[TowerTalk] rewiring SUMMARY

[Jeff Stai KQ6VQ]

Below is a summary of replies received to my question:

"So: imagine that you are having your house completely rewired
from scratch.

"What would you have done (or would do) beyond the usual to-code
stuff and "service to the tower" and "plenty of 220 to the shack"?
Anything special with grounding etc.?

"I don't want to miss the chance to Do It Right...!"

First off, I'd like to especially thank Fred K1VR for his great
FAQ on the subject - I won't reprint it here, but it was very
cool, as we say here in '6' land...;-)

And thanks to all who replied - I certainly have more homework to do!

Here are the other replies, with some interesting food for thought:

From: "Leonard Kay" <k1nu@mediaone.net>

Don't forget to wire the computer network - run CAT-5
network cable to every room and pick the best place
to put the hub.  It's on my list if I ever build a house!

73 Len K1NU
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From: LYN Williams <designserv@ipass.net>

Well, "from scratch" opens the door for the suggestion that the tower
radials obviously should go straight under the house instead of around
the perimeter of the house, doesn't it?

Lyn, W4WDN

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From: "DavidC" <eDoc@netzero.net>

I have set up my radio room with no internal wiring connected to
the main house.  I want it electrically isolated for two reasons,
lightning protection and RFI.

I have instead designed the room as all-DC.  All of my gear is
12vdc, the Boatanchors are on dc-to-dc converters.  The 
computers are on inverters.

Just a thought!

- Thanks! & 73, DavidC  K1YP in Hudson, FL

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More From: "DavidC" <eDoc@netzero.net>

> hmmm... this certainly would not have occurred to me! My first
> thought, however, was to wonder how RFI-clean the inverters were?
> (They must be or you wouldn't be doing this!-)

I don't have the inverters yet but you may rest assured that I will be
checking them to be certain they are "clean"!

> As far as lightning goes, that is a beast we aren't very familiar
> with out here in coastal so. cal., though we do see it and I do
> plan to over-design for it

Polyphasers and a well grounded entry panel go a long way.

> - where do you make the transition to
> 12VDC relative to the rest of the house? Or do you run a big
> bank of batteries and charge them when you are not operating?
> (this also sounds cool, actually!)

I'm sorry, I was unclear.  The house runs on AC, the radio room will
run on DC.  There is only one AC outlet in the radio room and that
is over 10 feet from the nearest radio.  I have removed the ceiling
fan/light and will pull out the central-house-speaker lines as well.
This eliminates an attractive path for lightning into the house from the
radio room should it get past all of my other defenses.  It also eliminates
RF noise along the house AC lines or speaker wires getting into the
radio room.

I have one huge bus battery (Super Crank from SAMS, 1300 cold
cranking amps and 450 reserve capacity.) for the moment and plan to
add at least one more since it/they must power the radios, lights, fans,
computers, etc.  It is currently charged from the AC outlet but I have
one solar panel (more to be added) that will trickle charge when I am
away during the day.  All but the desktops will be DC devices.

We do plan a generator and perhaps a small windmill as well.

Thanks! & 73, DavidC  K1YP in Hudson, FL

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From: Brad Bradford <kz5q@bellsouth.net>

1st, eveyone wants a certain layout, what I like , you might not, etc.
Keep  every thing handy & L shape or U shape in room is fine, Mine is 

How ever u lay it out, Electrucal out are a premium.  I have 3 shelves
24" x 12' and 1 36" x 12, under that I have cabinets with Flourescent
lights in them. Try finding somethin in dard cabinet. Drawers under
3 foot shelf.  The equipment rest on the 3 foot shelf. Shelves are
made of 2 3/4 sheets of Waferboard Glued together  and scraewed.

On each shelf, every 2 feet, I have electrical outlets. There are
4 shelves.  At the end for the Amps, I have 4 220 recepticals.
BTW, No more than 2 outlets per breaker and the room is home to the
Main Breakers. I installled addition box just for the room
It has room for 48 breakers, I don't plan to ever run out of space !
seperate #10 romex to each set of outlets.

50 amp power supply to Strip under 2 foot shelf above 3 foot shelf.
Use a regular 12 volt plug & use 12 volt DC and no way to mix up.

Computer Desk, fits against  3 foot shelf and makes L shape. Pigeon
hole Shelves behind that, 

Never enuff shelves & outlets & Cabinets, &  grounding is another story.

good luck  73  BRAD   KZ5Q

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From: K4SB <k4sb@mindspring.com>

I would put a complete copper rod network covering the entire
hamshack floor + maybe 5 feet just under the foundation.

73
Ed

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From: "Curtis, David B" <david.b.curtis@intel.com>

Either a manual DPDT or automatic transfer switch to change over from
mains
to generator power.

UPS a few circuits, like the computer circuits in the shack, and the
family
file server.

-n6nz

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From: "Timothy L. Bratton" <k5ra@mail.pulse.net>

Get Polyphaser's book, and see what they recomend about grounding. 
Things like tying all the foundation re-bar together, and making it a
part of the exterior grounding system.  Run a copper wire ring around
the house, with ground rods every few feet (according to their formula -
depends on length of rods).  Plan an entrance box for cables just
outside the window of the shack, and tie it to the house "single-point"
ground.  

It is better if your tower is some distance from the house.  Reduces
magnetic effects on your equipment when a 50,000-amp lightning stroke
goes to ground through your tower.  

It is important that the telephone, AC power, and coax entrances all be
grounded to the same point.  Read the Polyphaser book. Also, ICE
(Industrial Communications Engineers?) has a whole series of "white
papers" that I think you can get for free.  They have a web site, but I
don't remember the URL.  Find one of their ads.    

Have dedicated-use AC power circuits to the shack to minimize voltage
drop.  Maybe a dedicated 120VAC circuit for your exciter, and the "other
side" of the 120/240 for the rest of the 120 VAC stuff in your shack. 
Use extra-heavy wire: #8 or #6 for a 30A 120/240, and #10 for the
regular 15A 120 outlets. It costs a few bucks more, but it is the
cheapest was to have solid high voltage on your final amp and other
high-current equipment.   Feed the room lights on a separate circuit so
they don't flicker when you send CW or talk SSB at full smoke.  

Good luck. 

---Timothy L. Bratton  K5RA

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From: "Mark Fossum" <mark@willetransport.com>

My first suggestion is to end-run everything. One single point of return
gives you many advantages for re-routing after the fact and for
additions
down the road.

Second, I would suggest you over-do everything. It's costly but when you
need it, you forget about the cost and realize how cheap and convenient
it
really becomes.

Third, spend the money for a speed wrap cable. Like the ones here:
http://www.hometech.com/techwire/combo.html You'll save a ton of time
when
it comes to labor and the redundancy will pay off. Note: A combination
of
different speed wraps works well too. Sometimes you just don't need the
extra Cat 5 here or there etc.

Fourth, don't combine power and service boxes. (I don't think it's
allowed
by code anyway, but just don't do it) 4x4 services boxes pay off in the
end
also. More room to make connections is always handy.

Hope that helps a little. Shop around for the cables but get the best
you
can. Some of these cheap Cat-5's really suck. Don't waste your time on
them.

Best of luck with your project!

Mark Fossum - N0NSV

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From: GNieborsky@kec.com

Your shack needs to have all the circuits serving it be on dedicated
breakers.  This solves a number of problems;  the wife's vacuum cleaner
surges (urges?) knocking your PC off line or worse taking the entire
shack
of line,  the kids PC's/video games etc. sending a raft of harmonics
down to
you and causing interference problems, harmonic currents from all the
switching power supply's we have overloading your circuit and causing
problems.

The amps all need seperate 240V circuits.  Wire is cheap.....tubes
aren't!

Grounding is important.  Make sure they're all tight.  If I ever build
another shack I'll put everything in conduit and use a 2 or 3 times
normal
equipment ground wire that's bonded solidly in the panel and then to the
cold water pipe.

GL es 73,

Gary K7FR  

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From: Roger Huntley <huntleyr@gte.net>

Hi Jeff,
I saw Fred's response to your mail and thought I would throw along some
additional comments.  I am a consulting electrical engineer that as a
profession designs electrical systems for buildings such as hospitals,
computer centers, etc.  We just recently built a new home out in the
country east of Seattle and wanted to design in as many electrical
"things" as I could think of, and afford!!

My shack is a bedroom on the main floor of a single story house with
crawl space with two 80 foot trees with antennas, one a tri bander and
the other a 40 mtr.  I mentally laid out my station in the room before
it was built and knew where everything was going to be located, at least
I thought it knew....

I have a 90 degree operating table with a straight section in the middle
of the 90 degree's.  The back side of the table is out about 18" from
the wall in back so I can get access to all of the cables without having
to lay on the floor and look up the back such as you must do if your
table is tight to the wall.  I ran a single 20 ampere, 240 Volt, single
phase circuit to two different walls, same circuit to both outlets since
I did not plan on operating more than one amplifier at a time.  I also
installed a double duplex (can plug 4 cords at a time) 120 Volt outlet
beside the 240 volt outlet on the two walls with a separate 20 Ampere
circuit to each of the two double duplex outlets.  From these I have
plug strips on the back of the table.  All 120 Volt receptacles are TVSS
type.  In addition we have a TVSS unit on the main service into the
house as well as standby generation since we live out in the country.
Generator has come in handy a few times. I strongly recommend that you
purchase a TVSS for your house service.  It will protect all of the
electronic equipment in the house, microwaves, ovens, TV, stereo, etc.

For grounding I have a braided strap, about 1" wide, that runs along the
back of the table that each piece of equipment is connected to with
smaller straps.  From there I have a heavier braided strap that goes
outside to two ground rods about 5 feet from the house.  Not sure how
long the silver plated copper will last underground so there is a #10
copper THWN conductor also attached to the rods and the copper braid.

Adjacent to each of the 120 Volt outlets I installed a TV and two
telephone outlets, one for the computer and one for normal telephone
use.  All telephone outlets throughout the house are CAT 5 cables.
Every room in the house has both a TV and Telephone outlet.  Cable into
the house is through the crawl space with a 4"Sq mud ring in the wall
and a hole through the bottom plate of the wall so there is direct
access to the crawl space from two locations in the room.  Must admit we
had a mouse in the house the first month and we think access was gained
through the holes so I packed steel wool and insulation around the
openings.

I ran a 2" PVC from the exterior of the house out towards each of the
two trees.  I only ran the pipe about 30 feet at which point the cables
lay exposed on the ground.  Probably not the best way to do that looking
back on it.  I should have used something like 4" flex drain pipe which
is fairly cheap or something similar.  4" Schedule 20 PVC does start to
get expensive but it is heavier and would be easier to pull through.
The problem with the flex pipe is the ribbed exterior walls may make it
hard to pull cables through.

Now for the main reason I wanted to write to you, yeah, know it is
getting a little long!!!

Being an engineer I wanted to put in some fancy lighting in the house.
We have around 20 dimmers in the house and originally they had night
lights to illuminate when they were off.  Well each of those went in the
first week due to the excessive noise they caused.  Had to go to
standard non illuminated type which seem to cause a lot less noise.
Next came the hot tub controller which when operating sounds like S-9 on
most bands.  I have not solved that one yet except to identify the
source.  Needless to say they get cold tubs during contest weekends!!
Next came the dimmers on the various night lights on the exterior of the
house.  We have security lights that are operated via motion detectors
and they have not been a problem but the fixtures that have integral
photocells are a big problem.  Will have to replace those with standard
fixtures and manual switches.

Well, hopefully I have given you some ideas to think about when you
build your new dream home.  It can be a lot of fun and it is a nice
feeling to have the home just the way you want it.

73, and good luck,

W7VV
Roger Huntley, P.E.

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-- 
jeff stai
KQ6VQ DM13
NAR #21059 TRA #3356 L2
jstai@home.com / kq6vq@arrl.net
ROC web page: http://www.rocstock.org/

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