Today's Message Index:
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1. 07:03 AM - Re: milspec wire chart? (Charlie England)
2. 08:27 AM - Re: milspec wire chart? (Charles Kuss)
3. 09:25 AM - Milspec wire followup: PTFE vs ETFE (Charlie England)
4. 11:39 AM - Re: VM-1000 current sensor question (AdventureD)
5. 04:39 PM - Re: VM-1000 current sensor question (user9253)
Message 1
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| Subject: | Re: milspec wire chart? |
Hi Kent,
That chart is just what I was looking for. Many thanks! Pretty good prices
on the color coded wire, too.
Charlie
On Wed, Mar 10, 2021 at 4:33 AM Kent or Jackie Ashton <kjashton@vnet.net>
wrote:
> See below. There is a seller on ebay called ApexJr who sells PTFE-coated
> wire in a large variety of colors. He advertises it as M22759/11 but I
> asked him about it once and in fact it is probably M16878/4 or similar (s
ee
> chart). Anyway, it's practically the same as M22759 PTFE aviation grade
> wire and it=99s handy to be able to buy colors for different circui
ts. Seems
> identical to me except for the colors.
>
> https://www.ebay.com/itm/100-Ft-22-Awg-Stranded-1-2-3-Striped-Mil-Spec-60
0V-Teflon-Wire-Audio-Tube-Amp/183768643409?epid=577237606&hash=item2ac9
76f751:g:DHcAAOSwDNdV53fC
> -kent
> <https://www.ebay.com/itm/100-Ft-22-Awg-Stranded-1-2-3-Striped-Mil-Spec-6
00V-Teflon-Wire-Audio-Tube-Amp/183768643409?epid=577237606&hash=item2ac
976f751:g:DHcAAOSwDNdV53fC-kent>
>
> > On Mar 9, 2021, at 12:06 PM, Charlie England <ceengland7@gmail.com>
> wrote:
> >
> > I troll ebay periodically looking for deals on various 'stuff' to keep
> on hand. One of the harder calls is milspec wire. I'm aware that the most
> common designator for what we'd normally use is M22759. But I've discover
ed
> that the number after the ' / ' can make a significant difference in what
> we're actually getting. It seems that it can spec not only the insulation
> type (PTFE, ETFE, and other stuff), but type of copper, plating on the
> copper (tin, silver, nickel, etc), and apparently other stuff, as well. '
> /16 ' seems to be tin plated copper with ETFE insulation. But there are
> others that would be useful to us (or not), if we knew the entire list of
> variants. For instance, I don't want any nickel plated stuff because I
> sometimes solder, and apparently the nickel plated stuff is intended only
> for crimping.
> >
> > M22759/X-Y-Z
> > I know that Y is gauge. Z is color, but I don't have the reference list
.
> And X is the biggie variable, to know what we're getting.
> >
> > Can anyone share a quick reference chart that breaks out each section
> of the spec, and shows all the numbers/letters with their meanings?
> >
> > Thanks,
> >
> > Charlie
>
Message 2
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| Subject: | Re: milspec wire chart? |
Charlie,
FYI, 22759/11 is Teflon coated wire, NOT Tefzel [22759/16] coated. They ar
e different. I have lots of the 22759/11 in colors for my 8A. Tefzel is rat
her stiff and very resistant to abrasion. Teflon is soft, has an even highe
r temperature rating, BUT you must be very careful when bundling it. You ne
ed to avoid any tight bundling, wrapping or security fixtures. That is beca
use Teflon insulation can extrude. That will cause the insulation to move a
way from the tight area, which could cause a short circuit. It's very handy
for use behind the instrument panel, as it bends much easier than Tefzel.
It's also recommended for areas under the cowl that are exposed to high hea
t. Note the higher heat rating of /4 & /11 compared to /16.
https://www.rdswire.com/uploads/Datasheets/SAE-AS22759-16%20Formerly%20MIL-
W-22759-16.pdf
https://www.rdswire.com/uploads/Datasheets/SAE-AS22759-11%20Formerly%20MIL-
W-22759-11.pdf
https://www.rdswire.com/mil-w-22759-4
If you don't already have it, download and read "the bible", aka FAA AC 43-
13-1B with Change 1
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-c
hg1.pdf
This is a big document. Chapter 11 deals with the electrical system.
Charlie K
On Wednesday, March 10, 2021, 10:24:01 AM EST, Charlie England <ceengl
and7@gmail.com> wrote:
Hi Kent,
That chart is just what I was looking for. Many thanks! Pretty good prices
on the color coded wire, too.
Charlie
On Wed, Mar 10, 2021 at 4:33 AM Kent or Jackie Ashton <kjashton@vnet.net> w
rote:
See below.=C2- There is a seller on ebay called ApexJr who sells PTFE-coa
ted wire in a large variety of colors.=C2- He advertises it as M22759/11
but I asked him about it once and in fact it is probably M16878/4 or simila
r (see chart).=C2- Anyway, it's practically the same as M22759 PTFE aviat
ion grade wire and it=99s handy to be able to buy colors for differen
t circuits.=C2- Seems identical to me except for the colors.
https://www.ebay.com/itm/100-Ft-22-Awg-Stranded-1-2-3-Striped-Mil-Spec-600V
-Teflon-Wire-Audio-Tube-Amp/183768643409?epid=577237606&hash=item2ac976
f751:g:DHcAAOSwDNdV53fC
-kent
> On Mar 9, 2021, at 12:06 PM, Charlie England <ceengland7@gmail.com> wrote
:
>
> I troll ebay periodically looking for deals on various 'stuff' to keep on
hand. One of the harder calls is milspec wire. I'm aware that the most com
mon designator for what we'd normally use is M22759. But I've discovered th
at the number after the ' / ' can make a significant difference in what we'
re actually getting. It seems that it can spec not only the insulation type
(PTFE, ETFE, and other stuff), but type of copper, plating on the copper (
tin, silver, nickel, etc), and apparently other stuff, as well. ' /16 ' see
ms to be tin plated copper with ETFE insulation. But there are others that
would be useful to us (or not), if we knew the entire list of variants. For
instance, I don't want any nickel plated stuff because I sometimes solder,
and apparently the nickel plated stuff is intended only for crimping.
>
> M22759/X-Y-Z
> I know that Y is gauge. Z is color, but I don't have the reference list.
And X is the biggie variable, to know what we're getting.
>
>=C2- =C2-Can anyone share a quick reference chart that breaks out each
section of the spec, and shows all the numbers/letters with their meanings
?
>
> Thanks,
>
> Charlie=C2-
Message 3
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| Subject: | Milspec wire followup: PTFE vs ETFE |
Question for Bob N. or others who've used a lot of milspec wire:
I'm aware of the obvious differences between PTFE & ETFE; 'P' has higher
temp rating but tends to 'cold flow'. I
I'm pretty sure I've encountered PTFE in pre-built harnesses from some
avionics mfgrs, based on the way the insulation strips, vs known-ETFE wire
I have on hand. If we install with reasonable care, is there any reason to
fear using PTFE for wiring throughout the airframe?
Thanks,
Charlie
Message 4
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| Subject: | Re: VM-1000 current sensor question |
Resurrecting this old thread.
Suppose the hall effect sensor is on the fat wire from battery 2 in Z-14 with a
70 amp alternator 1 and a 20 amp alternator 2. Here are my questions (recognizing
that this is not debugging done in the airplane -- its for understanding
how this stuff works).
1. Under normal conditions, when both alternators and batteries are on and the
crossfeed is not closed, what will the gauge connected to the hall effect sensor
show? Will it show the voltage of the #2 battery and zero amps since the current
on the number 2 bus is being drawn from the alternator rather than from
the battery? Something else?
2. Suppose the #2 alternator craps out and the low voltage light comes on. If
I shut down the #2 alternator and leave the crossfeed open, what will the gauge
show? Will it show the same voltage for the #2 battery and the current draw
of the instruments on the #2 bus? Something else?
3. Suppose I close the cross feed contactor after the #2 alternator goes kaput
and is shut down. Does the gauge now show the voltage of the #2 battery and zero
current if the #1 alternator is sufficient to supply both buses?
4. Suppose I shut down both alternators, turn on both batteries, and close the
crossfeed. Since battery 1 and battery 2 are now connected, what will the gauge
show?
This is all by way of trying to understand what these volts/amps meters do.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=500930#500930
Message 5
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| Subject: | Re: VM-1000 current sensor question |
Hall effect sensors only measure current, not voltage.
If the hall effect sensor is located to measure current into or out of a battery,
then once the battery is recharged, the current into the battery will be near zero.
If the hall effect sensor is located to measure alternator output current, the
ammeter will show the combination of aircraft load current and battery recharge
current.
If the hall effect sensor is located to measure aircraft load current, then it
will
not be known if that current is coming from the battery or from an alternator.
Some builders elect to not install an ammeter. As long as the voltage is above
13.5 VDC, then the alternator must be working.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=500931#500931
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