Talking about the National Electrical Code (NEC) and Amateur Radio the NEC
has a section devoted exclusively to Amateur Radio. I wrote an article 15
years ago about it, I also retired at the same time, wonder if anyone has a
copy of the current code and are the rules the same?
http://www.angelfire.com/art2/wa6ipd/Small.jpg
de WA6IPD
----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
To: <tentec@contesting.com>
Sent: Sunday, September 24, 2006 2:06 PM
Subject: Re: [TenTec] Centurion Amplifier - 110 volt?
> On Sun, 2006-09-24 at 17:16 -0400, John wrote:
>> Please correct me if I am wrong , the 240 line should not even be
>> extended
>> with a extension cord let alone using a 110 line . John kbn2huk
>
> By the National Electrical Code you aren't supposed to use an extension
> cord for any application except one that is temporary. You are supposed
> to get a permanent outlet wired so that the extension is not needed. And
> an outlet strip, even if UL approved is one of those not to be used
> permanently.
>
> Commercial extension cords for 240 volt applications are in home centers
> as well as hardware stores and electrical distributors.
>
> Over the years extension cords have been given a poor rap, because they
> are easily abused. In the past cords made of 18 gauge zip cord fit the
> same outlets and had the same outlets as cords made of 12 gauge copper
> wire. And the 18 gauge cords cost much less than the sturdy cords.
> However the 15 or 20 amp fuse/breaker lets the 18 gauge cord burn if
> shorted. Today the smallest in the stores uses 16 gauge which may almost
> be protected by a 15 amp fuse or breaker.
>
> Extension cords tend to be run behind couches where the legs smash them
> against the wall baseboard when the people sit on the couch hard. And
> sometimes get run through doors where the door pinches them or cuts them
> off leading to hot spots, if not fires. Then cords sometimes get run
> under carpets and traffic on top the carpet smashes the insulation off
> and the thermal insulation of the carpet makes that more than fully
> loaded wire run on the warm side melting the wire insulation... Carpets
> burn.
>
> I've seen 18 guage zip cord from a clock stapled to a plywood wall in a
> school. I didn't leave it that way. No staple made it all the way
> through the insulation on both conductors but some were close. The fire
> marshal wanted that school district to close several schools unless an
> engineer would certify them safe. I inspected and certified them UNSAFE.
>
> There are gadgets sold so that neatnicks can wrap up one of those
> excessively long 18 gauge cords concentrating the heat in a small space.
> I cringe when I seem them advertised.
>
> I do own outlet strips and extension cords. They are all UL approved,
> and most have sturdy conductors unless the load is controlled to be a
> clock or a single table lamp. Some have been in place excessively long
> in this place I rent.
> --
> 73, Jerry, K0CQ,
> All content copyright Dr. Gerald N. Johnson, electrical engineer
>
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