It appears that my cold water pipe is made completely of copper (no
PVC). If I attach to it right where it enters the house (but on the
inside), will this be an effective lightning ground? The electrical
panel connects at this point also.

Thanks,

-JJ

wrote
It appears that my cold water pipe is made completely of copper (no
PVC). If I attach to it right where it enters the house (but on the
inside), will this be an effective lightning ground? The electrical
panel connects at this point also.

Thanks,

-JJ

The simple answer is "Yes".

The simple reason is because having a station ground (or any antenna ground)
tied to the same point of the building's electrical ground is mandatory, not
just an option.

As far as the attachment point being "inside the house", that's not the best
arrangement for some situations. It's really phenomenal luck for your
station-ground to be close enough to make the home's service entrance ground
your station's "single point ground". But not so good to route grounding
(down conductor) from a rooftop antenna [inside the house] to reach the same
point.

For your electrical service to be grounded at the cold water pipe, this
implies an inspector approved the connection, and there must be no break in
the bond (all metal continuous) for at least 10' underground. That's an
excellent ground btw, better than any driven (10') ground rod could provide.
If your station equipment is located very close to the service-entrance
ground, you are so lucky! If it's not, like most of us, additional planning
is required to have a safe grounding system.

Remember that anything you connect to ground from a rooftop antenna could
feel hundreds of thousands of volts potential from a strike. That
connection should normally be made straight to an earth-driven grounding
electrode outside the home. You would then bond that grounding electrode to
the service-entrance ground and your station ground, were they separated.

You can review this in greater detail at:
http://members.cox.net/pc-usa/station/ground0.htm

73,
Jack Painter
Virginia Beach, Virginia

On 27 Feb 2005 14:01:14 -0800, wrote:

It appears that my cold water pipe is made completely of copper (no

I get a lot of flack when I mention using a ground for my radio and
antenna because of electrical code. I don't believe that my station
causes a ground loop because of it's design, but there is the issue
for other places as well.

First of all, I have a deep cycle battery for a power supply for my
Icom 706 MKII. I use a smart charger to keep the battery charged.
The charger only uses two wires. The radio is grounded through a
lightning/static arrestor by way of the outer brass casing that screws
into the SO-239 connector on the radio. My ground is a copper pipe
stuck about 5 or 6 feet deep next to the window where the radio is
located. A large wire goes from the radio to the ground-rod.

The reason I feel this does not create a ground loop, is that the only
electricity is run through an isolation transformer (the charger) to
the twelve volt battery which powers only the rig and an emergency
light.

However, there are others with this issue. Assuming they have
'normal' stations, they are likely to have a 3-wire grounded power
supply or a radio with a grounded power supply built in. For these
people (and possibly me in the future) I am wondering about the best
means of a ground especially when the rig is far away from the
electrical panel.

My thought is to run a solid #8 wire underground from the electrical
ground rod to the closest point to the radio. There, set an 8 foot
ground rod giving a close to zero loss from the radio ground to the
electrical ground. The fact that the copper lead between the two rods
is buried will only improve the radio ground rather than create a
resonant loop.

Any thoughts?

Buck
N4PGW

--
73 for now
Buck
N4PGW

My thought is to run a solid #8 wire underground from the electrical
ground rod to the closest point to the radio. There, set an 8 foot
ground rod giving a close to zero loss from the radio ground to the
electrical ground. The fact that the copper lead between the two rods
is buried will only improve the radio ground rather than create a
resonant loop.

Any thoughts?

Buck
N4PGW

Tie them together at a common point. In one of the radio stations I
worked at, I was always trying to second guess the engineer who was before
me. There were plenty of grounds loops that the RF loved to bug us with.
That was a 10KW AM'er, RF getting into an audio console was a real source of
irritation for the production people as well as me. We resorted to screening
one control room with copper screening. THAT was cool, we got 30 DB of
isolation when the door was closed. Wish I had that screened room for my
SHACK!!!!

73
WB7FFI

"Buck" wrote

I get a lot of flack when I mention using a ground for my radio and
antenna because of electrical code. I don't believe that my station
causes a ground loop because of it's design, but there is the issue
for other places as well.

First of all, I have a deep cycle battery for a power supply for my
Icom 706 MKII. I use a smart charger to keep the battery charged.
The charger only uses two wires. The radio is grounded through a
lightning/static arrestor by way of the outer brass casing that screws
into the SO-239 connector on the radio. My ground is a copper pipe
stuck about 5 or 6 feet deep next to the window where the radio is
located. A large wire goes from the radio to the ground-rod.

The reason I feel this does not create a ground loop, is that the only
electricity is run through an isolation transformer (the charger) to
the twelve volt battery which powers only the rig and an emergency
light.

However, there are others with this issue. Assuming they have
'normal' stations, they are likely to have a 3-wire grounded power
supply or a radio with a grounded power supply built in. For these
people (and possibly me in the future) I am wondering about the best
means of a ground especially when the rig is far away from the
electrical panel.

My thought is to run a solid #8 wire underground from the electrical
ground rod to the closest point to the radio. There, set an 8 foot
ground rod giving a close to zero loss from the radio ground to the
electrical ground. The fact that the copper lead between the two rods
is buried will only improve the radio ground rather than create a
resonant loop.

Any thoughts?

Buck
N4PGW

Hi Buck,

You do not have a ground loop or avoid one because you are on or off the
grid, or using a separate station ground system, even when bonded to the
service entrance ground as code requires.

Grounding multiple pieces of equipment in series before the common ground is
what allows ground loops. That can happen whether the building's three wire
120v system is the only ground, or a station ground is also involved. Avoid
it by not daisy-chaining the bonds of individual equipments with the station
single point ground. As awkward as it seems to individually bond equipment
to the single point ground, this is how to avoid a ground loop.
Practicality often overrides this design concept (using a bus-bar for
multiple equipment grounding, etc). But if noise could be isolated as caused
by such series-grounding, then you know how to eliminate it.

The station ground IS an awful thing to have, and a major cause of lightning
damage to the station IF it is both: 1. separate from the service entrance
ground, and 2. not properly bonded to the service entrance ground. We would
avoid most of the outdoor grounding and bonding systems required to control
this condition IF we just brought all antenna feeds into the structure AT
the service entrance ground. And then shield grounded and used arrestors
right there.

For HF-only feedlines (where an extra 40-60' of coax would add superficial
loss) there should be no excuse for not bringing all feedlines into the
structure only at the service entrance. UHF systems that suffer much higher
line loss tempt us to bring antenna feedlines directly into the radio shack.
THAT causes a major bonding headache. This is because we have to achieve
such low impedance connections to the service ground that lightning will
never choose a path up from ground, through our equipment, and out via the
house wiring to get back to the service entrance ground. We are never fully
protected from such occurrence if the station ground and service ground are
apart from each other, no matter how well they are bonded. But we can be
reasonably protected in that respect, when the bonding jumper is of
significantly lower impedance than the AC wiring in the home.

#8 copper is no where near the "significantly lower impedance" we're talking
about. Either wide copper strapping or #2 or #4 copper would be a better
example for the bonding connection between service entrance and station
ground. The more places along the way that bonding jumper is also bonded to
the outdoor antenna ground fields, radials, etc, the better. Voltage
division plays a big part when everything is bonded and many grounding
electrodes are used.

Hope this helps,
73,
Jack Painter
Virginia Beach, Virginia

Thank you, Jack... (see below)

On Mon, 28 Feb 2005 00:38:18 -0500, "Jack Painter"
wrote:

Hi Buck,

SNIP

For HF-only feedlines (where an extra 40-60' of coax would add superficial
loss) there should be no excuse for not bringing all feedlines into the
structure only at the service entrance. UHF systems that suffer much higher
line loss tempt us to bring antenna feedlines directly into the radio shack.
THAT causes a major bonding headache. This is because we have to achieve
such low impedance connections to the service ground that lightning will
never choose a path up from ground, through our equipment, and out via the
house wiring to get back to the service entrance ground. We are never fully
protected from such occurrence if the station ground and service ground are
apart from each other, no matter how well they are bonded. But we can be
reasonably protected in that respect, when the bonding jumper is of
significantly lower impedance than the AC wiring in the home.

#8 copper is no where near the "significantly lower impedance" we're talking
about. Either wide copper strapping or #2 or #4 copper would be a better
example for the bonding connection between service entrance and station
ground. The more places along the way that bonding jumper is also bonded to
the outdoor antenna ground fields, radials, etc, the better. Voltage
division plays a big part when everything is bonded and many grounding
electrodes are used.

Hope this helps,
73,
Jack Painter
Virginia Beach, Virginia

While I am still digesting this a bit, I at least understand why I was
so confused about the ground loop in the first place. This also
explains why some contradict each other.

As for trying to reach the service entrance here, it is almost not
practical to do so with the antenna elements. The Service entrance
here is kitty-cornered from both the shack and the direction of the
antennas. The antennas would have an extra 150 + feet to feed to go
directly to the service entrance. (dipoles only, no verticals at this
time).

The more I re-read what you said, the more I think I understand. I am
in the process of planning a move so I am not planning to improve
conditions here but at least I know how to plan for the new QTH.

My battery charger is double fused (positive and negative leads) so I
would assume that if lightning tried to find its way to the ground
side, it would blow the fuses first. Of course, if it takes 10,000
volts to jump approximately one inch and lightning is typically
hundreds or thousands of feet high.... little good the fuse would be
in a direct hit.

One of my plans for my next QTH will be to mount feed-through SO-239s
on an metal plate and connect my lightning arresters and ground them
before the antennas come into the shack. Based on your message, I am
thinking that a good connection from there to the service panel ground
would be good too?

Thanks again,


--
73 for now
Buck
N4PGW

"Buck" wrote
/snip
One of my plans for my next QTH will be to mount feed-through SO-239s
on an metal plate and connect my lightning arresters and ground them
before the antennas come into the shack. Based on your message, I am
thinking that a good connection from there to the service panel ground
would be good too?

Thanks again,
--
73 for now
Buck
N4PGW

Yes Buck, it would be good. Real good ;-)

Even if you add a 120/240v service branch panel to your new shack (as I
did), NEC prohibits a separate neutral/ground bonding at that panel. For our
purposes, it could be argued that we would be much safer if we could do
that, and then let that ground share with the station single point ground.
But if you ever had a fire for any reason the insurance would distance
themselves from you fast when they saw that. Better to stay code and suffer
the (cost) consequences of making the bond to the main service entrance.

73,
Jack

On Sun, 27 Feb 2005 14:01:14 -0800, wizard12342002 wrote:

It appears that my cold water pipe is made completely of copper (no
PVC). If I attach to it right where it enters the house (but on the
inside), will this be an effective lightning ground? The electrical
panel connects at this point also.

Thanks,

-JJ

Despite all the Noise about grounding...

Household Plumbing should never be used as an lightning protection ground!