Power Losses And Air Cooling Requirements - Siemens PM330 Hardware Installation Manual

3.2

Power losses and air cooling requirements

General requirement
Installation in the cabinet and the cooling must guarantee that the air temperature - under all
operating conditions and all possible cabinet equipment configurations - inside the Power
Module at the top in the area of the rectifier modules is a maximum of 65 °C - and the air
intake below the Control Unit (behind the left hand housing flap) is a maximum of 60 °C.
Cooling requirements
Depending on the power losses of the various components a specific cooling air flow is
required to protect the components from overheating. The following equation shows you how
to calculate the required air flow.
1. Add the power losses of the individual components.
2. Calculate the air flow required, using the formula.
3. Ensure that the air intake and air discharge openings are adequately large so that the
pressure drop in the cabinet at the required cooling air flow rate (for the Power Modules,
see Specific technical data (Page 87)) remains ≤100 Pa, even when filter mats are used.
4. Ensure that no equipment is mounted that has a negative impact on the cooling air flow.
5. Ensure that the air openings in the Power Modules are free so that the airflow is not
obstructed (for the necessary clearances, see Chassis units (Page 26)).
Power Module PM330
Hardware Installation Manual, 12/2018, A5E32844552B AF
3.2 Power losses and air cooling requirements
Installing/Mounting
21