{Collins} Re: 30S-1 230V wiring

William highlights the need (use) for the neutral conductor in the 
30S-1.  In addition, the neutral is needed to power the 516F-2 power supply 
should it be installed within the power supply cabinet. The neutral is a 
current carrying conductor needed to complete the 115 (120) volt circuit 
powering the lower voltage components associated with the 30S-1.  The 
neutral, although considered a grounded conductor, must only be grounded at 
the entrance panel under today's National Electric Code.  The (green wire) 
ground conductor that is is grounded at the entrance panel through the 
building wiring represents safety ground that is available for fault 
current should something go awry within the device being powered and should 
be connected to the equipment chassis.  The safety ground is the green wire 
in the 4-wire cord and typically a bare wire in residential building wiring.

A 4-wire plug/receptacle combination is the best way to ensure convenient 
and correct application of the neutral and safety ground.  In addition to 
safety ground, it is also desirable to ensure a good RF ground.  To be 
effective, this ground is applied directly to the cabinet grounding terminal.

Another amplifier with the same 230 volt power issues as the 30S-1 is the 
National NCL-2000.  The NCL-2000 was originally furnished with a 3-wire 
cord.  Since this amplifier uses 120-volt components, it too must be 
provided the neutral conductor.  Hence, the 4-wire cord, plug/receptacle is 
recommended here as well.

Jerry Kessler

At 07:56 PM 7/7/2004, you wrote:
>I wrote this prior to seeing the message from Bob, WB4TGG, and he covered
>much of the 30S-1 230 volt thing, but since I have already written this, I
>will send it anyway.
>A clothes dryer is a 230 volt device.  It does not use 115 volts, and the
>three wires consist of two wires that supply 230 volts and a non-current
>carrying ground wire for a safety ground.
>The 30S-1 uses 230 volts for the plate transformer and 115 volts for
>filament transformers, bias transformers, blower motors, time delay relays,
>etc.  Therefore it must have a current carrying neutral to supply the 115
>To meet the current National Electrical Code, the 30S-1 must NOT have the
>neutral conductor connected to the chassis. (I do not have a 30S-1, but I do
>have a schematic of unknown date, and the neutral is not shown as being
>connected to the chassis.)   The ground wire (the green wire) is connected
>to the chassis/cabinet, and it must be a separate conductor all the way back
>to the ground buss in the breaker panel.  And, the 30S-1 must have a four
>prong plug to meet the current code.  (It MIGHT meet some provision of the
>code if it has a separate ground wire from the "ground" connection on the
>amplifier to a "real" ground, and this is obviously what The Collins Radio
>Company intended, but I would prefer the four prong plug with green wire
>back to the panel.)  The power cord meeting the current code will have four
>wires - two wires carrying 230 volts, usually black and red; a white neutral
>and a green ground wire.
>I might not have read all of this thread, and I apologize if I am repeating
>someone before me, but I believe the National Electrical Code was changed
>between the time the first and last 30S-1 was manufactured.  If the
>amplifier was manufactured prior to the code change, it is probably
>"grandfathered" in, but that won't help you if you get electrocuted with it,
>which is not very likely, but the Code was changed to require a separate
>ground for a good reason.  If you don't understand it, get competent help.
>I do not consider myself competent on the Code, and I solicit a critique of
>the above from anyone who disagrees with anything I have said.
>Sponsored by the Collins Collectors Association http://www.collinsradio.org
>Nets: Tues: 3.805 Mc-2000 Central / Thur: 3.875 Mc-2000 Central
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Sponsored by the Collins Collectors Association http://www.collinsradio.org
Nets: Tues: 3.805 Mc-2000 Central / Thur: 3.875 Mc-2000 Central
Fri: 3.895 Mc-2000 Pacific / Sun: 14.263 Mc-2000 UTC
1st Wed (of the month) AM Net 3.880 Mc-2000 local (ET, CT, MT, PT)
Sun AM Net: 29.050 Mc-1200 Central

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