Why are dishes not earthed

[fmak]

Here in Cyprus we have largish dishes and big thunderstorms.

Why are dishes not separately bonded to earth for safety?

[dig deep]

If they are made of metal, and grounded then the microwaves will take the easy way, instead of bouncing they will be grounded

[2cvbloke]

Don't forget you'd also have a nice big lightning conductor, the very reason why I won't ground my TV aerial cable even though there is a voltage float which can cause a nasty zap (probably my dodgy TV causing it!!!)...

[PoloMint]

Even if the dish was earthed I doubt it would stop a direct hit frying whatever receiver was connected to the LNB. When radio aerials are grounded a direct hit on the aerial still causes the radio to burn out, just not as dramatically or extensively (in terms of connected equipment) than if it wasn't earthed.

[2cvbloke]

Even if the dish was earthed I doubt it would stop a direct hit frying whatever receiver was connected to the LNB. When radio aerials are grounded a direct hit on the aerial still causes the radio to burn out, just not as dramatically or extensively (in terms of connected equipment) than if it wasn't earthed.

You should have seen the inside of a Time PC that I saw that took a full whack through the phone line, the parts between the modem connectors to the chassis were fried to a crisp...

[snap]

My system took a hit from lightning one week ago. I heard a loud crack inside the house. I had disconnected my Sky+, routers and computers.
My Pace 2600 was still connected when the bolt struck. It survived, (Pace once told me that their boxes have some lightning protection) but the LNB did not. Only one polarity on one of the four outputs was working. There are four cables buried leading from the dish, about 25 metres. The dish mounting is earthed, as it is bolted into the ground. The dish is a fibreglass Prodelin.
There are two earth terminals on a quad Invacom. Would it have made any difference had the LNB been earthed?

[PoloMint]

Are there signs of physical damage on the LNB? If not then it probably didn't take the hit, but instead was damaged by the effects of one nearby. As for the grounding, I'm not sure if that would have helped or not.

[2cvbloke]

My system took a hit from lightning one week ago. I heard a loud crack inside the house. I had disconnected my Sky+, routers and computers.
My Pace 2600 was still connected when the bolt struck. It survived, (Pace once told me that their boxes have some lightning protection) but the LNB did not. Only one polarity on one of the four outputs was working. There are four cables buried leading from the dish, about 25 metres. The dish mounting is earthed, as it is bolted into the ground. The dish is a fibreglass Prodelin.
There are two earth terminals on a quad Invacom. Would it have made any difference had the LNB been earthed?

The lightning probably Earthed itself through the buried cable sheath (it's pretty powerful stuff!!!), so you might want to dig up the cable and check it's condition incase the sheath is fried and the cable(s) gets waterlogged....

As for the LNB, personally I wouldn't think it would make any difference if it was grounded, as if it was struck again it would probably get fried anyway, you'd probably have better luck setting up a lightning rod nearby and hope that it attracts any lightning away from your dish...

[dig deep]

I think that it is the EMP that kills the lnb´s so no lightning rod in the world will help the lnb, but (perhaps) the reciever will survive

I have a huge metallic construction just some 50 meters from my house. It is grounded and when there is a thunder close to it the bolt goes into that monster. Still, last time we had a hit it fried my new fancy telephone and that was the EMP

[2cvbloke]

I think that it is the EMP that kills the lnb´s so no lightning rod in the world will help the lnb, but (perhaps) the reciever will survive

I have a huge metallic construction just some 50 meters from my house. It is grounded and when there is a thunder close to it the bolt goes into that monster. Still, last time we had a hit it fried my new fancy telephone and that was the EMP

EMP is a nightmare, especially for fancy flash modern computerised cars...

I've replaced many computer parts (not my own, I always unplug during a storm) due to EMP caused by lightning, usually it's just the PSU's, but most cases it's also the modem (dialup usually, not sure how many people use them these days), it was only that Time PC I ever saw that had taken a direct strike through the phoneline...

[Topper]

it was only that Time PC I ever saw that had taken a direct strike through the phoneline...

The lightening did everyone a favour then

[2cvbloke]

The lightening did everyone a favour then

Of course...

I nearly got the case (I wanted it just cos it had been lightning damaged) but at the last moment the customer wanted it back even though everything inside was dead...

[dig deep]

About lightning

Can U believe that there was this guy in the US playing with kites and keys during a thunder storm ? and that he did survive to tell others to try it

Some did not make it

We are talking BIG Amps here and some Volts as well.

Take care next time, don´t stand under a tree or a metallic pole, stay inside away from the walls and the elextric outlets

U never know when and how it will struck Thor is dangerus/ still /

[2cvbloke]

About lightning

Can U believe that there was this guy in the US playing with kites and keys during a thunder storm ? and that he did survive to tell others to try it

Some did not make it

We are talking BIG Amps here and some Volts as well.

Take care next time, don´t stand under a tree or a metallic pole, stay inside away from the walls and the elextric outlets

U never know when and how it will struck Thor is dangerus/ still /

Those who play with lightning are, well, not the fittest (as in survival of)...

I always usually cower in a corner of the house where there's no pipes or cables/sockets to discharge through me, but on occasion I do like to look out through an open skylight window (tha is assuming I have access to one!!!)...

[benidormgary]

..... but most cases it's also the modem (dialup usually, not sure how many people use them these days)...

Yep-went down that road last year

[2cvbloke]

Yep-went down that road last year

I hope you have a surge protector now (as Kirk would say, you fixed the barn door after the horse has come home!!! ), but the easiest surge protection is to unplug everything you value as useful before a storm is close enough to damage anything...

[Rd100]

All my dishes are earthed my fixed dish on 28.2/28.5 east for Sky HD and my 1.2m andrews is earthed so is my uhf tv aerial and so will my 1.8m prodelin when i put it up.

If a dish is not earthed along with the coax cable it is not installed correct,

Here in Cyprus we have largish dishes and big thunderstorms.

Why are dishes not separately bonded to earth for safety?

[Rd100]

Yes the lnb would have been ok if you did earth it, If some one else installed the dish for you you can claim a replacement lnb from them as the installation was not done correct,

All lnb feeds cables should be eathed useing a ground block,

My system took a hit from lightning one week ago. I heard a loud crack inside the house. I had disconnected my Sky+, routers and computers.
My Pace 2600 was still connected when the bolt struck. It survived, (Pace once told me that their boxes have some lightning protection) but the LNB did not. Only one polarity on one of the four outputs was working. There are four cables buried leading from the dish, about 25 metres. The dish mounting is earthed, as it is bolted into the ground. The dish is a fibreglass Prodelin.
There are two earth terminals on a quad Invacom. Would it have made any difference had the LNB been earthed?

[benidormgary]

I hope you have a surge protector now ...

I had one then.......,but I forgot that you need a seperate kind to deal with the phone- line!

[2cvbloke]

I had one then.......,but I forgot that you need a seperate kind to deal with the phone- line!

As in one with phoneline In and Out sockets in it?

I haven't got one myself actually, but then again, I don't have a phoneline at the moment, and my UPS's have surge protection built in (I think... ), so I'm OK if I'm not in during a storm (and I hope I'm not out during a storm either!!! )....

[rolfw]

Yes the lnb would have been ok if you did earth it, If some one else installed the dish for you you can claim a replacement lnb from them as the installation was not done correct,

All lnb feeds cables should be eathed useing a ground block,

I disagree there RD, as the LNB would be wiped out before anything got to the earth bond, that is simply there to offer marginal protection to the inside equipment.

[2cvbloke]

Wouldn't surprise me if Sky suddenly deemed LNBs to be a consumable alongside the likes of batteries....

[snap]

With global warming, this kind of event is probably going to be more common.
In the space of 10 months, from two lightning strikes near to the house, I've lost:
A nearly- new Pace Sky+ Digibox
An ADSL wireless router
A quad Invacom LNB
Two power supplies
We are 3000 feet up in the mountains just outside Madrid, near the top of a hill. I am now taking this problem very seriously. I did the installation myself, and had not even thought about lightning before.
My power supply to the digiboxes is now a UPS (Uninterruptible Power Supply). These come with surge protection for both telephone and power lines. I would recommend one of these to anyone in parts of Europe with unreliable electricity networks, or a weak Astra 2 north beam signal.
When I came to replace the LNB, one of the cables was blackened near the F connector. I am still trying to work out where the main surge came from, either the ground or through the mains. the first strike was probably passed by the phone line, as it blew the router and the Sky+, which was connected to it. (I use VOIP for Sky box office)
If the best opinion is to earth the cables and LNB, then I'll do it straight away, there are still storms about.

[PoloMint]

I agree with Rolf, I really don't see earthing the LNB as doing much to save it.

Unplugging everything in a storm is the best option IMO, but not always practical I know, and won't do much for the poor LNB.

Everything else is might reassure you and offer some protection, but don't count on it. UPSes aren't even that reliable with a direct hit to the power line, however but the makers might offer some insurance on damaged equipment connected to the UPS.

[dig deep]

U can´t secure the LNB´s from the EMP
(well, U can if U hide them inside a bottle covered with thin foil)

So, U better pray next time Thor visits Your area