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-   -   Z-14 Modified for VPX and SDS EFI (https://vansairforce.net/community/showthread.php?t=181685)

b727capt 04-22-2020 01:23 PM

Z-14 Modified for VPX and SDS EFI
 
I am getting close to having to commit to an electrical system design and I would like to get some feedback. I am going to have an electrically dependent airplane and would like to keep procedures as simple as possible yet incorporate innovative ideas like the VPX. I plan on normal operation with the cross-feed closed and the Aux voltage regulator set lower than the primary.

Do I use a single switch to control the relays for the Eng/Ess buss or do I use 2 different switches to be able to test and isolate?

Do I use a B&C standby regulator for the Aux Gen or the main regulator?

Any other suggestions?


unitink72 04-22-2020 02:26 PM

switches
 
My opinion on one of your questions -
I'm going with two switches. I've seen pictures of panels that just use one switch for fuel pump and bus selection. But I design safety critical control systems at work and letting a simple thing like a switch be a single point failure is beyond my comfort level.

KatanaPilot 04-22-2020 03:14 PM

I lost a lot of sleep over this very issue. Don't know if you have a 4 or 6 cylinder engine and a single or dual channel SDS, but they operate differently depending on which setup you have.

If you have a 6 cylinder engine and dual channel SDS, Ross and Barry have come up with an improved design for their injector relay box to allow redundant power sources for the injectors.

I too am using Z-14 and a VPX, but all of the SDS components are powered through CB's and hot battery busses. Dual B&C alternators and external regulators. One PC-680 and one EarthX. Dual independent busses.

I rarely check PM's so mail me if you want to discuss. I'm building an RV-10 and have a dual channel full SDS EFI and ignition.

krea dot ellis at gmail dot com

SabreFlyr 04-22-2020 07:57 PM

Quote:

Originally Posted by KatanaPilot (Post 1424580)
If you have a 6 cylinder engine and dual channel SDS, Ross and Barry have come up with an improved design for their injector relay box to allow redundant power sources for the injectors.

Does that only apply to a 6-cyl? I'm building an RV-14 with a VP-X and was originally planning on a dual-channel full SDS but lack of redundant power for the injection and the complexity of the electrical system made me change my mind. I have since decided to just go with a single CPI-2 and simplify the electrical system. The ability to have redundant power sources for the injection could change my mind again.

KatanaPilot 04-22-2020 08:40 PM

The 4 cylinder relay box(es) are different from what I understand. Barry was able to modify the 6 cylinder box for redundant power. This was an important upgrade for me.

I suggest you reach out to Ross or Barry or possibly Ross will chime in.

b727capt 04-22-2020 08:47 PM

I have a 200hp IO360 and plan on having the dual ECU SDS system.

Quote:

letting a simple thing like a switch be a single point failure is beyond my comfort level.
I thought about that...but the chances of a switch failing if not actuated are very slim. If it turns on before flight there should be no reason to operate that switch until you are back on the ground therefore very little chance of failure.

Foghorn 04-23-2020 05:06 AM

Are you on the Matronics list server or aeroelectic? If not, you should check them out. Bob Nuckolls is putting out new diagrams for electrically dependent engines that are much less complex than Z14. Look in the architecture PDFs under Z101P5.

SabreFlyr 04-23-2020 07:11 AM

Quote:

Originally Posted by Foghorn (Post 1424678)
Look in the architecture PDFs under Z101P5.

I don't know how anyone finds what they're looking for on Matronics lists. I'd like to look at those architecture PDFs but all I can ever see is a chronological list of messages; no subforums whatsoever.

KatanaPilot 04-23-2020 07:49 AM

Agreed
 
Quote:

Originally Posted by SabreFlyr (Post 1424704)
I don't know how anyone finds what they're looking for on Matronics lists. I'd like to look at those architecture PDFs but all I can ever see is a chronological list of messages; no subforums whatsoever.

There is a lot of useful (and some less so) information and it's really difficult to navigate.

Take a look here for the various Z architectures.

SabreFlyr 04-23-2020 08:19 AM

Thanks! Someday, I'm going to have to figure out Matronics lists myself.


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