Siemens SINAMICS G130 Engineering Manual page 123

Arrangement of Motor Modules according to their power rating
The power rating-related sequence is mechanically and electrically the most convenient method of arranging the
Motor Modules along the DC busbar, i.e. they are placed to the left or right of the SINAMICS S120 Infeed in
descending order of power rating. In this case, the highest power rating is placed directly next to the Infeed, and the
lowest rating at the far end to the left or right.
The diagram below illustrates an example configuration comprising a SINAMICS S120 Infeed in Chassis format with
S120 Motor Modules in Chassis and Booksize format positioned on the right of the Infeed in descending order of
power rating.
Power rating-related arrangement of Motor Modules in drive configurations with SINAMICS S120
The power rating-related arrangement of Motor Modules is recommended because this option offers a number of
advantages afforded by the relatively small differences in mechanical dimension and electrical rating between
adjacent Motor Modules in the line:
·
S120 Motor Modules in Chassis or Booksize format can be mounted adjacent to one another without any
problem, because those modules placed directly next to one another generally have similar mechanical
dimensions. In other words, only slight differences in height and depth need to be leveled out between most
types of Motor Module when they are installed in the cabinet.
·
The partitioning required between Motor Modules in Chassis or Booksize format in order to ensure optimum
guidance of cooling air in the cabinet is relatively easy to implement. This is because adjacent Motor
Modules are of similar dimensions, have similar cooling air requirements and thus create similar air
pressures. As a result, relatively simple measures can be taken to prevent parasitic air circulation inside the
cabinets. For further information about cooling air guidance and partitioning, please refer to chapter "General
Engineering Information for SINAMICS", section "Cabinet design and air conditioning".
·
The lower the output power rating of the connected Motor Modules, the smaller the cross-section of the DC
busbar can be, allowing significant savings on material costs in many cases. However, it is important to
ensure that the line-side fuses or the line-side circuit breaker for the S120 Infeed is capable of protecting the
entire DC busbar in the event of a short circuit.
·
In the case of a serious defect in a Motor Module (caused, for example, by a defective IGBT or DC link
capacitor), generally only the fuses of the defective Motor Module will trip. This is due to the fact that Motor
Modules installed adjacent to one another have similar output ratings. The fuses of other Motor Modules in
the line remain intact.
Arrangement of Motor Modules according to the position of the drives in the production process
Some plant operators require the Motor Modules to be arranged along the DC busbar in a process-related sequence,
i.e. according to the position of the drives in the production process. The Infeed is thus placed at the beginning of the
DC busbar and the Motor Modules are arranged, irrespective of their mechanical dimensions and electrical ratings, to
correspond to the position of the drives in the production process.
Fundamental Principles and System Description
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Engineering Information
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