Siemens SINAMICS S120 Equipment Manual page 20

System Overview
1.2 SINAMICS S120 drive system
Boundary conditions for use
The Power Modules, Line Modules and Motor Modules are designed for connection to a
liquid coolant circuit which must be provided by the customer.
The design of this liquid coolant circuit is an important factor in determining the operational
reliability and service life of the equipment and the entire installation.
The main criteria are described in the following chapters.
Advantages of liquid cooling over air cooling
Liquid cooling systems are considerably more efficient at dissipating heat losses than air
cooling systems. As a result, liquid-cooled devices are much more compact than air-cooled
units with the same output rating. Since the heat losses generated by the electronic
components are almost completely dissipated by the liquid coolant, only very small cooling
fans are required. This makes the devices extremely quiet in operation. Due to their compact
dimensions and almost negligible cooling air requirement, liquid-cooled units are the
preferred solution wherever installation space is restricted and/or the ambient operating
conditions are rough. Control cabinets with liquid cooling are easy to implement as
hermetically sealed units with degrees of protection of IP54 or above.
1-6
SINAMICS S120 Equipment Manual, Edition 12/2007, 6SL3097-2AM00-0BP4
Chassis Power Units Liquid Cooled