Heat Generation And Cooling; Humidity; Ambient Conditions - HEIDENHAIN TNC 410 M Technical Manual

4.5 Ambient Conditions

4.5.1 Heat Generation and Cooling

4.5.2 Humidity

4 – 18
Warning
The permissible ambient temperature for operation of the inverter systems
is between 0 °C and 40 °C. Any deviation from this will impair the operating
safety.
The following measures can ensure adequate heat removal:
Provide sufficient space for air circulation.
An integrated ventilation system must remove the warm air and introduce
cooling air, while ensuring that the permissible degree of contamination of
the cooling air is not exceeded (See "Contamination" on page 4 – 21.). If this
is not possible, a heat exchanger must be provided to avoid failures.
HEIDENHAIN recommends that these units (with separate internal and
external cooling circuit) always be installed for reasons of operational safety.
Exit air from cooling systems of other devices must not be introduced into
the unit.
The warm air should flow over surfaces that have good thermal conductivity
to the external surroundings.
For a closed steel housing without assisted cooling,
the figure for heat conduction is 3 W/m
difference between inside and outside.
Use of a cooler.
Permissible humidity
Maximum 75% in continuous operation
Maximum 95% for not more than 30 days a year (equally distributed)
In tropical areas it is recommended that the devices not be switched off, so
that condensation is avoided on the circuit boards.
HEIDENHAIN Technical Manual for Inverter Systems and Motors
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of surface per °C air temperature