Earth Rods
Driving Options and Driving Depth of Earth Rods
Earth Rods
Earth rods usually consist of composable single rods with a length of 1.5 m. DEHN earth rods have a self-locking coupling with bore and pin.
Advantage of this construction is that the coupling locks automatically during the driving process, thus implementing a mechanically high-strength and electrically safe connection. Additional work steps such as screwing are not necessary.
Different types of impact tool are used to drive in the earth rods. Driving-in should be carried out at 1200 blows/min. At a considerably higher blow rate the power usually is not sufficient to reach the required depth with the earth rod. At a too low blow frequency as typical for compressed-air driven hammer tool, the blow power often is too high and the blow rate too low.
The own weight of the driving hammer should be ≥ 20 kg.
The possible driving depth of earth electrodes depends on the geological conditions. In light soil areas, e.g. in coastal areas or in wetlands, depths of 30 m to 40 m can be reached. In extremely heavy soils, e.g. sandy soils the driving depth often is max. 12 m.
The more the soil around the earth rod is compressed on driving in, the better the electrical contact. An earth rod of 20 mm outer diameter provides less compression than an earth rod of 25 mm outer diameter.
According to experience, 25 mm outer diameter earth rods provide the best result in heavy soils with regard to the maximum driving depth and soil compression.
Recommended vibration hammers are listed below.
Earth rods usually consist of composable single rods with a length of 1.5 m. DEHN earth rods have a self-locking coupling with bore and pin.
Advantage of this construction is that the coupling locks automatically during the driving process, thus implementing a mechanically high-strength and electrically safe connection. Additional work steps such as screwing are not necessary.
Different types of impact tool are used to drive in the earth rods. Driving-in should be carried out at 1200 blows/min. At a considerably higher blow rate the power usually is not sufficient to reach the required depth with the earth rod. At a too low blow frequency as typical for compressed-air driven hammer tool, the blow power often is too high and the blow rate too low.
The own weight of the driving hammer should be ≥ 20 kg.
The possible driving depth of earth electrodes depends on the geological conditions. In light soil areas, e.g. in coastal areas or in wetlands, depths of 30 m to 40 m can be reached. In extremely heavy soils, e.g. sandy soils the driving depth often is max. 12 m.
The more the soil around the earth rod is compressed on driving in, the better the electrical contact. An earth rod of 20 mm outer diameter provides less compression than an earth rod of 25 mm outer diameter.
According to experience, 25 mm outer diameter earth rods provide the best result in heavy soils with regard to the maximum driving depth and soil compression.
Recommended vibration hammers are listed below.
Details
- For implementing earth-termination systems for down conductors or transformer stations.Features:
- No cross section thickening at the coupling point
- Self-locking coupling
- Corrosion resistance
- Easier storage and transport
- Universal application according to local soil conditions
- Constant resistance values
- Easy driving-in by vibration hammer
