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