Earthing Satellite

peter_dublin

Hi All.

We need to engage an electrician to earth a satellite system, currently we have two sky dishes (one per building) and a large satellite feeding a multiswitch and also which has multiple units sharing a single LNB.

Currently there is no earth bonding at all and I'm trying to see what our options are, prior to now all lnbs / dishes where only used by a single unit so there was not multiple units on a single lnb but this has now changed and we need to sort it asap.

Any advise on what we should be requesting, specifically what offers the best protection rather than cheapest.

Thanks

Par1

http://www.lightningprotection.ie/about-us/

2011

peter_dublin wrote: »

Hi All.

We need to engage an electrician to earth a satellite system, currently we have two sky dishes (one per building) and a large satellite feeding a multiswitch and also which has multiple units sharing a single LNB.

Currently there is no earth bonding at all and I'm trying to see what our options are, prior to now all lnbs / dishes where only used by a single unit so there was not multiple units on a single lnb but this has now changed and we need to sort it asap.

Any advise on what we should be requesting, specifically what offers the best protection rather than cheapest.

Thanks

Hi Peter,

Is your concern that lightning may strike a satellite dish?
I have never seen lightning protection provided to a dish before.
If it were to be installed I imagine that it would be a short piece of copper tape (3 x 25mm) connected from the dish to the structural steel or lightning protection system (which ever is closest or most practical).

However the normal procedure is that buildings over a certain hight are risk assessed to determine the probability of a lighting strike. Based on this some sort of a lightning protection system may be installed. Normally lightning conductor rods known as "air terminations" are installed at the top of buildings to encourage the lightning to strike them to reduce the damage to the building itself. The tip of these rods are generally the highest point of the building. The intention is that these rods provide a protective zone under them. You may find that your dish is within this zone. You can read about it here.

However be under no illusion, if a satellite dish receives a direct lightning strike it will be toast regardless of the protection installed.

Is there a reason that you have a particular concern?
Do the buildings have lightning protection installed at present?
How tall are the buildings (or how many floors)?
Are there taller buildings near by?

peter_dublin

2011 wrote: »

Hi Peter,

Is your concern that lightning may strike a satellite dish?
I have never seen lightning protection provided to a dish before.

However the normal procedure is that buildings over a certain hight are risk assessed to determine the probability of a lighting strike. Based on this some sort of a lightning protection system may be installed. Normally lightning conductor rods known as "air terminations" are installed at the top of buildings to encourage the lightning to strike them to reduce the damage to the building itself. The tip of these rods are generally the highest point of the building. The intention is that these rods provide a protective zone under them. You may find that your dish is within this zone. You can read about it here.

However be under no illusion, if a satellite dish receives a direct lightning strike it will be toast regardless of the protection installed.

Is there a reason that you have a particular concern?
Do the buildings have lightning protection installed at present?
How tall are the buildings (or how many floors)?
Are there taller buildings near by?

Hi.

Each apartment has its own separate ESB supply. So we can concerned about shock possibility due to them being on different phases. So they would be linked via the LNB or Multiswitch.

Thanks

Par1

peter_dublin wrote: »

Hi.

Each apartment has its own separate ESB supply. So we can concerned about shock possibility due to them being on different phases. So they would be linked via the LNB or Multiswitch.

Thanks

Sounds like you need surge protection with O/L cutouts. ESB phase selection should have no bearing on your problem, i dont see how the phases will ever meet?

2011

peter_dublin wrote: »

Each apartment has its own separate ESB supply. So we can concerned about shock possibility due to them being on different phases. So they would be linked via the LNB or Multiswitch.

Peter, is a lightning strike your concern?
If not what is your concern?

Par1

2011 wrote: »

Peter, is a lightning strike your concern?
If not what is your concern?

He seems to want to earth the satellite system from OP. Im with you on this 2011....if lightening hits the satellite then no earth in the world is going to save it as LNB will fry for starters

peter_dublin

2011 wrote: »

Peter, is a lightning strike your concern?
If not what is your concern?

Primarily its the lack of any earth bonding at all and something becoming live. Such as discussed here:

http://www.satellites.co.uk/forums/threads/electrical-safety-%E2%80%93-earth-bonding.88258/
http://www.satcure.co.uk/tech/multiswitches.htm

Thanks

2011

peter_dublin wrote: »

Primarily its the lack of any earth bonding at all and something becoming live. Such as discussed here:

http://www.satellites.co.uk/forums/threads/electrical-safety-%E2%80%93-earth-bonding.88258/
http://www.satcure.co.uk/tech/multiswitches.htm

Ok, I see what you are talking about, from your second link:

If a multiswitch is feeding separate dwellings, which may be on different mains power supply phases, it is essential to get a qualified electrician to "earth-bond" the multiswitch. He will understand what this means and will know how to do it. Please consult him first, to ensure that the multiswitch is installed reasonably close to a suitable earthing point. As most electricians are not qualified to install signal cables, please do this yourself (using our information) or employ a qualified aerial/dish installer to install the multiswitch and cables.

This is known as "equipotential bonding". I assume that the multiswitch is installed in a landlords area? If so is it near a distribution board (fuse board)?
It sounds like the multiswitch needs to be connected to a local earth bar (not the dish itself). I would imagine that this will be a simple task and shouldn't cost much.

peter_dublin

2011 wrote: »

Ok, I see what you are talking about, from your second link:



This is known as "equipotential bonding". I assume that the multiswitch is installed in a landlords area? If so is it near a distribution board (fuse board)?
It sounds like the multiswitch needs to be connected to a local earth bar (not the dish itself). I would imagine that this will be a simple task and shouldn't cost much.

Thanks, yes this is what I mean, from looking into it online it seems generally the multiswitch is earthed and also the individual coax cables are also earthed. It is just a case of having an F connector earth plate put inline of the cables and brought to a fuse board. The multiswitch is actually run off one of the units supply.

From reading online I taught we may have to install an earth rod as the large dish is 20m from the building.

Thanks again.