Grounding And Lightning Protection; Equipment Grounding; Internal Grounding Of Pwd22/52; Grounding The Remote Units And The Communication Cable - Vaisala PWD22/52 User Manual

Chapter 4 _______________________________________________________________ Installation

Grounding and Lightning Protection

WARNING
VAISALA _______________________________________________________________________ 31

Equipment Grounding

Equipment grounding protects the electrical modules of PWD22/52
among other things against lightning and prevent radio frequency
interference. Equipment grounding for PWD22/52 is done via the
weather station grounding cable.
The grounding principles are the following:
Install the grounding rod as close to the pole mast as possible. That is,
minimized the length of the grounding cable. The grounding cable can
also be cast inside the concrete base.
The length of the grounding rod depends on the local groundwater level.
The lower end of the grounding rod should touch moist soil continuously.
The quality of the grounding can be checked with a georesistance meter.
The resistance must be less than 10 Ω.

Internal Grounding of PWD22/52

The electronics enclosure of PWD22/52 is grounded using the
power/data cable jacket. The other parts of the sensor are in galvanic
contact with each other.
Grounding the Remote Units and the
Communication Cable
It is also necessary to ground the remote units such as the PC data logger
and display, and protect them against lightning.
A lightning strike through a communication wire can cause voltage surge
dangerous to life at remote sites if the remote units are not properly
grounded.