Dave Platt wrote:

The intent of the third prong on the power plug is to provide a safe
path from the equipment chassis, back to the power panel (where the
neutral and hot are bonded together). This ensures that if there's a
fault inside the equipment, and a "hot" wire touches the chassis, the
stray current will immediately flow back to the panel via this ground
connection (and likely cause a fuse to blow or a breaker to trip very
quickly). It ensures that you don't end up with a chassis which is
"hot", and isolated from ground... just waiting for somebody to touch
it, accidentally complete a path to ground via their body, and get
themselves mildly dead.

One of the reasons that Ground fault interrupters are around. If you
have a hundred feet or even more of neutral wire going back to that
panel, you can still get an appreciable current flowing through you
without tripping a breaker. I've had my tookus saved by one of those
GFCI things when a power tool failed in the manner you just described. I
felt the shock for just a fraction of a second, then it tripped.



the chassis, or sneak back into the microphone wiring and cause weird
squawking sounds when you transmit).

Ahh, that happens to me all the time even without RF on the mic! ;^)


- 73 de Mike N3LI -

wrote:


This whole topic area seems to be eternally confused and confusing and
I'm in the parade of the confused. On a common sense basis I
absolutely agree with your connecting the station grounds to the
'lectric service entrance ground for the reasons you've stated.

But somewhere along the line somebody in the ham groups stated that
the National Electrical Code states that there shall be one and *only
one* grounding point per power drop and the neighborhood code cops and
the insurance companies reportedly get stiff about it.

There is a whole lot of misinformation regarding grounding. An
interesting mental exercise is taking a tower say 50 feet from your
house. According to some, in order to comply with NEC, the tower has to
be grounded by sending a lead back to the house to that single ground
point. I guess they want to insulate the tower base from ground - no
ufer's here, thanks. Sounds like a disaster waiting to happen.


The good folks at Polyphaser have some excellent Technical notes. Kept
me busy a long time reading the stuff:

http://www.polyphaser.com/technical_notes.aspx


Of particular interest is Ham Radio Station Protection:

http://tinyurl.com/2aymw9 (tinyurl needed - its a long one)


It is largely about lightning protection, but has good stuff pertaining
to grounding.


- 73 d eMike N3LI -

On Nov 29, 9:39 pm, (Dave Platt) wrote:
In article ,
.. . . . .

So is it legal to connect a phalanx of ham station ground rods to the
service entrance ground?? Or not.

As I understand it, according to the NEC, you must have only one
grounding *system* per building. This system may include two or more
ground rods, and/or a bare grounding wire buried in a trench around
the outside of the building. The ground rods and wires must be
securely bonded together with heavy-gauge wire... that's what ensures
that it's all one grounding "system".
.. . . . . . .

Makes complete sense and answers my basic question. Thank you David.

I have five 8' ground rods already installed with more coming. All of
them will be bonded together with about 100' of #8 bare solid copper.

Let's try one mo This place is a "This Old House" type abode. There
is no basement and no visible service entrance ground rod. There's a
tight dirt crawl space under the place which I'm not about to even try
to wiggle and squirm through to find the power wiring ground
connection. If there is a ground it's the 3/4" copper water supply
line from the street which pops up somewhere in the crawl space per
normal practice in days of yore around here. I know for a fact that
it's an old ~80' 100% copper line, not plastic. On the other hand the
service entrance panel box is quite accessible. Would it be OK if I
connected my ham grounding system to the neutral/ground bus in the
panel box instead of to the water line??

--
Dave Platt AE6EO

w3rv

wrote in message
...
On Nov 27, 8:46 pm, Dave Heil wrote:
James Barrett wrote:

But somewhere along the line somebody in the ham groups stated that
the National Electrical Code states that there shall be one and *only
one* grounding point per power drop and the neighborhood code cops and
the insurance companies reportedly get stiff about it.

the NEC refering only to the household AC wring(soon hopefully to DC circuts

at least according to the local electrical inspector

our system for RF are another affair all together

the inspector also aprooves the use if desired of seperate eletectal ground
when service of more than one voltage and/ot freq is ainvolved

in my case I have a houshold from the ower company enterance a seprate
gorund for my various solar and wind systems 12-48 v DCdepending on the
location plus the seperate Ground from my station

most inspector in my experence would rather our rf system were not grounded
in to the mais ground since they don't uderstand RF at all

On Nov 30, 11:05 am, Michael Coslo wrote:
wrote:


There is a whole lot of misinformation regarding grounding.

Understatement of the day . . .

An
interesting mental exercise is taking a tower say 50 feet from your
house. According to some, in order to comply with NEC, the tower has to
be grounded by sending a lead back to the house to that single ground
point. I guess they want to insulate the tower base from ground - no
ufer's here, thanks. Sounds like a disaster waiting to happen.

Of course.

Over the years I've dealt with a grand total of two lightning
"events". I had a 70' 45G tower with a monster mast which was topped
by a homebrewed clone of a 2M Ringo Ranger which went to 90+ feet.
Lightning magnet. There was one ground rod alongside the concrete base
which was bonded (clamped and silver soldered) to the tower by a 1/8"
x 1/2" copper strap.

There were three runs of coax, a run of shielded rotator cable and an
unshielded run of 14/3 Romex up the tower with all shields and the
Romex ground bonded to the tower. All the radio gear in the basement
shack was grounded to the water line which was ~25' from the radios.
Not slick by today's standards.

Along came the first hit and my whole world turned "bright electric
blue". Power line/brown underwear hit. The thunder was still rumbling
loudly so I scrambled behind the gear and furiously got into yanking
plugs out of outlets when *bang* another hit . .

In the end there was all kinds of damage to the house wiring, TV sets
and kitchen appliances toasted, second floor wall outlets atomized,
etc. The only damage in the "radio room" was to the two vaporized disc
ceramic AC line bypass caps in the 75A4.

From this experience I learned that (a) lightning certainly can strike
the same place twice in rapid succession and that (b) lightning can
choose to hit power lines which are 30-40 feet *below* mongo grounded
objects like a towers which makes no sense at all and (c) there are no
manmade "cures" for lightning. Except maybe paid-up insurance coverage
and prayer . .

The good folks at Polyphaser have some excellent Technical notes. Kept
me busy a long time reading the stuff:

http://www.polyphaser.com/technical_notes.aspx

Of particular interest is Ham Radio Station Protection:

http://tinyurl.com/2aymw9 (tinyurl needed - its a long one)


That's a really good one. I'll print it out and dig into it. Tank yew
Michael.


It is largely about lightning protection, but has good stuff pertaining
to grounding.

- 73 d eMike N3LI -

w3rv

On Fri, 30 Nov 2007 02:08:18 EST, (Dave Platt)
wrote:

The intent of the third prong on the power plug is to provide a safe
path from the equipment chassis, back to the power panel (where the
neutral and hot are bonded together).

You do mean the neutral and ground, right?
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net

The intent of the third prong on the power plug is to provide a safe
path from the equipment chassis, back to the power panel (where the
neutral and hot are bonded together).

You do mean the neutral and ground, right?

Erp. Yes, indeed! Bonding neutral and hot at the panel would be
spectacular, but rather useless :-)

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

konstans wrote:
wrote in message
...
On Nov 27, 8:46 pm, Dave Heil wrote:
James Barrett wrote:

But somewhere along the line somebody in the ham groups stated that
the National Electrical Code states that there shall be one and *only
one* grounding point per power drop and the neighborhood code cops and
the insurance companies reportedly get stiff about it.

the NEC refering only to the household AC wring(soon hopefully to DC circuts

at least according to the local electrical inspector

our system for RF are another affair all together

the inspector also aprooves the use if desired of seperate eletectal ground
when service of more than one voltage and/ot freq is ainvolved

in my case I have a houshold from the ower company enterance a seprate
gorund for my various solar and wind systems 12-48 v DCdepending on the
location plus the seperate Ground from my station

most inspector in my experence would rather our rf system were not grounded
in to the mais ground since they don't uderstand RF at all



Any electrical contractor will tell you that not all electrical
inspectors are well educated or trained. Ive had electrical inspectors
state a preference for plastic boxes in a run of metallic conduit or
cable. What those inspectors preferred was a direct violation of the
National Electrical Code. I've had electrical inspectors try to order
me to make a grounding connection in the meter enclosure which was
totally unacceptable to the power utility and is not required by the
NEC. I've had an electrical inspector fail my installation because I
had made the Grounding Electrode Conductor connection to the service
entry neutral conductor drip loop to comply with the requirements of the
legacy Rural Electrification Administration (REA) power cooperative
service standards even though the National Electrical Code specifically
permits that location to be used.

What the electrical inspector may prefer may be directly adverse to your
best interest. Bond all of your Grounding Electrodes together even if
your have to wait until after the electrical inspection to do so.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

wrote:
On Nov 29, 9:39 pm, (Dave Platt) wrote:
In article ,
. . . . .
So is it legal to connect a phalanx of ham station ground rods to the
service entrance ground?? Or not.
As I understand it, according to the NEC, you must have only one
grounding *system* per building. This system may include two or more
ground rods, and/or a bare grounding wire buried in a trench around
the outside of the building. The ground rods and wires must be
securely bonded together with heavy-gauge wire... that's what ensures
that it's all one grounding "system".
. . . . . . .

Makes complete sense and answers my basic question. Thank you David.

I have five 8' ground rods already installed with more coming. All of
them will be bonded together with about 100' of #8 bare solid copper.

Let's try one mo This place is a "This Old House" type abode. There
is no basement and no visible service entrance ground rod. There's a
tight dirt crawl space under the place which I'm not about to even try
to wiggle and squirm through to find the power wiring ground
connection. If there is a ground it's the 3/4" copper water supply
line from the street which pops up somewhere in the crawl space per
normal practice in days of yore around here. I know for a fact that
it's an old ~80' 100% copper line, not plastic. On the other hand the
service entrance panel box is quite accessible. Would it be OK if I
connected my ham grounding system to the neutral/ground bus in the
panel box instead of to the water line??
--
Dave Platt AE6EO

w3rv


It is not necessary to bring your bonding conductor to the inside of the
panel cabinet. Bonding it to the cabinet itself is sufficient. If any
portion of the Grounding Electrode Conductor is accessible then that is
the best place to connect your inter electrode bonding conductor.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

On Dec 5, 6:48 pm, "Tom Horne, Electrician"
wrote:
wrote:

snip

Let's try one mo This place is a "This Old House" type abode. There
is no basement and no visible service entrance ground rod. There's a
tight dirt crawl space under the place which I'm not about to even try
to wiggle and squirm through to find the power wiring ground
connection. If there is a ground it's the 3/4" copper water supply
line from the street which pops up somewhere in the crawl space per
normal practice in days of yore around here. I know for a fact that
it's an old ~80' 100% copper line, not plastic. On the other hand the
service entrance panel box is quite accessible. Would it be OK if I
connected my ham grounding system to the neutral/ground bus in the
panel box instead of to the water line??
--


w3rv

It is not necessary to bring your bonding conductor to the inside of the
panel cabinet. Bonding it to the cabinet itself is sufficient.

I would have thought that would'nt be kosher. Good info
If any
portion of the Grounding Electrode Conductor is accessible then that is
the best place to connect your inter electrode bonding conductor.

Roger that.

Thanks Dave.

--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

Many yeards ago I read an article which stated that back in World War
One days President Wilson convened an advisory council composed of a
number of prominent Americans from different fields. Edison was a
member. Somebody suggested that Einstein would make a good addition to
the group. Edison's comment was something like "Somebody like Einstein
might be handy to have around in case somethimg needs to be figured
out."

w3rv