[Amps] Amps Digest, Vol 110, Issue 30

[Wayne Rogers]

This was as problem in one of the early 1870's handbooks.  In one of their 
amplifier projects they showed a three wire 220 circuit, with no neutral. 
and they had a blower connected across one leg to ground.  What that does is 
cause current to flow on the ground leg .  Not good!

I wrote to the technical editor about it - next version of the handbook came 
out with a 4 wire 220 circuit!

73, Wayne N1WR

P.S.  Thsat 6 X 3-500z amp would be a real killer on Topband.  Even with 
4-250's.


> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
> On Behalf Of Al Kozakiewicz
> Sent: Tuesday, February 14, 2012 11:08 AM
> To: TexasRF at aol.com; km1h at jeremy.mv.com; ranchorobbo at gmail.com;
> steve at dx4win.com
> Cc: amps at contesting.com
> Subject: Re: [Amps] Source for plate xfrmer
>
> First off, NEC codes end at the outlet.  An amp is an "appliance" and
> would be covered by UL, which is entirely optional.  There is nothing
> that forbids such a practice - an electric range is a good example as
> the overn elements are typically 240v, while the burners, controls and
> lamps are 120v.
>
> The issue is that a range uses a 4 prong outlet - 2 x hot, neutral and
> ground, while your typical amp/AC outlet is missing the neutral.  You
> may NOT connect your fan between a hot and the chassis ground, even
> though it would be electrically rational.  If the safety ground failed,
> the chassis would then be at 120v with respect to ground.
>
> Al
> AB2ZY