Grounding And Lightning Protection; Equipment Grounding; Internal Grounding Of Pwd22; Grounding The Remote Units And The Communication Cable39 - Vaisala PWD22 User Manual

Chapter 4_________________________________________________________________ Installation

Grounding and Lightning Protection

WARNING
VAISALA ________________________________________________________________________ 39

Equipment Grounding

Equipment grounding protects the electrical modules of PWD22
among other things against lightning and prevent radio frequency
interference. Equipment grounding for PWD22 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

The electronics enclosure of PWD22 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.