Interesting that "silver solder" is rated to a higher temp than compression
fittings. Silver solder is really brazing, by definition. For instance Harris
"StaySilv15" (a common "silphos" braze w/15% silver, often used in
refrigeration tubing joints), has a solidus temp of 1190 F (643 C); it's
liquidus point (melting point) is a couple hundred higher. A very common silver
solder, Harris StaySilv56 (56% silver), has its solidus temp 40 degrees F
lower; it is often used to join cast iron and steel together, where you don't
want to melt the parent metal. It is *definitely not* soft solder.
I'm with K8RI - a brazed connection is not an inferior electrical connection
when compared with the usual compression fitting. I wonder if the term
"compression", as used by the IEEE, includes the Nicopress-types, usually
installed with a big-ass, hydraulic crimper. I always thought those would be
excellect connections, mechanically and electrically.
73,
geo - n4ua
> -----Original Message-----
> From: Wilson Lui [mailto:wilsonlui@atitec.com]
> Sent: Wednesday, May 26, 2004 2:30 PM
> To: 'Tower (K8RI)'; TowerTalk@contesting.com
> Subject: RE: [TowerTalk] Power ground
>
>
> Here's a little clarification for the different types of
> connections. IEEE
> Std. 80 recognizes the following maximum limits for the
> different types of
> connections. These limits are measured in Celsius (C), if
> exceeded, the
> connections may fail.
>
> Copper Wire (no connector) - 1083 (C)
> Exothermic - 1083 (C)
> Silver Solder - 450 (C)
> Compression Fitting - 350 (C)
> Screw Type - 250 (C)
> Solder (50/50) - 220 (C)
> Wires Twisted Together - 100 (C)
>
>
> Wilson Lui
> ATI Tectoniks
> wilsonlui@atitec.com
>
>
> Please visit our website at http://www.atitec.com for more
> information.
>
> -----Original Message-----
> From: Tower (K8RI) [mailto:tower@rogerhalstead.com]
> Sent: Wednesday, May 26, 2004 10:57 AM
> To: K7LXC@aol.com; wilsonlui@atitec.com; davidw@copper.net;
> TowerTalk@contesting.com
> Subject: Re: [TowerTalk] Power ground
>
> I've been following this for a while and keep seeing
> reference to "brazed"
> water pipes.
> I've never seen a brazed joint in water pipes. Soldered, but
> never brazed.
>
> The temperature for brazing is much higher than soldering and would be
> enough to show some serious oxidation on the copper. Brazing
> would require
> the copper to be at a "cherry red" heat to get the stuff to
> melt. In most
> homes the amount of heat required would cause charring on any
> wood near the
> joint.
>
> It may not be permitted, but I'd trust a good brazed joint
> any day over a
> compression fitting that can corrode. I've had compression fittings
> completely lose contact with ground rods.
>
>
> Roger Halstead (K8RI, EN73 & ARRL Life Member)
> N833R, World's Oldest Debonair (S# CD-2)
> www.rogerhalstead.com
>
>
> > In a message dated 5/26/04 10:17:54 AM Pacific Daylight Time,
> > wilsonlui@atitec.com writes:
> >
> > > However using
> > > brazed water pipes is not recommended. The brazed
> connections represent
> a
> > > seriously weak electrical joint and may fail prematurely
> under thermal
> > > stress of high currents.
> >
> > Yessireebob. The only NEC ground connections allowed
> are compression
> and
> > exothermic (i.e. Cadweld).
> >
> > Cheers,
> > Steve K7LXC
> > TOWER TECH -
> > Professional tower services for commercial and amateur
> > 888-833-3104
> >
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting
> Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free,
> 1-800-333-9041 with any
> questions and ask for Sherman, W2FLA.
> >
> > _______________________________________________
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> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
>
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
> "Wireless Weather Stations", and lot's more. Call Toll Free,
> 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>
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>
>
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