[TenTec] Centurion Amplifier - 110 volt?

[Ron]

Gary,
Looks like we have a discussion going.

As I understand it, a ground rod at a secondary panel is usual if the
secondary panel is located in a separate building.  The ground rod at the
secondary panel is more for lightening protection than for electrical
grounding and would connect via the safety ground and not the neutral back
to the main panel. The neutral and safety ground would be isolated from each
other in this secondary panel. In a radio shack this ground rod has use for
RF ground and equipment case bonding.  I think you are correct about the 240
VAC only on the 3 wire circuit passing code.  I think Jerry is correct on
everything else and his assumption of ROMEX being the likely cable being
considered is well taken.

The NEC has required a safety ground and a neutral for a total of 4 wires to
240 VAC subpanels for 2 or 3 decades now.  Anybody ever cut the ground lug
off of an extension cord to be able to plug it into a 2 wire receptacle?  Or
considered how the chassis ground on your older tube rigs makes it back to
the electrical panel...

A little knowledge can be useful but also dangerous.  Then again, what is
life without some risk.  Oh... and never trust a tenant improvement!  :)
Ron
KA7U


-----Original Message-----
From: tentec-bounces at contesting.com
[mailto:tentec-bounces at contesting.com]On Behalf Of Gary Hoffman
Sent: Sunday, September 24, 2006 4:14 PM
To: geraldj at storm.weather.net; Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Centurion Amplifier - 110 volt?


It will pass code if you ONLY wire the sub-panel to supply 240 VAC and NOT
120.  That is, one hot lead is in the black lead.  The other hot lead is in
the white wire, which is taped conspicuously at both ends with black tape to
indicate it is hot.  The bare lead is used as the required safety ground.
There is no neutral - hence you may not draw 110 from this box.  You MAY add
a ground rod, but it is not required and will not suffice to meet code.  If
you do add a ground rod, for an abundance of safety for instance, then it
must be bonded to your other ground rods.

I cannot see that this would be at all useful however.

73 de Gary, AA2IZ


----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: <tentec at contesting.com>
Sent: Sunday, September 24, 2006 3:06 PM
Subject: Re: [TenTec] Centurion Amplifier - 110 volt?


> On Sat, 2006-09-23 at 11:09 -0600, Ron wrote:
> > Ed,
> > Not knowing all the particulars of the circuit feeding into your shack
my
> > suggestion may not be relevant, but here goes anyway.  If your 110 VAC 3
> > wire circuit in the shack is dedicated to that location (as in it does
not
> > serve other outlets prior to entering the shack), you should be able to
> > install a 220 VAC circuit breaker of appropriate amp rating for the wire
> > gauge at the panel and feed the circuit to the shack from this new
breaker
> > giving you 220 VAC to the shack.  Install a new sub panel in the shack
and
> > provide an earth ground for the new sub panel and split off 220 and 110
VAC
> > circuits in your shack from this source.  Once you have this installed,
you
> > can use the 220 VAC amps. Surface runs of EMT are cheap and quick to
> > install. This improvement may require an electrical inspection and
permit
> > from the local building code folks.
> > Ron
> > KA7U
> >
> This will not pass inspection. You are trying to supply a subpanel that
> requires a 4 wire cable with a three wire cable. The addition of a local
> ground rod does not meet the code requirements, nor is running the
> neutral in the bare conductor in the romex allowed by the code. Nor is
> running 120 volts on the white conductor.
>
> It will work but with much reduced shock safety. Don't do it.
> --
> 73, Jerry, K0CQ,
> All content copyright Dr. Gerald N. Johnson, electrical engineer
>
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>


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