The telephone world specifies 185% overhead for electric wiring.
It also specifies 0.25 VDC drop in a conductor under full load, but
that's for DC
Battery circuits.
The size of the circuit breaker should determine the conductor.
No one wants a thin wire heating up in a wall and the corresponding
circuit
breaker not kicking off when the wire is warm.
Hal
W4HBM
On Wed, 19 Oct 2005 09:17:09 -0500 "Keith Dutson" <kdutson@sbcglobal.net>
writes:
> I agree with you Tony. I ran a new 240 VAC circuit for my Alpha
> which
> specifies 20A. I used 10 AWG for the run to ensure least voltage
> drop over
> the 100 foot path from the mains panel and put it on a 30A breaker.
> I think
> the difference in cost from 14 AWG wire and 20A breaker was less
> than $5.
> This was back in 1995, so the cost difference is likely a bit higher
> now
> with increased cost of copper.
>
> 73, Keith NM5G
>
> -----Original Message-----
> From: amps-bounces@contesting.com
> [mailto:amps-bounces@contesting.com] On
> Behalf Of Tony King - W4ZT
> Sent: Tuesday, October 18, 2005 10:47 PM
> To: amps@contesting.com
> Subject: Re: [Amps] AC wiring
>
> Technically speaking you're right about not exceeding the 15 amp
> rating
> placed on the wire and breaker but since you're less than 15% from
> the
> maximum rating, I wouldn't even consider it. The rating is
> considered a
> maximum, not the current you want to run the thing at. As I stated
> in my
> earlier post, the cost of the wire isn't anything compared to the
> cost of
> the amp and the rest of your station. If you have no other choice
> and your
> entire house is already wired with #14, including your 240 outlet in
> the
> shack, do what you gotta do, but that's not what I'd do. If you're
> pulling
> wire for a new circuit, pull something bigger than what you think
> you will
> need. I prefer the safe practical approach to running things rather
> than
> pushing them to their limits. After all, the discussion was pushing
> IR drop
> and when you're trying to prevent that, bigger is better. Thanks
> for your
> comments.
>
> 73, Tony W4ZT
>
> Bill Coleman wrote:
> >
> > On Oct 15, 2005, at 10:22 AM, Tony King - W4ZT wrote:
> >
> >> Now let's try 240 volts
> >> which would give us 2944/240=12.3 amps. If your line voltage is
> low
> >> and you have 220 volts the current would be 2944/220=13.4 amps.
> From
> >> this example it is obvious you can't run a full legal limit amp
> on
> >> even a 20 amp, #12 wire, 120 volt circuit much less any 120/240
>
> >> volt, 15 amp #14 wire circuit.
> >
> >
> > Seems to me that 12.3 A and 13.4 A are both less than 15 A. So a
> #14
> > circuit seems adequate for your example.
> >
> > Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
> > Quote: "Not within a thousand years will man ever fly!"
> > -- Wilbur Wright, 1901
> >
>
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>
Harold Mandel
Const. Supt.
Baran/Greenville
606 - 205 - 0172
hmandel@barantelecom.com
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