Lightning Strikes & Two Systems?

[Lone Gunman]

I've got the two systems that are listed in my signature. The Winegard dish is mounted on the north side of my parking area and the SAMI is mounted on the South side near the rear corner of my house. The Winegard system has been up and running since June of 2000. The SAMi has only been up about 2 years or less.


So here's the problem I have. This Winegard dish/system has NEVER suffered ANY damage from lightning strikes and believe me, in past years I've had some strikes that were VERY close. The whole time it was connected to my GI920 and now to my Openbox and AZBox receivers I have had ZERO problems with lightning.


The SAMI on the other hand has been a freaking lightning rod, for some unknown reason?? That thing has damaged more equipment than I care to count in it's short time up. Last year my new 24” TV got hit TWICE and the first time both receivers connected to that TV lost HDMI ports along with the LAN function on the Elite. I also lost a DMX 741s last year too. This year I've lost TWO DMX 741s LNBFs (second one today) and these two strikes were probably more than a half mile from my house as I didn't see a flash at all?


So after the incident last year I had an Eaton CHSPT2ULTRA Surge trap put on the 200 amp service box that feeds the circuit used by that system. That and I also have a surge protector type receptacle in that location that feeds everything there.


So this brings up the question of how those LNBFs are getting fried? My guess is that it's got to be coming from the receivers or the Vbox X that have a direct line attached to the electronics inside that LNBF, or is it?


Do any of you have ground wires attached to your dishes? Neither of mine do and neither had grounds on them in their previous installs either?


So anyone know how to stop this? These LNBFs aren't that expensive but this makes 3 that have been fried on that one install??


Any suggestions?

 

[primestar31]

That's a good one, I'm not sure, but I'd say there's some sort of "ground loop potential" induced currents of some sort going on. Not necessarily lightning itself. Personally, I'd hire a master electrician to see what he could find. Are you sure your electrical system for your house is even properly grounded with a rod? I bought one house where the wire had come off the rod. I reconnected it. I'd think in your case, an electrician would be good money well spent. Perhaps you can talk your home insurance agent into footing the bill?

I have NEVER grounded any of my systems, either 55 foot, and later a 70 foot antenna tower, 4 C-band systems over 30+ years, many various KU dish systems, NONE of them have been grounded with ground blocks, ground rods, nothing. I always thought it was stupid, because what's the difference between a tv tower or 15' tall c-band dish that's at ground potential, and a lightning rod on your roof at ground potential? Answer = NOTHING, they are the same thing! Only the tower is much higher, so is far more likely to get hit

I've never had anything damaged by lightening, and I've had some close hits.

 

[gabshere]

They used to make an online coax surge protector. I know most of the newer surge protectors also have them. Since your having problems. I would suggest to place another ground at the dish. ( provided your already grounded once like to the house grounding rod. I placed an extra at( grounding rod) the dish on mine. And had no problems.

 

[Lone Gunman]

Yup, a friend of mine is a Master Electrician and has been in the business 45 years. I worked for him part time for two years after I retired. He and I wired the house when I built it. There's TWO 8' ground rods, one at the electrical service entrance and another in the HVAC room to ground the OTA TV antenna I put on the roof a few years back. He was the one that installed that Eaton Surge Trap last year.

When the LNBF got fried today the power blinked off then back on in like 2 seconds and when the Openbox rebooted I got the dreaded "No Signal" from the LNBF. Everything else "seems" to be OK, just another fried DMX 741s!

The board inside those DMXes is isolated from the housing so the only way for electricity to get into it is through the coax? Wonder if there's a surge protector worth a damn that works with coax? I guess it's time for another Google search, hey!

EDIT: OK so someone posted while I was composing this one but yeah, I've already planned to sink another ground rod at the dish and will search for coax surge protectors.

Thanks

 

[johann12]

4 years ago a lighting hit the main coax for our cable TV ( that I had back then ) between my neighbors pole and my pole.
At my pole where the coax came down, the coax got up to flame. At the pole the coax goes under ground for about 35-40 feet to the cable box and all the coax from pole to the box was charred/burned up.
It stopped at the grounding block inside the cable box, where the grounding block is grounded to the main electrical grounding rod.
Non of my TV's and cable boxes where damaged. I lost my microwave though.

All my TV's, computer's, cable boxes back then, had surge protector power strips. Except my microwave.
So far I never lost any electronic equipment because of lighting, except that microwave, but a lot of folks around here lost them.

Here is the setup I have now. No more payed subscription.

OTA antenna 20 foot pole on top of house is grounded to pole to main electrical ground rod, bottom of pole ground block for coax and surge protector for amplifier. Coax going to cable box is hooked up to ground block again inside cable box before going into the house.
KU on top of house is grounded to main electrical ground rod. Coax to ground block in cable box.
C dish is not grounded yet but if I find extra time I will do so. But coax is grounded to ground block.
All my TV's, receiver, v-box and electronics have surge protector power strips.

A concreted in dish pole may not be a good ground. Concrete itself is a very poor electrical conductor, the moister in the concrete makes it a better conductor. But having the pole 3 foot in the ground makes a poor ground again, to note here ..a ground rod is 8 foot in the ground. If you painted the pole before you concrete the pole that makes it a poor ground since paint is a insulator.

A ground rod at the dish would better than nothing.
But,....you have to re-think that option.
A ground rod at the dish still could create a potential/voltage between dish ground rod and main electrical ground rod since the chemistry of the ground could be different and that could produce voltage or if lighting strikes there will be a big potential/voltage between the 2 ground rods. To overcome this small risk a ground wire between the 2 ground rods will eliminate that.

 

[Zeb128]

We took a close hit on Aug. 10th which hit our neighbor's tree approx.fifty feet from the house. The strike took out both DMX 741's, a V Box X, three Ku lnbs, an SG2100 motor, my new MicroHD , the 500GB hdd attached to it, as well as two other FTA recvrs attached at the time to those dishes, not to mention other things like the HDMI ports on one TV, the control board in the refrigerator, and washing machine...the list goes on.

The repairman who assessed the fried equipment for the insurance company told me that we were "pulsed" by the lightning strike, and regardless of the grounding we still would have suffered as much damage with or without the grounding we have and that includes one 4 foot ground rod at each of the 10 foot dishes as well as an eight foot rod at the grounding block at the cable entrance. The electrician who also inspected the damage told me that our ground system is more than adequate and had seen this type of damage before and explained it as a very sharp electromagnetic spike that destroys the most sensitive components. Example...my wife's Iphone, a wireless router, USB ports on a desktop computer.

So we have been sitting dead in the water so to speak, without any FTA, and until the insurance adjuster decides where to go with this. We will replace all this stuff but plan on using the inline surge suppressors providing they are not too lossy.

BTW...I notice that several sat vendors stopped selling the DMX741's. Have they been discontinued? If so, can anyone recommend a replacement for these?

 

[johann12]

When the LNBF got fried today the power blinked off then back on in like 2 seconds and when the Openbox rebooted I got the dreaded "No Signal" from the LNBF. Everything else "seems" to be OK, just another fried DMX 741s!

It is weird that you mentioned blinking power and I had an hunch but I never gave much thought until now.

When I set up my 7 1/2 foot c dish a while back I had my s10 and tV outside at the dish to make the adjustments. I ran an extension cord from inside the house to the outside.
My wife un-plugged the cord for 1 second by accident and plugged it right back in again while I ran a scan.
After the s10 booted up my BSC 621 d did not work anymore either.
I had to get a replacement for it.

Last week when I set up my 10Foot dish she done it again, but she did not plug it in right away.
I waited 1 minute to power the s10 up again and I had no problem.

I will build me a box where the power will stay off when the power flickers until I press a button.
It could be easily made with an relay and a momentary switch.

Makes me wonder If you had problems with flickering power before that could had damaged the other equipment.

 

[Lone Gunman]

It is weird that you mentioned blinking power and I had an hunch but I never gave much thought until now.

When I set up my 7 1/2 foot c dish a while back I had my s10 and tV outside at the dish to make the adjustments. I ran an extension cord from inside the house to the outside.
My wife un-plugged the cord for 1 second by accident and plugged it right back in again while I ran a scan.
After the s10 booted up my BSC 621 d did not work anymore either.
I had to get a replacement for it.

Last week when I set up my 10Foot dish she done it again, but she did not plug it in right away.
I waited 1 minute to power the s10 up again and I had no problem.

I will build me a box where the power will stay off when the power flickers until I press a button.
It could be easily made with an relay and a momentary switch.

Makes me wonder If you had problems with flickering power before that could had damaged the other equipment.

I guess one could install an uninterruptable power supply to see if that eliminated the problems but dayumn those things can be expensive! Well, I guess 3 of those DMX LNBFs are getting expensive also though. Hummmm.........................

Thanks for sharing that!!

 

[jimdandyvi]

Nearby lightning will most likely overwhelm any surge protector money can buy. They are worth having to protect from other electrical spikes.

Having a whole house surge protector and individual surge protectors through out the house may actually give you less protection than just having the whole house protection.

Instead you might want to use isolation transformers where ever you have a number of electronic devices. They help to stabilize voltages which reduces wear and tear on power supplies and they also slow down voltage spikes giving more time for your surge protector to react and shunt spikes and surges to ground.

Finally have your ground tested. You may not need a new rod, but find that by keeping the dirt around the rod moist will reduce the resistance and improve your ground. This is important since so many areas are experiencing a drought this summer. Also test the ground at key outlets particularly if your house was built using the metal conduit for the ground corrosion may have significantly reduced its effectiveness as well as loose joints.

 

[westom]

So this brings up the question of how those LNBFs are getting fried? My guess is that it's got to be coming from the receivers or the Vbox X that have a direct line attached to the electronics inside that LNBF, or is it?

Answer starts with what was taught in elementary school science. Lightning is an electrical current the flows from the cloud, through air, (through a wooden church steeple,) to earthborne charges miles away. Wood is an electrical conductor. But not a very good conductor. So it creates a voltage when conducting a current called lightning. Voltage times current is high energy. Church steeple damaged.

Franklin connected a lightning rod to what does protection. The superior (low impedance) conductor creates near zero voltage when conducting a current (ie lightning). Near zero voltage times current is near zero energy. No damage.

AC electric wires far down the street are a direct connection incoming to every household appliance. Which appliance is damaged? Only ones that make a better connection to earth. Anything that would attempt to stop or block that current only increases voltage. Voltage times current is destructive energy; damage to selected household appliances.

Informed consumers earth that current where it might enter the building. Either via a protector or via a direct wire connection (the term 'low impedance' is critical). No protector does protection. How conductive is that connection to earth (not reistance; impedance)? If that connection ceates a near zero voltage, then (near zero voltage times current) no damage.

Apparently you have created a better connection to earth destructively via one dish. Apparently you don't have a single point earth ground. Incoming on AC mains, through the house, outgoing via that dish connection and LNB, and into earth. One of many possible explainations. But in every scenario, a best connection to earth is destructively via electronics.

Do for appliance protection similar to what Franklin did for church steeple protection. No lightning rod or protector does protection. Protection means you have earthed that current before it even enters the building (or LNB). The single point earth ground. All solutions start with an analysis of your earthing system.

Safety ground inside homes is not earth ground. To lightning, that safety ground is just another conductor like any other AC electric, telephone, or satellite dish cable.

Treat each dish as if a separate structure. Each dish must have its own single point earth ground. Any wire that 'enters' (ie coax cable) must connect to that earth ground. Only then does the LNB not become a destructive connection to earth.

All wires must be earthed before entering the building. Any wire entering unearthed compromises protection. Again, the single point earth ground. A utility demonstrated the 'low impedance' concept (good, bad, and ugly earthing) (unfortunately the system needs your to reconstruct the URL):
www. duke-energy dot com slash indiana-business/products/power-quality/tech-tip-08 dot asp

Disconnecting earthing only makes damage easier. No just any earthing. Each of four words has significance: single point earth ground.

Protectors are simple science. No protector does protection. A wire to earth ground is better. A protector only does what a wire might do when the incoming utility cable connect be earthed directly. Single point earth ground (an art) defines protection and should have most of your attention.

BTW, most of this is unknown to electricians. Electricians are taught concepts relevant to code only for human safety. Transistor safety means the earthing must also exceed what code requires. In your cases, all coax cables to all dishes must enter at the service entrance. Because the earth ground connection must exceed what electricians are taught (ie 'less than 10 foot' connection. no sharp wire bends, ground wire not inside metallic conduit, no splices, etc). Earthing is an art that exceeds what is done to only meet code.

 

[rv1pop]

Being in lightning AND fire country ... I agree with what Westom said -- mostly -- might be over many peoples heads. And some to add.... The power company "ground" is to provide another harmonics canceling path for energy between the power plant / substation / industrial / residential locations. In farming areas now so many animals have being killed around barns, etc. they are making common potential areas with underground grids (welded fence wire here) buried about 6" to a foot down and all tied together under the barns (or tied to the rebar in the concrete) and some distance away from the buildings. Then they run bare (usually galvanized bare steel) wire along fence lines, underground, with taps up to the barbed wire and wires along the paths back to the main feed ground at the power pole. There is something like this in the code now.
Since the cattle seem to like to walk the fence lines they often make a small fire break along the fence line and a lightning fire may burn under a fence for hundreds of feet until the energy from the lightning dissipates. Some argued that would make more fires, but it SEEMS that these fires flash fast enough that they seldom spread.

With all that information - we still do not know much! But I would tie all outside ground points together and to the house ground with BARE wire or metal conduit if I was concerned. I am using old steel fence wire as a messenger / locator in my burial trenches with the ends twisted to make it a continuous 'conductor', but it was not intended to be a ground to begin with....

 

[sergei]

Do any of you have ground wires attached to your dishes? Neither of mine do and neither had grounds on them in their previous installs either?

On my system which is eight dishes I have no grounds on any of the dishes, I only use grounding blocks for the cables which are then grounded.

 

[turbosat]

Lone, I don't think it's the SAMI, most likely the location it is in. No lightning strikes so far on my sami, it's been in the same place since about 1997, and looks, to me, to be in a great location to catch a strike, lol. We've had some great electrical storms over that time too. Maybe just have been lucky so far!

 

[Skyv1]

I've been told that sometimes the "ambient static electricity" associated with lightening can overwhelm the sensitive amplifier in an LNB(F), causing burn-out.

 

[Lone Gunman]

I only use grounding blocks for the cables which are then grounded.

Say, would you happen to have a part number or picture of those "Grounding blocks" that you are using?

A little update here too, I just switched over to a Ku TP on that SAMI system and it works on Ku, not on C. Was thinking the switch may be bad but since it requires 22Hz to make the switch to Ku, then that theory is shot. Since I've got an external 22Hz switch in my spare parts I may just put it in to double check it though.

Ennywhoot, there's a UPS and an 8' ground rod in this system's future! Anyone have a suggestion on the UPS?

 

[westom]

Anyone have a suggestion on the UPS?

Quite simple. Destructive surges are hundreds of thousands of joules. The only UPS that addresses your problem will state in its spec numbers how many hundreds of thousands of joules it can absorb.

Be extremely cautious. Many will recommend a UPS only rated at hundreds of joules. Near zero protection. Recommended if critical numbers - manufacturer specification numbers - were ignored.

Ground blocks such as GRB-1 and GRB-2 at (system requires you to reconstruct URLs):
www dot qintar dot com slash html/tv/f-con.htm
or
www dot dbsinstall dot com slash N-images/Whatis/Driploop-1.jpg
may even cost as much as $4 in Lowes or Home Depot.

 

[SimpleSimon]

I've been told that sometimes the "ambient static electricity" associated with lightening can overwhelm the sensitive amplifier in an LNB(F), causing burn-out.

Bingo. Someone finally came up with the REAL reason to ground your gear.

Noting back to someone that said the LNBF wasn't attached to anything - well, it IS. The feedhorn probe will pick up static and a discharge can fry the beast.

Making sure the dish and the LNBF (via coax shield) are at the same potential is important. Beyond that, the arguments abound!
Usually, more than one "side" is right - depending on where you are.

Me, I live in the #2 lightning strike county in the USA, in the land of Pikes Peak granite. It's almost impossible to drive an 8' rod anywhere - but when that 4'er mashes directly into bedrock, I'd say you're "grounded". We rarely lose outdoor equipment - even with an extremel lightning hazard.

Indoor stuff on the other hand gets hit all the time - in houses that have wiring faults or don't use REAL surge protectors - often daisy-chained. Me, I run UPS behind 3000+ joule surge protectors. The electric company has spent a lot of money on lightning breakers, too - they work quite well.

P.S. Ground blocks are nothing more than a way to connect a wire to the coax shield. Electrically, they are the same as soldering a wire to the shield, but a LOT easier. They are NOT the same as a "lightning protector" which is usually a gas discharge bulb.

 

[sergei]

Say, would you happen to have a part number or picture of those "Grounding blocks" that you are using?

There just standard Quad cable ground blocks that are at electronic stores or on Ebay which are all grounded to my house panel in the basement. One thing I didn't mention is I also have Spike Arrestor ( SA-1F ) on all my dishes LNB & LNBF's and on all the receivers inputs.