasn't grounded since he stole mine for a few days....but the point is there are many other items that will give you more problems in my opinion.

Good luck with what ever you choose - eitherway flying an RV was your best choice

[Jeff A]

Originally Posted by jimevison

In the event your EFIS fails, you also lose your monitor and control functions and the option of resetting breakers. Something I'd like to keep within my control.

Not completely true....you will lose the ability to monitor and reset, but the VP-X will continue to operate normally if your EFIS gives up the ghost. If I lose my EFIS and other electrical components due to overload, I'm landing ASAP, no need to try and reset anything.

[jimevison]

Originally Posted by Jeff A

Not completely true....you will lose the ability to monitor and reset, but the VP-X will continue to operate normally if your EFIS gives up the ghost. If I lose my EFIS and other electrical components due to overload, I'm landing ASAP, no need to try and reset anything.

What I said here is correct, you lose the ability to monitor circuit status and to reset breakers if your EFIS fails. If your EFIS had been powered through a stand alone breaker, you would still have the option of resetting it. I prefer to have that judgment left open to me rather than have it taken away. It's often taught that one reset of a breaker is acceptable. But that's a personal decision - depending on the component and circumstances.

[MCA]

The difficulty lies, not in the new ideas, but in escaping from the old ones, which ramify, for those brought up as most of us have been, into every corner of our minds.
John Maynard Keynes, 1935

BTW, I'm not a fan of Keynes, but I do like this one quote.

[bcondrey]

There are elements of truth in many of the posts here but like many other things it comes down to tradeoffs. WRT complexity, it seems to me that while the VP series is self contained, talks to the EFIS, etc. If you're concerned about the box failing there are "bypass" switches for critical systems that you can add (shown on the Vertical Power website). Granted that adds complexity (not unlike backup/redundant flight instruments). A little can go a long way but over doing it marginalizes the complexity and labor savings however.

just my .02.

Bob

[WenEng]

VPX (and his other offerings) are a step into the next generation of power management. I have not seen ANY failures of their ECBs and I have resolved those same concerns as mentioned in previous posts. Its VPX for me and thank goodness Dynon will incorporate display of it soon. Just in time for my Sun N Fun spending spree.

[bird]

Ok I have been an electrician for over 35years, I have seen old technogy evolve into the new tech. We use solid state electronics exclusively at my job. Why? No down time, very very few failures, usually branch circuit wiring not the electronics. ECB's are good for about 1billion cycles, is that enough for an airplane? YES it is. VP have spilt buss? YES Does it have more than one circuit controller? YES it does. Are the ecb in series to prevent single point failure? YES
Does one part failure kill the whole thing? NO, Does 10 failures kill the whole thing? NO If I throw my efis out the window of my airplane will vertical power still do its job? YES 100%.

I plan on putting vertical power in my airplane without any reservations. Maybe I can get a discount from this plug for vp are you watching VP?

bird