 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
rv7a(at)cox.net
Guest
|
 Posted: Sun Feb 03, 2008 2:05 pm Post subject: Z-13/8 RE: P/E-Mags Bus Feed |
 |
|
Looking carefully at the drawing the inset in the lower right side shows the P-Mag fed from the "Main Bus" and the E-Mag fed through the S700-2-10 switch from the "Battery Bus". Then if you look at the upper left hand part of the drawing at the "Main Battery Bus" you see both the right and left ignitions coming off this bus. I think my question is this...Is the "Battery Bus" and the "Main Bus" nomenclature in the lower right inset really the "Main Battery Bus" and not the Battery Bus and the Main Power Distribution Bus? Probably a dumb question for anyone than has done more electrical work than changing a light bulb. Do not archive.
Jim Thorne
RV7A CHD
[quote][b]
| | - 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 |
|
 |
n8zg(at)bellsouth.net
Guest
|
| Posted: Sun Feb 03, 2008 3:15 pm Post subject: Z-13/8 RE: P/E-Mags Bus Feed |
|
|
Jim -
The Battery Bus and the Main Bus are indeed two separate circuits. The EMag is an electrically dependent ignition - lose or remove electrical power and it quits sparking. Conversely, PMag is NOT electrically dependent - once above about 900 RPM, it makes it's own power via a small internal alternator.
Bob's philosophy has been to connect electrically dependent ignitions directly to the Battery Bus, so that in the event of smoke or other electrical misbehavior, one can throw the Master OFF and not lose the engine. Hanging the EMag off the Battery Bus ensures that it will continue to make sparks with the Master OFF.
Neal George
RV-7 N8ZG
Canopy & Cowling
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jim Thorne
Sent: Sunday, February 03, 2008 3:59 PM
To: aeroelectric-list(at)matronics.com
Subject: Z-13/8 RE: P/E-Mags Bus Feed
Looking carefully at the drawing the inset in the lower right side shows the P-Mag fed from the "Main Bus" and the E-Mag fed through the S700-2-10 switch from the "Battery Bus". Then if you look at the upper left hand part of the drawing at the "Main Battery Bus" you see both the right and left ignitions coming off this bus. I think my question is this...Is the "Battery Bus" and the "Main Bus" nomenclature in the lower right inset really the "Main Battery Bus" and not the Battery Bus and the Main Power Distribution Bus? Probably a dumb question for anyone than has done more electrical work than changing a light bulb. Do not archive.
Jim Thorne
RV7A CHD
[quote] [b]
| | - 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 |
|
|
nuckolls.bob(at)cox.net
Guest
|
| Posted: Mon Feb 04, 2008 6:10 am Post subject: Z-13/8 RE: P/E-Mags Bus Feed |
|
|
At 02:59 PM 2/3/2008 -0700, you wrote:
| Quote: | Looking carefully at the drawing the inset in the lower right side shows
the P-Mag fed from the "Main Bus" and the E-Mag fed through the S700-2-10
switch from the "Battery Bus". Then if you look at the upper left hand
part of the drawing at the "Main Battery Bus" you see both the right and
left ignitions coming off this bus. I think my question is this...Is the
"Battery Bus" and the "Main Bus" nomenclature in the lower right inset
really the "Main Battery Bus" and not the Battery Bus and the Main Power
Distribution Bus?
|
The distribution suggestions you've cited are
artifacts left over from the Pre-Emag era where
individuals with electrically dependant engines
are encourage to run all engine feeds from the
battery buss. This would include up to 2 two
electronic ignitions including E-mags.
In the new era of best-we-know-to-do for
aircraft ignitions, the earlier architecture
still holds for two E-mags. However, the
special nature of the P-mag's internal power
supply combined with the owner/operator's
desire to occasionally test a P-mag for
full functionality, running the P-mags
(whether one or two devices) from the main
bus keeps the switching simple while allowing
for the occasional testing of the P-Mag's
alternator.
So the short answer to your question is, it
depends. If you have any combination of ignition
system products that depend on the ship's
electrical system, run them from the battery
bus. If you have one or two P-mags, run them
from the main bus.
Bob . . .
| | - 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 |
|
|
hotwheels
Joined: 01 Jun 2007
Posts: 240
|
| Posted: Mon Feb 04, 2008 7:28 am Post subject: Re: Z-13/8 RE: P/E-Mags Bus Feed |
|
|
Devices hanging off the battery bus (like EMags or electronic ignition) don't have any way to be shut down when the master is switched off. Each of the above must therefore have it's own switch to de-energize that circuit, right?
Jay
do not archive
| | - 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 |
|
|
nuckolls.bob(at)cox.net
Guest
|
| Posted: Mon Feb 04, 2008 8:55 am Post subject: Z-13/8 RE: P/E-Mags Bus Feed |
|
|
At 07:28 AM 2/4/2008 -0800, you wrote:
| Quote: |
Devices hanging off the battery bus (like EMags or electronic ignition)
don't have any way to be shut down when the master is switched off. Each
of the above must therefore have it's own switch to de-energize that
circuit, right?
|
Seems like the way to go. If you were flying a J-3
with NO electrical system, you'd still have a couple
of switches that control the magnetos. Further,
operation of those switches would be addressed in
your pre-fight/post-flight protocols.
The supporting simple-idea is that one selects
the accessories that are needed to meet
design/mission goals for the aircraft. Then
figure out ways to minimize weight, parts
count, pilot workload, costs of ownership,
and still have an acceptable failure mode
effects analysis (favorable = failure tolerant).
The collection of switches, the things they
control, the manner in which they are operated
and the sources for power are all ingredients
that go into the recipe for success. Further,
there are MANY recipes for success that select
from a HUGE array of ingredients.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
| | - 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
