Grounding dishes

[KernowMan]

Do you have to ground a satellite Dish as I am a discussion with my brother and he says that you have to ground the dish

Any help would be grateful

Cheers

 

[Channel Hopper]

Where is the dish sited, on your property ?

 

[william-1]

It depends if fixed to the side of a wall it may be a good idea to earth it if it is made of steel,
My dishes are on a pole ground mounted but as one is made of aluminium it does not matter,
What material is your dish made of is a plastic composite ?

 

[KernowMan]

Made of steel and mounting on a wall

 

[KernowMan]

Should I ground it to the Houses ground?

 

[Analoguesat]

Knock a grounding rod into the soil under the dish & run some thickish earth cable from the dish mount to the rod.

 

[KernowMan]

Would surge protector for the LNB work as well as the grounding rod?

 

[Analoguesat]

Ive never heard of a surge protector for an lnb. At the end of the day the dish is extremely unlikely to get hit by lightning unless its exceptionally exposed in a lightning prone location. And if lightning hits the house or immediate area a fried Eumetcast system is going to be the least of your worries.

 

[KernowMan]

https://cpc.farnell.com/slx/19146hc...I2P4W9on1Pe55CkCGzqxoBE854u56010aAizpEALw_wcB

 

[jeallen01]

.. And if lightning hits the house or immediate area a fried Eumetcast system is going to be the least of your worries.

Absolutely - all the cables and kit would fry and then catch fire, as then might the house!

OTOH, it's extremely rare for lightning strikes in the UK to hit domestic properties because a) large strikes are relatively extremely rare in the UK , & b) they are more likely to hit higher altitude and largely wooded areas, and/or large/tall buildings (especially the metal-framed ones!), because the strikes are "attracted" to the easiest/lowest resistance/impedance paths to ground - and trees and large buildings provide those far better than normal domestic buildings (unless, of course, one lives in a modern block of flats or a modern factory-built structure!)

AND, of course, the likelihood of strikes depends on where one lives - this shows some historical UK strike-location data The UK's lightning hotspots revealed on a map

 

[Sleepingwiththefish]

Thunderstorms are not very common here, but sometimes seems like thunderseason, one after another, with very powerful lightning strikes, is not uncommon a house get hit directly or just a few meters away (on trees).

I had many fried equipment in the past, earth grounding seem useless for those strikes, also surge protectors, killing power to the house would only help a bit (for keeping grid surges out), but powerful strikes always seem to 'energize' any cables and then anything sensitive connected will 'blow'.
The last one I remember, a washing machine, control module burned out completely. (just for beeing connected to the wall, but the power was disconnected)
So, the only thing that seems to work for me is disconnecting everything, still with a direct powerful hit there's no escape...

And yes, modern large buildings are more likely to get hit but provide much better protection (as they provide many low resistance paths to the ground...)

 

[jeallen01]

@TonyilCapo

Since you are in Portugal which is Iberia, TBH (sadly!) that country is far more prone to lightning strikes than we (& that includes the OP) are in the UK - looks like you might need permanently-grounded "spacesuits" to even survive at some times of the year

 

[Analoguesat]

When I first went onine 20 years ago (dial up days for you youngsters!) I had 2 modems zapped. Our phone lines at the old gaff were on poles running along the valley and ground strikes on the hills in the area induced enough current onto the phone wires to destroy an unprotected modem. After replacing them at about 70 quid a time I bought a surge protected 4 gang adaptor - that eventually got fried too although the modem survived! The power side still worked - just the phone line protector fried.

I eventually decided they were just expensive fuses as their static induced death meant my computer equipment survived

 

[Terryl]

I would ground (or Earth) any RF system, it will protect you, and help keep unwanted RF from the outside from getting into the system through the coax shield.

 

[PaulR]

Grounding will bleed away any static build-up. Whether that's actually necessary is another question!

 

[jeallen01]

Grounding will bleed away any static build-up. Whether that's actually necessary is another question!

In addition, it will bleed away any minor (but cumulative!) leakage currents coming back down the cables from the settop boxes in the house - had a few minor "nips" from those in the past.

Therefore when I replace the existing, probably faulty (seems to have "lost" a few LNB inputs!), 10-way DiSEqC switch with the EMP 16-1 one that I bought at Xmas, I will be added a linking cable from that to one of the sat dish posts which is buried in the ground - should sort that issue!

 

[Fisty McB]

Lightning is a rare occurrence in my neck of the woods, even a rather "thundery" year would see just barely more than a handful of events. And when it does occur it is very likely to be "sheet" lightning that discharges in the clouds. But "fork" lightning can happen on quite rare occasions, I was once out in the open when I seen the peak of a mountain a few miles away that has a couple of towers on it being struck several times in a thunderstorm. Back when I was a teenager a school friend was very unfortunate in that his house was struck by lightning, setting the roof on fire but thankfully not causing any structural damage beyond that, I think they traced the strike to the metal hot water tank - with dark humour myself and a few other friends blamed it on the fact (coinciding that his parents are quite the committed Catholics) that the last three digits of the phone number for the house was 666!

But aside from that freak event, because of its rareness I've never seen a domestic aerial installation (terrestrial or satellite) in a 80km radius be grounded for lightning protection - and to be honest if a direct lightning strike hits a dish or terrestrial aerial, pretty much any additional grounding on the installation will be as useful as a chocolate teapot. What might be of benefit to such grounding is to help drive current surges from nearby strikes to earth to give you a better chance of your connected electricals not being damaged. That said, I've read conflicting reports about the usefulness of surge protectors placed in line with coax cabling.

 

[Channel Hopper]

I have a pair of surge protectors in my box of bits, they have been there since the last millenium and I doubt they would protect anything struck by lightning, even if they were installed.

They are probably rather lossy at certain frequencies, if I get a few minutes spare I'll run one up with the analyser.

 

[Terryl]

Surge protectors or true lighting arrestors, there is a difference.

A surge protector can be used for protection from lighting as once the trigger voltage is reached it will direct the excess voltage to ground via the household grounding system or a true Earth ground like a ground rod, these types normally use what is called a MOV, (Metal Oxide Varistor) the MOV can be set (internally) to trigger at any voltage level, and are normally directly connected across the incoming AC power circuits to ground.

A true lighting protector for an RF circuit uses a gas discharge tube that is connected to the incoming coax, one end directly connected to the center conductor (or conductors) the other to ground, these are normally used on outside circuits and will trigger instantly when lighting hits the circuit under protection, and are meant to direct the lightning way from the structure it's protecting, thus helping to keep it outside the building.

In some lighting prone areas they are a requirement on any metal antenna structure, and also used in conjunction with an internal surge protection system, in the broadcast industry we had to use one on every antenna mounted on the tower or other structure. (except for the big AM radio towers, they used a lightning ring)

Now dont confuse the ground blocks used on antenna systems using coax to deliver the signals, these are NOT lightning protectors or surge protectors, all they do is ground the shield (or shields) of the coax, they have no internal circuitry (MOV's or gas discharge devices) to direct anything to ground from the center conductor, all they do is ground the coax shield.

 

[a33]

Now dont confuse the ground blocks used on antenna systems using coax to deliver the signals, these are NOT lightning protectors or surge protectors, all they do is ground the shield (or shields) of the coax, they have no internal circuitry (MOV's or gas discharge devices) to direct anything to ground from the center conductor, all they do is ground the coax shield.

Absolutely true, "earthing" is quite something different than lightning protection.
So what does KernowMan want to know: earthing, or lightning protection? Or both?

Greetz,
A33