STVTalk.com

Jerry · Guest

I'm wondering if anyone has this thread marked, I have a similar problem. I
have a LNB with 4 feeds. 2 got to a TIVO'd TV, 1 goes to an HD receiver/TV,
and 1 goes to a Hughes receiver/TV. We recently had a thunderstorm with
enough intensity to block the signals, and a little bit of lightning. After
this was done, only the last TV didn't work.

I checked that cable back to the dish and there are two connectors. When I
unthreaded them, I found the conductor was gone and a black spot remained!!
So I ran the cable all the way from the TV to the LNB - no splices at all.
I tested the TV and I got some channels - very strange. I checked the
connector at the TV and noticed the conductor was short, so I replaced it
with a new one (careful to follow these instructions), but I don't get any
channels now. The transponder readings seem to fit this 'experiencing what
we call transponder null on the ODD number transponders' situation, although
the even ones aren't that high (50's or so).

I actually replaced the LNB, but think maybe the factory connector at the
dish/LNB end of the run is maybe defective too (was part of the splice that
'ate' the connector). So I'll go up on the roof and try to replace that end
of the connector when it's a little warmer than the current 30s....

Anyone have other suggestions?

Thanks for any ideas!

"Jim" <spamaddyREMOVE@bellsouth.net> wrote in message
news:3PmLe.13025$rp.12868@bignews1.bellsouth.net...

lnh · Guest

You have been a victim of lightning. Consider yourself lucky that your
receivers still work!!

In article <vZFff.13688$cg.10024@news02.roc.ny>,
"Jerry" <jlieberm@frontiernet.net> wrote:

Billy Ryman · Guest

Yup, and I'll bet the dish wasn't grounded.

w_tom · Guest

If lightning protection - a good path to earth - was not
provided, then equipment is damaged for same reasons that 1750
church steeples were damaged. Without a non-destructive path
to earth as Franklin did in 1752, then lightning will find
destructive paths through electronics.

First your dish should have a shortest and direct path to
earth ground. Second, cable should enter building where all
incoming utilities enter. Coax cable ground block makes a
less than 10 foot connection to the same earth ground used by
all other utilities. Earthing - not a protector - is
protection. Quality of single point earth ground determines
the quality of your lightning protection. Quality of a
connection from any surge protector to that earth ground
determines the effectiveness of that protector - which is why
plug-in protectors are so ineffective.

You may also learn about overstress on semiconductors.
Components exposed to excessive transients may be overstressed
- fail days or months later. Lessons to be learned from
experience - unfortunately.

Jerry wrote:

Jerry · Guest

This is great - thanks all

I did cut and put a new f connector on the end of the cable and everything
works fine now - all 32 transponders around 90.

It's interesting about this lightning, it was not a very 'electric'
thunderstorm, mostly really heavy rain. We do have the dish grounded - and
it's the shortest path too. It's different than the utilities because
they're on the other side of the house and underground too. Still seems odd
that of the 4 feeds off the dish, only one was impacted, and both the
splices had these burnt out connectors. I'm wondering if it's safer to turn
off the receivers in future storms.

Thanks again for all the help - found the 'odd null condition' in one of the
posts that helped me determine that the end connection has to be real clean
(there was carbon or copper residue on the connection).

"Billy Ryman" <b1sdf@amico.net> wrote in message
news:nmSff.72655$qk4.180@bgtnsc05-news.ops.worldnet.att.net...

Billy Ryman · Guest

What do you have the dish itself grounded to?

The reason that it only affected "one" connector is that was the least path
of resistance.

Keep in mind that gounding in accordance with NEC (National Electrical Code)
is not designed to handle a lightning strike. You'd need a conductor about
8' in diameter to handle that. The ground merely provides an outlet for
"static" electricity, which is ever present in the atmosphere, to be safely
taken to ground. When this is done, it does away with the potential
(electron flow). (+ ) and (-) charges must come together to cause electron
flow, i.e. electricity.

Jerry · Guest

Thanks Billy, it's grounded to a water outlet about 30 ' from the dish (kind
of straight down). That TV is not even the closest, it's about 70' away.

I'll go recheck that grounded connection to the faucet housing, maybe it's
not that clean anymore. Hopefully that will prevent recurrences of this
problem (it has occurred a few times over the past few years, but once
DirectTV's contractor fixed it, the other time I thought it was a faulty
connector (on that same circuit)

Thanks again! I appreciate the advice/guidance!

"Billy Ryman" <b1sdf@amico.net> wrote in message
news:4Y1gf.135734$zb5.9562@bgtnsc04-news.ops.worldnet.att.net...

w_tom · Guest

That water faucet connection violates National Electrical
Code (NEC) requirements. It creates a human safety threat.
Earthing for lightning protection also provides human safety
(NEC) requirements.

Previous post defined how direct lightning strikes cause no
damage, and how that dish is installed to meet NEC
requirements.

Static electricity is completely irrelevant. Even
components in both the LNB and receiver make static
electricity irrelevant.

From the code: Articles 810
810.21(E) The grounding conductor for an antenna mast of
antenna discharge unit shall be run in as straight a line as
practicable from the mast or discharge unit to the grounding
electrode.
[That defined your 30' connection from dish]

810.21(F) The grounding conductor shall be connected as
follows:
(1) to the nearest accessible location on the following:
(a) The building structure grounding electrode system ....
[as defined in previous post]
(b) The grounded interior metal water piping systems, within
1.52 meters from its point of entrance to the building
....
[which water faucet completely violates - is
that unacceptable]
(c) The power service accessible means external to the
building ...
(d) The metallic power service raceway
(e) The service equipment conductor, or
(f) The grounding electrode conductor or the grounding
electrode
conductor metal enclosures ...

810.21(I) A single grounding conductor shall be permitted for
both protective and operating purposes.

810.21(J) A bonding jumper not smaller than 6 AWG copper or
equivalent shall be connected between the radio and television
equipment grounding electrode and the power grounding
electrode system ... where separate electrodes are used.

Article 810.21(J) says 30' dish ground directly to earth as
defined in 810.21(E) must be connected to the breaker box
earth ground if both are not the same earth ground electrode.

That wire from dish going 30' straight down must be earthed
with an electrode per Article 250.50, which means an 8 foot
earth ground rod or equivalent. Faucet connection has long
been a code violation which even a home insurance company may
take exception to should a major claim be filed. That dish
ground rod must be connected to the household breaker box
earth ground using a dedicated 6 AWG wire. This is best
accomplished by a buried wire outside the building since the
30' 'straight down' wire must carry a direct lightning strike
into earth - without damage.

The mythical 8' wide lightning conductor is in direct
contradiction to every responsible lightning protection
product, in direct contradiction to US Army standard TM5-690,
British standard BS6551, ISO 61001-x standards, professional
papers from the IEEE and others, AND in direct contradiction
to what Ben Franklin demonstrated in 1752. In short, Billy
posted a myth. We earth the antenna for human safety -
especially the direct lightning strike.

BTW, with basic Electromagnetic wave theory training, then
one would have known that lightning does not even penetrate 1
inch inside that 8' diameter conductor. Billy posted in
direction contradiction to NEC, in direct contradiction to
first year electrical principles taught in wave theory (also
known as the skin effect), and in direct contradiction to
common knowledge. It is routine to suffer direct lightning
strikes without apparent damage even to trees, which is why
heavy 6 AWG wire is sufficient - as also required by code.

A most significant reason for your connector damage would be
that connection from dish to a faucet which, is turn, used 70'
of pipe - too far. That faucet connection makes earth easier
to obtain via other potentially destructive paths such as the
receiver. Notice lightning did not vaporize the connector -
which again demonstrates why the 8' conductor is bogus.

One final point. If the 8' conductor was required, then
lightning would melt solder joints on household water pipes -
causing house flooding. That faucet connection is wrong as
well as dangerous.

Jerry wrote:

w_tom · Guest

The earthing system for human safety shares components of
the transistor safety system. For human safety, code has been
significantly upgraded since 1990 to require all incoming
utilities use a common and dedicated earth ground. That
means, for example, the telephone and cable must connect less
than 20 feet to the same earth ground used by AC electric.
Furthermore, water pipe is no longer sufficient as an earth
ground. The code calls for a dedicated earth ground such as
the 8 foot ground rod.

Above is for human safety. For transistor safety, the
earthing system has additional requirements. For example,
that telephone and cable earthing connection should be less
than 10 feet, no sharp bends, no splices, not bundled with
other non-grounding wires, not inside metallic conduit, and
all wires meet at a common point on the earth ground.

Water pipe sharp bends and solder joint are undesirable for
transistor safety even though pipe will conduct and properly
trip circuit breakers - for human safety.

Provide lightning with a shortest electrical path from dish
to earth. That is the 30' wire that also must not have sharp
bends, etc. This so that little to no lightning need find
other paths to earth such as via coax cable and receiver.

If water pipe is at least 10 feet from the building into
earth, then that dish ground wire could route into building;
clamped right where pipe enters foundation. IOW water pipe
has no solder joints between ground wire clamp and earth.
This would also make a good earth ground for the dish.
Earthing wire separated from all other conductors by one foot
- more is preferred.

BTW, another ground wire jumper (6 AWG) connects both sides
of the water meter so that a meter change does not break water
pipe safety ground.

Of course water pipe, where it enters the building, is also
bonded to breaker box via a (typ.) 6 AWG bare copper wire.
That wire also clamped close to where water pipe enters
through foundation. Bonding wire to remove electricity from
water pipes; for human safety. That wire would then also
connect dish earth ground to the building's earth ground - via
breaker box. That common connection to water pipe meets
requirement of 810.21(J).

Fundamental - we earth for human safety (as defined by code)
and for transistor safety (earthing system enhanced beyond
what code demands). All this because we still don't build new
homes as if the transistor exists. Earthing being the most
critical component of a transistor protection system. Having
all earthings interconnected into a single point system is
demonstrated by wrong, right, and preferred examples from
utility in:
http://www.cinergy.com/surge/ttip08.htm

The way I read a previous post, the faucet was 70' from
where utility water entered the building. Since it is only
1.5 meters and damage occurred, then I am somewhat concerned.
Moving the wire to water pipe entrance does not improve
earthing as much as we would want. IOW I would be looking for
something else that might also compromise the earthing
system. For example, is utility water service completely
copper or did they replace a section with plastic?

Not something to worry about. But something worth
considering to make future damage significantly less likely.

BTW, we are discussing the secondary protection system. You
might also inspect your household primary protection system:
http://www.tvtower.com/fpl.html

Don't make this a hobby. But its a good excuse buy new
things from the local super hardware store - and to maybe
wield a big ass hammer on a defenseless thin rod. for some
reason, women don't like to have this fun.

Jerry wrote:

Jerry · Guest

Wow, I'm impressed, thanks for all the detail on this!!

I'm still a little puzzled about the lightning - the faucet connection is
right at the house, and happens to be 1.5m away from where the water pipe
enters the house. The breaker box is on the other side of the house, about
50' away, so it sounds like if I just bring the grounding wire inside the
house and connect it to the pipe, that would be an acceptable means -
although it's only 8 inches away.

Alternatively, I think I'd have to invest in an 8' grounding rod asap - I
guess it should be a 10' rod if 2' is above ground. But then I'd need a 50'
run of 6 ga wire...

And, to clarify, the conductor did get vaporized at the 2 male to male cable
connectors in that cable run

Thanks again! Hope I interpreted this right!

"w_tom" <w_tom1@hotmail.com> wrote in message
news:4381446D.341DF2F1@hotmail.com...

	STVTalk.com Forum Index -> Satellite TV	All times are GMT
Page 1 of 1