IEC 60721-3-4:2019/COR1:2023

IEC 60721-3-4:2019/COR1:2023 – 1 –
 IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
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IEC 60721-3-4 IEC 60721-3-4
Edition 3.0  2019-05 Édition 3.0  2019-05


CLASSIFICATION OF ENVIRONMENTAL CLASSIFICATION DES CONDITIONS
CONDITIONS – D'ENVIRONNEMENT –

Part 3-4: Classification of groups of Partie 3-4: Classification des groupements des
environmental parameters and their severities – agents d'environnement et de leurs sévérités –
Stationary use at non-weatherprotected Utilisation à poste fixe, non protégé contre les
locations intempéries


CO RRI G E NDUM 1



Corrections to the French version appear after the English text.
Les corrections à la version française sont données après le texte anglais.

Table 1 – Classification of climatic conditions
In the "Low absolute humidity" row, for climatic conditions 4K23, 4K24, 4K26 and 4K27,
replace the existing values "0,2", "0,003", "0,1" and "0,003" with the new values "0,05",
"0,004", "0,05" and "0,004", respectively, as shown:
Classification
Environmental parameter Unit Sheltered Open-air
4K23 4K24 4K25 4K26 4K27
Low air temperature °C +5 -50
−45 −50 −20
i i i
High air temperature °C +70 +70
+45 +50 +45
a
% 4 4 30 4 10
Low relative humidity
a
% 100 100 100 100 100
High relative humidity
a 3
0,05 0,004 6 0,05 0,004
Low absolute humidity g/m
a 3
35 20 35 30 25
High absolute humidity g/m
b
°C/min 1,0 1,0 1,0 1,0 1,0
Rate of change of temperature
c
kPa 70 70 70 70 70
Low air pressure
c
kPa 106 106 106 106 106
High air pressure
l l l
2
h h
1 090 1 090 1 090
Solar radiation W/m


f f
Heat radiation Not specified No No No

d d, f d, f f f f
m/s
Movement of surrounding air 5,0 5,0 22 22 22
Condensation Not specified Yes Yes Yes Yes Yes
IEC 60721-3-4:2019-05/COR1:2023-07(en-fr)

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  IEC 2023
Classification
Environmental parameter Unit Sheltered Open-air
4K23 4K24 4K25 4K26 4K27
m
g g
Precipitation (rain, snow, hail, etc.) Not specified Yes Yes Yes
Yes Yes
g g
Rain intensity mm/min 15 15 15
No No
Driving rain m/s No No 18 18 18
2 g g
Snow load No No No
kg/m
e g g
°C +5 +5 +5
Low rain temperature No No
j j j
Not specified Dripping Dripping
Water from sources other than rain
water water
k k k
Not specified Yes Yes
Formation of ice and frost Yes Yes Yes
a
The low and high relative humidity levels are limited by the low and high absolute humidity. See Annex A.
b
Averaged over a period of 5 min.
c
The value of 70 kPa represents a limit for open-air conditions, normally at an altitude of 3 000 m. In some
geographical areas, open-air conditions may occur at higher altitudes. Conditions in mines are not considered.
If applicable, a special value may be selected from Table 2.
d
A cooling system based on non-assisted convection may be disturbed by adverse movement of surrounding
air.
e
This rain temperature should be considered together with high air temperature and solar radiation. The
cooling effect of the rain should be considered in connection with the surface temperature of the product.
f
If applicable, a special value may be selected from Table 2.
g
Applies only to wind-driven precipitation at sheltered locations.
h
Thermal effect of solar radiation is included in the temperature.
i
Thermal effect of solar radiation is not included in the temperature.
j
Sources of water other than rain are encompassed in driving rain.
k
Formation of frost can oc
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