Today's Message Index:
----------------------
1. 08:13 AM - two-battery, fuel pump circuit protection (Patrick Brannan)
2. 09:41 AM - Re: Re: Too many Circuit breakers.... (Robert L. Nuckolls, III)
3. 10:34 AM - Confessions of abuse (Bob Verwey)
4. 01:10 PM - Re: Confessions of abuse (Art Zemon)
5. 03:25 PM - Re: two-battery, fuel pump circuit protection (Roger)
6. 04:47 PM - Re: two-battery, fuel pump circuit protection (user9253)
7. 04:56 PM - Re: two-battery, fuel pump circuit protection (Charlie England)
8. 05:14 PM - Re: Hangar Electrical Work (user9253)
9. 05:34 PM - Re: two-battery, fuel pump circuit protection (johnbright)
10. 06:20 PM - Re: Hangar Electrical Work (Charlie England)
11. 07:35 PM - 30A PM alternator and Z101? (johnbright)
Message 1
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| Subject: | two-battery, fuel pump circuit protection |
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Message 2
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| Subject: | Re: Too many Circuit breakers.... |
>the second alternator will, if it will fit at all. (Long EZ...)
The SD-8 was B&C's first product for OBAM aviation. Bill
Bainbridge began studying ways to put a lightweight
alternator on the vacuum pump pad of an engine at the
request of Burt Rutan. Bill's early explorations
brought him to Electro-Mech where I was employed as
a design engineer. Bill asked if he could purchase
raw, front end bell castings we were using on our
own AND20000 drive pad product; a standby generator
for Bonanzas (Boy, did that turn out to be a clunker
project . . . we should have taken a hint from Bill's
work with PM machines. It would have served
our customers as well. Best yet, we would have got
the concept qualified onto TC aircraft!)
I was surprised when boss Fred agreed to sell castings
to Bill. Bill later approached me for assistance in
evaluating performance tweaks . . . this began
my association with B&C back about 1985.
In any case, the SD-8 should fit your LongEz . . .
>Why is the wire from the Main power bus to the master switch 20FLW,
>to 16 AWG, to 20AWG?
The segment between the main bus and the alternator
field circuit breaker is an EXTENSION of a bus
out to the remotely located breaker on the
panel. If you're going with breakers on the
panel, then that segment can be deleted and your
alternator field breaker driven directly from
the bus with other breakers.
>On the engine bus - if I'm feeding a single ignition at < 5A, Do I
>need the relay and all, or can I just switch and fuse it?
Eliminate the engine bus. Drive ignition from
battery bus via 5A fuse . . . also any electric
fuel pumps can have their own fuses driven directly
from the battery.
>I do understand the push for the second alternator... I may do it if
>I can fit it in due time.
I think it's physically possible and practically
valuable.
>Bob, Great work in converting another pilot/builder (and maybe a few
>more) and to your years of great work and service to us builders and
>pilots... Thank you!
You're welcome.
Speaking of pad driven power sources, I found
an exemplar Electro-Mech standby generator for
sale on eBay. Pictures . . .
https://tinyurl.com/y5j3gjbl
That regulator was a project that prompted boss
Fred to ask me back to EM about 1978 (long story).
A variation was crafted for the generator project
a year or so later. First engine driven power
machine we ever attempted. Sold a boat-load
of the things. Very unpopular in the field.
Brush life was terrible.
I wasn't much into rotating machines back then
being pre-occupied with herding electrons. But
I participated in the program with a variation
on the family of regulators we'd already
qualified onto Beech piston products.
In retrospect, a variation of the B&C SD-8
would have filled the bill nicely in the
Bonanzas with an essentially zero failure
rate!
Too soon we get old . . . to late we get smart?
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 3
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| Subject: | Confessions of abuse |
So while this post is not directly aircraft related, it is a kind of
confessional missive that serves to remind us that "temporary fixes" should
remain just that; temporary!
5 years ago I moved into a new shop in mid-summer and needed a small
fridge. All I had was this 12v camping fridge, but no 12v source.
[image: image.png]
Undeterred, I jury rigged a small transformer and PC board kit to supply
the requisite power, just for a short while.
I am ashamed to say it is still operating to this day! A long time ago I
noticed that the board was discolouring from the very hot diodes and
promised myself to replace the power supply.
[image: image.png]
I cannot believe the abuse visible yet this fridge is still running!
Today I bought a new power supply.
Forgive me, the god of electrons, for I have sinned...
Bob V
Message 4
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| Subject: | Re: Confessions of abuse |
The good Lord smiles on little children and us idiots with soldering
pencils. :-)
-- Art Z.
On Mon, May 16, 2022 at 1:01 PM Bob Verwey <bob.verwey@gmail.com> wrote:
> So while this post is not directly aircraft related, it is a kind of
> confessional missive that serves to remind us that "temporary fixes" shou
ld
> remain just that; temporary!
>
> 5 years ago I moved into a new shop in mid-summer and needed a small
> fridge. All I had was this 12v camping fridge, but no 12v source.
>
> [image: image.png]
>
> Undeterred, I jury rigged a small transformer and PC board kit to supply
> the requisite power, just for a short while.
>
> I am ashamed to say it is still operating to this day! A long time ago I
> noticed that the board was discolouring from the very hot diodes and
> promised myself to replace the power supply.
>
> [image: image.png]
>
> I cannot believe the abuse visible yet this fridge is still running!
> Today I bought a new power supply.
>
> Forgive me, the god of electrons, for I have sinned...
>
> Bob V
>
>
--
My blog: CheerfulCurmudgeon.com
*=8BWisdom is knowing what to do next. Virtue is doing it. -- David S
tarr
Jordan*
Message 5
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| Subject: | two-battery, fuel pump circuit protection |
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Message 6
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| Subject: | Re: two-battery, fuel pump circuit protection |
Patrick, The wire downstream of the dual diodes is a single point of failure.
When it fails, both pumps stop working. The diodes can be eliminated and wire
as Roger did. Another option is to install a second dual diode so that any single
failure will not shut off both pumps.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=506794#506794
Message 7
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| Subject: | Re: two-battery, fuel pump circuit protection |
On 5/16/2022 10:13 AM, Patrick Brannan wrote:
> Hello all,
>
> I have Bob's book and am working on a schematic for an
> electrically-dependent (SDS EFII) aircraft. SDS calls for redundant
> fuel pumps and a 15A fuse/cb for each pump. This makes good sense.
>
> In Z-19 there are two engine busses. One called Master. The other I
> have renamed to backup. These busses bypass the contacters and are
> always hot. All that is required to power either engine is to turn the
> MASTER POWER, or BACKUP power switches on.
>
> You will notice a FUEL PUMP fuse on both busses.
>
> It seems to me that the #2 fuel pump should have it's own fuse / CB.
>
> There should not be two fuses in series for either pump.
>
> I'm not wild about running unprotected wire off a bus.
>
> I think that leaves me with putting a backup fuel pump fuse on both
> the master and backup engine busses and using triple-throw switches
> for the engine switches.
>
> Does anyone see a better way of handling this? I'm not wild about
> having redundant circuit protection for each fuel pump, I think it
> could be confusing, but I'm also not seeing a great alternative.
>
> A partial screenshot of my schematic, created in Inkscape, is
> attached. It shows fuses for the primary fuel pump on both engine
> busses. I will probably use circuit breakers for this application
> instead, so don't take that too literally.
>
> Thoughts on fuse vs circuit breaker for fuel pumps will also be
> appreciated.
>
> Thanks,
>
> Patrick
>
>
Hi Patrick,
A few 'FWIW' comments.
I can see the logic of using the diode array for the primary pump and
using separate buses for the two ignitions, but my choice was a single
engine bus controlled by a high current switch, and an alternate feed
path to the bus from the main airframe bus. My dual pumps are both on
that engine bus, but have individual switches.
There's no way to avoid a more complicated control system when running
electronic engine controls, but I tried to get 'buttonology' (really,
the actions we've trained ourselves to take when we have engine issues
in flight) to act like traditional engine troubleshooting. I can switch
between engine controllers (mine is full fuel/ignition control) without
switching pumps, and I can switch pumps without switching controllers.
The most significant FMEA issue I see with your drawing is the diode
block. While failure may be very rare, if it does fail you lose both
pumps. Sometimes we must accept single point of failure situations to
accomplish something else, but this one seems pretty easy to fix. My
choice would obviously to go with separate switches, but separate diode
blocks (with outputs Y'd together) could mitigate the risk of one
diode's failure taking out the other in a single block.
Charlie
--
This email has been checked for viruses by Avast antivirus software.
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Message 8
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| Subject: | Re: Hangar Electrical Work |
Use the same size new wire as the existing wire.
The trailer electrical load determines the amount of current, not the receptacle
size.
Use a 30 amp receptacle.
Use gray plastic conduit or use rigid metal conduit if there is a damage risk.
Buy conduit one size bigger than you think that you need.
Use a shop vac to suck a pull string through the conduit.
Bury the conduit 2 feet deep or more.
Use the green/white/black wires, but not the red one.
Search Google for "how to wire 30 amp RV plug"
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=506797#506797
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| Subject: | Re: two-battery, fuel pump circuit protection |
Patrick Brannan wrote:
> ... I have Bob's book and am working on a schematic for an electrically-dependent
(SDS EFI+I) aircraft.
> .
> .
> In Z-19...
> .
> .
Questions:
What engine and aircraft?
Dual ECUs?
Quick comments re your "engne-busses.png" and Z19:
Z19 was designed for automotive engines that do not accommodate two alternators.
It shows one ECU but does not show the coils and injectors. Note how fuel pump
2 is powered in Z19.
You have SPOFs downstream of the fuel pump diodes.
You do not show the injectors or coilpacks.
Be aware the injectors are not powered by the ECU but driven to ground by its open
collector section.
Preflight will require turning off pump 1 while pump 2 is running, your proposal
"engne-busses.png" does not support this.
Preflight will want to depower a pump with depowering the ECUs.
I imagine you want Z101, it's not the the Aeroelectric Connection book at this time, find it in folder " Adobe_Architecture_Pdfs/" at https://www.aeroelectric.com/PPS/
Have a look at my Z101-inspired power schematic for dual SDS EFI+I equipped RV-6A
if you like. It's in folder 1 of my Google drive linked in my signature below.
It meets the spirit of FAR 23.1361 and allows for the fire-in-the-cockpit-main-master-off
scenario. I also have a flight checklist and FMEA.
--------
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
https://drive.google.com/folderview?id=1u6GeZo6pmBWsKykLNVQMvu4o1VEVyP4K
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=506798#506798
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| Subject: | Re: Hangar Electrical Work |
On 5/14/2022 2:19 PM, William Hunter wrote:
> Hi All.
>
> So this question is about a hangar at an airport albeit a slight off
> topic question for the multi-knowledgeable among us...
>
> I have a 50 amp RV receptacle box mounted to the outer side wall of my
> steel hangar and it is fed by the four red/green/white/black wires
> that are routed from the inside of the building through metal conduit
> that is inserted through the side wall out to the steel box where the
> receptacle is installed as per code.
>
> I want to decommission that receptacle so I can extend the wires
> outside underground to a newly installed pedestal about 20 feet
> away...in other words I need to open the existing metal box, eliminate
> the receptacle and put a cover over the opening, run a conduit from
> the bottom of the existing box down the outside hangar wall and into
> the ground and then run it under ground out horizontal 20 feet, and
> then up the side of a newly installed "pedestal" (4X4 pressure treated
> post sticking out of the ground) to a new receptacle.
>
> So the questions are:
>
> -What method should I use to electrically connect the 4 wires at the
> side wall box to the new wires that are being run through the conduit
> to the new pedestal mounted receptacle?
>
> -The travel trailer that will occupy my new trailer park is a 30 Amp
> unit so I presume I should run the four 50 Amp wires through the new
> underground conduit to the new new pedestal mounted receptacle so as
> to take advantage of the additional conductor?
>
> -Regarding the new receptacle should I go with a 50 Amp or a 30 Amp?
> -If I install a 50 Amp receptacle to the new pedestal then I
> could plug in the trailer using a 50 Amp to 30 Amp adapter plug...or...
> -Should I install a 30 Amp plug at the new receptacle so as to
> limit the current draw considering the the additional 30 feet of wire
> resistance?
> -If I went with a 30 Amp receptacle, then how would I
> connect the 4 wires to the 3 wire 30 Amp plug?
>
> -What is an economical conduit for the underground run that is
> appropriate for the exposed sections (down hangar wall and up pedestal)?
> -How deep does conduit need to be buried?
> -What diameter conduit should I use?
>
> -Where is a good source to procure the plastic pink flamingos, tiki
> torches, and rolled out fake grass required to amplify the tackiness
> of my new trailer park?
>
> Sorry for the slightly off topic question however you all are the
> smartest people I know on any subject so I'm sure there is someone on
> this list who used to do this work and could provide some "if it were
> me I would..." statements.
>
> Thanks for your patience and offline responses are good so as to avoid
> spamming of my off topic post!!!
>
> Bill
Is this under a grass area, with little to no vehicle traffic? If so,
direct burial cable will get the job done. I've had a run buried from my
house to hangar for over 20 years, with frequent tractor traffic
(mowing) & occasional cars & trucks on it. Depth is a 'code' thing; if
your location isn't subject to heavy traffic or code inspectors, but
anything over 15-20 inches would protect the wire, but it might be more
vulnerable to later digging. Schedule 40 PVC down the wall and into the
ground, then just bury the cable to the post, and sched40 up the post to
the box. If it's driven on constantly, then I'd use the PVC all the way
and run individual conductors in the pipe. Steel isn't that much tougher
than sched40 PVC for a burial application, and it *will* rust away
eventually. The power company here always uses PVC when going under
gravel driveways, and direct burial cable elsewhere (with PVC pipe
protection above ground).
In the US, 4 wire is now the 'standard' for 220VAC; typically hot black,
hot red, neutral white, ground green or bare. If you have to deal with
inspectors, 4 wires & a 4 hole outlet might save you some grief. Also
give future flexibility; the next RV might be bigger.
I'm not an electrician, but I've done quite a bit of electrical work (my
dad was a licensed electrician), and the above is what I've done for my
own applications.
FWIW,
Charlie
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| Subject: | 30A PM alternator and Z101? |
The Monkworkz 30A PM alternator is in production as an early-adopter option. Ref
VAF thread https://vansairforce.net/community/showthread.php?t 6179
It cannot be connected directly to the battery because it presents a passive load
that will drain the battery. there is a resistive voltage divider on the output
that keeps tabs on the output voltage and that will over time drag your battery
down
BTW it is said to start and work well with battery disconnected.
Question for Bob and others best way to incorporate it into Z101? Simply a 40A
automotive relay between alternator and battery?
--------
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
https://drive.google.com/folderview?id=1u6GeZo6pmBWsKykLNVQMvu4o1VEVyP4K
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=506801#506801
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