The SINAMICS S120 liquid-cooled drive units are specifically designed to address the requirements relating to liquid cooling; they are characterized by their high power density and optimized footprint. Liquid cooling dissipates heat much more efficiently than air cooling systems. As a result, liquid-cooled units are much more compact than air-cooled units with the same power rating. Since the power losses generated by the electronic components are almost completely dissipated by the liquid coolant, only very small cooling fans are required. This makes the drive units 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 higher.

The product portfolio includes the following liquid-cooled SINAMICS S120 chassis units:

• Ready-to-connect AC/AC units:
  • Power Modules
• Infeed units:
  • Basic Line Modules
  • Active Line Modules
• Inverters (Motor Modules)

System components such as line reactors, Active Interface Modules, motor reactors and motor filters are air-cooled.

Highlights of the liquid-cooled units

• Up to a 60 % smaller footprint than air-cooled drive converters
• All main components such as power semiconductors, DC link capacitors and balancing resistors are cooled by the cooling circuit
• Only a low flow rate is required
• Uniform pressure drop of 0.7 bar
• Automatic protective functions
• Plated busbars
• Extremely quiet with < 56 dB
• Compatible with all components and functions and tools of the SINAMICS system family
• The power rating can be extended by connecting units in parallel
• No equipment fans

Cabinet units in liquid-cooled version

Liquid-cooled SINAMICS S120 drive units are also available as cabinet units, including cooling system. These are tailored to the specific requirements and represent a tailor-made, all-in-one solution for every drive task. You can obtain information about these units from your local Siemens office.

Example of a drive line-up with SINAMICS S120 liquid-cooled