Environmental Conditions

This standard applies to equipment designed to be safe under the following conditions:

Indoor use.
Altitude up to 2 000 m.
Maximum relative humidity 80% for temperatures up to 31 °C decreasing linearly to 50% relative humidity at 40 °C.
Transient overvoltage up to the levels of overvoltage category II NOTE: These levels of transient overvoltage are typical for equipment supplied from the building wiring.
Temporary overvoltage occurring on the mains supply.
Applicable pollution degree of the intended environment.(degree 2 in most cases).
Mains supply voltage fluctuations up to ±10 % of the nominal voltage.
Transient over voltages typically present on the mains supply
Transient overvoltage up to the levels of overvoltage category II
Pollution degree 2