REFLECTOR:Buss material
Nolan Frederick
reflector@tvbf.org
Mon, 26 Apr 2004 12:44:57 -0600
This is a multi-part message in MIME format.
------=_NextPart_000_0012_01C42B8C.47B497D0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Re: REFLECTOR:Buss materialThere has to be a misunderstanding here. It =
is the Cross-Sectional Area and the length of the conductor that =
determines it's resistance. R=3Droh*L/A Where roh is the resistivity of =
the material, L is it's length and A it's cross-sectional area NOT it's =
surface area. The power in watts dissipated in the conductor is I*I*R. =
I is the current in amperes, R, the resistance in ohms. The conductor's =
ability to stay cool depends on all the paths of heat flow associated =
with it, e.g., lugs screwed to it and wires leading from it, how it's =
mounted, AND finally it's additional heat loss mechanisms are radiation, =
and convection, both of which depend on it's surface area. =20
nolan.=20
----- Original Message -----=20
From: David Scharfenberg=20
To: reflector@tvbf.org=20
Sent: Monday, April 26, 2004 9:57 AM
Subject: Re: REFLECTOR:Buss material
on 4/25/04 10:23 AM, Al Gietzen at ALVentures@cox.net wrote:
Aluminum is at least a good conductor; resistance about 1.6 times that =
of copper. Brass, on the other hand, has resistance about 4 times that =
of copper. The 1/8=B2 x =BD=B2 copper I had I got from Aeroelectric; I =
was surprised to find that he is now selling .025 thick brass instead. =
In a =BD=B2 width, that=B9s equivalent to about a #15 wire. Seems =
pretty marginal for a buss with half dozen or more circuits running off. =
I had the same concern about the thickness of my bus bar. Bob Nuckols =
told me that, in a DC circuit, it's the surface area, not the cross =
section, of the conductor that determines the current carrying capacity. =
I can't remember the thickness of mine but it seemed thin at the time.
Dave Scharfenberg
------=_NextPart_000_0012_01C42B8C.47B497D0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Re: REFLECTOR:Buss material</TITLE>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 6.00.2800.1400" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT size=3D2><FONT size=3D3>There has to be a misunderstanding =
here. It=20
is the Cross-Sectional Area and the length of the conductor that=20
determines it's resistance. R=3Droh*L/A Where roh is the =
resistivity of=20
the material, L is it's length and A it's cross-sectional =
area NOT=20
it's surface area. The power in watts dissipated in the conductor =
is=20
I*I*R. I is the current in amperes, R, the resistance in ohms. The=20
conductor's ability to stay cool depends on all the paths of heat flow=20
associated with it, e.g., lugs screwed to it and wires leading from =
it, how=20
it's mounted, AND finally it's additional heat loss mechanisms=20
are radiation, and convection, both of which depend =
on it's=20
surface area.</FONT> </FONT></DIV>
<DIV><FONT size=3D2>nolan.</FONT> </DIV>
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Ddave@winco.net href=3D"mailto:dave@winco.net">David =
Scharfenberg</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, April 26, 2004 =
9:57=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: REFLECTOR:Buss=20
material</DIV>
<DIV><BR></DIV>on 4/25/04 10:23 AM, Al Gietzen at <A=20
href=3D"mailto:ALVentures@cox.net">ALVentures@cox.net</A> =
wrote:<BR><BR><FONT=20
size=3D2>Aluminum is at least a good conductor; resistance about 1.6 =
times that=20
of copper. Brass, on the other hand, has resistance about 4 =
times that=20
of copper. The 1/8=B2 x =BD=B2 copper I had I got from =
Aeroelectric; I was=20
surprised to find that he is now selling .025 thick brass =
instead. In a=20
=BD=B2 width, that=B9s equivalent to about a #15 wire. Seems =
pretty marginal=20
for a buss with half dozen or more circuits running=20
off. <BR></FONT><BR><BR>I had the same concern about the =
thickness of my=20
bus bar. Bob Nuckols told me that, in a DC circuit, it's the =
surface=20
area, not the cross section, of the conductor that determines the =
current=20
carrying capacity. I can't remember the thickness of mine but it =
seemed=20
thin at the time.<BR><BR>Dave Scharfenberg </BLOCKQUOTE></BODY></HTML>
------=_NextPart_000_0012_01C42B8C.47B497D0--