BS 7404-2.1(1991) : 1991
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
Hardcopy , PDF
12-15-1996
English
01-01-1991
Committees responsible
Foreword
Specification
1. Scope
2. Object
3. Temperature, humidity and barometric pressure
classification of locations
3.1 General
3.2 Air conditioned locations (Class A)
3.3 Heated and/or cooled enclosed locations (Class B)
3.4 Sheltered locations (Class C)
3.5 Outdoor locations (Class D)
3.6 Summary of location classes
3.7 Barometric pressure
4. Mechanical influences
4.1 General
4.2 Vibration
4.3 Mechanical shock
4.4 Seismic effects (earthquakes)
5. Power supply
5.1 General
5.2 A.C. supply
5.3 D.C. supply
5.4 Supply interruption
5.5 Voltage withstand
Appendix
NA. Deletions from and IEC text amended by Common
modifications to IEC Publication 870-2-1 (1987)
(informative)
Tables
I. Air temperature and humidity classes for air
conditioned locations
II. Air temperature and humidity classes for enclosed
locations
III. Air temperature and humidity classes for
sheltered locations
IV. Air temperature and humidity classes for outdoor
locations
V. Summary of location classes
VI. Location classes of barometric pressure
VII. Low frequency vibration classes
VIII. High frequency vibration classes
IX. Vibrational severity classes
X. Vibration time classes
XI. Mechanical shock classes showing preferred
combinations of a and t
XII. Shock acceleration values
XIII. Free fall height classes
XIV. Shock repetition classes
XV. Intensity classes of earthquakes
XVI. Phenomena of earthquakes related to the scales of
Richter and Mercalli
XVII. Untitled
XVIII. A.C. voltage tolerance classes
XIX. Frequency tolerance classes
XX. Harmonic content level classes
XXI. Untitled
XXII. D.C. voltage tolerance classes
XXIII. Earthing condition classes
XXIV. Ripple classes
XXV. Interruption time classes
XXVI. Withstand voltage classes
Figures
1. Humidity versus temperature for air conditioned
locations
2. Humidity versus temperature for enclosed locations
3. Humidity versus temperature for sheltered locations
4. Peak displacement (amplitude) and velocity with
low frequency vibrations
5. Peak displacement (amplitude) and velocity with
high frequency vibrations
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