To comply with high requirements regarding installation and ambient conditions, SINAMICS S120 Cabinet Modules are also available in a liquid-cooled version.

The power loss of the units is transferred to the cooling liquid and dissipated, without noticeably increasing the temperature of the surrounding environment. As a consequence it is possible to save the expense of controlling the climate of the electrical room.

The system consists of liquid-cooled Basic Line Connection Modules, Active Line Connection Modules, Motor Modules, an Auxiliary Power Supply Module, and a suitably selected cooling unit (Heat Exchanger Module).

Basic Line Connection Modules

Basic Line Connection Modules comprise a Line Connection Module and a liquid-cooled Basic Line Module. Basic Line Connection Modules are only suitable for infeed operation, i.e. they are not capable of feeding regenerative energy back into the supply system.

If regenerative energy is produced, e.g. when the drives brake, it must be converted into heat in external braking resistors using a supplementary Motor Module, which is used as a Braking Module.

When a Basic Line Connection Module is used as the infeed, a line reactor appropriate for the supply conditions must be installed. If the infeed is realized via a transformer with an appropriate rating in 6-pulse operation with a Basic Line Connection Module or in 12-pulse operation with two Basic Line Connection Modules, the line reactor is optional and can be omitted.

If two or more Basic Line Connection Modules are operated in parallel on a common supply system in order to increase power, then line reactors must also be used.

Basic Line Connection Module ≤ 800 A

Basic Line Connection Module > 800 A

Active Line Connection Modules

Active Line Connection Modules comprise a Line Connection Module, a liquid-cooled Active Interface Module and a liquid-cooled Active Line Module. Active Line Connection Modules can supply energy to the DC link and return regenerative energy to the line supply (energy recovery). The use of an additional Motor Module as a Braking Module is only required if the drives need to be decelerated in a controlled manner after a power failure (i.e. when energy cannot be fed back into the line supply).

In contrast to Basic Line Connection Modules, Active Line Connection Modules generate a regulated DC voltage which remains constant irrespective of fluctuations in the line voltage. However, in this case, the line voltage must remain within the permissible tolerance range. Active Line Connection Modules draw a virtually sinusoidal current from the supply system. Almost no harmonics occur. The total harmonic distortion factors of current THD(I) and voltage THD(U) are typically in the range of approx. 3 %. The stringent limit values of IEEE 519 (2014) are complied with.

Active Line Connection Modules always contain an Active Interface Module which, in addition to a Clean Power Filter, also includes the necessary pre-charging circuit for the Active Line Module.

Active Line Connection Module with Active Interface Module and Active Line Module ≤ 800 A

Active Line Connection Module with Active Interface Module and Active Line Module > 800 A

Motor Modules

Each Cabinet Module is fitted with one SINAMICS S120 Motor Module in chassis format and covers the power range from 90 kW to 1500 kW (380 V to 480 V or 500 V to 690 V). The power rating can be extended up to approx. 5700 kW by connection in parallel.

The Motor Modules can also be used as Braking Modules (braking chopper) if a 3-phase braking resistor is connected instead of a motor.
For additional information, please refer to the SINAMICS Low Voltage Engineering Manual.

Auxiliary Power Supply Modules

Auxiliary Power Supply Modules supply power to the auxiliary power supply system of the SINAMICS S120 Cabinet Modules. The heat exchangers, which are installed in the SINAMICS S120 Cabinet Modules with degree of protection IP55, are one of the connections to the auxiliary power supply system. In addition, the auxiliary power supply system supplies the electronic modules with an external 24 V DC voltage. This is required when the DC link is not charged, for instance, in order to maintain PROFIBUS or PROFINET communication. The installation is analogous to the air-cooled Auxiliary Power Supply Modules with an additional water pipe system. The Auxiliary Power Supply Modules provide an expansion to the option K76 (auxiliary voltage generating unit) if higher power ratings are required.