[Elecraft] Subject: 240V Line

Edward R Cole kl7uw at acsalaska.net
Thu Dec 25 11:34:32 EST 2014


First best wishes for a Merry Christmas and Happy New Year!

I think I chose a 25A twist-lock receptacle for my 4KV-1A PS.  I ran 
8-3 plus No. 10 safety ground cable because I did want to split out 
120vac to two duplex outlets using two separate 20A breakers.  That 
gives me 120v for my station 12v-50A supply and a Motorola 26v/12v PS 
that powers my HF 300w and 222-MHz 150w PA's.  120v also goes to the 
HVPS and last outlet powers my mini mw oven (for heating coffee, 
etc.).  I will add another 25A outlet for the 50v-50A PS for my 1100w 
6m linear that is planned to be added, soon.

Having the 240v 20A breaker in the room is handy if the PS trips it 
off.  Took me about half a day to run it.

The bedroom that serves as my ham shack has standard No. 12 romex run 
to the outlets that power the computer stuff, lights and some small 
wall warts, wx station, 24v PS for my relays.  Outlets are typical 15A rating.

My home has a 4-foot high crawl space so running the 240v line was 
easy.  I drilled a hole in the floor of the utility room where the 
main load center is located and ran PVC conduit from box to floor.  I 
did the same thing in the bedroom next to  the wall where my radio 
rack is installed.  The HVPS outlet is wired with a short run of No. 
10 thru conduit to standard metal surface 4x4 box with single 25A outlet.

I see about 3v sag in 240vac when I key my 8877 at 1400w (draws 
3.8kV at 700ma on anode).  the 240v run is about 35-foot.  The extra 
remnant of the 8-3 wire was used to wire my 6500w Honda generator 
into a 200A cutover switch mounted next to my meter box.

I have just enough of the 8-3 left to use for wiring 28vdc at my dish 
for my 1296 300w amplifier from the 18A Astron PS that sits in a 
wx-tight box under the 16-foot dish.

73, Ed
----------
From: Jim Brown <jim at audiosystemsgroup.com>
To: Reflector Elecraft <elecraft at mailman.qth.net>
Subject: [Elecraft] 240V Line
Message-ID: <549B087E.1010108 at audiosystemsgroup.com>
Content-Type: text/plain; charset=utf-8; format=flowed

Installing a 240V outlet is not a big deal unless the construction of
your home makes it difficult to run the cable. Barring that, a competent
electrician should be able to do that in a half day; a difficult run
could double the work. All that is required is a pair plus a Green wire.
If you also want 120V outlets from the same circuit, you'll need another
conductor for the neutral.

A single 20A 120/240V circuit will run all the ham gear in most
stations, even for SO2R. If you're smart, you'll use #10 copper, 20A
outlets, and a 20A breaker. While #10 is rated for 30A, our stations
don't need 30A, but the bigger copper will reduce the voltage drop.

There are MAJOR advantages to running all the gear in our stations from
outlets that share the same Green wire, or outlets whose Green wires are
bonded together. See http://k9yc.com/GroundingAndAudio.pdf

73, Jim K9YC


73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
Dubus Mag business:
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