Grounding Systems - RWS200 - RWCC - AWS310-SITE - AWS310 - FOC201 - AWS430 - RME111

Grounding and Lightning Protection in Vaisala Outdoor Installations Technical Reference

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

International standard IEC 60364 describes three families of grounding arrangements, using two-letter codes: TN, TT, and IT systems.

The first letter indicates the connection between the ground and the power-supply equipment (such as a generator or a transformer). The second letter indicates the connection between the ground and the electrical device being supplied.

  • T: direct connection of a point with ground (from Latin ‘terra’)
  • I: no point is connected with ground (isolation), except perhaps through a high impedance route
  • N: direct connection to neutral at the origin of installation, which is connected to the ground