NEMA 14-30 lash up for shack

[stevef]

Are the NEMA 14-30 plugs/outlets sufficient (overkill?) for providing 230 to my shack and my future 813 maul???   These appear to be the standard dryer cord and plugs.  The neutral tab/prong is L-shaped.  I am thinking running 10awg from the service panel to the outlets - about 30 feet.

Steve KK7UV

[n2bc]

Hi Steve,  The 14-30 is a 3-pin arrrangement, the "L" shaped pin is ground not neutral.  If your rig does not need neutral then it's fine.

Every outlet must have ground but neutral is not required if the device is purely 240V.  If you have some 120V goodies in your amplifier, you will need a 4-wire outlet to bring the neutral along.

I use the twist-lock 3 and 4 wire outlets (L6 for 3-wire, L14 for 4-wire).

73, Bill  N2BC

[W3RSW]

Agree with Bill's posting.  I was laborously typing this as he posted so there's some duplication.

I used one on my twin 813 transmitter purchased at Lowes. It has fine, flexible strands and very thick grey plastic insulation amounting to about 8 to 10 guage total for each lead.  The plug is at the end of about 4 ft. of three conductor wire and has one "L" shaped common terminal and the two hot terminals are at skewed angles (not parallel to each other 'below' the centerline of the "L."

I ran the matching outlet for it to a 240/40amp breaker in my 400A house load ctr. right above it that feeds a burial line to a small shop/outbuilding.  There is a separate box mounted switch this line.

And as per Bill's posting, even dryers nowdays and other 240 volt appliances now come with 4 leads. The two hots and center being same as the old three pronger but with a forth, green lead prong for safety ground, not "just" the common between the two 120 hots.  Typical color code is colored wire (red, black, or blue, black, etc.) for the hots, white for the common between the two 120's, and green for the safety ground.

The above does not necessarially match Nat. Elec. Code's  explanation or terminology but should give you the proper direction to research.

For your safety, I recommend a licensed electrician if your not already knowledgable or so licensed yourself to make the 240 drop. The installation will consist of proper tin-in and breaker in your load center, proper disconnect, wiring (armoured if necessary), and proper outlet for your transmitter.

[stevef]

The four-prong receptacles at the local hardware star say 14-30, as does my old NEC book, and the Leviton website.  Irregardless of the nomenclature, I am going to run the 4-wire cable (since I also will have an amp that uses both 120/240) but I wanted to be sure I got properly rated hardware and cable for the future 813 transmitter project.  I was looking at this:

http://www.amwindow.org/tech/htm/813/813ps.htm

and wondering why 40 amps is specified there.

And yes, I will be having a pro doing the hookup for me, while I take care of patching the drywall afterward.



Steve KK7UV

[n2bc]

Steve, it appears I was a bit 'done in' by a quick GOOGLE!  I was looking at a Leviton web page at NEMA 14-30 and the pix is a bit confusing... it shows a 3-pin plug and 4-pin socket.  If you stick with 4-wire from end-to-end you will have all the bases covered.

I think you are planning to use a molded dryer cord/plug.  I have always made up the cord set out of SO or SJ cable with the appropriate twist lock connectors.  The SO or SJ cable is much more flexible that the typical dryer cord set. It is also easy to make up an 'extension cord' so I can wheel whatever monster into the workshop. 

[W1AEX]

I ran a 10/3 line from my service panel up to my studio B station a couple of months ago. I opted for a 3 prong outlet/plug assembly simply because none of my equipment up here has a need for a 4 wire system. The 4th wire is capped off in the outlet should it be required some day. The twist lock arrangement is really nice, never have to worry about it pulling out by mistake.