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Re: [Amps] 220V wiring: Was Question about safety ground

To: <amps@contesting.com>
Subject: Re: [Amps] 220V wiring: Was Question about safety ground
From: "John Finner" <finnerjf@worldnet.att.net>
Date: Wed, 16 Nov 2005 18:55:59 -0500
List-post: <mailto:amps@contesting.com>
To describe the 220v power wiring used in my shack.  I bought a Kenmore
electric dryer in 1970.  Since it came without a line cord, I also bought
the Sears recommended cord.  The 10/3 cord came equipped with a NEMA type
10-30P plug (3 pole 3 wire 2 hots a neutral and no ground).  I realized the
NEC has changed since then.  The dryer came with a ground wire, with
instructions to connect to a suitable ground such as a copper water pipe.
The dryer heating element requires 220 and the timer and lamp require 110
making the neutral necessary.

I ran 40 feet of 10/3 romex with ground from the mains panel to my shack
where the dryer is located.  I installed two wall receptacles, one a NEMA
type 10-30R for the dryer and the other a NEMA type 14-30R (3 pole 4 wire
with ground) for the amp.  The amp is a SB221 is connect through a 15 foot
extension cord made with 12/4 SJ cord.  One end with a NEMA type 14-30P plug
and the other end with a NEMA type 6-20R (2 pole 3 wire with ground)
receptacle for the amp.  The amp is wired as per Heathkit with a 12/3 cord
using 2 hots, a ground and a NEMA type 6-20P plug.  The neutral in the
extension cord not being used.

There is a bag of cloths pins on top of the dryer in case the XYL needs to
dry cloths while the amp is in use.

John WA4EPI

----- Original Message -----
> Date: Wed, 16 Nov 2005 10:27:37 -0600
> From: Doug Renwick <ve5ra@sasktel.net>
> Subject: Re: [Amps] 220V wiring: Was Question about safety ground
> connection
> To: amps@contesting.com
> Message-ID: <MFBBJHMMGJLHBMKINBGLOEDCECAA.ve5ra@sasktel.net>
> Content-Type: text/plain; charset=iso-8859-1
>
> The wiring manual I use states the following:
>
> A) A 120/240-volt, 30 amp receptacle (4 wires); connect the white
> wire to the white receptacle terminal.  Connect the red and black
> cable wires to receptacle terminal. Connect the bare ground
> wire to the outlet box.  The bare ground wire does not attach
> to the terminal.
>
> B) A 240-volt, 30 amp receptacle (3 wires); connect the white, black
> cable wires to the receptacle terminal and recode the white
> wire (red marker or tape).  Connect the bare wire to two green
> jumpers, one screwed to the terminal box and the other attached
> to the green receptacle terminal.  This terminal needs no neutral
> wire.
>
> Doug/VA5DX
>
>
>
> On Wed, 16 Nov 2005 04:05:51 -0800, R.Measures wrote:
>
> >My 240V, 40A circuit is wired 2-hot and 1-neutral.  I assumed that no
> >"safety" ground wire was needed because neutral is connected to
> safety
> >ground in the circuit breaker box.  Under normal operation, virtually
> >zero current flows in the neutral wire.
>
> NO, NO, NO, NO, NO!
>
> Neutral is intended to carry current (although it is not used in the
> 240 volt circuits in homes). Ground is a PROTECTIVE conductor that
> should NOT carry current except in the case of a fault. (A fault is a
> failure of some component or wiring that results in an equipment
> enclosure being hot).
>
>
> Jim Brown  K9YC
>
>
>
>
>
>
> ------------------------------
>
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