Installing Horizontal Ground Electrodes in Shallow Topsoil - RWS200 - RWCC - AWS310-SITE - AWS310 - FOC201 - AWS430 - RME111

Grounding and Lightning Protection in Vaisala Outdoor Installations Technical Reference

Document code
English (United States)
Document type
User guide
Figure 1. Horizontal Y-shaped Ground Electrode in Shallow Topsoil

Use horizontal ground electrodes when the topsoil is shallow. Horizontal ground electrodes distribute a lightning current to a large area of soil very efficiently with a small risk of dangerous step voltages.

  • Route the ground electrodes from the grounding connector at the mast base to each guy wire foundation.
  • Use two or three electrodes. Using more electrodes lowers the impedance.
  • Bury the ground electrodes to a minimum of 0.6 m (2 ft) deep and connect them to the lower ends of the guy wires.
  • If the soil is very dry, extend the electrodes further away and/or bury them deeper to where soil is moist.
  • To lower resistance, terminate the ends with vertical ground rods if the soil allows it or use backfill compounds to increase soil conductivity.
Figure 2. Example Guy Wire Distance and Angle

The electrodes do not need to be evenly spaced. You can guide the transient current to the most desirable direction, for example away from buildings or other equipment, or towards better conducting soil by arranging the wires to that direction.

Do not make the wires run parallel any longer than absolutely necessary.

Using ground electrodes where one electrode is longer than 50 m (164 ft) is not useful. Longer electrodes do not bring better results.