, material, design) may
influence the installation. Therefore IEC
has issued relevant standards for classification external influences and environmental
conditions, e. Such external influences
may be: ambient temperature, humidity, altitude, water, mechanical stresses, flora, fauna, etc..;
but also utilization equipment the construction buildings (e.
Chapter IEC 364-3 establishes the classification external influences which require
assessment the design and erection electrical installations..
B .
3 .....
Note: This classification not intended used for marking equipment.
Chapter 32: Classification external influences
IEC Publication 721 Classification environmental conditions.
Explanation the codification for external influences Chapter IEC 364-3 (1977):
Each condition external influence designed code comprising group two capital
letters and number follows:
The first letter relates the general category external influence:
A environment
B utilization
C construction buildings
The second letter relates the nature the external influence:
A .
All these external influences may hamper the safety electrical installations.
For example the code AC2 signifies:
A environment
AC environment-altitude
AC2 environment-altitude 2000 m.
Part Assessment general characteristics.... EXTERNAL INFLUENCES EFFECTING ELECTRICAL EQUIPMENT
AND INSTALLATION
Electrical equipment and electrical installations are exposed external influences, not only
during their use, but also during transportation, storage, and erection.g.
.
The number relates the class within each external influence:
1 .g.1 shows list of
external influences.:
IEC Publication 364-3 (1977) Electrical installations buildings.
C . Table 8...EXTERNAL INFLUENCES EFFECTING ELECTRICAL EQUIPMENT AND INSTALLATION
76
8.
2 .
