[Amps] RE 220 V

[Bill Coleman]

OK Rich,

The green I was referring to was the green labeled wire on the schematic for
the SB-220. This wire is connected to the ground terminal of the plug in the
schematic.

You are saying that your outlet's neutral wire "connects back to the 240v
neutral (the C.T.)
terminal in the breaker box",   Here the color does matter, if you care
about the electrical code.  This wire must be bare copper or green or some
other color "tagged" with green tape.  I could be wrong about "tagging" a
non-green wire.

More importantly - and the real point here... is that the bare or green wire
is not neutral. In today's code, the neutral and the ground are two separate
conductors.  While they are indeed connected together in the service
entrance panel, they are two separate conductors once they leave the panel.

Neutral carries current - the 'return' for 120V circuits. The safety ground
never carries current unless there is a fault.

The SB-220/221 diagram that I have correctly shows a safety ground to the
chassis (labelled green) for both 120V and 240V setups. When wired for 240V
the SB-221/221 uses both "hot" sides of the AC circuit with no connection to
neutral. When wired for 120V the SB-220/221 uses one "hot" side and neutral.
I am carefully avoiding using color references.

Your installation:

> I Have a 3-wire 240v outlet in the radio-room.  The
> Neutral wire on this outlet connects back to the 240v neutral (the C.T.)
> terminal in the breaker box.- which is also the ground terminal in the
> breaker box.

If the wire you call "neutral"  is connected to safety ground only, then it
is probably wired correctly for 240V only device.  I would call that wire
safety ground, I would make sure that wire was bare or green.

If the wire you call "neutral" in your outlet connects to neutral anywhere
outside of the service entrance breaker box, then it is indeed a neutral and
not a safety ground. This would not be proper wiring for a 3-wire 240V
outlet.

I am being careful to specify service entrance breaker box. This is the only
place that safety ground and neutral are connected together. If there is a
downstream branch circuit box, the safety ground is bonded physically to the
box and the neutrals are isolated on their own bus above ground.

On the subject of colors... they are important, but all too often ignored.
The electrical code spells out acceptable colors and standards for marking
conductors correctly.  Unfortunately they are ignored or misused or
misinterpreted.  I personally never trust someone else's wiring, that can
get you killed.

On that note, this subject is truly beat to death.


----- Original Message ----- 
From: "R.Measures" <r at somis.org>
To: "Bill Coleman" <n2bc at stny.rr.com>; <Ku4uk at aol.com>; "AMPS"
<amps at contesting.com>
Sent: Sunday, December 07, 2003 1:18 AM
Subject: Re: [Amps] RE 220 V


>
>
> >Sorry Rich, you are not correct.  The voltage is irrelevant.  Neutral
> >carries current, ground never carries current unless there is a fault.
The
> >diagram of the SB220/221 plug that I have clearly shows the green wire to
> >ground in the plug for both 120V and 240V setups.
> Bill -- 
> **  What I am telling you is that green is not a sacred color to this
> radio operator.  I Have a 3-wire 240v outlet in the radio-room.  The
> Neutral wire on this outlet connects back to the 240v neutral (the C.T.)
> terminal in the breaker box.- which is also the ground terminal in the
> breaker box.   If I had not connected the green wire in the SB220's
> 3-wire cord to 240v neutral, I would not have a ground return on the
> SB-220's chassis.  -  -  How would you have wired the 240V 3-wire plug?
> >
> >Bill  N2BC
> >
> >
> >----- Original Message ----- 
> >From: "R. Measures" <r at somis.org>
> >To: "Bill Coleman" <n2bc at stny.rr.com>; <Ku4uk at aol.com>; "AMPS"
> ><amps at contesting.com>
> >Sent: Saturday, December 06, 2003 5:01 PM
> >Subject: Re: [Amps] RE 220 V
> >
> >
> >>
> >>
> >> >NOT TRUE.
> >>
> >> **  It's true on my SB-220.  When wired for 240V, the third wire
(green)
> >> goes to the neutral on the 240v 3-conductor plug and the other end of
> >> this wire goes to chassis.  On a 3-conductor 240v circuit, the ground
is
> >> the neutral.    0v = 0v.
> >> >
> >> >There may be older vintages of the SB-220.  But I looked at an undated
> >> >SB-220 schematic and an SB-221 schematic dated 1976.  Both of these
> >clearly
> >> >show GROUND to the chassis - the wire is labelled GREEN and the
> >picto-gram
> >> >of the plug clearly shows it connected to the ground lug.  When wired
for
> >> >240V, there is no need for a neutral on an SB-220/221.
> >> >
> >> >If in fact early SB-220s wired neutral to the chassis, they should be
> >> >changed.  Just because they did it at one time doesn't make it correct
> >> >today.  The Collins KWS-1 shipped with neutral to the chassis and they
> >> >should all be changed.  Lots of Johnson and Heath gear shipped with
those
> >> >deadly fuse plugs - they should be changed!
> >> >
> >> >We need to move on.
> >> >
> >> >
> >> >----- Original Message ----- 
> >> >From: "R.Measures" <r at somis.org>
> >> >To: <Ku4uk at aol.com>; "AMPS" <amps at contesting.com>
> >> >Sent: Friday, December 05, 2003 9:25 PM
> >> >Subject: Re: [Amps] RE 220 V
> >> >
> >> >
> >> >>
> >> >>
> >> >> >No one has said anything about the heathkit SB 22O wiring. It has
two
> >hot
> >> >> >wires to transformer and neutral to chassis
> >> >>
> >> >> Neutral does not go to the chassis when a 220 is wired for 120V, but
> >> >> wired for 240v it does
> >> >>
> >> >> >....
> >> >> _______________________________________________
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> >> >> Amps at contesting.com
> >> >> http://lists.contesting.com/mailman/listinfo/amps
> >> >>
> >> >
> >> >
> >> >
> >>
> >
> >
> >
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