The general principle in grounding Vaisala weather station systems and masts is to install a lightning protection system, including an air terminal, down conductor, and a ground electrode, and ground the mast and the enclosure with separate wires.
The wire for grounding the mast runs from the air terminal down to the grounding connector at the base of the mast. This wire is the (mast) down conductor.
The wire for grounding the enclosure runs from the bottom of the enclosure down to the grounding connector at the base of the mast. This wire is the (enclosure) down conductor.
From the grounding connector, cables run to the ground, terminating in ground electrodes such as ground rods or plates.
Warning Failure to provide proper grounding may result in personnel injury or
death from electrical shock and may severely damage the equipment. Ground the system for
safety and optimal performance.
Warning Lightning protection is generally required to prevent personnel injury
and equipment damage due to direct lightning strikes.
Warning Consult the local electricity provider for local safety grounding
requirements.
Warning Lightning and thunderstorms present a risk to personnel. Do not start
working with or installing masts or their lightning protection systems when there is a risk of
thunderstorm.If thunder is heard or lightning seen by personnel, cease any activity near the
mast and move to shelter or to hardtop vehicles.
Figure 1. Example of Lightning Protection System
on Pole Mast
1
Air terminal
2
Upper attachment of (mast) down conductor
3
Ground electrode
4
Mast down conductor
5
Signal cables
6
Grounding connector
Figure 2. Example of Lightning Protection System
on Lattice Mast
1
Air terminal
2
Mast down conductor
3
Enclosure down conductor
4
Grounding connector
5
Ground electrode
For instructions on installing an air terminal and grounding the enclosure, see the product-specific manuals.
Periodic inspection of the lightning protection system is recommended. When using lighter materials or materials that corrode fast, the role of inspection and maintenance is even more important.
