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Re: Lightning and neutral grounding



I also have the same problem.  Service entrance is on the north side of the 
house, the radio antenna ground is on the mid west side of the house and TV 
antenna ground is mid way between on the west side also.  All are grounded 
by 8 foot ground rods and connected together by a #8 solid copper wire.

I have a 240 volt three conductor line from the service entrance breaker 
box to the shack desk where I have a small panel fused disconnect box. 
With one lever on the side of the box I disconnect the entire desk from the 
240 line.  There I split the phases to supply 120 volts (each fused) to the 
various pieces of equipment for load balance purposes.  The neutral is 
carried, of course, to both phases on the desk.  Inside the 120v lines 
carrying the Hot and Neutral lines, there is also the third wire, a ground 
wire.  This ground wire goes all the way back to the entrance box where it 
is tied to the service entrance ground along with the neutral.  So, the 
ground wire and neutral wire both go to ground at the entrance box.

If the shack equipment has three conductor AC power leads, the ground lead 
is usually connected to the equipment chassis.  This ground is carried via 
the metal chassis to the braid conductor of any coax cable coming from the 
antennas to the shack equipment.  If the antennas are connected to an 
external ground rod, haven't you already connected the neutral conductor to 
ground at a point other than the entrance ground?  I see no way of avoiding 
this if the house ground wires are tied to the equipment chassis.  If this 
is the case, why not connect the ground wire on the radio desk phases to 
the 240v neutral conductor at the desk instead of taking a separate ground 
lead all the way back the the entrance panel?

I see this as the reason for, very definitely, connecting the external 
ground rods together with a heavy, low inductance conductor.  Have I 
misunderstood this?  I am not arguing for tying neutral leads to ground at 
any point except at the entrance box.  I just don't see how you avoid 
having it happen as described above.  Can you?

Jon Ogden wrote:
> NO! NO! NO!!
> 
> Do NOT mess with the NEUTRAL!!!!
> 
> You tie your GROUNDS together.  This means you tied your tower, surge, and
> shack grounds to the electrical service ground.
> 
> The neutral should ONLY be tied to ground at the service panel which it
> already is.
> 
> on 3/11/03 1:17 AM, Greg D. at ko6th_greg@hotmail.com wrote:
> 
> 
>>So the question:  I believe everything is done more-or-less
>>correctly, EXCEPT that I need to tie the neutral of the electrical
>>plug in the shack to the same grounded bar that the arrestors are
>>bolted to.  "Neutral" is "white wire" side of the plug.  (The hot
>>side is black, as in charcoal, which is what happens to your
>>finger if you touch it...).
> 
> 
> Please don't do this.
> 
> 
>>I can't depend on the service entrance
>>ground to be at the same potential as the ham ground during a strike,
>>since they are too far apart.
> 
> 
> You are correct here.  That's why you tie all grounds to the service
> entrance ground via a network of ground wires.
> 
> 
>>The safety ground (green wire) is
>>left alone.  This means snaking a heavy wire from the lightning
>>arrestor mounting bar, into the wall, and over to the electrical
>>outlet box, and attaching it to the neurtal side of that wall plug.
>>I don't need any other sort of lightning arrestor on the power line,
>>other than a good "surge protector"; our electrical service has an
>>underground feed.
> 
> 
> Please again no.  There can be AC voltages present from netural to ground on
> an AC line.  Neutral is not ground.  Don't run the lightning protection
> ground lines through the house.
> 
> If your tower is roof mounted run several, heavy braided ground lines (good
> surface area) from the tower to the earth.  As an alternate you can use some
> big, arc welding cable.  Avoid sharp bends and turns.  Each line from the
> roof goes to its own ground rod.  Then connect all ground rods together
> (outside) via #4 copper wire or copper strap.  Additionally, you need ground
> rods every 16 feet.  All should be interconnected.  Everything gets tied to
> the electrical service ground.
> 
> 73,
> 
> Jon
> NA9D
> 
> -------------------------------------
> Jon Ogden
> NA9D (ex: KE9NA)
> 
> Citizen of the People's Democratic Republik of Illinois
> 
> Life Member: ARRL, NRA
> Member:  AMSAT, DXCC
> 
> http://www.qsl.net/na9d   <- Updated on 1/22/03!!!
> 
> "A life lived in fear is a life half lived."
> 
> 
> ----
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> 


-- 
73, Roy -- W0SL

E-Mail: rdwelch@swbell.net
Home Page: http://home.swbell.net/rdwelch

----
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