You can operate the S7-300 at the following ambient temperatures:
- in a vertical position from 0°C to 40°C
- in a horizontal position from 0°C to 60°C
The aforementioned temperature values are based on an air pressure of 1080 hPa to 795 hPa, which corresponds to 2000 m above sea level. Under these conditions SIMATIC S7 controllers can be operated with natural convection.
At a lower air pressure (and thus lower air density), when operating at greater heights, the cooling performance of natural convection drops. If you use an S7-300 in an environment other than mentioned, please contact Technical Support for alternative configuration options at: http://www.siemens.com/automation/support-request
More detailed information on setting up the S7-300 is available in the operating instructions "CPU 31xC and CPU 31x: Setting Up", in the "Configuration" chapter, in Entry ID: 13008499 .