07-07-2023, 12:22 PM
Hi Scott
I would go ahead with the earth stake. It will provide an earthing path. You are fortunate in the soil type you have as it has a lower resistivity and as a result it is easier to obtain a low earth resistance then say in sand.
An alternative to earth rod electrodes is strip electrodes. In simple terms it is an electrode laid horizontally a short distance below ground level. They are not as effective as vertical electrodes as they can only make use of the soil below their level. However they provide an alternative option that can be useful suitable in circumstances where vertical electrode are not very suitable or viable. One can of course use a combination of both. One option is to run a number of strip electrode radials out from an earth stake. If so, the strip electrodes need to go some distance away from the earth electrode so as to get away from the proximity of the vertical electrode. Possible use for old guy wires?
Basically you have to contend with the earth system resistance/impedance and the resistance/impedance of the cable used to get to it. The way RF sees the earthing systems is likely to be different to that seen by lightning as the frequencies involved are somewhat different. Impedance will be of greater importance with RF as the cable length comes into play with regards to wavelength.
From the point of view of lighting protection you have to deal with a short pulse of extremely high current origination from a extremely very high voltage source. The high voltage means it can jump over locations that present obstacles to it. The high voltage and very high current involved means that you are dealing with a short pulse of very high energy. This requires heavy cabling and strong fixing for the cabling to cope with the heat and forces involved in the event of a direct lightning strike.
Peter's article deals with achieving the connection to the actual earthing point from the RF point of view.
The important thing is to have all the electronic equipment earthed together so that the potential difference between it is kept as low as possible. During a lighting strike any difference between the equipment will translate into a voltage difference and if high can have an detrimental impact on the equipment. Now if the equipment location is some distance from the earthing electrode system the equipment will go up in voltage with reference to the local earth. If this is low it is not a problem but can be if it is referenced to a remote earth as the local earth voltage will rise above the "real" earth point due to its earth resistance as the remote earth will be at the "real" earth potential.
73
Igor
I would go ahead with the earth stake. It will provide an earthing path. You are fortunate in the soil type you have as it has a lower resistivity and as a result it is easier to obtain a low earth resistance then say in sand.
An alternative to earth rod electrodes is strip electrodes. In simple terms it is an electrode laid horizontally a short distance below ground level. They are not as effective as vertical electrodes as they can only make use of the soil below their level. However they provide an alternative option that can be useful suitable in circumstances where vertical electrode are not very suitable or viable. One can of course use a combination of both. One option is to run a number of strip electrode radials out from an earth stake. If so, the strip electrodes need to go some distance away from the earth electrode so as to get away from the proximity of the vertical electrode. Possible use for old guy wires?
Basically you have to contend with the earth system resistance/impedance and the resistance/impedance of the cable used to get to it. The way RF sees the earthing systems is likely to be different to that seen by lightning as the frequencies involved are somewhat different. Impedance will be of greater importance with RF as the cable length comes into play with regards to wavelength.
From the point of view of lighting protection you have to deal with a short pulse of extremely high current origination from a extremely very high voltage source. The high voltage means it can jump over locations that present obstacles to it. The high voltage and very high current involved means that you are dealing with a short pulse of very high energy. This requires heavy cabling and strong fixing for the cabling to cope with the heat and forces involved in the event of a direct lightning strike.
Peter's article deals with achieving the connection to the actual earthing point from the RF point of view.
The important thing is to have all the electronic equipment earthed together so that the potential difference between it is kept as low as possible. During a lighting strike any difference between the equipment will translate into a voltage difference and if high can have an detrimental impact on the equipment. Now if the equipment location is some distance from the earthing electrode system the equipment will go up in voltage with reference to the local earth. If this is low it is not a problem but can be if it is referenced to a remote earth as the local earth voltage will rise above the "real" earth point due to its earth resistance as the remote earth will be at the "real" earth potential.
73
Igor