Today's Message Index:
----------------------
1. 05:36 AM - Re: Z13-8 modification and LSE ignition wiring (Tailwind1)
2. 06:16 AM - Re: Re: Z13-8 modification and LSE ignition wiring (Robert L. Nuckolls, III)
3. 06:49 AM - Re: Re: Z13-8 modification and LSE ignition wiring (Kent or Jackie Ashton)
4. 11:14 AM - GPS/WAAS antenna install help needed (rparigoris)
5. 11:45 AM - Re: GPS/WAAS antenna install help needed (Ralph E. Capen)
6. 06:29 PM - Re: GPS/WAAS antenna install help needed (Robert L. Nuckolls, III)
7. 08:08 PM - Re: Z13-8 modification and LSE ignition wiring (Tailwind1)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z13-8 modification and LSE ignition wiring |
nuckolls.bob(at)aeroelect wrote:
>
> >
> > To protect the wire itself, I like using fusible links. For light consumers
like the ignitions, a few inches of 22ga wire at the battery bus (sleeved with
a fiberglass jacket) soldered to 18ga wire feeding the switch/ignition will
protect the always-hot section of wire from catastrophic faults.
>
> but doesn't satisfy the crash safety condition
>
> Fusible links are generally limited to use in
> areas protected by battery master but included
> to isolate hard-faulted feeders from the remainder
> of normally functioning distribution.
>
> The battery bus should (1) drive fuse or breaker
> protected feeders at 7A or smaller -OR- if protection
> is larger, then a relay at the bus to manage that
> feeder's crash safety recommendations.
>
>
> Bob . . .
Bob, am I understanding correctly from your above statement that fusible links
are NOT a good alternative for a fuse block AT the battery bus in this case?
I was looking at the links to simplify and avoid the extra fuse block but are the
links too slow for the crash safety aspect of this (say a 22AWG link and 18
AWG feeder wire with the 5A pullable breaker at the cockpit end as per the LSE
recomendation)?. I will install a fuse block for the batt bus items if this
is the recommended procedure.
Also, what are your thoughts on the LSE manual procedure of using the wire shield
as a ground return versus a separate conductor? Seems to be possibly be less
robust?
Thanks, Tim M
--------
Flying Sonerai II with A80 Continental. Wittman W10 Tailwind under construction,
O360, dual LSE electronic ignition, airframe complete and covered, engine hung,
cowl built. Working on electrical, instrumentation, and other details.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498513#498513
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z13-8 modification and LSE ignition wiring |
>
>Bob, am I understanding correctly from your above statement that
>fusible links are NOT a
>good alternative for a fuse block AT the battery bus in this case?
Correct
>I was looking at the links to simplify and avoid the extra fuse
>block but are the links
>too slow for the crash safety aspect of this (say a 22AWG link and
>18 AWG feeder
>wire with the 5A pullable breaker at the cockpit end as per the LSE
>recomendation)?.
>I will install a fuse block for the batt bus items if this is the
>recommended procedure.
Installing those breakers in the cockpit
on extended feeders from the battery bus
has no foundation in physics or practice.
Feeder protection needs to be a close as
practical to the energy source that puts
the feeder at risk. The time constant for
operating that protection should be
consistent with protection of that feeder
from anticipated threats discovered in
the FMEA for protection of that feeder.
The crash safety issue is stacked on top
of feeder protection intended to limit the
electrical energy that raises risks of
post crash fire ignited by always hot
feeders.
Hence the 5A limit (FARS) or my own suggestion
for 7A fuses which would limit fault energy
to much less than breakers.
>Also, what are your thoughts on the LSE manual procedure of using the
>wire shield as a ground return versus a separate conductor? Seems
>to be possibly be less robust?
You are correct. I had some discussion with
Klause with respect to shields in his system.
I inquired as to any testing or analysis done
that called for shielding his wires as either
potential victims or antagonists.
He admitted to no such testing but thought
it wasn't hard to do and was good insurance.
Powering the hall sensors through twisted
pair shields is probably a good thing to
do. Shielding the power leads makes no sense.
Those paths are not (or at least should
never be) bad actors in the ship's electro-
magnetic compatibility study.
If ANYONE says that shielding power wires
into or out of his product is a necessary
thing, then they've admitted that their
design falls short of some fundamental
and easily achieved requirements of DO-160.
Shielding breaks electro-static coupling
which is very weak. No such risks exist on
DC power feeders.
Klause wasn't claiming that it was necessary,
only easy and a good thing to do.
The recommended DC power feeder to the LSE system is
a mish-mash of electrical joints that add
complexity and failure points without
adding EMC value. Asking for direct
connections to batteries is also without
foundation in physics or practice.
You will never see such a recommendation
in TC aircraft designs. I would ground the
ignition electronics via wire to the firewall
ground bus; feed DC power through contemporary,
FAST protection at the battery bus and then
through what ever switch is selected. Fuses
are fine . . . if a fuse pops, something is
broke and there is no value in fiddling
with them in flight. That breaker-on-the-
panel thing is simply not well thought out.
Bob . . .
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z13-8 modification and LSE ignition wiring |
I use dual Lightspeeds in my Cozy. Direct feed off the batteries forward about
8 to the switches and back to the LSE boxes in back. Of course, the wire is
in a non-conductive composite airplane but I do not worry about the wire shorting
in a crash. There is no telling what can happen in a crash. Maybe the battery
gets ripped loose in a hard crash and shorts on your airframe or part of
the metal in the airframe crushes on the battery and creates a dead short. I
suppose the idea for a fusible link is OK but 4 wire-sizes smaller than the 18
awg shielded wire Klaus recommends is pretty small wire. I would rather have
the more robust, continuous wire with no solder joints and shrink-wrap, install
it carefully, protected against rubs and vibration.
-Kent
> On Sep 24, 2020, at 8:35 AM, Tailwind1 <timmikus38@gmail.com> wrote:
>
>
>
> nuckolls.bob(at)aeroelect wrote:
>>
>>>
>>> To protect the wire itself, I like using fusible links. For light consumers
like the ignitions, a few inches of 22ga wire at the battery bus (sleeved with
a fiberglass jacket) soldered to 18ga wire feeding the switch/ignition will
protect the always-hot section of wire from catastrophic faults.
>>
>> but doesn't satisfy the crash safety condition
>>
>> Fusible links are generally limited to use in
>> areas protected by battery master but included
>> to isolate hard-faulted feeders from the remainder
>> of normally functioning distribution.
>>
>> The battery bus should (1) drive fuse or breaker
>> protected feeders at 7A or smaller -OR- if protection
>> is larger, then a relay at the bus to manage that
>> feeder's crash safety recommendations.
>>
>>
>> Bob . . .
>
>
> Bob, am I understanding correctly from your above statement that fusible links
are NOT a good alternative for a fuse block AT the battery bus in this case?
>
> I was looking at the links to simplify and avoid the extra fuse block but are
the links too slow for the crash safety aspect of this (say a 22AWG link and
18 AWG feeder wire with the 5A pullable breaker at the cockpit end as per the
LSE recomendation)?. I will install a fuse block for the batt bus items if this
is the recommended procedure.
>
> Also, what are your thoughts on the LSE manual procedure of using the wire shield
as a ground return versus a separate conductor? Seems to be possibly be less
robust?
>
> Thanks, Tim M
>
> --------
> Flying Sonerai II with A80 Continental. Wittman W10 Tailwind under construction,
O360, dual LSE electronic ignition, airframe complete and covered, engine
hung, cowl built. Working on electrical, instrumentation, and other details.
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=498513#498513
>
>
>
>
>
>
>
>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | GPS/WAAS antenna install help needed |
Hi Group To comply with ADS-B requirements we are installing a Garmin GDL-82 along
with our Becker transponder. I have some questions about the install of the
GA35 GPS/WAAS antenna. I want to mount it inside our Europa aft of the doors
by 2 feet. Questions: 1) Garmin calls for a ground plane extending for minimum
of 7.5" from edges of antenna, that equates to a circle of about 19", is a ground
plane needed at all? If so could I make it out of a Brass base and perhaps
6 soldered copper tapes? Does it have to be the full 7.5" overhang? 2) I have
both RG400 and RG142B cable, run is going to be about 6', is there a preference?
(Garmin wants between 1.5dB and 6.5dB) 3) The connection to the bottom of
the antenna is a screw on TNC, can I use a 90 degree connector? 4) If I wanted
could I mount the antenna inside the top engine cowl? (fiberglass) 5) Garmin
calls for antenna to be parallel with longitudinal axis, how critical is this?
What sort of angle would begin to cause problems? If a ground plane is required,
if I kept the antenna parallel with longitudinal axis, could I angle the
antenna to the ground plane? 6) My Aeroelectric Connection (old) doesn't have
any info on GPS antenna install, a note said that it will probably be added in
future. Is there any Aeroelectric info on GPS antenna installation? Thx. Ron
P.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498516#498516
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: GPS/WAAS antenna install help needed |
>From what I have read about the Europa it is a composite airframe. Based on that,
you should install a ground plane....
-----Original Message-----
>From: rparigoris <rparigor@hotmail.com>
>Sent: Sep 24, 2020 2:07 PM
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: GPS/WAAS antenna install help needed
>
>
>Hi Group To comply with ADS-B requirements we are installing a Garmin GDL-82 along
with our Becker transponder. I have some questions about the install of the
GA35 GPS/WAAS antenna. I want to mount it inside our Europa aft of the doors
by 2 feet. Questions: 1) Garmin calls for a ground plane extending for minimum
of 7.5" from edges of antenna, that equates to a circle of about 19", is a
ground plane needed at all? If so could I make it out of a Brass base and perhaps
6 soldered copper tapes? Does it have to be the full 7.5" overhang? 2) I have
both RG400 and RG142B cable, run is going to be about 6', is there a preference?
(Garmin wants between 1.5dB and 6.5dB) 3) The connection to the bottom
of the antenna is a screw on TNC, can I use a 90 degree connector? 4) If I wanted
could I mount the antenna inside the top engine cowl? (fiberglass) 5) Garmin
calls for antenna to be parallel with longitudinal axis, how critical is this?
What sort of angle would begin to cause problems?
!
> If a ground plane is required, if I kept the antenna parallel with longitudinal
axis, could I angle the antenna to the ground plane? 6) My Aeroelectric Connection
(old) doesn't have any info on GPS antenna install, a note said that
it will probably be added in future. Is there any Aeroelectric info on GPS antenna
installation? Thx. Ron P.
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=498516#498516
>
>
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: GPS/WAAS antenna install help needed |
At 01:07 PM 9/24/2020, you wrote:
>
>Hi Group To comply with ADS-B requirements we are installing a
>Garmin GDL-82 along with our Becker transponder. I have some
>questions about the install of the GA35 GPS/WAAS antenna. I want to
>mount it inside our Europa aft of the doors by 2 feet. Questions: 1)
>Garmin calls for a ground plane extending for minimum of 7.5" from
>edges of antenna, that equates to a circle of about 19", is a ground
>plane needed at all?
Yes . . . from the dimensions cited, it's
not a 'tuned' ground plane . . . so the
goal is to put as much conductor under the
antenna base as practical. It doesn't have
to be round. Rectangular of similar square
area works.
>If so could I make it out of a Brass base and perhaps 6 soldered
>copper tapes? Does it have to be the full 7.5" overhang?
use single sheet thin aluminum . . . maybe 0.020" Mechanical
robustness doesn't get you anything here.
2) I have both RG400 and RG142B cable, run is going to be about 6',
is there a preference? (Garmin wants between 1.5dB and 6.5dB)
Either is fine.
3) The connection to the bottom of the antenna is a screw on TNC,
can I use a 90 degree connector?
Yes
4) If I wanted could I mount the antenna inside the top engine
cowl? (fiberglass)
I'd stay away from the engine. Back in the empennage is best.
5) Garmin calls for antenna to be parallel with longitudinal axis,
how critical is this?
What sort of angle would begin to cause problems? If a ground plane
is required,
if I kept the antenna parallel with longitudinal axis, could I
angle the antenna
to the ground plane?
Ground plane arallel to upper/lower skin, antenna centrally
located and perpendicular to ground plane.
6) My Aeroelectric Connection (old) doesn't have any info on GPS antenna
install, a note said that it will probably be added in future. Is there
any Aeroelectric info on GPS antenna installation? Thx. Ron P.
GPS antennas need no ground plane. Just clearest
practical view of sky above the horizon all around.
Some folks have enjoyed satisfactory performance
under the cowl . . . give it a try . . . but best
is probably under upper surface of empennage.
Bob . . .
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z13-8 modification and LSE ignition wiring |
When asked , Klaus stated that his reasoning for the pullable breakers at the panel
was that an overvoltage or lightening strike could open the breaker and it
could be reset whereas a fuse could not, any thoughts on this?
Tim M
--------
Flying Sonerai II with A80 Continental. Wittman W10 Tailwind under construction,
O360, dual LSE electronic ignition, airframe complete and covered, engine hung,
cowl built. Working on electrical, instrumentation, and other details.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498522#498522
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|