 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
Garyw
Joined: 27 Jun 2015
Posts: 1
Location: CA
|
 Posted: Sun Jun 28, 2015 3:37 pm Post subject: Z-11 Diagram and E-bus feeder length |
 |
|
Z-11 has a note of 6" max write length to the diode and again to the E-bus. Is this purely a function of the particular write size sunken (16 ga) or is there and underlying reason to keep this run short?
Tia,
Gary
| | - 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 |
|
_________________
Gary |
|
| Back to top |
|
 |
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Sun Jun 28, 2015 4:39 pm Post subject: Z-11 Diagram and E-bus feeder length |
|
|
At 06:37 PM 6/28/2015, you wrote:
| Quote: | --> AeroElectric-List message posted by: "Garyw" <gaw.ebm(at)gmail.com>
Z-11 has a note of 6" max write length to the diode and again to the E-bus. Is this purely a function of the particular write size sunken (16 ga) or is there and underlying reason to keep this run short?
|
This is a legacy hand-me-down rule-of-thumb
that goes back a few years . . . at least 50
that I know about.
The GENERAL RULE for protection of wires is
defined in AC43-12 and the FARS. But . . .
suppose you wanted to feed some device in
very close proximity to the high current
feeder. The rule of thumb (which I don't
recall having ever been articulated in
regulation) was any wire of 6" or less that
can be 'burned' without putting the airframe
and passengers at risk, does not need to
be protected (meaning fuse, circuit breaker,
fusible link, etc.).
The first time I recall this r-o-t being exercised
was in the wiring of a fat electrolytic capacitor
to the bus (ostensibly for spike/noise/gremlim
protection) and later for the wiring of a 50W zener
to the bus for the same purpose.
In retrospect, I am amazed at the thrashing and
agonizing brought on by worries about spikes, noises
and things that go "bump in the night" when in fact,
DO-160/MIL-STD-704 suggestions applied with understanding
made all those concerns evaporate.
So you will find SOME wires on my drawings marked
with an (*) wherein no protection is shown upstream
of the potential fault path for burning the wire.
In some places I use the symbol (*) to suggest that
the devices so connected should be in close proximity
to each other. So the rationale behind the symbol
may not be immediately obvious . . . but there is
one.
Bob . . . [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 |
|
|
|
|
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
