Today's Message Index:
----------------------
1. 07:18 AM - Z14 with SDS EFI... (gtae07)
2. 09:15 AM - Re: order aero electric book and cd bundle about week and a half ago (Lawrence Handberg)
3. 10:28 AM - Re: Z14 with SDS EFI... (C&K)
4. 10:37 AM - Re: Z14 with SDS EFI... (user9253)
5. 11:41 AM - Re: Z14 with SDS EFI... (Charlie England)
6. 11:47 AM - Re: Z14 with SDS EFI... (Charlie England)
7. 12:59 PM - Re: Z14 with SDS EFI... (C&K)
8. 02:48 PM - Re: Z14 with SDS EFI... (Charlie England)
9. 03:26 PM - Re: order aero electric book and cd bundle about week and a half ago (Robert L. Nuckolls, III)
10. 03:55 PM - Re: Z14 with SDS EFI... (C&K)
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| Subject: | Z14 with SDS EFI... |
I'm planning on a dual ECU SDS EFI system for my RV-7. I'm also planning to (eventually)
equip for IFR. Given all that, I'm looking strongly at a Z14-based
electrical architecture, but I have a few questions/concerns about it.
My plan was to split the critical engine systems and the PFDs across both battery
buses, so the aircraft could run solely on one bus or the other. I wanted
to maintain the ability to fly indefinitely after one failure and provide a minimum
of two hours on battery power alone.
However, as I dug into it I started realizing that this plan might have a problem.
Unlike the ignition, there aren't redundant injectors, so the install manual
splits power for them across two (or four) separate sources for some level
of redundancy (which I assume will give a rough engine but some reduced power).
If I split two injectors to one bus and the other two on the second bus, I'm
not fully redundant. If I lose one bus entirely, I'm down to two injectors.
Plus, the way Z14 is drawn, if I lose either the main or aux contactor, that
side's injectors are now running on battery power--the crossfeed doesn't help
because it connects after the battery contactors.
That prompted a couple of ideas. First, is there any reason why the crosstie has
to be "downstream" of the battery contactors? Could I not just place it directly
between the batteries, and feed its switch through diodes off the battery
bus? (I called this Mod 1 in the attached item)
Second, does anyone see a problem with feeding the injector power through diode
bridges? (mod 1a)
As an expansion off that, does anyone see a problem with feeding an "engine bus"
off a pair of Schottky diodes straight from the batteries? (mod 2)
Finally, does anyone see a problem with "hard wiring" (through fuses of course)
components that will not draw power without the engine running--that is, the
coils, injectors, and injector relays?
I've attached simple block diagrams of the above ideas. They aren't full wiring
diagrams so please don't get wrapped up around wire protection or details like
that yet.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=471104#471104
Attachments:
http://forums.matronics.com//files/electrical_block_diagram_793.pdf
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| Subject: | Re: order aero electric book and cd bundle about week |
and a half ago
He didn't charge me until he shipped mine. You may want to call him to make sure
he receive the order.
From: Jeffrey C Warren <heffnhane@mac.com>
To: aeroelectric-list@matronics.com
Sent: Sunday, July 16, 2017 5:48 PM
Subject: AeroElectric-List: order aero electric book and cd bundle about week
and a half ago
recieved confirmation from aeroelectric but never a paypal notice.
Jeffrey C WarrenRV14A #140195864-275-3798heffnhane@mac.com(SC47)
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| Subject: | Re: Z14 with SDS EFI... |
With Z14, I run each of my separate EFI systems off it's own battery
buss on each of my two little 8 amp-Hr batteries. Neither goes thru a
battery contactor. I would not be comfortable running them thru a
contactor. There are no "battery contactors" between the crossfeed and
my batteries. I have one contactor that feeds the non engine busses
instead of a classic battery contactor that disconnects the battery. The
general advice here seems to be NOT to plan for 2 independent failures
on the same day or you tend to get tied up in overly complicated knots
with little or even sometimes negative safety advantage.
Losing half your injectors will lose MORE than half your power.
In my case I can maintain flight with one injector offline without
shaking the airplane apart. Not so much with 2 offline. I did look at
relays and feed diodes but my solution for simple operating procedures
and independent electronics was to simply weld in a second set of
injectors. It also avoided some other failure points that can take down
some dual ecu systems such as relying on a single mechanical fuel
pressure regulator that may be less reliable than the ecu's...
Two alternators plus 2 hours of battery power seems like a lot of
overkill. I can run for an unlimited time on either alternator so I
happily take advantage of small and light batteries. The crossfeed auto
closes during cranking so if the engine cranks smartly I know the
crossfeed is working which is it's operational check. Has worked well
for 11 years and 730 hours.
I can't comment on diode bridges.
Ken
On 17/07/2017 10:15 AM, gtae07 wrote:
>
> I'm planning on a dual ECU SDS EFI system for my RV-7. I'm also planning to
(eventually) equip for IFR. Given all that, I'm looking strongly at a Z14-based
electrical architecture, but I have a few questions/concerns about it.
>
>
> My plan was to split the critical engine systems and the PFDs across both battery
buses, so the aircraft could run solely on one bus or the other. I wanted
to maintain the ability to fly indefinitely after one failure and provide a
minimum of two hours on battery power alone.
>
> However, as I dug into it I started realizing that this plan might have a problem.
Unlike the ignition, there aren't redundant injectors, so the install manual
splits power for them across two (or four) separate sources for some level
of redundancy (which I assume will give a rough engine but some reduced power).
If I split two injectors to one bus and the other two on the second bus,
I'm not fully redundant. If I lose one bus entirely, I'm down to two injectors.
Plus, the way Z14 is drawn, if I lose either the main or aux contactor, that
side's injectors are now running on battery power--the crossfeed doesn't help
because it connects after the battery contactors.
>
> That prompted a couple of ideas. First, is there any reason why the crosstie
has to be "downstream" of the battery contactors? Could I not just place it
directly between the batteries, and feed its switch through diodes off the battery
bus? (I called this Mod 1 in the attached item)
>
> Second, does anyone see a problem with feeding the injector power through diode
bridges? (mod 1a)
>
> As an expansion off that, does anyone see a problem with feeding an "engine bus"
off a pair of Schottky diodes straight from the batteries? (mod 2)
>
>
> Finally, does anyone see a problem with "hard wiring" (through fuses of course)
components that will not draw power without the engine running--that is, the
coils, injectors, and injector relays?
>
> I've attached simple block diagrams of the above ideas. They aren't full wiring
diagrams so please don't get wrapped up around wire protection or details
like that yet.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=471104#471104
>
>
> Attachments:
>
> http://forums.matronics.com//files/electrical_block_diagram_793.pdf
>
>
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| Subject: | Re: Z14 with SDS EFI... |
gtae07,
Any of your options will work. Of them, I like MOD 1A the best. If the cross
tie contactor is left on after shut down, both batteries will be run down.
Loosing a battery contactor does not cause a loss of power because power comes
from the alternator, not the battery. Most alternators will keep on working
if the battery is disconnected, although the voltage could be unstable.
Another option is to wire an automotive 40-amp relay in parallel with the battery
contactor. The relay must be disabled during engine cranking.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=471109#471109
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| Subject: | Re: Z14 with SDS EFI... |
On 7/17/2017 9:15 AM, gtae07 wrote:
>
> I'm planning on a dual ECU SDS EFI system for my RV-7. I'm also planning to
(eventually) equip for IFR. Given all that, I'm looking strongly at a Z14-based
electrical architecture, but I have a few questions/concerns about it.
>
>
> My plan was to split the critical engine systems and the PFDs across both battery
buses, so the aircraft could run solely on one bus or the other. I wanted
to maintain the ability to fly indefinitely after one failure and provide a
minimum of two hours on battery power alone.
>
> However, as I dug into it I started realizing that this plan might have a problem.
Unlike the ignition, there aren't redundant injectors, so the install manual
splits power for them across two (or four) separate sources for some level
of redundancy (which I assume will give a rough engine but some reduced power).
If I split two injectors to one bus and the other two on the second bus,
I'm not fully redundant. If I lose one bus entirely, I'm down to two injectors.
Plus, the way Z14 is drawn, if I lose either the main or aux contactor, that
side's injectors are now running on battery power--the crossfeed doesn't help
because it connects after the battery contactors.
>
> That prompted a couple of ideas. First, is there any reason why the crosstie
has to be "downstream" of the battery contactors? Could I not just place it
directly between the batteries, and feed its switch through diodes off the battery
bus? (I called this Mod 1 in the attached item)
>
> Second, does anyone see a problem with feeding the injector power through diode
bridges? (mod 1a)
>
> As an expansion off that, does anyone see a problem with feeding an "engine bus"
off a pair of Schottky diodes straight from the batteries? (mod 2)
>
>
> Finally, does anyone see a problem with "hard wiring" (through fuses of course)
components that will not draw power without the engine running--that is, the
coils, injectors, and injector relays?
>
> I've attached simple block diagrams of the above ideas. They aren't full wiring
diagrams so please don't get wrapped up around wire protection or details
like that yet.
>
I can't hit every point, but do have a few thoughts. I wouldn't split
injector power across buses. If you lose a bus & half your injectors,
you've lost close to 75% of your power, & stuff could break just from
the abnormal firing with only two cyls working.
My choice (full disclosure: not yet flying) is to do something closer to
what you have as mod 2. My attitude is to build a good engine bus, make
sure my wiring practice is sound, and live with it, just as I live
without backups for my single pair of wings (redundant controllers on
the same bus). I have the luxury (automotive engine) of running
identical alternators, so I have only one battery. I have one engine
bus, controlled with a high current toggle switch (no contactor) fed
directly from the battery utilizing a fusible link in the feed. The
'rest of the airplane' bus is controlled by a master contactor, as is
typical. I have an emergency crossfeed switch (same high current model)
so that either bus can draw on the other, as needed. I can shut down
either alternator's output, either bus's feed (and crossfeed from the
other bus), or if there's a serious fire, I can still shut down all
electrical power if needed as a last resort ('standard' aviation design
practice).
As drawn, your mod 2 has no way to isolate anything from the batteries;
the contactors just interrupt power from the alternators. is that what
you intend? It also doesn't show the 'rest of the airplane' buss
(avionics, etc). How will that be integrated?
Charlie
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| Subject: | Re: Z14 with SDS EFI... |
Ken,
How big are your batteries? With two alternators you shouldn't ever need
to know battery capacity, but I can tell you that most automotive style
engine controllers (high pressure injection) will suck a PC680 dry in
about 40 minutes. That's just the electrical loads of the engine itself
+ fuel pump; no avionics, etc.
Charlie
On 7/17/2017 12:28 PM, C&K wrote:
>
> With Z14, I run each of my separate EFI systems off it's own battery
> buss on each of my two little 8 amp-Hr batteries. Neither goes thru a
> battery contactor. I would not be comfortable running them thru a
> contactor. There are no "battery contactors" between the crossfeed and
> my batteries. I have one contactor that feeds the non engine busses
> instead of a classic battery contactor that disconnects the battery.
> The general advice here seems to be NOT to plan for 2 independent
> failures on the same day or you tend to get tied up in overly
> complicated knots with little or even sometimes negative safety
> advantage.
>
> Losing half your injectors will lose MORE than half your power.
>
> In my case I can maintain flight with one injector offline without
> shaking the airplane apart. Not so much with 2 offline. I did look at
> relays and feed diodes but my solution for simple operating procedures
> and independent electronics was to simply weld in a second set of
> injectors. It also avoided some other failure points that can take
> down some dual ecu systems such as relying on a single mechanical fuel
> pressure regulator that may be less reliable than the ecu's...
>
> Two alternators plus 2 hours of battery power seems like a lot of
> overkill. I can run for an unlimited time on either alternator so I
> happily take advantage of small and light batteries. The crossfeed
> auto closes during cranking so if the engine cranks smartly I know the
> crossfeed is working which is it's operational check. Has worked well
> for 11 years and 730 hours.
>
> I can't comment on diode bridges.
>
> Ken
>
>
> On 17/07/2017 10:15 AM, gtae07 wrote:
>>
>> I'm planning on a dual ECU SDS EFI system for my RV-7. I'm also
>> planning to (eventually) equip for IFR. Given all that, I'm looking
>> strongly at a Z14-based electrical architecture, but I have a few
>> questions/concerns about it.
>>
>>
>> My plan was to split the critical engine systems and the PFDs across
>> both battery buses, so the aircraft could run solely on one bus or
>> the other. I wanted to maintain the ability to fly indefinitely
>> after one failure and provide a minimum of two hours on battery power
>> alone.
>>
>> However, as I dug into it I started realizing that this plan might
>> have a problem. Unlike the ignition, there aren't redundant
>> injectors, so the install manual splits power for them across two (or
>> four) separate sources for some level of redundancy (which I assume
>> will give a rough engine but some reduced power). If I split two
>> injectors to one bus and the other two on the second bus, I'm not
>> fully redundant. If I lose one bus entirely, I'm down to two
>> injectors. Plus, the way Z14 is drawn, if I lose either the main or
>> aux contactor, that side's injectors are now running on battery
>> power--the crossfeed doesn't help because it connects after the
>> battery contactors.
>>
>> That prompted a couple of ideas. First, is there any reason why the
>> crosstie has to be "downstream" of the battery contactors? Could I
>> not just place it directly between the batteries, and feed its switch
>> through diodes off the battery bus? (I called this Mod 1 in the
>> attached item)
>>
>> Second, does anyone see a problem with feeding the injector power
>> through diode bridges? (mod 1a)
>>
>> As an expansion off that, does anyone see a problem with feeding an
>> "engine bus" off a pair of Schottky diodes straight from the
>> batteries? (mod 2)
>>
>>
>> Finally, does anyone see a problem with "hard wiring" (through fuses
>> of course) components that will not draw power without the engine
>> running--that is, the coils, injectors, and injector relays?
>>
>> I've attached simple block diagrams of the above ideas. They aren't
>> full wiring diagrams so please don't get wrapped up around wire
>> protection or details like that yet.
---
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| Subject: | Re: Z14 with SDS EFI... |
Charlie
Yes I would not want to count on my little Dekka 8 amp-hr for much more
than 10 or maybe 15 minutes at most based on my typical 16 amp primary
system load and original testing. (I run a few things like strobes off
the other alternator.) The BRL (Big Red flashing Light) low volts light
from the EIS is pretty attention getting though and it just takes a
switch flick to fix things. The second alternator certainly removes
worrying much about battery capacity. It's not a capacity check, but
these 120 CCA batteries do fairly well on 60 and 100 amp load tests
even after 5 to 12 years. Interestingly I picked up a new one a few
months ago special order at Lowes (America not Canada). $60. was a
better price than anywhere else I found on the internet and it was
manufactured in PA within the previous month.
Ken
On 17/07/2017 2:49 PM, Charlie England wrote:
> <ceengland7@gmail.com>
>
> Ken,
>
> How big are your batteries? With two alternators you shouldn't ever
> need to know battery capacity, but I can tell you that most automotive
> style engine controllers (high pressure injection) will suck a PC680
> dry in about 40 minutes. That's just the electrical loads of the
> engine itself + fuel pump; no avionics, etc.
>
> Charlie
>
> On 7/17/2017 12:28 PM, C&K wrote:
>>
>> With Z14, I run each of my separate EFI systems off it's own battery
>> buss on each of my two little 8 amp-Hr batteries. Neither goes thru a
>> battery contactor. I would not be comfortable running them thru a
>> contactor. There are no "battery contactors" between the crossfeed
>> and my batteries. I have one contactor that feeds the non engine
>> busses instead of a classic battery contactor that disconnects the
>> battery. The general advice here seems to be NOT to plan for 2
>> independent failures on the same day or you tend to get tied up in
>> overly complicated knots with little or even sometimes negative
>> safety advantage.
>>
>> Losing half your injectors will lose MORE than half your power.
>>
>> In my case I can maintain flight with one injector offline without
>> shaking the airplane apart. Not so much with 2 offline. I did look at
>> relays and feed diodes but my solution for simple operating
>> procedures and independent electronics was to simply weld in a second
>> set of injectors. It also avoided some other failure points that can
>> take down some dual ecu systems such as relying on a single
>> mechanical fuel pressure regulator that may be less reliable than the
>> ecu's...
>>
>> Two alternators plus 2 hours of battery power seems like a lot of
>> overkill. I can run for an unlimited time on either alternator so I
>> happily take advantage of small and light batteries. The crossfeed
>> auto closes during cranking so if the engine cranks smartly I know
>> the crossfeed is working which is it's operational check. Has worked
>> well for 11 years and 730 hours.
>>
>> I can't comment on diode bridges.
>>
>> Ken
>>
>>
>> On 17/07/2017 10:15 AM, gtae07 wrote:
>>>
>>> I'm planning on a dual ECU SDS EFI system for my RV-7. I'm also
>>> planning to (eventually) equip for IFR. Given all that, I'm looking
>>> strongly at a Z14-based electrical architecture, but I have a few
>>> questions/concerns about it.
>>>
>>>
>>> My plan was to split the critical engine systems and the PFDs across
>>> both battery buses, so the aircraft could run solely on one bus or
>>> the other. I wanted to maintain the ability to fly indefinitely
>>> after one failure and provide a minimum of two hours on battery
>>> power alone.
>>>
>>> However, as I dug into it I started realizing that this plan might
>>> have a problem. Unlike the ignition, there aren't redundant
>>> injectors, so the install manual splits power for them across two
>>> (or four) separate sources for some level of redundancy (which I
>>> assume will give a rough engine but some reduced power). If I split
>>> two injectors to one bus and the other two on the second bus, I'm
>>> not fully redundant. If I lose one bus entirely, I'm down to two
>>> injectors. Plus, the way Z14 is drawn, if I lose either the main or
>>> aux contactor, that side's injectors are now running on battery
>>> power--the crossfeed doesn't help because it connects after the
>>> battery contactors.
>>>
>>> That prompted a couple of ideas. First, is there any reason why the
>>> crosstie has to be "downstream" of the battery contactors? Could I
>>> not just place it directly between the batteries, and feed its
>>> switch through diodes off the battery bus? (I called this Mod 1 in
>>> the attached item)
>>>
>>> Second, does anyone see a problem with feeding the injector power
>>> through diode bridges? (mod 1a)
>>>
>>> As an expansion off that, does anyone see a problem with feeding an
>>> "engine bus" off a pair of Schottky diodes straight from the
>>> batteries? (mod 2)
>>>
>>>
>>> Finally, does anyone see a problem with "hard wiring" (through fuses
>>> of course) components that will not draw power without the engine
>>> running--that is, the coils, injectors, and injector relays?
>>>
>>> I've attached simple block diagrams of the above ideas. They aren't
>>> full wiring diagrams so please don't get wrapped up around wire
>>> protection or details like that yet.
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>
>
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| Subject: | Re: Z14 with SDS EFI... |
Not to get too far into the weeds, but what are you testing at 60 & 100
amps? If you're just testing whether it will grunt the load for a few
seconds or minutes, it won't tell you much about how long it will last when
loaded at, say, 10-20 amps (typical range of automotive style injection
plus fuel pump, depending on the system). There have been in-flight tests
of PC680's, and they're good for around 40 minutes to an hour, tops, when
being loaded at around 10-15 amps. If you look at Odessey's spec sheet for
a PC680, it's a 16 ampere-hour battery, but with a 15 amp load, it lasts
for ~45 minutes; a virtually exact match for 'real world' tests. When load
gets close to or above the AH rating, life gets *really* short.
8AH batteries should be a lot cheaper than that. IIRC, I've bought from
Apex in the past (and several other vendors, as well, and they have pretty
good prices. Here's a pair for $20:
https://www.apexbattery.com/apc-back-ups-xs-900-12v-8ah-replacement-battery-160798.html?gclid=Cj0KCQjwwLHLBRDEARIsAN1A1Q67Bm55WDDHCRfTkPBhdUZNs9zNyRdHkiBlSIlgAhFDJMFcXbHCBGsaAr2oEALw_wcB
Not sure of their shipping prices. But Amazon has them for $20 each, free
shipping if you have Prime.
Charlie
On Mon, Jul 17, 2017 at 2:58 PM, C&K <yellowduckduo@gmail.com> wrote:
>
> Charlie
> Yes I would not want to count on my little Dekka 8 amp-hr for much more
> than 10 or maybe 15 minutes at most based on my typical 16 amp primary
> system load and original testing. (I run a few things like strobes off the
> other alternator.) The BRL (Big Red flashing Light) low volts light from
> the EIS is pretty attention getting though and it just takes a switch flick
> to fix things. The second alternator certainly removes worrying much about
> battery capacity. It's not a capacity check, but these 120 CCA batteries
> do fairly well on 60 and 100 amp load tests even after 5 to 12 years.
> Interestingly I picked up a new one a few months ago special order at Lowes
> (America not Canada). $60. was a better price than anywhere else I found on
> the internet and it was manufactured in PA within the previous month.
> Ken
>
> On 17/07/2017 2:49 PM, Charlie England wrote:
>
>> ceengland7@gmail.com>
>>
>> Ken,
>>
>> How big are your batteries? With two alternators you shouldn't ever need
>> to know battery capacity, but I can tell you that most automotive style
>> engine controllers (high pressure injection) will suck a PC680 dry in about
>> 40 minutes. That's just the electrical loads of the engine itself + fuel
>> pump; no avionics, etc.
>>
>> Charlie
>>
>> On 7/17/2017 12:28 PM, C&K wrote:
>>
>>>
>>> With Z14, I run each of my separate EFI systems off it's own battery
>>> buss on each of my two little 8 amp-Hr batteries. Neither goes thru a
>>> battery contactor. I would not be comfortable running them thru a
>>> contactor. There are no "battery contactors" between the crossfeed and my
>>> batteries. I have one contactor that feeds the non engine busses instead of
>>> a classic battery contactor that disconnects the battery. The general
>>> advice here seems to be NOT to plan for 2 independent failures on the same
>>> day or you tend to get tied up in overly complicated knots with little or
>>> even sometimes negative safety advantage.
>>>
>>> Losing half your injectors will lose MORE than half your power.
>>>
>>> In my case I can maintain flight with one injector offline without
>>> shaking the airplane apart. Not so much with 2 offline. I did look at
>>> relays and feed diodes but my solution for simple operating procedures and
>>> independent electronics was to simply weld in a second set of injectors. It
>>> also avoided some other failure points that can take down some dual ecu
>>> systems such as relying on a single mechanical fuel pressure regulator that
>>> may be less reliable than the ecu's...
>>>
>>> Two alternators plus 2 hours of battery power seems like a lot of
>>> overkill. I can run for an unlimited time on either alternator so I happily
>>> take advantage of small and light batteries. The crossfeed auto closes
>>> during cranking so if the engine cranks smartly I know the crossfeed is
>>> working which is it's operational check. Has worked well for 11 years and
>>> 730 hours.
>>>
>>> I can't comment on diode bridges.
>>>
>>> Ken
>>>
>>>
>>> On 17/07/2017 10:15 AM, gtae07 wrote:
>>>
>>>>
>>>> I'm planning on a dual ECU SDS EFI system for my RV-7. I'm also
>>>> planning to (eventually) equip for IFR. Given all that, I'm looking
>>>> strongly at a Z14-based electrical architecture, but I have a few
>>>> questions/concerns about it.
>>>>
>>>>
>>>> My plan was to split the critical engine systems and the PFDs across
>>>> both battery buses, so the aircraft could run solely on one bus or the
>>>> other. I wanted to maintain the ability to fly indefinitely after one
>>>> failure and provide a minimum of two hours on battery power alone.
>>>>
>>>> However, as I dug into it I started realizing that this plan might have
>>>> a problem. Unlike the ignition, there aren't redundant injectors, so the
>>>> install manual splits power for them across two (or four) separate sources
>>>> for some level of redundancy (which I assume will give a rough engine but
>>>> some reduced power). If I split two injectors to one bus and the other two
>>>> on the second bus, I'm not fully redundant. If I lose one bus entirely,
>>>> I'm down to two injectors. Plus, the way Z14 is drawn, if I lose either
>>>> the main or aux contactor, that side's injectors are now running on battery
>>>> power--the crossfeed doesn't help because it connects after the battery
>>>> contactors.
>>>>
>>>> That prompted a couple of ideas. First, is there any reason why the
>>>> crosstie has to be "downstream" of the battery contactors? Could I not just
>>>> place it directly between the batteries, and feed its switch through diodes
>>>> off the battery bus? (I called this Mod 1 in the attached item)
>>>>
>>>> Second, does anyone see a problem with feeding the injector power
>>>> through diode bridges? (mod 1a)
>>>>
>>>> As an expansion off that, does anyone see a problem with feeding an
>>>> "engine bus" off a pair of Schottky diodes straight from the batteries?
>>>> (mod 2)
>>>>
>>>>
>>>> Finally, does anyone see a problem with "hard wiring" (through fuses of
>>>> course) components that will not draw power without the engine
>>>> running--that is, the coils, injectors, and injector relays?
>>>>
>>>> I've attached simple block diagrams of the above ideas. They aren't
>>>> full wiring diagrams so please don't get wrapped up around wire protection
>>>> or details like that yet.
>>>>
>>>
>>
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| Subject: | Re: order aero electric book and cd bundle about |
week and a half ago
At 07:32 PM 7/16/2017, you wrote:
>recieved confirmation from aeroelectric but never a paypal notice.
>
>
>Jeffrey C Warren
>RV14A #140195
>864-275-3798
><mailto:heffnhane@mac.com>heffnhane@mac.com
>(SC47)
>
I had invoiced you on the 7th then inadvertently double invoiced a
few days later. When I caught the error, I canceled the second
invoice but it seems that BOTH of them got canceled. You should have
been receiving email notices on each of the snafus . . . Sorry 'bout that!
Just re-issued the invoice . . .
Bob . . .
Message 10
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| Subject: | Re: Z14 with SDS EFI... |
Agree with most of what you are saying but don't forget that there are
relatively cheap standby power AGM batteries and then there are power
sports batteries that are rated and capable of cranking engines. In
that last group there are ones with proven reliability such as the
Odysey and Dekka lines. You won't find those for $20.
Ken
On 17/07/2017 5:44 PM, Charlie England wrote:
> Not to get too far into the weeds, but what are you testing at 60 &
> 100 amps? If you're just testing whether it will grunt the load for a
> few seconds or minutes, it won't tell you much about how long it will
> last when loaded at, say, 10-20 amps (typical range of automotive
> style injection plus fuel pump, depending on the system). There have
> been in-flight tests of PC680's, and they're good for around 40
> minutes to an hour, tops, when being loaded at around 10-15 amps. If
> you look at Odessey's spec sheet for a PC680, it's a 16 ampere-hour
> battery, but with a 15 amp load, it lasts for ~45 minutes; a virtually
> exact match for 'real world' tests. When load gets close to or above
> the AH rating, life gets *really* short.
>
> 8AH batteries should be a lot cheaper than that. IIRC, I've bought
> from Apex in the past (and several other vendors, as well, and they
> have pretty good prices. Here's a pair for $20:
> https://www.apexbattery.com/apc-back-ups-xs-900-12v-8ah-replacement-battery-160798.html?gclid=Cj0KCQjwwLHLBRDEARIsAN1A1Q67Bm55WDDHCRfTkPBhdUZNs9zNyRdHkiBlSIlgAhFDJMFcXbHCBGsaAr2oEALw_wcB
>
> Not sure of their shipping prices. But Amazon has them for $20 each,
> free shipping if you have Prime.
>
> Charlie
>
> On Mon, Jul 17, 2017 at 2:58 PM, C&K <yellowduckduo@gmail.com
> <mailto:yellowduckduo@gmail.com>> wrote:
>
> <yellowduckduo@gmail.com <mailto:yellowduckduo@gmail.com>>
>
> Charlie
> Yes I would not want to count on my little Dekka 8 amp-hr for much
> more than 10 or maybe 15 minutes at most based on my typical 16
> amp primary system load and original testing. (I run a few things
> like strobes off the other alternator.) The BRL (Big Red flashing
> Light) low volts light from the EIS is pretty attention getting
> though and it just takes a switch flick to fix things. The second
> alternator certainly removes worrying much about battery
> capacity. It's not a capacity check, but these 120 CCA batteries
> do fairly well on 60 and 100 amp load tests even after 5 to 12
> years. Interestingly I picked up a new one a few months ago
> special order at Lowes (America not Canada). $60. was a better
> price than anywhere else I found on the internet and it was
> manufactured in PA within the previous month.
> Ken
>
> On 17/07/2017 2:49 PM, Charlie England wrote:
>
> <ceengland7@gmail.com <mailto:ceengland7@gmail.com>>
>
> Ken,
>
> How big are your batteries? With two alternators you shouldn't
> ever need to know battery capacity, but I can tell you that
> most automotive style engine controllers (high pressure
> injection) will suck a PC680 dry in about 40 minutes. That's
> just the electrical loads of the engine itself + fuel pump; no
> avionics, etc.
>
> Charlie
>
> On 7/17/2017 12:28 PM, C&K wrote:
>
> <yellowduckduo@gmail.com <mailto:yellowduckduo@gmail.com>>
>
> With Z14, I run each of my separate EFI systems off it's
> own battery buss on each of my two little 8 amp-Hr
> batteries. Neither goes thru a battery contactor. I would
> not be comfortable running them thru a contactor. There
> are no "battery contactors" between the crossfeed and my
> batteries. I have one contactor that feeds the non engine
> busses instead of a classic battery contactor that
> disconnects the battery. The general advice here seems to
> be NOT to plan for 2 independent failures on the same day
> or you tend to get tied up in overly complicated knots
> with little or even sometimes negative safety advantage.
>
> Losing half your injectors will lose MORE than half your
> power.
>
> In my case I can maintain flight with one injector offline
> without shaking the airplane apart. Not so much with 2
> offline. I did look at relays and feed diodes but my
> solution for simple operating procedures and independent
> electronics was to simply weld in a second set of
> injectors. It also avoided some other failure points that
> can take down some dual ecu systems such as relying on a
> single mechanical fuel pressure regulator that may be less
> reliable than the ecu's...
>
> Two alternators plus 2 hours of battery power seems like a
> lot of overkill. I can run for an unlimited time on either
> alternator so I happily take advantage of small and light
> batteries. The crossfeed auto closes during cranking so if
> the engine cranks smartly I know the crossfeed is working
> which is it's operational check. Has worked well for 11
> years and 730 hours.
>
> I can't comment on diode bridges.
>
> Ken
>
>
> On 17/07/2017 10:15 AM, gtae07 wrote:
>
> <icebrain@gmail.com <mailto:icebrain@gmail.com>>
>
> I'm planning on a dual ECU SDS EFI system for my
> RV-7. I'm also planning to (eventually) equip for
> IFR. Given all that, I'm looking strongly at a
> Z14-based electrical architecture, but I have a few
> questions/concerns about it.
>
>
> My plan was to split the critical engine systems and
> the PFDs across both battery buses, so the aircraft
> could run solely on one bus or the other. I wanted to
> maintain the ability to fly indefinitely after one
> failure and provide a minimum of two hours on battery
> power alone.
>
> However, as I dug into it I started realizing that
> this plan might have a problem. Unlike the ignition,
> there aren't redundant injectors, so the install
> manual splits power for them across two (or four)
> separate sources for some level of redundancy (which I
> assume will give a rough engine but some reduced
> power). If I split two injectors to one bus and the
> other two on the second bus, I'm not fully redundant.
> If I lose one bus entirely, I'm down to two injectors.
> Plus, the way Z14 is drawn, if I lose either the main
> or aux contactor, that side's injectors are now
> running on battery power--the crossfeed doesn't help
> because it connects after the battery contactors.
>
> That prompted a couple of ideas. First, is there any
> reason why the crosstie has to be "downstream" of the
> battery contactors? Could I not just place it directly
> between the batteries, and feed its switch through
> diodes off the battery bus? (I called this Mod 1 in
> the attached item)
>
> Second, does anyone see a problem with feeding the
> injector power through diode bridges? (mod 1a)
>
> As an expansion off that, does anyone see a problem
> with feeding an "engine bus" off a pair of Schottky
> diodes straight from the batteries? (mod 2)
>
>
> Finally, does anyone see a problem with "hard wiring"
> (through fuses of course) components that will not
> draw power without the engine running--that is, the
> coils, injectors, and injector relays?
>
> I've attached simple block diagrams of the above
> ideas. They aren't full wiring diagrams so please
> don't get wrapped up around wire protection or details
> like that yet.
>
>
> ---
> This email has been checked for viruses by Avast antivirus
> software.
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