 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
 Posted: Wed Aug 05, 2020 10:28 am Post subject: Rotax install |
 |
|
Hello all! I started my research some time ago and have read and read on the electrics of this thing. I am building what I thought would be a fairly simple airplane. It has a 912 engine, dual ignition and fuel injection, but will be VFR flying only. With the single EFIS, radios, lighting, etc. I fear the Amperage will be too much for the stock alternator alone, so I will be supplementing with a Rotax external alternator.
Now, I see drawing Z-16 and that is what I was going to go with, but now I am adding quite a major component and can't seem to figure out how/where it will add in to the scheme. I'm not sure if it should be switched or not as it will be "always on". The Z-16 idea for the Batt switch now does not seem like it would be appropriate in this case, but I really don't know. I was looking at the Rotax installation of the external alternator, and it is wired completely differently than Bob's Z-16, which confused me even more.
I feel like I am making too much of this and that it should still be "simple" to make happen, but I have a hard time putting the written word into practice without being hands on. Can someone help? Any advice would certainly be appreciated. If there is another place to find a diagram similar to what I am talking about, that would be helpful as I am a visual learner.
Thanks all!!
Rob
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
 |
user9253
Joined: 28 Mar 2008
Posts: 1920
Location: Riley TWP Michigan
|
| Posted: Wed Aug 05, 2020 11:06 am Post subject: Re: Rotax install |
|
|
The integrated alternator should be adequate without an external alternator.
Have you done a load analysis? How many amps will your system require?
What is the exact model of your engine, 912ULS or what?
What kind of plane are you building?
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
Joe Gores |
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Wed Aug 05, 2020 11:27 am Post subject: Re: Rotax install |
|
|
| user9253 wrote: | The integrated alternator should be adequate without an external alternator.
Have you done a load analysis? How many amps will your system require?
What is the exact model of your engine, 912ULS or what?
What kind of plane are you building? |
Thanks, Joe.
I would agree with you, except after going through the manuals for everything, it appears the alternator won't be adequate...assuming I am doing things correctly. It will be a stock 912 ULS beefed up power-wise to about 145 HP and will be installed into a Just Aircraft Highlander.
Below are the components and the strobes are what puts it over the edge, even though they are LEDs. Hopefully, this is where I am incorrect. By my excel calculation, add all those up and you get 21.96 amps
All Advanced Flight Systems/Dynon components.
AF5600 PFD/MFD 2.8 amps
SV-COM-C25 RADIO 3 amps
SV-INTERCOM-2S INTERCOM 0.1 amps
SV-XPNDR-261 ADSB OUT 0.4 amps
SV-ADSB-472 ADSB IN 0.1 amps
SV-EMS-220 ENGINE MONITOR 0.11 amps
SV-ADAHRS-200 ADAHRS 0.15 amps
SV-MAG-236 REMOTE MAGNETOMETER 0.15 amps
AF-BAT-3AH BACKUP BATTERY 1 amps
Video Adapter for SkyView 0.15 amps
SkyView Wi-Fi Adapter 0.1 amps
SV-GPS-2020 GPS RECEIVER/ANTENNA 0.1 amps
AeroLEDs Pulsar NSP Strobe 10 amps
Position 0.8 amps
AeroLEDs MicroSun Landing 1.5 amps
Taxi 1.5 amps
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
kenryan
Joined: 20 Oct 2009
Posts: 426
|
| Posted: Wed Aug 05, 2020 11:50 am Post subject: Rotax install |
|
|
No electric fuel pump(s)? How are you getting 145 hp from a Rotax 912 without a turbo?
On Wed, Aug 5, 2020 at 11:40 AM meat_ball <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)>
user9253 wrote:
> The integrated alternator should be adequate without an external alternator.
> Have you done a load analysis? How many amps will your system require?
> What is the exact model of your engine, 912ULS or what?
> What kind of plane are you building?
Thanks, Joe.
I would agree with you, except after going through the manuals for everything, it appears the alternator won't be adequate...assuming I am doing things correctly. It will be a stock 912 ULS beefed up power-wise to about 145 HP and will be installed into a Just Aircraft Highlander.
Below are the components and the strobes are what puts it over the edge, even though they are LEDs. Hopefully, this is where I am incorrect. By my excel calculation, add all those up and you get 21.96 amps
All Advanced Flight Systems/Dynon components.
AF5600 PFD/MFD 2.8 amps
SV-COM-C25 RADIO 3 amps
SV-INTERCOM-2S INTERCOM 0.1 amps
SV-XPNDR-261 ADSB OUT 0.4 amps
SV-ADSB-472 ADSB IN 0.1 amps
SV-EMS-220 ENGINE MONITOR 0.11 amps
SV-ADAHRS-200 ADAHRS 0.15 amps
SV-MAG-236 REMOTE MAGNETOMETER 0.15 amps
AF-BAT-3AH BACKUP BATTERY 1 amps
Video Adapter for SkyView 0.15 amps
SkyView Wi-Fi Adapter 0.1 amps
SV-GPS-2020 GPS RECEIVER/ANTENNA 0.1 amps
AeroLEDs Pulsar NSP Strobe 10 amps
Position 0.8 amps
AeroLEDs MicroSun Landing 1.5 amps
Taxi 1.5 amps
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=497509#497509
===========
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer" target="_blank">http://wiki.matronics.com
===========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
===========
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Wed Aug 05, 2020 12:10 pm Post subject: Re: Rotax install |
|
|
| kenryan wrote: | No electric fuel pump(s)? How are you getting 145 hp from a Rotax 912 without a turbo?
On Wed, Aug 5, 2020 at 11:40 AM meat_ball <arjayefem> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem>
user9253 wrote:
> The integrated alternator should be adequate without an external alternator.
> Have you done a load analysis? How many amps will your system require?
> What is the exact model of your engine, 912ULS or what?
> What kind of plane are you building?
Thanks, Joe.
I would agree with you, except after going through the manuals for everything, it appears the alternator won't be adequate...assuming I am doing things correctly. It will be a stock 912 ULS beefed up power-wise to about 145 HP and will be installed into a Just Aircraft Highlander.
Below are the components and the strobes are what puts it over the edge, even though they are LEDs. Hopefully, this is where I am incorrect. By my excel calculation, add all those up and you get 21.96 amps
All Advanced Flight Systems/Dynon components.
AF5600 PFD/MFD 2.8 amps
SV-COM-C25 RADIO 3 amps
SV-INTERCOM-2S INTERCOM 0.1 amps
SV-XPNDR-261 ADSB OUT 0.4 amps
SV-ADSB-472 ADSB IN 0.1 amps
SV-EMS-220 ENGINE MONITOR 0.11 amps
SV-ADAHRS-200 ADAHRS 0.15 amps
SV-MAG-236 REMOTE MAGNETOMETER 0.15 amps
AF-BAT-3AH BACKUP BATTERY 1 amps
Video Adapter for SkyView 0.15 amps
SkyView Wi-Fi Adapter 0.1 amps
SV-GPS-2020 GPS RECEIVER/ANTENNA 0.1 amps
AeroLEDs Pulsar NSP Strobe 10 amps
Position 0.8 amps
AeroLEDs MicroSun Landing 1.5 amps
Taxi 1.5 amps
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=497509#497509
===========
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer" target="_blank">http://wiki.matronics.com
===========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
===========
|
|
What a great question!!! See?!? Yet another reason I’m posting here. I knew someone would critique my stupidity. Add those in and you an add more amperage still. Yes I will be using a turbo and a couple fuel pumps. I’ll have to find that info...what else have I forgotten I wonder.
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Wed Aug 05, 2020 12:41 pm Post subject: Re: Rotax install |
|
|
I suppose I was thinking all that was taken care of by the on board, internal generator. I’m new to Rotax do this entire thing is a learning process for me. I appreciate everyone’s help!!
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
ceengland7(at)gmail.com
Guest
|
| Posted: Wed Aug 05, 2020 12:45 pm Post subject: Rotax install |
|
|
On 8/5/2020 2:27 PM, meat_ball wrote:
| Quote: |
user9253 wrote:
> The integrated alternator should be adequate without an external alternator.
> Have you done a load analysis? How many amps will your system require?
> What is the exact model of your engine, 912ULS or what?
> What kind of plane are you building?
Thanks, Joe.
I would agree with you, except after going through the manuals for everything, it appears the alternator won't be adequate...assuming I am doing things correctly. It will be a stock 912 ULS beefed up power-wise to about 145 HP and will be installed into a Just Aircraft Highlander.
Below are the components and the strobes are what puts it over the edge, even though they are LEDs. Hopefully, this is where I am incorrect. By my excel calculation, add all those up and you get 21.96 amps
All Advanced Flight Systems/Dynon components.
AF5600 PFD/MFD 2.8 amps
SV-COM-C25 RADIO 3 amps
SV-INTERCOM-2S INTERCOM 0.1 amps
SV-XPNDR-261 ADSB OUT 0.4 amps
SV-ADSB-472 ADSB IN 0.1 amps
SV-EMS-220 ENGINE MONITOR 0.11 amps
SV-ADAHRS-200 ADAHRS 0.15 amps
SV-MAG-236 REMOTE MAGNETOMETER 0.15 amps
AF-BAT-3AH BACKUP BATTERY 1 amps
Video Adapter for SkyView 0.15 amps
SkyView Wi-Fi Adapter 0.1 amps
SV-GPS-2020 GPS RECEIVER/ANTENNA 0.1 amps
AeroLEDs Pulsar NSP Strobe 10 amps
Position 0.8 amps
AeroLEDs MicroSun Landing 1.5 amps
Taxi 1.5 amps
Ask Dynon about idle current on the radio. That looks pretty steep
|
except when transmitting. Same with the strobe. It might spike to 10A,
but average should be *much* lower than that.
Remember that anything that sees intermittent use needs different
treatment from constant draw devices. Short term peaks can be absorbed
by the battery, as long as there's excess *average* charging ability to
replenish the battery.
The backup battery shouldn't draw anything, once it's fully charged
(unless it has its own charging circuit that draws power all the time).
Landing/taxi shouldn't see more than 5 or 10 minutes per flight, unless
you intend to leave them on as recognition lights.
As you just realized, you need to add the fuel pump draw. If you're
running automotive style injection with fuel supplied by only an
electric pump, it will obviously be running all the time. Most injection
pumps draw between 4 & 10 amps, with 5-6 amps being the most common draw.
Charlie
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
kenryan
Joined: 20 Oct 2009
Posts: 426
|
| Posted: Wed Aug 05, 2020 12:51 pm Post subject: Rotax install |
|
|
So if it's a turbo 912 you will need to add in the two fuel pumps and the
turbo control unit. But the strobes don't draw 10 amps continuously. Since
they are intermittent, you can use a lower number for that (others might
know what actual number to use). Also, I believe the number for the comm
radio is only when transmitting, so that number might be brought down as
well. You have 1 amp for the backup battery, but that would only apply when
that battery needs charged.
There are other considerations as well. For one thing, the stock voltage
regulator that Rotax supplies (Ducati) has not proven to be particularly
robust. Many believe that it is not good to run them at full capacity
because it might lead to regulator failure.
Also, if you look at the Rotax wiring diagram for the 914 (which is
basically what you have) you will notice that the primary fuel pump is
wired directly to the internal generator, and that the bus and auxiliary
fuel pump are powered by the optional external alternator and battery. This
is a safety feature that completely separates the main fuel pump from the
auxiliary fuel pump. If, after re-assessing your loads you decide that you
can get by without the external alternator, remember that your engine
requires an electric fuel pump to keep running, and make sure that your
design does not introduce any common point of failure for the two fuel
pumps.
Ken
On Wed, Aug 5, 2020 at 12:25 PM meat_ball <arjayefem(at)fastmail.net> wrote:
[quote]
arjayefem(at)fastmail.net>
kenryan wrote:
> No electric fuel pump(s)? How are you getting 145 hp from a Rotax 912
without a turbo?
>
> On Wed, Aug 5, 2020 at 11:40 AM meat_ball wrote:
>
>
> >
> >
> >
> > user9253 wrote:
> > > The integrated alternator should be adequate without an external
alternator.
> > > Have you done a load analysis? How many amps will your system
require?
> > > What is the exact model of your engine, 912ULS or what?
> > > What kind of plane are you building?
> >
> >
> > Thanks, Joe.
> >
> > I would agree with you, except after going through the manuals for
everything, it appears the alternator won't be adequate...assuming I am
doing things correctly. It will be a stock 912 ULS beefed up power-wise to
about 145 HP and will be installed into a Just Aircraft Highlander.
> >
> > Below are the components and the strobes are what puts it over the
edge, even though they are LEDs. Hopefully, this is where I am incorrect
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
ceengland7(at)gmail.com
Guest
|
| Posted: Wed Aug 05, 2020 12:58 pm Post subject: Rotax install |
|
|
On 8/5/2020 3:41 PM, meat_ball wrote:
| Quote: |
I suppose I was thinking all that was taken care of by the on board, internal generator. I’m new to Rotax do this entire thing is a learning process for me. I appreciate everyone’s help!!
Sorry; all of what was taken care of by the internal generator?
|
(Those of us using email delivery instead of reading the forum sometimes
lose context.)
Charlie
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
kenryan
Joined: 20 Oct 2009
Posts: 426
|
| Posted: Wed Aug 05, 2020 12:59 pm Post subject: Rotax install |
|
|
If it's a Ronnie Smith turbo, ask Ronnie what the turbo control unit draws. Probably 1 - 2 amps.
On Wed, Aug 5, 2020 at 12:53 PM meat_ball <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)>
I suppose I was thinking all that was taken care of by the on board, internal generator. I’m new to Rotax do this entire thing is a learning process for me. I appreciate everyone’s help!!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=497514#497514
===========
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer" target="_blank">http://wiki.matronics.com
===========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
===========
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Wed Aug 05, 2020 1:07 pm Post subject: Re: Rotax install |
|
|
| kenryan wrote: |
Also, if you look at the Rotax wiring diagram for the 914 (which is
basically what you have) you will notice that the primary fuel pump is
wired directly to the internal generator, and that the bus and auxiliary
fuel pump are powered by the optional external alternator and battery. This
is a safety feature that completely separates the main fuel pump from the
auxiliary fuel pump. If, after re-assessing your loads you decide that you
can get by without the external alternator, remember that your engine
requires an electric fuel pump to keep running, and make sure that your
design does not introduce any common point of failure for the two fuel
pumps.
Ken |
And this is where I get confused...Looking at the 914 diagram side by side with Bob’s diagram. How can I incorporate all the safeguards Bob suggests while wiring? They are wired so differently and I have a hard time figuring out how to join the two safely. I’ve looked for previously posted wiring diagrams for inspiration/reference but haven’t been able to find what I need.
As far as the strobes and other higher draw units, I was using worst case scenario for them in case they were all on at the same instant. However, I’m hearing the battery will be able to absorb those spikes, correct? Especially since the strobes are so instantaneous I presume?
Thanks again.
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
kenryan
Joined: 20 Oct 2009
Posts: 426
|
| Posted: Wed Aug 05, 2020 1:07 pm Post subject: Rotax install |
|
|
"I suppose I was thinking all that was taken care of by the on board, internal generator."
You may be thinking of the Rotax 912iS. It has two internal generators and indeed one of them is dedicated to powering the engine electronics.
On Wed, Aug 5, 2020 at 12:55 PM Ken Ryan <keninalaska(at)gmail.com (keninalaska(at)gmail.com)> wrote:
| Quote: | If it's a Ronnie Smith turbo, ask Ronnie what the turbo control unit draws. Probably 1 - 2 amps.
On Wed, Aug 5, 2020 at 12:53 PM meat_ball <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)>
I suppose I was thinking all that was taken care of by the on board, internal generator. I’m new to Rotax do this entire thing is a learning process for me. I appreciate everyone’s help!!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=497514#497514
===========
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer" target="_blank">http://wiki.matronics.com
===========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
===========
|
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
ceengland7(at)gmail.com
Guest
|
| Posted: Wed Aug 05, 2020 1:43 pm Post subject: Rotax install |
|
|
On Wed, Aug 5, 2020 at 4:20 PM meat_ball <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)>
kenryan wrote:
>
>
> Also, if you look at the Rotax wiring diagram for the 914 (which is
> basically what you have) you will notice that the primary fuel pump is
> wired directly to the internal generator, and that the bus and auxiliary
> fuel pump are powered by the optional external alternator and battery. This
> is a safety feature that completely separates the main fuel pump from the
> auxiliary fuel pump. If, after re-assessing your loads you decide that you
> can get by without the external alternator, remember that your engine
> requires an electric fuel pump to keep running, and make sure that your
> design does not introduce any common point of failure for the two fuel
> pumps.
>
> Ken
And this is where I get confused...Looking at the 914 diagram side by side with Bob’s diagram. How can I incorporate all the safeguards Bob suggests while wiring? They are wired so differently and I have a hard time figuring out how to join the two safely. I’ve looked for previously posted wiring diagrams for inspiration/reference but haven’t been able to find what I need.
As far as the strobes and other higher draw units, I was using worst case scenario for them in case they were all on at the same instant. However, I’m hearing the battery will be able to absorb those spikes, correct? Especially since the strobes are so instantaneous I presume?
Thanks again.
|
Right. You need to look at *average* continuous load. Extreme example: the transponder has 250W output. At 14V, that's almost 18 amps. But it's a microsecond burst, so the electrical system never really 'sees' it.
If you already own the strobe, hook it up through an amp meter to a 14V supply (clipleads to your car battery with the engine running would work if you don't have a power supply). An old analog meter would be easier to read with a pulsing load like that, but you might be able to get useful info even with a digital meter, especially one that includes an analog 'bar graph' in the display. Or just call the mfgr. they should be able to tell you the true average current consumption of the device, if you explain that you are doing a load analysis and not trying to size a fuse for it.
Can't help much with the wiring diagrams; I don't have the 914 drawings. You do need to specify whether you have a version with carbs or auto style (high pressure) fuel injection to do load calcs.
Charlie
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Wed Aug 05, 2020 2:15 pm Post subject: Re: Rotax install |
|
|
I found that the strobes have average output at 14V of .6 amps. As far as the rest of the “stuff,” I’ll have to look into that when I can sit down at the computer with all my docs in one place.
Thanks again for everyone and their input! This is a huge reason I love the aviation community! You can come dumb as you are and people are willing to impart their knowledge.
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Thu Aug 06, 2020 5:43 am Post subject: Re: Rotax install |
|
|
I've done a bit of homework. The strobes are average 0.8 Amps and comm radio comes down to about .5 amps. The engine components work out like this (I've used a guesstimate for the Fuel pumps as I haven't heard back from manufacturer yet):
Fuel pump 3amps
fuel pump 3amps
TCU .3 amps
Servomotor 1 amp
two indicating lamps .25 amps each
extra ~8 amps.
using the averages of the other high draw components, it comes out to 17.86 amps (which is using the draw for the backup battery as well). From my understanding, the 18 amp internal alternator can handle that, but you want a bit of buffer. It appears I will indeed need the external...do you agree? Am I thinking correctly?
Thanks,
Rob
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
ceengland7(at)gmail.com
Guest
|
| Posted: Thu Aug 06, 2020 5:59 am Post subject: Rotax install |
|
|
On Thu, Aug 6, 2020 at 8:49 AM meat_ball <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem(at)fastmail.net (arjayefem(at)fastmail.net)>
I've done a bit of homework. The strobes are average 0.8 Amps and comm radio comes down to about .5 amps. The engine components work out like this (I've used a guesstimate for the Fuel pumps as I haven't heard back from manufacturer yet):
Fuel pump 3amps
fuel pump 3amps
TCU .3 amps
Servomotor 1 amp
two indicating lamps .25 amps each
extra ~8 amps.
using the averages of the other high draw components, it comes out to 17.86 amps (which is using the draw for the backup battery as well). From my understanding, the 18 amp internal alternator can handle that, but you want a bit of buffer. It appears I will indeed need the external...do you agree? Am I thinking correctly?
Thanks,
Rob
|
You only need one fuel pump at a time (except takeoff & landing), but have you told us whether it's carb'd or electronic injection? Electronic injection pumps will use an absolute minimum of 4A each; likely more like 6A each. On the other hand, a little Facet cube pump for a carb only draws around 2.5A.
But bottom line is, you need a decent margin between constant draw and alternator capacity. Otherwise, you can't recharge the battery after engine start and idle operation ('dynamo' style permanent magnet alternators don't have much if any output when the engine is running near idle).
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Thu Aug 06, 2020 6:04 am Post subject: Re: Rotax install |
|
|
| ceengland7(at)gmail.com wrote: | On Thu, Aug 6, 2020 at 8:49 AM meat_ball <arjayefem> wrote:
| Quote: | --> AeroElectric-List message posted by: "meat_ball" <arjayefem>
I've done a bit of homework. The strobes are average 0.8 Amps and comm radio comes down to about .5 amps. The engine components work out like this (I've used a guesstimate for the Fuel pumps as I haven't heard back from manufacturer yet):
Fuel pump 3amps
fuel pump 3amps
TCU .3 amps
Servomotor 1 amp
two indicating lamps .25 amps each
extra ~8 amps.
using the averages of the other high draw components, it comes out to 17.86 amps (which is using the draw for the backup battery as well). From my understanding, the 18 amp internal alternator can handle that, but you want a bit of buffer. It appears I will indeed need the external...do you agree? Am I thinking correctly?
Thanks,
Rob
|
You only need one fuel pump at a time (except takeoff & landing), but have you told us whether it's carb'd or electronic injection? Electronic injection pumps will use an absolute minimum of 4A each; likely more like 6A each. On the other hand, a little Facet cube pump for a carb only draws around 2.5A.
But bottom line is, you need a decent margin between constant draw and alternator capacity. Otherwise, you can't recharge the battery after engine start and idle operation ('dynamo' style permanent magnet alternators don't have much if any output when the engine is running near idle). |
Sorry, I thought I mentioned that at the top of this thread. It is electronic ignition and fuel injected.
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Thu Aug 06, 2020 6:48 am Post subject: Re: Rotax install |
|
|
Attached is the Rotax 914 Electrical Diagram (hopefully you can make sense of it). It shows just what kenryan suggests as far as the fuel pumps. What about the master switch? From what I see when you turn it on, the battery gets connected to the bus, but that also gives a ground to the master relay which allows the Internal and External Alternators to connect to the bus/battery. Now turning off the Master Switch will kill all power to the Bus Bar and battery from the Alternators. Am I missing something? That seems like a bad thing...
Is this where I would wire in the s700-2-10, 3 position ON-ON-ON switch? the positions would be off, battery on, and battery/alternators on. Or would it be better to have a separate switch for the external alternator just after the field output and before the master switch?
Again, I sincerely appreciate all the help!
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
| Description: |
|
Download |
| Filename: |
Scannable Document on Aug 6, 2020 at 9_27_03 AM.pdf |
| Filesize: |
417.08 KB |
| Downloaded: |
299 Time(s) |
|
|
| Back to top |
|
|
ceengland7(at)gmail.com
Guest
|
| Posted: Thu Aug 06, 2020 6:57 am Post subject: Rotax install |
|
|
On 8/6/2020 9:04 AM, meat_ball wrote:
| Quote: |
ceengland7(at)gmail.com wrote:
> On Thu, Aug 6, 2020 at 8:49 AM meat_ball wrote:
>>
>>
>> I've done a bit of homework. The strobes are average 0.8 Amps and comm radio comes down to about .5 amps. The engine components work out like this (I've used a guesstimate for the Fuel pumps as I haven't heard back from manufacturer yet):
>>
>> Fuel pump  3amps
>> fuel pump 3amps
>> TCUÂ Â .3 amps
>> Servomotor  1 amp
>> two indicating lamps  .25 amps each
>>
>> extra ~8 amps.Â
>>
>> using the averages of the other high draw components, it comes out to 17.86 amps (which is using the draw for the backup battery as well). From my understanding, the 18 amp internal alternator can handle that, but you want a bit of buffer. It appears I will indeed need the external...do you agree? Am I thinking correctly?
>>
>> Thanks,
>>
>> Rob
>>
> You only need one fuel pump at a time (except takeoff & landing), but have you told us whether it's carb'd or electronic injection? Electronic injection pumps will use an absolute minimum of 4A each; likely more like 6A each. On the other hand, a little Facet cube pump for a carb only draws around 2.5A.
> But bottom line is, you need a decent margin between constant draw and alternator capacity. Otherwise, you can't recharge the battery after engine start and idle operation ('dynamo' style permanent magnet alternators don't have much if any output when the engine is running near idle).Â
Sorry, I thought I mentioned that at the top of this thread. It is electronic ignition and fuel injected.
You probably did and I missed it. I was probably confused by the
|
reference to it being a 912, and the 145 HP reference; didn't know what
mods were made. In that case, you need to budget at least 4A per pump.
Do you have the brand/model number of the pump you intend to use? As an
example, the Walbro GSL393, likely the most common pump being used in
aircraft electronic injection systems, is recommended to be fused at 15A
and average current consumption is 5 A-6 A.
Charlie
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
meat_ball
Joined: 05 Aug 2020
Posts: 27
|
| Posted: Thu Aug 06, 2020 7:04 am Post subject: Re: Rotax install |
|
|
| ceengland7(at)gmail.com wrote: | On 8/6/2020 9:04 AM, meat_ball wrote:
| Quote: |
ceengland7(at)gmail.com wrote:
> On Thu, Aug 6, 2020 at 8:49 AM meat_ball wrote:
>>
>>
>> I've done a bit of homework. The strobes are average 0.8 Amps and comm radio comes down to about .5 amps. The engine components work out like this (I've used a guesstimate for the Fuel pumps as I haven't heard back from manufacturer yet):
>>
>> Fuel pump  3amps
>> fuel pump 3amps
>> TCUÂ Â .3 amps
>> Servomotor  1 amp
>> two indicating lamps  .25 amps each
>>
>> extra ~8 amps.Â
>>
>> using the averages of the other high draw components, it comes out to 17.86 amps (which is using the draw for the backup battery as well). From my understanding, the 18 amp internal alternator can handle that, but you want a bit of buffer. It appears I will indeed need the external...do you agree? Am I thinking correctly?
>>
>> Thanks,
>>
>> Rob
>>
> You only need one fuel pump at a time (except takeoff & landing), but have you told us whether it's carb'd or electronic injection? Electronic injection pumps will use an absolute minimum of 4A each; likely more like 6A each. On the other hand, a little Facet cube pump for a carb only draws around 2.5A.
> But bottom line is, you need a decent margin between constant draw and alternator capacity. Otherwise, you can't recharge the battery after engine start and idle operation ('dynamo' style permanent magnet alternators don't have much if any output when the engine is running near idle).Â
Sorry, I thought I mentioned that at the top of this thread. It is electronic ignition and fuel injected.
You probably did and I missed it. I was probably confused by the
|
reference to it being a 912, and the 145 HP reference; didn't know what
mods were made. In that case, you need to budget at least 4A per pump.
Do you have the brand/model number of the pump you intend to use? As an
example, the Walbro GSL393, likely the most common pump being used in
aircraft electronic injection systems, is recommended to be fused at 15A
and average current consumption is 5 A-6 A.
Charlie
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus |
I just got a reply. He said pumps draw 5-7 amps but only one pump used at a time.
| Quote: | No we never do as you effectively are doubling the workload on the fuel pressure regulator and the electrical system.
I always run one pump then both for a few seconds and then switch to the other during run-up to ensure its primed and ready to go when needed
Also make sure to wire each pump with its own switch and breaker to ensure proper electrical system redundancy |
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
