Today's Message Index:
----------------------
1. 08:16 AM - Re: Brass bus bar (Eric M. Jones)
2. 09:09 AM - Re: Re: Brass bus bar (Robert L. Nuckolls, III)
3. 10:10 PM - Re: Re: Brass bus bar (B Tomm)
Message 1
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| Subject: | Re: Brass bus bar |
By the way. My local airport, Southbridge, MA had 33 aircraft of which 30 were
totalled by a tornado last week. Jeeeeezz..........
On the subject of wires and materials, as has been mentioned. Silver is the best
conductor ---and this is the important part--per unit volume. Aluminum is 2X
as good as anything else in the universe per unit mass. This is important to
people where weight (and MONEY) is concerned.
I sell a lot of Copper-Clad Aluminum to race car drivers, helicopter builders and
anyone who wants to lose a pound or two. I sell many thousands of feet to military
drone builders. I even sell to top-fuel dragsters. (Hey, I can shave a
pound off your 320 mph in 1/4 mile dragster!).
But for really short runs, or bus bars, it doesn't save much. There is a copper
clad aluminum bus bar material (which I am considering carrying), but I really
recommend configuring wiring so as to not need a bus bar.
Factoids: Gold is good for low corrosion and its resulting low resistance. But
it only makes sense for very low voltages/currents. You might think gold might
would be a great conductor, but it isn't.
Factoid: Copper and other metals works even if oxidized, but curiously CuO etc.
was used for diodes. This can cause bizarre electrical problems--for example
at high frequencies, strange DC biases appear. This is a problem in electro-surgery
where the connection may have been electroplated but now the plating has
scratches, chips and corrosion. I surmise that transmitters are not totally immune
to this, so keep those connections clean and tight.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=342295#342295
Message 2
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| Subject: | Re: Brass bus bar |
>I really recommend configuring wiring so as to not need a bus bar.
Not sure what this means. In the classic sense, a
bus bar is a solid conductor distribution point from
which multiple branch feeds are taken. The strip of
conductor behind rows of breakers on the panel is
a "bus". The strip of conductor down the center of
a multiple slot fuse holder is a "bus".
But when you want to connect two closely spaced
studs together, like on a pair of contactors with
bar stock, that's a rectangular wire. I can deduce
no value in designing "not to need a bus bar."
They are used wherever they present the elegant
solution for minimizing parts count.
>Factoids: Gold is good for low corrosion and its resulting low
>resistance. But it only makes sense for very low voltages/currents.
The only time gold has a 'voltage/current' significance
is in the use of gold for switching. The very best
switches and relays for switching tiny signal
levels feature gold plated contacts. But gold
is easily eroded away if the wattage levels
in the switch circuit get very high. We generally
limit the use gold switches and relays in the tens
of milliamps and tens of volts range. See:
http://www.aeroelectric.com/Reference_Docs/Microswitch/
> You might think gold might would be a great conductor, but it isn't.
But it's not "bad" either. The conductivity
of gold is relatively insignificant because
nobody makes either wire or bus bars out of gold.
They do PLATE certain conductors with gold for
the purpose of minimizing surface corrosion
. . . the layers are so thin as to add no
significant resistance to the joint.
>Factoid: Copper and other metals works even if oxidized
??? Don't know what "works" means. Every material
and the manner in which joints are made with other
materials will drive system performance. If the
materials are particularly reactive with each other
and with oxygen in the presence of moisture, performance
levels will degrade with time.
It's true that the observable surfaces of conductors
can be severely corroded without observable
performance issues . . . this happens because
the metal-to-metal interface between components
is sealed from the environment . . . i.e. GAS
TIGHT.
So whether your "rectangular wires" of choice
are copper, aluminum or brass, both initial
and future performance is dependent upon maintaining
gas-tightness of the joint either by exemplary
craftsmanship on assembly, periodic maintenance
later or both.
> so keep those connections clean and tight.
Hear, HEAR!!!!
Bob . . .
Message 3
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| Subject: | Re: Brass bus bar |
Wow,
I had no idea what a lively discussion my original question would initiate.
I have learned much but not the answer to the original question. Maybe it is
less important than the sum of all the new knowledge in my old noggin.
OK, I understand that my electrician friend's advice about using stainless
bar stock with the stainless terminals is not ideal for aircraft. I still
have not found 1/8" copper bar stock locally and really don't want to ship
it.
What about using some 1/2" copper plumbing pipe, hammer flatten each end of
it's 3" length, drill mounting holes as required and bolt it in?
By the way, the current going through this bar stock connector will max out
at about 55amp under max (everything on) load and is protected by the 60 amp
ANL fuse, to which it is connected.
Bevan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Tuesday, June 07, 2011 9:06 AM
Subject: Re: AeroElectric-List: Re: Brass bus bar
--> <nuckolls.bob@aeroelectric.com>
>I really recommend configuring wiring so as to not need a bus bar.
Not sure what this means. In the classic sense, a
bus bar is a solid conductor distribution point from
which multiple branch feeds are taken. The strip of
conductor behind rows of breakers on the panel is
a "bus". The strip of conductor down the center of
a multiple slot fuse holder is a "bus".
But when you want to connect two closely spaced
studs together, like on a pair of contactors with
bar stock, that's a rectangular wire. I can deduce
no value in designing "not to need a bus bar."
They are used wherever they present the elegant
solution for minimizing parts count.
>Factoids: Gold is good for low corrosion and its resulting low
>resistance. But it only makes sense for very low voltages/currents.
The only time gold has a 'voltage/current' significance
is in the use of gold for switching. The very best
switches and relays for switching tiny signal
levels feature gold plated contacts. But gold
is easily eroded away if the wattage levels
in the switch circuit get very high. We generally
limit the use gold switches and relays in the tens
of milliamps and tens of volts range. See:
http://www.aeroelectric.com/Reference_Docs/Microswitch/
> You might think gold might would be a great conductor, but it isn't.
But it's not "bad" either. The conductivity
of gold is relatively insignificant because
nobody makes either wire or bus bars out of gold.
They do PLATE certain conductors with gold for
the purpose of minimizing surface corrosion
. . . the layers are so thin as to add no
significant resistance to the joint.
>Factoid: Copper and other metals works even if oxidized
??? Don't know what "works" means. Every material
and the manner in which joints are made with other
materials will drive system performance. If the
materials are particularly reactive with each other
and with oxygen in the presence of moisture, performance
levels will degrade with time.
It's true that the observable surfaces of conductors
can be severely corroded without observable
performance issues . . . this happens because
the metal-to-metal interface between components
is sealed from the environment . . . i.e. GAS
TIGHT.
So whether your "rectangular wires" of choice
are copper, aluminum or brass, both initial
and future performance is dependent upon maintaining
gas-tightness of the joint either by exemplary
craftsmanship on assembly, periodic maintenance
later or both.
> so keep those connections clean and tight.
Hear, HEAR!!!!
Bob . . .
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