Stand-alone Outdoor Equipment (< 6 m / 20 ft) - RME111 - RWS200 - AWS310-SITE - AWS430 - RWCC - AWS310 - FOC201

Grounding and Lightning Protection in Vaisala Outdoor Installations Technical Reference

Document code
M211786EN
Revision
B
Language
English (United States)
Product
RME111
RWS200
AWS310-SITE
AWS430
RWCC
AWS310
FOC201
Document type
User guide

Stand-alone outdoor equipment that are less than 6 m (20 ft) tall have a low to moderate probability of a lightning strike in most locations.

If a system (such as a visibility meter) is installed in an open airfield with no other taller structures nearby, the risk of a direct lightning strike increases.

The feasibility of a separate lightning protection system increases when approaching the equator.

The main reason for local grounding is electrical safety, especially in TT distribution systems where the ground is made with a local ground electrode. Observe local or contractual requirements for the needed maximum grounding resistance.

Local safety ground also enables the AC (mains) power line and signal line transient protectors (such as Termbox1200) to conduct the transient currents safely to ground. Systems with two or more structures (for example transmissometers) use a local bonding electrode to interconnect the units to the same potential for signal integrity. This bonding wire also acts as a moderate grounding electrode.

Even in cases of TN or IT systems, connecting the equipment chassis to the ground potential is beneficial to the transient protection.