Importance of grounding the dish
Daniel Prince
block. When the installer came out two weeks later to correct some
problems with the installation, I asked him about the ground block and
he said that it wasn't necessary and that he has seen them cause
problems.
Are ground blocks necessary or desirable in Southern California where
lightning is rare? Thank you in advance for all replies.
--
My child is TERRIBLY deprived. He just had his fourth birthday and he
didn't get a party, a cake, any presents, or even an extra serving of
canned cat food which he loves. (My child is a cat.)
Bill Rosen
:
: When my Dish 500 was installed the installer didn't install a ground
: block. When the installer came out two weeks later to correct some
: problems with the installation, I asked him about the ground block and
: he said that it wasn't necessary and that he has seen them cause
: problems.
:
: Are ground blocks necessary or desirable in Southern California where
: lightning is rare? Thank you in advance for all replies.
ALL DBS systems should have a ground running from either a ground
block or from a multi-dish switch (and it should be connected to
the common electrical NOT a seperate ground rod). ANY installer
that tells you otherwise is NOT qualified to install DBS systems.
--
Bill R. - "The information beacon of the Ohio valley"
Joseph Frietze
quick reply Bill. I just wanted everyone else to know that others had
similar questions):
I was just getting ready to ask a similar question. My system is on the
way,
and I was looking through the pdf file on installation. I need to install
my
dish in the front of my house, and my electrical meter is around back, with
(what I assume is) the ground. Does the install kit come with a ground
wire?
In that case, what all is included with the install kit? I'd like to know
so
I can buy whatever else I might need tomorrow.
Thanks,
(I'll be back with more questions, I'm sure)
Joe
<Bill's Response -- He truly is the information beacon>
Joe,
It depends on where you buy the install kit from as to what you
get with it. Some dealers make up their own kit to make sure
you have everything you need, others don't. Normally all install
kits do include a dual grounding block and at least some ground
wire (usually #10 bare wire).
Normally you run the wires from the dish to a ground block or multi-
dish switch and run the ground from the ground block (or switch). The
ground wire does NOT need to run all the way back to your electrical
panel. If you have a outside METAL water connection for your hose you
can put your ground there. Hardware stores sell either ground straps
or grounding clamps (that fit around the pipe) that work fine. Your
ground wire should not be more than 25 feet but I have seen our local
cable company run them for distances of over 75 feet.
One very good site that I would recommend for DBS information (and
a lot of helpful people) is http://www.dbsforums.com
--
Bill R. - "The information beacon of the Ohio valley"
Bill Rosen <bro...@shell1.iglou.com> wrote in message
news:3abfb...@news.iglou.com...
Joe
> lightning is rare? Thank you in advance for all replies.
I may be wrong, but I believe it's the law to have your cable or satellite
system grounded. Now I was in a different situation earlier. I had a
satellite on my apartment complex roof. It took me 2 years to talk the
management into it. I was a very, very good tenant which they didn't want to
lose. The complex manager had some strict rules though, the dish had to be
hidden on the roof, so it wasn't visible plus no cables were to be on any
outside wall. This wasn't a problem since I was in one of the top
apartments. The installer simply put the dish at the very top of the roof(so
it wasn't visible from the street or backside of the building) and ran the
cable through the roof vent. There was absolutely no grounding cable
available to attach to on the roof or anywhere near. The installer had came
across many installs as mine and had a simple fix. To do the install, he
MUST include a coaxial surge protector(pretty standard, one that includes
your normal 7 electrical inputs, coaxial and phone surge protection) which
grounds the cable through your interior home electrical ground. While
obviously not the best, it protected everything the cable eventually went
to. He sited this was a very common fix since most apartment complexes have
no way to install outside grounding.
Joseph Frietze
a ggod surge protector, and that woudl help with the run I need to make to
my ground. Or can I just install a metal stake in the ground to ground it
to? I don't have any metal plumbing, all CPVC.
Joe
Joe <nos...@nospam.com> wrote in message
news:tc0dgh1...@corp.supernews.com...
Bill Rosen
:
: On Mon, 26 Mar 2001 21:42:42 GMT, Daniel Prince <neut...@mediaone.net>
: wrote:
:
:>Are ground blocks necessary or desirable in Southern California where
:>lightning is rare? Thank you in advance for all replies.
: Nope. Not at all. It may be "code" in some areas, but reality is that it
: just isn't needed in most places - like yours.
:
: Flame away......
I'll start with the flames Jason. Where did YOU get your information.
Are you an an Electrical Engineer? I am, and I can tell you that proper
electrical grounds are EXTREMELY important no matter where you live.
Some installers do not put them in because they take more time and
require more material. Proper electrical grounds do NOT stop lighting
strikes but they do help prevent them. They provide a drain for static
buildups that can occur on the dish itself.
Electrical grounds are required in ALL states. It is part of the NEC
(National Electrical Code) which is the miminum code (many states have
much stronger codes). Article 820-40 of the NEC provides guidelines
for proper grounding and in particular specifies that the cable ground
shall be connected to the grounding SYSTEM of the building, as close
to the point of cable entry as practical.
One other thing that is worth considering is your home owners insurance.
If you have an electrical fire of ANY nature, one of the first things
that the fire department or insurance inspector will check will be proper
electrical grounding. Missing grounds (that result in a fire) CAN be a
reason for denying an insurance claim.
There is a lot of bad information posted in newsgroups but some
information (like Jason's) is not only wrong but it is dangerous
and can be quite costly.
Lee Myers
Could any water pipe that goes underground be used, or is this metal
connection some kind of ground wire on the water pipe that connects to the
main ground?
"Joseph Frietze" <jdfr...@peoplepc.com> wrote in message
news:tc02url...@corp.supernews.com...
Bill Rosen
:
: On 27 Mar 2001 10:38:51 -0500, Bill Rosen <bro...@shell1.iglou.com> wrote:
:
:>:
:>: On Mon, 26 Mar 2001 21:42:42 GMT, Daniel Prince <neut...@mediaone.net>
:>: wrote:
:>:
:>:>Are ground blocks necessary or desirable in Southern California where
:>:>lightning is rare? Thank you in advance for all replies.
:>:
:>: Nope. Not at all. It may be "code" in some areas, but reality is that it
:>: just isn't needed in most places - like yours.
:>:
:>: Flame away......
:>
:>
:>I'll start with the flames Jason. Where did YOU get your information.
: The real world. Practicallity. The law of averages.
:
:>Are you an an Electrical Engineer?
:
: Nope.
:
:>I am,
:
: So?
:
:>Electrical grounds are required in ALL states.
:
: Where did I say it wasn't?
:
:>There is a lot of bad information posted in newsgroups but some
: Wrong by some old outdated junk? Bah!
:
: Knock yourself out doing something that just isn't necessary in most parts of
: the US.
:
:
: Flame away again....
Jason,
There is no use in responding. You have your mind made up. So do I. I
will ALWAYS recommend grounding no matter where the person resides.
Bill Rosen
:
: Could you clarify your statement about the metal water connection please.
: Could any water pipe that goes underground be used, or is this metal
: connection some kind of ground wire on the water pipe that connects to the
: main ground?
Lee,
In most homes that have METAL plumbing it is acceptiable (check your
local electrical code) to connect a ground to the pipe that runs to
any pipe that is connected to the common building ground. Normally
this applies to pipes that run underground too since they are usually
connected to where the electrical ground is. Just be sure that you
don't have some plastic plumbing in the line somewhere. If you do
it is permissable (in most codes) to use a ground strap (or run ground
wire) between the PVC pipes and the metal pipes so there is a good
ground (you may notice that the water company is doing this with their
meters).
Jim Riggs
--
Jason <no@mail> wrote in message
news:f3n1ctgmaku157s45...@4ax.com...
> On 27 Mar 2001 10:38:51 -0500, Bill Rosen <bro...@shell1.iglou.com> wrote:
>
> >Jason <no@mail> wrote:
> >:
> >: On Mon, 26 Mar 2001 21:42:42 GMT, Daniel Prince
<neut...@mediaone.net>
> >: wrote:
> >:
> >:>Are ground blocks necessary or desirable in Southern California where
> >:>lightning is rare? Thank you in advance for all replies.
> >:
> >: Nope. Not at all. It may be "code" in some areas, but reality is that
it
> >: just isn't needed in most places - like yours.
> >:
> >: Flame away......
> >
> >
> >I'll start with the flames Jason. Where did YOU get your information.
>
> The real world. Practicallity. The law of averages.
>
> >Are you an an Electrical Engineer?
>
> Nope.
>
> >I am,
>
> So?
>
> >Electrical grounds are required in ALL states.
>
> Where did I say it wasn't?
>
> >There is a lot of bad information posted in newsgroups but some
> >information (like Jason's) is not only wrong
>
viking
> Jim Riggs <jri...@islc.net> wrote:
> :
> : I have a metal power vent on my roof, does that come under the same code.
> :
> : --
>
> Jim,
>
> You have to check your local electrical code (a good place to
> check is with your local building inspector's office). My local
forget lightning- ground the dish to get rid of the
static it picks up from the wind
Bill Rosen
:
: I have a metal power vent on my roof, does that come under the same code.
:
: --
Jim,
You have to check your local electrical code (a good place to
check is with your local building inspector's office). My local
code does not allow one to be used as a ground (even though power
vents are electrically grounded).
Stan
wrote:
>When my Dish 500 was installed the installer didn't install a ground
>block. When the installer came out two weeks later to correct some
>problems with the installation, I asked him about the ground block and
>he said that it wasn't necessary and that he has seen them cause
>problems.
>
Both installers I've dealt with said it wasn't necessary.
Seth
news:99rjc5$7icu$1...@newssvr06-en0.news.prodigy.com...
>
> "Stan" <296...@mail.com> wrote in message
> news:0nj2ct4qaemclonl1...@4ax.com...
>
> > Both installers I've dealt with said it wasn't necessary.
>
Even better, I agree with you!
John Fischer
> Both installers I've dealt with said it wasn't necessary.
They're both dead wrong - and the NEC agrees with me :-)
Bill Rosen
:
:
: "Stan" <296...@mail.com> wrote in message
: news:0nj2ct4qaemclonl1...@4ax.com...
:
:> Both installers I've dealt with said it wasn't necessary.
:
: They're both dead wrong - and the NEC agrees with me :-)
I agree with John. The NEC should always be followed even in
non-lightening prone areas. I would never trust an installer
who says a ground is not needed. Get an installer that knows
and follows the local and national electrical codes.
A properly grounded system helps pervent ground loops which can
cause rolling bars in the picture and an audio hum and it also
pervents static buildup on the dish and LNB.
ja...@mere1.meredevtech.com
don't.
For example. My electrical service was grounded to a steel well pipe
that went 70' into the ground. Everything worked great, no problems.
Then, I had to have the well replaced and the well driller put in one
of these new PVC plastic wells. Soon after the well was replaced, I
started having electrical problems. The Dish receiver would go blank
for 2-10 seconds at a time, my computers would reboot for no apparent
reason. An electronically controlled ceiling fan would turn on all by
itself. I was constantly replacing light bulbs.
Then one day an electronic control module in my cental air unit blew
out. The AC guy just happened to notice that the ground wire for my
electrical service panel was hanging loose on the wall where it used
to attach to the old steel well pipe. Apparently the well driller
didn't bother to put in a new ground. Anyway, an electrician came out
and installed a new central point ground system and all those
mysterious electrical problems have disappeared.
CanadianDSS
"Daniel Prince" <neut...@mediaone.net> wrote in message
news:nedvbt0aq62fqa15t...@4ax.com...
Hallerb
>>Are ground blocks necessary or desirable in Southern California where
>>lightning is rare? Thank you in advance for all replies.
>
Dishes in wind can pick up a static charge that can damage receivers and cause
flakey problems.
w_tom
ground for two important reasons - human safety and transistor safety.
Yes, code requires that the dish be connected to the human safety ground -
even if you are not concerned with surge protection. Unfortunately many
so little understand either requirements as to even think a power strip
surge protector is effective surge protection. The code is quite
specific. Everything, even CATV must have a connection to the household
ground system. This was previously posted to the alt.satellite.direcpc
newsgroup last Nov:
"" One important fact concerning grounding. 30 feet wire to the service
entrance ground is good for human safety; but not sufficient to protect
a receiver from lightning. Wire that is 0.1 ohms on the Ohm Meter can
be 150 ohms reactive impedance to lightning. IOW a wire run to the
service entrance may be so long that lightning seeks a better ground
via receiver.
Better grounding is a 10 foot copper rod in the ground immediately
adjacent to the dish AND and underground bare wire (per NEC specs)
connecting that rod to the service ground. Therefore the dish has a
good lightning protection, connects to the central human safety ground,
and the interconnection wire improves quality for both grounds (dish
and service). I believe the wire must be 4 AWG and buried about 1.5
feet - check with NEC article 250 for better numbers.
Don't expect effective surge protection from power strip surge
protectors adjacent to the receiver. They are too far from earth ground
to be effective. For effective lightning protection, a surge protector
must be located at the electric service entrance, connected less than
10 feet to the service ground, and must be rated, at minimum, about
1000 joules. These 'whole house' units cost less than $50 - or less
than $1 per protected appliance. Surge protectors located next to the
electronics are too close to transistors, too far from earth ground,
too expensive to only protect one appliance, and typically too
undersized to be effective protection. A power strip rated at 345
joule can never deliver more than 230 joules protection and maybe as
little as 115 joule - because of where it is located and how it
connects internally. That is undersized - too small for your needs.
Effective lightning protection is possible and well proven over many
generations. Surge protectors are only as good as their earth ground
which is why that ground rod at the dish also will be such effective
protection.
If possible, even the coax from dish to receiver should pass the
household service ground so that it can dump any lightning surge into
that ground before connecting to receiver. That is the concept for
effective surge protection as proven since before WWII. Surge
protectors shunt a surge to earth ground before the surge can get into
the building - that is how effective surge protection works. ""
ElecConnec
<seth_ler...@hotmail.com> writes:
>Even better, I agree with you!
I agree with both sides! ;-) Grounding CAN cause additional problems (extra
connections to deteriorate, etc.), is probably not necessary in most cases, but
we wouldn't think of NOT grounding a system!
Fire insurance isn't "necessary" in most cases either- just for the people with
fires! It would be nice if we knew ahead of time which customers "need" the
grounding, but we don't! ;-)
--
Todd Allcock, DISH/DirecTV Dealer
Electronic Connection, Lee's Summit, MO
"People say the Internet brings a library to your doorstep... only if the
librarian is a Nazi pedophile, that is." Bill Maher 1/19/2001
TomB
Fire Insurance.
Health Insurance.
Homeowners Insurance.
Medical Insurance.
Safety Glasses.
Hard Hats.
Seat Belts.
Grounding blocks.
You don't need any of them until you do.
Some are more affordable.
Grounding's pretty cheap.
Why NOT do it?
TomB
Kai-ming Mei
what I gather the ground block should be run all the way down to a metal
pipe in the earth, which should be then connected to the service ground?
Is that right?
What ga. should the wire to the earth be (solid/stranded)?
How bout the earth to service panel (about 45 ft.)?
Should the coax be attached to this ground as well?
What about just attacting the ground to some metal conduit outlet on the
top floor, how bad is that.
in NYC
In article <3ac15...@news.iglou.com>, Bill Rosen
<bro...@shell1.iglou.com> wrote:
Bill Rosen
:
: Bill, or others, my dish is at the top of a 4 story brownstone. From
: pipe in the earth, which should be then connected to the service ground?
:
: Is that right?
The ground block does not have to be connected to a metal pipe in the
earth. It can just be connected to the service ground.
:
: What ga. should the wire to the earth be (solid/stranded)?
The ground wire should be solid wire, at least 10 gauge copper
or 8 gauge aluminum.
: How bout the earth to service panel (about 45 ft.)?
Your service panel is grounded and it is fine to hook up the
satellite ground to it. If you use a seperate ground rod it
should be bonded (connected) to the common service ground.
: Should the coax be attached to this ground as well?
You don't need to do anthing with the coax. It contains a shield
and that shield IS connected to the ground block so it IS grounded.
: What about just attacting the ground to some metal conduit outlet on the
: top floor, how bad is that.
:
You should check your local electrical code to see if that is permitted.
In my city it is not allowed.
: in NYC
:
Grounding in a high rise or appartment complex can be a problem. It may
be best to call in an expert or at least give a call to your local
housing inspector's office and ask their advice.
Mike Nassour
Pure Evil! <pur...@singapore.com> wrote in message
news:skd3ctc5kr0pl2tte...@4ax.com...
> I think they told you a story. What your protecting against is 1. A
> direct lightening strike, which blows everything. 2. Static from a
> nearby lightening strike, can blow everything. Unplugging the dish
> during a storm, stops two.
> A good ground should stop one. But, most surge suppressor aren't fast
> enough to trip to stop one. Buy one warranted for 50k.
With all due respect...a DIRECT lightining strike will blow the dish off the
side of the house and blow a hole in the side of the house itself! Now, HOW
does a block protect against that?<G>...
Not being a smart-a**, just making a point! <G>....mn
David Kelly
I agree, nothing protects in the event of a direct strike.
But amazing how soon the city-fied population forgets how a "lightning
rod" protects a structure. By putting a rod atop a structure and
connecting that/those rods to a low impedance ground one discharges the
static buildup due to wind (and nature) and *prevents* direct lightning
strikes.
Lightning comes half from structures and half from the sky.
brobri
> "" One important fact concerning grounding. 30 feet wire to the service
> entrance ground is good for human safety; but not sufficient to protect
> a receiver from lightning. Wire that is 0.1 ohms on the Ohm Meter can
> be 150 ohms reactive impedance to lightning. IOW a wire run to the
> service entrance may be so long that lightning seeks a better ground
> via receiver.
>
> Better grounding is a 10 foot copper rod in the ground immediately
> adjacent to the dish AND and underground bare wire (per NEC specs)
> connecting that rod to the service ground.
CAN I GET AN AMEN HERE!
The ultimate ground is of course is a GRID!
City of Denver (lots of lightening here) uses a grid of interconnected
grounds on all new traffic signal installations. A 8ft ground rod at each
corner
(of the intersection), along with gnd rod in control cabinet. This is all tied
togeter
with number 8 I think.
I've seen wimpy grounds that tested just fine with a megger, not even able
to sink a 5 amp load. Wierd
> Therefore the dish has a
> good lightning protection, connects to the central human safety ground,
> and the interconnection wire improves quality for both grounds (dish
> and service). I believe the wire must be 4 AWG and buried about 1.5
> feet - check with NEC article 250 for better numbers.
Wow, this is SANE TALK, in a world of spin and opinion.
If everyone saw how bad their ground strap on "some water pipe" was,
maybe they would believe in a good ground near the panel. Many houses
don't have a good ground, because they never had a 8 ft rod, or as you say,
interconnected grounds.
Grouding grids Rule!
w_tom
ability. In fact most strikes don't leave a significant trace and usually less
than a 2" surface mark. According to research from the US Forest Service and
reprinted in a number of Dr Uman's books, well over 90% of all strikes on trees
don't even leave a significant mark nor kill the tree. These are facts - not some
feeling that lightning is an all powerful godlike force.
There is much urban legend about energy in lightning. Millions of volts and
tens of thousands of amps. The problem is that those two number don't coincide.
Basic high school science therefore says less power in a strike. From those who
use facts rather than FEEL, the energy levels are quite low. For those who use
feeling rather than facts, the "woe is me" urban legends persist.
From Colin Balisss "Transmission & Distribution Electrical Engineering":
"Although lightning strikes have impressive voltage and current values (typically
hundreds to thousands of kV and 10-100 kA) the energy content of the discharge is
relatively low..."
It is routine for lightning to strike with no damage when the human installs
some simple systems. Surge damage is directly traceable to a human.
Unfortunately lightning damage is common where some cry "Woe is me" rather than
deal with the realities of lightning. Effective surge protection keeps direct
strikes from creating the damage.
Critical earth ground. Notice that the purveyors of the "Woe is me" must avoid
discussion of earth ground and the so many commonly struck locations that never
suffer damage. Critical earth ground was even known to Franklin in 1752. Here we
are in 2001 and still some don't understand those basic principals.
It should also be noted that wind created static discharge on skyscrapers is a
different system from Air Terminals (lightning rods). Wind created static has
nothing to due with surge damage.
w_tom
Better than the ground grid is Ufer grounds - again another very
old, proven part of effective surge protection from direct lightning strikes.
Testimonials from professionals will probably be openly disputed or ignored
by "purveyors of urban legend" because it does not agree with what they
'feel'. But here is it - testimonials of effective, direct strike
surge protection, and Ufer grounds defined by people who come from
where the work gets done:
http://scott-inc.com/html/ufer.htm
http://lists.contesting.com/_towertalk/199909/0143.html
.
Then there is the first sentence from another serious surge protection
company:
http://www.lightning-protection.com/solutions/solearth.htm
:
"Even the best surge protection device is of no use if incorrectly
installed. Installation, and more specifically earthing, is a critical
aspect of surge protection."
We have many previously posted urban legends. Not one mentions the benchmark for all surge protection: www.polyphaser.com . Either we believe previously posted urban legends OR read the facts in Polyphaser's application notes. Urban legend purveyors claim that nothing can protect from direct lightning strikes (a feeling). Polyphaser equipment provides that protection daily (a fact).
brobri
Subject:
Re: Importance of grounding the dish
Date:
Wed, 28 Mar 2001 21:10:52 -0700
From:
brobri <whir...@my-deja.com>
Newsgroups:
alt.dbs.echostar
References:
1 , 2
Grouding grids Rule!
>
>
Nicholas Riegel
Echostar company that is responsible for installations and service calls), I
see that in general there tends to be much misinformation in this discussion
about the importance and operation of grounding and surge protection.
To start things off, first read the disclaimer below. The purpose of
grounding as specified by the National Electric Code and the Nation Fire
Protection Agency is to provide for safety. Nowhere does it state that
grounding is to protect equipment. When you ground the dish to either a
grounding block or switch then to a ground, you are doing two things. You
are turning the dish into a grounding rod (this is a good thing because
contrary to popular belief a grounding rod deflects lightening from itself)
and second, through the ground block and the switches, you are grounding the
shielding only of the coaxial cable. THE GROUNDING WIRE IS NOT DESIGNED TO
DISSIPATE THE ENERGY IN A LIGHTENING STRIKE!!!!
If you have ever taken a look at coaxial cable, you will notice a few
common items. Center copper wire - this carries the downconverted signal
from the LNBFs @ ~ 2150Mhz to the receivers. Dielectric - the white stuff
that surrounds the copper wire that insulates and keeps that signal in the
copper wire. Shielding - the metal braiding that keeps electrical energy
(EMF) out. The whole purpose of this setup is to keep the signal on the
copper wire and everything else out, therefore the center copper wire does
not contact anything but the LNBFs, the internals of any switches or
grounding blocks, and the receivers. THE CENTER COPPER WIRE IS NOT GROUNDED.
The purpose in connecting a ground wire from the dish to the switch / ground
block then to a common ground is to dissipate electrical energy in the
SHIELDING only.
When a lightening bolt strikes it creates an electromagnetic pulse (EMP)
that propagates outward from the center of the strike (henceforth a pulse).
This pulse creates an electromagnetic field (EMF) that propagates and
dissipates as it moves out. As a basic theory of electrical physics
whenever you place a metal wire (the center copper wire, shielding, ect) in
a EMF a current is induced in that wire. Likewise when a current flows
through a wire it creates an EMF (this is how those wire finder that allow
you to find electrical wire in a wall partition work). At any rate because
the center copper wire is not attached to grounding, a current gets induced
in the wire that has on 1 of two places to get dissipated: the receivers(s)
or the LNBF. This is the reason why it is a good idea to buy a quality
surge protect that not only provides surge protection for electrical
outlets, but one that also protects the coaxial cable as well as phone lines
( IMHO good ones are the Panamax surge protectors that are designed
specificity for DBS systems
http://www.panamax.com/applications/satellite.asp). Make sure you purchase
one that is designed for satellite systems and allows the 2150Mhz signal
pass through though.
Lastly about using grounding rods: The very best ground to use is the
existing building ground because there is no opportunity to produce
different electric potentials. A grounding rod will work though especially
when it is too impractical to find the building ground. Where you run into
problems is when one grounding source comes into contact with another. The
different electrical potentials that the two grounding sources have will
induce a current in one direction.
There is an excellent but somewhat technical article on grounding at
http://www.echostaruser.org/ekb/1.htm
Hope this all helps.
--
The above message and information is entirely the property and thoughts of
Nicholas Riegel and not of any other person or corporation no matter the
affiliation. Use at your own risk.
Bill Rosen
be found at http://www.dbsforums.com/reviews/tech1_5.html
It will answer a lot of questions about why you should ground and has
links to sites that have additional information.
It is well worth taking the time to read it.
w_tom
William Austin
:-) Due to the semi-temporary nature of my system, I don't have it
grounded. I did, however, install a two-receiver system in my parent's
house and gave it its own ground rod (because the house *itself* was built
before codes, grounding, etc.) because the water main was on the opposite
side of the house from the installation. I wasn't about to belly crawl that
distance for one more wire! :-)
My question has to do with multiple ground systems. I may have flunked ham
radio school <G> but doesn't the electrical code require that all ground
systems in a building be tied together? I know ground loops could be a
problem, but I seem to remember this somewhere. Illumine me, please. :-)
Will
w_tom
provide safety - but only for human safety. The NEC and NFPA do not address
electronics safety - nor do they claim to do so. Even UL1449 only defines
standards to protect a human life from dangerous surge protectors as
demonstrated in many 1980s issues of PC Magazine, (rumored) in Consumer Reports,
and shown in these scary pictures: http://www.zerosurge.com/truth.htm . NEC,
et al do not address transistor safety. However those same grounds installed
for human safety are also either installed or upgraded to provide transistor
safety.
Many don't even understand basic electrical principals of surge protection.
Take, for example, the 12 AWG AC electric wire. How much impedance in a 50' 12
AWG wire? From outlet to breaker box, it is 0.2 ohms to AC power or the DC
meter. IOW it is a conductor to AC power. Not true, though, for a surge.
That same wire typically appears as 150 ohms reactive impedance to a surge. We
are now talking about electrical principals that are beyond the scope of NEC,
NFPA, etc. Therefore so many are misinformed by urban legends associated with
plug-in surge protectors - such as the panamax unit - that forgets to mention a
short, direct, and independent (all three adjacetives have electrical
engineering meanings) critical earth ground connection.
The poster, unfortunately believes that a plug-in panamax unit has a
connection to earth ground when plugged into an AC outlet. It may be 0.2 ohms
to 60 hz AC. But an incoming 100 amp surge trying to get to earth ground - 100
amp times 150 ohms leaves the panamax and adjacent electronics at 15,000 volts.
What kind of protection leaves the adjacent appliance at 15,000 volts relative
to earth ground? Ineffective surge protection.
In reality, the panamax and adjacent 'protected' appliance will not obtain
15,000 volts because the surge will find other, destructive paths to earth
ground. Three such outgoing paths would be a phone line, the speaker wire
draped over a water pipe, or the linoleum tile - all will become conductors,
destructively, to that surge.
We know from over 3 generations of experience and from the underlying theory
that surge protection adjacent to electronics is not effective. Unfortunately,
many falsely believe that wire is a low resistance conductor to surges. When
discussing surges, wire becomes an electronic component - and must be treated as
such. That is why the distance - less than 10 feet to earth ground - is so
critical.
Many unfortunately will cite inferior surge protection manufactuers as sources
only because those inferior retail products have the hype of Geritol, Listerene,
and every new, medically unproven, hair restoring cream. If you know anything
of surge protection, then you know the name 'Polyphaser' and the applications
notes at http://www.polyphaser.com . Those application notes constantly
reference the need for earth grounds in surge protection. Of course if
Polyphaser app notes are too complicated, then try this professional's
explaination: http://www.powerquality.com/art0047/art1.html .
Those who know surge protection know that no lightning strike need every
damage electronics. When damage does occur, the human must return to correct a
human mistake.
Unfortunately electricans and even satellite dish installers are not fully
versed in surge protection. They know the code for human safety. Those codes
don't cover transistor safety. For example, electricans don't understand the
150 ohm impedance in the 12 AWG wire.
To agree with the previous post, then you have to be in disagreement with
testimonials from people who come from where the work gets done:
Either you ground also for surge protection - ground both to meet NEC
requirements and to provide surge protection, OR you cannot ground for surge
protection. Which is it? Personally I put more faith in the engineering
principals demonstrated in the above 12 AWG wire example, in those above
testimonials of those who do effectively surge protect, in the many articles
on effective surge protection in the IEEE Transactions on Electromagnetic
Compatibility, and in the many personal successful experiments I have performed
over many decades in shunting direct lightning strikes with what today we regard
as grossly undersized protection. Provided in this one post, alone, is
fundamental theory, testimonials, professional papers, and my own personal
experience that says, we also ground for effective surge protection. Appliance
adjacent surge protection is not effective surge protection. Sometimes the
manufacturer's own specifications demonstrate same. What technical facts say
otherwise?
w_tom
not in evidence from the best experts in lightning and surge protection.
This sentence alone is simply wrong:
>The third reason to ground the coaxial cable is to prevent lightning
from striking the dish.
>This is NOT to carry the voltage from a lightning strike safely to
ground. In order to do
>that, the ground wire would have to be the width of a tree trunk to
carry the millions of
>volts and thousands of amps contained in a lightning strike without
melting to slag.
The millions of volts are elsewhere. If a lightning bolt is 1 million
volts and all 1 million volts appear at the ground strike, then there is
0 volts in that 3 or 5 mile bolt? The post is full of these urban
legends.
Instead read accurate facts from people who do professional work:
From Colin Balisss "Transmission & Distribution Electrical Engineering":
>Although lightning strikes have impressive voltage and current values
(typically
>hundreds to thousands of kV and 10-100 kA) the energy content of the
>discharge is relatively low ...
The www.dbsforum 'urban legend' would have you believe that the
millions of volts and thousands of amps 1) exist simultaneously, and 2)
both appear at the strike location. Both parts of that 'urban legend'
are false.
Instead real world researchers such as a world renown expert, Dr Martin
A Uman from U of FL in his book "All About Lightning":
>"Most of the energy available to the lightning is converted along the
lightning
>channel to thunder, heat, light, and radio waves, leaving only a
fraction available
>at the channel base for immediate use or storage."
Another grossly erroneous sentence in www.dbsforum:
>Contrary to popular opinion, lightning rods are not designed to attract
>lightning, but rather to repel it.
This is a classic half truth. Air terminals (lightning rods) are not
designed to attract lightning. But they are not to repel lightning
either. An air terminal diverts a surge to earth ground. The idea is to
channel the surge in a safe path to earth ground. Notice also that
lightning rods are not connected to wires "the width of a tree trunk" -
an exact and erroneous quote from www.dbsforum.
There is so much 'urban legend' associated with surge protection that
the misinformed will loudly declare these **lies** that have been
disproven for 3 generations:
1) you cannot protect from a direct lightning strike
2) purchase one of the better brand name power strip or UPS surge
protectors such as ....
3) surge protectors absorb a surge to protect your equipment
4) a good surge protector will fry to absorb a surge
5) surge protectors block a surge from destroying your equipment.
6) surges are induced in the various cables entering the home by a "near
miss"
7) most important thing to understand about MOVs is that they can be used
only once
8) an indicator light that verifies protection is being provided (it can
only report that protection is not available - ternary logic - a big
difference)
These and many other erroneous urban legends abound. Effective surge
protection exists. But fundamentals for effective surge protection are
not correctly provided in www.dbsforum. However one accurate point is
made - a surge protection system is only as good as its earth ground.
Central earth ground is essencial for effective surge protection. That
central earth ground does not exist in plug-in, power strip and UPS,
surge protectors.
Joe
> Lastly about using grounding rods: The very best ground to use is the
> existing building ground because there is no opportunity to produce
> different electric potentials. A grounding rod will work though
especially
> when it is too impractical to find the building ground. Where you run
into
> problems is when one grounding source comes into contact with another.
The
> different electrical potentials that the two grounding sources have will
> induce a current in one direction.
>
> There is an excellent but somewhat technical article on grounding at
> http://www.echostaruser.org/ekb/1.htm
I was wondering when the topic of ground loops would come out. Grids are
great ideas and really the only idea if multiple ground rods are to be used.
If someone can't find a service ground to begin with, adding an additional
grounding rod will surely produce some type of grounding loop trouble if not
used with a grounding grid. I read a few posts how ohm meters won't work. Of
course not. How much current does most ohm meter's 9 volt batteries output?
A 9 volt battery can't mirror a lighting bolt(or a normal appliance using
current)! Ground loops are a _itch to troubleshoot when it's in the system
wiring, but when it's related to outside connections, you're talking some
major headaches!
The surge protector on my old apartment setup was merely to protect my
equipment.
Nice statement. I like the electronic theory right along with the electrical
theory.
In theory, the shielding would literally evaporate from a lightning bolt's
high current. In the unlikely event, a high voltage(low current)spike was
induced on that shielding, that spike could make it though the coaxial cable
all the way to the surge protector. In a situation like that, that shielding
could act as an earth ground, and a surge protector would help in that
situation also. Obviously, now the shielding is part of a circuit including
high voltage. Although the ground run will have a lot of resistance, it
should still be the path of the least resistance to earth ground. So my
belief is it still offers some protection.
Joe
> Lastly about using grounding rods: The very best ground to use is the
> existing building ground because there is no opportunity to produce
> different electric potentials. A grounding rod will work though
especially
> when it is too impractical to find the building ground. Where you run
into
> problems is when one grounding source comes into contact with another.
The
> different electrical potentials that the two grounding sources have will
> induce a current in one direction.
>
> There is an excellent but somewhat technical article on grounding at
> http://www.echostaruser.org/ekb/1.htm
I was wondering when the topic of ground loops would come out. Grids are
Santa
wrote:
Yes but did you know studies have shown that houses with lighting
arresters are more like to get a direct hit .................. go a
head hold up that golf club :)
Santa
I still wont hold up a golf club in the rain "Woe is me"
Santa
<jdfr...@peoplepc.com> wrote:
>Interesting. Has anyone else run into something like this? I plan on buying
>a ggod surge protector, and that woudl help with the run I need to make to
>my ground. Or can I just install a metal stake in the ground to ground it
>to? I don't have any metal plumbing, all CPVC.
if you want to go that rought that is the best way to do it but im
here to till your ground is not necessary and a serge protectore is a
waist of money never seen one work yet fixed tons of stuff hit with
spikes and costomer allways say" I had it pluged into a serge
protector to" but go ahead and ground it just a plasebo :)
>Joe
>Joe <nos...@nospam.com> wrote in message
>news:tc0dgh1...@corp.supernews.com...
>> > Are ground blocks necessary or desirable in Southern California where
>> > lightning is rare? Thank you in advance for all replies.
>>
>> I may be wrong, but I believe it's the law to have your cable or satellite
>> system grounded. Now I was in a different situation earlier. I had a
>> satellite on my apartment complex roof. It took me 2 years to talk the
>> management into it. I was a very, very good tenant which they didn't want
>to
>> lose. The complex manager had some strict rules though, the dish had to be
>> hidden on the roof, so it wasn't visible plus no cables were to be on any
>> outside wall. This wasn't a problem since I was in one of the top
>> apartments. The installer simply put the dish at the very top of the
>roof(so
>> it wasn't visible from the street or backside of the building) and ran the
>> cable through the roof vent. There was absolutely no grounding cable
>> available to attach to on the roof or anywhere near. The installer had
>came
>> across many installs as mine and had a simple fix. To do the install, he
>> MUST include a coaxial surge protector(pretty standard, one that includes
>> your normal 7 electrical inputs, coaxial and phone surge protection) which
>> grounds the cable through your interior home electrical ground. While
>> obviously not the best, it protected everything the cable eventually went
>> to. He sited this was a very common fix since most apartment complexes
>have
>> no way to install outside grounding.
>>
>>
>
>
Daniel Prince
>: On Mon, 26 Mar 2001 21:42:42 GMT, Daniel Prince <neut...@mediaone.net>
>: wrote:
>:
>:>Are ground blocks necessary or desirable in Southern California where
>:>lightning is rare? Thank you in advance for all replies.
>I can tell you that proper
>electrical grounds are EXTREMELY important no matter where you live.
>Some installers do not put them in because they take more time and
>require more material. Proper electrical grounds do NOT stop lighting
>strikes but they do help prevent them. They provide a drain for static
>buildups that can occur on the dish itself.
>
>Electrical grounds are required in ALL states. It is part of the NEC
>(National Electrical Code) which is the miminum code (many states have
>much stronger codes). Article 820-40 of the NEC provides guidelines
>for proper grounding and in particular specifies that the cable ground
>shall be connected to the grounding SYSTEM of the building, as close
>to the point of cable entry as practical.
I noticed that you wrote "cable" above. Does the NEC specifically
mention small dish satellite receiver systems?
Does the NEC say anything about conventional over-the-air TV antennas?
Our installers installed one and didn't ground it either unless it is
grounded through the vent pipe it is mounted to. (I doubt if the TV
antenna is grounded by the vent pipe because shortly after we bought
the house, we had all the drain pipes replaced with ABS plastic pipes.
The vent pipes are still steel.)
Can I get a copy of the part of the NEC that pertains to small dish
satellite systems on the web? If I can, do you know where? If not,
can I get it at the library?
w_tom
air. They challenged the gods and the gods feared to strike back - I thought. Oh,
to be young again.
Bill Rosen
:
: I noticed that you wrote "cable" above. Does the NEC specifically
: mention small dish satellite receiver systems?
:
: Does the NEC say anything about conventional over-the-air TV antennas?
: Our installers installed one and didn't ground it either unless it is
: grounded through the vent pipe it is mounted to. (I doubt if the TV
: antenna is grounded by the vent pipe because shortly after we bought
: the house, we had all the drain pipes replaced with ABS plastic pipes.
: The vent pipes are still steel.)
:
: Can I get a copy of the part of the NEC that pertains to small dish
: satellite systems on the web? If I can, do you know where? If not,
: can I get it at the library?
When it comes to electrical codes you also need to be concerned with
your LOCAL code. Many cities (or counties) have local codes that you
have to comply with that are usually more strict than the NEC. Your
local code as well as the NEC should be available at your local
library and at you city's (or county) home inspectors office.
I have not bought a satellite system in the last few years but when I
bought mine I did get an installation manual that contained NEC information
for the dish installation. Since most systems are now "professionally
installed" I don't know if that information is still included with a
system (it SHOULD be). Your installed should have that information and
should be willing to give you a copy of it.
A good site for NEC information is Mike Holt's site. It is
http://www.mikeholt.com/nec/nec.htm
w_tom
connection to the building ground system. Suppose the receiver has an internal
failure. Now the ungrounded antenna is 'hot' ; a threat to human life. If
that antenna has a connection to electricl ground, then the receiver short will
only blow a fuse. No antenna ground connection means a potential shock
hazard. The NEC is quite specific on this however even many professional
installers don't take that requirement seriously.
Appreciate that the NEC grounds only for human safety. That same ground may
not be adaquate for transistor saftey. We often install the same ground to
address both safety issues. Sometimes that means exceeding NEC requirement.
Daniel Prince wrote:
> I noticed that you wrote "cable" above. Does the NEC specifically
> mention small dish satellite receiver systems?
>
> Does the NEC say anything about conventional over-the-air TV antennas?
> Our installers installed one and didn't ground it either unless it is
> grounded through the vent pipe it is mounted to. ...
K Tronics
w_tom <w_t...@usa.net> wrote in message news:3AC2CD73...@usa.net...
> Rmor based upon urban legend. Most lightning strike don't have that
destructive
> ability. In fact most strikes don't leave a significant trace and usually
less
I realize you said "usually" here...
Several years ago I went on a service call to a (new) customer who called
claiming he had a "catastrophic lightning strike" and needed insurance
paperwork and repair.
Upon arrival, the customer led me to the dish. Here I found a mid to late
1980's Channel Master 10 foot fiberglass "BUD". Demolished. In about 60
pieces. My first thought was of course: "WTF?". Customer points to two HUGE
pine trees and says "That tree hit it.". Looking up, I saw that the two
trees were actually one. The tree (about 4 feet across at the trunk) had
been severed (clean) about 30 feet up. The top section came strait down, and
plunged itself with such force, the top section remained standing. A large
limb protruding laterally from the top section obliterated the dish upon
impact.
But wait, it gets better!
Apparently, the lightning found the satellite cable a nice path to ground.
Following the path of the cable toward the house. I found that the last 150
feet of the cable run had been blown out of the ground, clean through the
sod. (The customer alleges that the cable was buried "at least a foot down"
at least 10 years earlier). All insulation had been burned from the cables.
After entering the house, the customer showed me the receiver, still
implanted (cleanly) in the sheetrock wall between his and his wife's chairs
at about head high. Glass front entertainment center was undamaged (except
the glass was broken). Ground wire in the receivers power cord was separated
from the rest of the cord and heavily burned. The Bakelite of the electrical
receptacle which the receiver was plugged into, was "crunchy". You could
tap it lightly with a small screwdriver an little crumbs would fall off it.
The 15 ampere circuit breaker connected to the circuit was knocked from the
electrical panel with such force, it dented the door of the electrical panel
door. He said he called the fire department 'cause he thought the house was
on fire, full of smoke, turns out there was no fire other than the brief
electrical fire which apparently extinguished itself.
The ONLY thing we were able to salvage from the original system was the
mounting pipe.
Again I realize this is an extreme instance, but I think NO amount of
grounding would have helped this guy.
w_tom
ground, so enters a home seeking earth ground. Then one would conclude that no
earth grounding was going to help this guy? That is contradictory. The surge
entered the home because it found better earth ground inside. What was the
better earth ground? It could have been a water well pump buried in a better
conductive earth. Lightning was then seeking a better path to a better earth
ground. Since cable and water well pump did not enter the home connected to a
central earth ground, then lightning had to pass through the house to find that
better earth ground - ie. the water well or something else.
We know from experience and even from the many telephone COs, cell phone
towers, and commerical broadcasters that MUST work during and after every
thunderstorm - that effective surge protection including good earth grounds do
avoid surge damage from lightning. Unfortunately your story examples what
happens when the good central earth ground is not provided. The proper
procedure in most places is to trace back surge paths, then correct faults in
the surge protection system. Unfortunately, misinformed home owners believe
that no surge protection system can be effective from the direct strike. That's
just not true. It is simply a matter of how effective a system is installed.
From the description, it sounds as if the home owner had no surge protection
system - especially no critical central earth ground.
brobri
w_tom wrote:
> We know from experience and even from the many telephone COs, cell phone
> towers, and commerical broadcasters that MUST work during and after every
> thunderstorm ...
I say impossible.
Here in Denver the late summer afternoon thunderstorms wreak havoc daily
There are at times 30 "all out", or "flashing" traffic signals due to signal damage
or power line damage.
Broadcasters get hit, and go off air frequently. The local power company
has to often rebuild, high voltage lines when they get torched by lightening.
We had a stone cathedral have one of its spires nearly destroyed, with massive
stones hurled to the ground.
It seems exciting when nature intervenes into mans smatrness.
> - that effective surge protection including good earth grounds do
> avoid surge damage from lightning.
How about vaporized neutrals on hi lines?
> Unfortunately your story examples what
> happens when the good central earth ground is not provided. The proper
> procedure in most places is to trace back surge paths, then correct faults in
> the surge protection system. Unfortunately, misinformed home owners believe
> that no surge protection system can be effective from the direct strike. That's
> just not true. It is simply a matter of how effective a system is installed.
> From the description, it sounds as if the home owner had no surge protection
> system - especially no critical central earth ground.
We have lots of grounding grids on signalized intersections, plenty of supression,
and still get hit hard. (signal damage that is). So does the power company
>
>
> K Tronics wrote:
>
> > The ONLY thing we were able to salvage from the original system was the
> > mounting pipe.
> >
> > Again I realize this is an extreme instance, but I think NO amount of
> > grounding would have helped this guy.
In many instances I fully agree. Lightening is just not as predictable as you might
like.
w_tom
towns. One had poor conductive soil and therefore few CG strikes. The adjacent town,
once home to many graphite mines, has numerous stikes and resulting damage. Their
geology is strips of conductive and poor condutive soil. Lightning is often striking
surface objects to get into those veins of better conductive soil. Again they have
grounded, but grounded insufficiently. Since lightning seeks earth ground, then it does
the statistically predictable thing - it bypasses those insufficient grounds to get to
better grounds destructively. All you have done is prove that humans again have failed
to properly install sufficient ground for surge protection. Each cited damaged item
contains connections to geology located elsewhere and deeper. For example, why should
lightning take a poor conductive ground at the signal when a better ground is
destructively through signal electronics and down the AC power line.
These principals were well known in the 1930s when both GE and Westinghouse did
research to explain why certain transmission lines were struck more often in certain
locations. The resulting solutions resulted in the word Counterpoise.
From Dr Abdul Mousa is this recent quote in www.lightningsafety.com:
""For lines equipped with the so-called "OHGW" (Overhead Ground Wires, also
called sky wires or shield wires), outages were found to still occur often
in areas of high soil resistivity. It was then concluded that the lightning
current, upon being discharged to ground through the high grounding
resistance of the footings of the towers was generating surges high enough
to cause "backflashovers", i.e. flashgovers from the towers to the live
conductors.
To prevent backflashovers, power line engineers started to make systematic
efforts to reduce the grounding resistance of the towers. The first
publication about such work appears to be an AIEE paper, also by Fortescue.
That was where he used the term "counterpoise" in connection with
grounding/lightning protection. This theoretical analysis was followed in
1934 by a paper reporting on field tests done at Trafford, Pennsylvania.""
Even in 1934, damage was routinely traced to poor grounding problems - in this case
high conductivity soil. Lightning is not caprious. Lightning is statistically
predicable (although we are not anywhere near as good yet as we would wish) and the
resulting damage is avoidable.
Currently the new NLDS is being used by electric companies to indentify where high
voltage wires are being struck so that they can enhance surge protection at those
locations - to avoid future failures. Where lightning still remains an non-decreasing
event, the power company has only itself to blame since new tools and methods are
constantly being developed to indentify and to correct problem areas.
In short, you have reasoned that we cannot learn from failure and should never expect
to do so. Therefore we can never increase reliability because lightning is so
caprious. That simply flys counter to the basic principles of being American.
brobri wrote:
> w_tom wrote:
>
> > We know from experience and even from the many telephone COs, cell phone
> > towers, and commerical broadcasters that MUST work during and after every
> > thunderstorm ...
>
> I say impossible.
>
> Here in Denver the late summer afternoon thunderstorms wreak havoc daily
> There are at times 30 "all out", or "flashing" traffic signals due to signal damage
> or power line damage.
>
> Broadcasters get hit, and go off air frequently. The local power company
> has to often rebuild, high voltage lines when they get torched by lightening.
>
> We had a stone cathedral have one of its spires nearly destroyed, with massive
> stones hurled to the ground.
> It seems exciting when nature intervenes into mans smatrness.
>
> > - that effective surge protection including good earth grounds do
> > avoid surge damage from lightning. ...