> -----Original Message-----
> From:
> amps-admin@contesting.com
> [mailto:amps-admin@contesting.com]On
> Behalf Of Gary Schafer
> Sent: Friday, March 08, 2002 10:20 AM
> To: Phil Clements
> Cc: Bill Coleman; Richard;
> Steve Katz; RMead100@aol.com; AMPS
> Subject: Re: [Amps] Source
> for 220V cords
>
>
>
>
> Phil Clements wrote:
>
> > > > Ground and Neutral are
> the same in the MAIN breaker
> box - not necessarily in
> > > > all breaker boxes... A
> branch circuit (probably
> quite common for
> > > > post-construction
> install of 240V in our
> shacks) must have the neutral and
> > > > ground separated. You
> should not wire up a device
> anywhere which requires
> > > > neutral (i.e. the
> neutral is carrying current)
> to the ground instead of
> > > > neutral.
> >
> > Right on, Bill!
> > This subject comes up
> several times per year, so
> let me try to draw a mental
> > picture for those who are
> planning 240 volt service
> into the shack.
> >
> > The location where the
> power lines come into the
> building and terminate in the
> > main breaker box is called
> the "service entrance" by
> those in the trade. As
> > close as possible to this
> breaker box, ground rod(s)
> are installed. The ground
> > rod should be 8 feet or
> longer. Do not try to save a
> few bucks by using cheap
> > rods; get a good one like
> the power companies use. As
> we will see later, this
> > rod plays an important part
> in the system. It is referred
> to in the trade as the
> > "service entrance ground."
> A good quality wire is run
> from the breaker box
> > ground bus bar ( a long bar
> with many holes and set
> screws for installing wires)
> > to the ground rod. As Bill
> stated, the difference
> between a main service panel
> > and a sub-panel is that on
> the main panel the ground bus
> bar and the neutral
> > bus bar (which is insulated
> from the box) are strapped
> together by a jumper
> > wire. When running romex
> throughout the building, the
> white wires go to the
> > neutral bus bar, and the
> bare wires go to the ground
> bus bar. When installing
> > a sub-panel down-line, the
> ground (un-insulated) bus bar
> in the sub panel
> > is unused. Both the white
> and bare romex wires are
> hooked to the neutral bus
> > bar.
>
> This is wrong. The neutral
> and ground are NEVER tied
> together except at the MAIN
> breaker panel.
> This is even true when in
> some installations the main
> house breaker is outside and
> the distribution panel with
> all the branch circuit
> breakers is mounted inside. The
> ground and neutral are NOT
> connected together even in
> this panel. They are only
> connected together at the
> outside main circuit breaker.
>
>
> >
> >
> > To get 240 volts, a dual
> breaker is installed in the
> sub-panel. The black and
> > white wires on the romex go
> to the terminals on the dual
> breaker, and the
> > bare wire hooks to the
> neutral bus bar. The 240 volt
> plug and socket in the
> > shack are wired so that the
> black white and green wires
> coming from the
> > amp hook to the black white
> and bare wires coming from
> the sub-panel.
>
> This is wrong also. First you
> never hook a white wire to a
> hot 220 terminal. White
> ALWAYS goes to the neutral
> line. If you are running 220
> you need a 4 wire line. They
> have RED, Black, White and a
> bare ground wire. Again the
> only place the neutral and
> bare ground wires are tied
> together is in the main
> breaker panel. The red and black
> wires are the two hot lines
> from either side of the 220.
>
> The exception to this is
> sometimes window air
> conditioners have a 220 line to them.
> Or a pool or well pump that
> is only 220 volts. In this
> case they have no need for a
> neutral as they only operate
> on 220 volts. A three wire
> line can be used. Sometimes
> a regular romex (black, white
> and ground wires) is used.
> The black goes to one side
> of the 220 and the white goes
> to the other side of the 220.
> BUT it is marked with
> RED tape at each end to
> identify it as a hot line.
> The bare wire is connected to the
> ground buss in the panel and
> the outlet end of the line
> goes to the ground pin.
> There is no neutral involved
> in this circuit.
>
> If a neutral is needed a 4
> wire line and 4 wire outlet
> must be used.
>
>
>
> >
> >
> > In an ideal installation,
> the power, phone, and TV
> antenna grounds should all
> > hook to the service
> entrance ground, and enter
> the building at the same place.
> > Another "RF Ground" rod(s)
> should be installed as close
> as possible to the
> > operating
> > position in the station,
> and solid strap, tubing, or
> wire run from the radio,
> > amp,
> > tuner and accessories to
> this rod. I also add several
> buried radials to this rod
> > to assist in keeping RF off
> all the equipment chassis.
> >
> > (((73)))
> > Phil, K5PC
>
> 73
> Gary K4FMX
A couple of missed points; The ground
rod is no longer legal for most states
in NEW construction. A UFER ground is
now required, rebar embedded in the
foundation wall or slab. Be sure to
check with local building codes
officials. Also, some localities
require MORE than one ground rod when
replacing an old one, soil conductivity
is now an issue.
If the sub panel is installed on a
DETACHED building (backyard shack) a
ground rod (or Ufer) may be required at
that panel as it a service entrance for
that building. Again check with local
officials
Paul
PAUL HEWITT
WD7S PRODUCTIONS
QRO HOMEBREW COMPONENTS
http://wd7s.home.att.net
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