Selecting The Baseunit - Siemens SIMATIC ET 200SP System Manual

End retainers
In the case of a vertical mounting position, use an end retainer at both ends of the ET 200SP
station: 8WA1808
Mechanical bracket
Use the mechanical bracket in the following situations:
● When using a 15 mm mounting rail
● With a vertical mounting position.
● For applications according to shipbuilding standards in all mounting positions with 7.5 mm
and 15 mm
3.5

Selecting the BaseUnit

The motor starter BaseUnits "BU30-MSx" are compatible with all motor starters. With the
different BaseUnits, you can form different potential groups for the 24 V DC electronics
supply (L+/M) and for the AC infeed.
Slot rules for the potential group of the DC infeed
For the potential group (L+/M), the following slot rules apply within the motor starter modules
and other I/O modules of the ET 200SP:
● The BU30-MS2 and BU30-MS4 BaseUnits can adopt the potential groups of other
BaseUnit types. Note, however, the following exception: Only a BaseUnit of type BU30-
MS1 or BU30-MS3 may follow an AS-i module (AS-i potential group) or an F-PM module.
● A BU30-MSx BaseUnit must only be followed by a BaseUnit with 24 V infeed (light
BaseUnit) of another type (e.g. A0).
● A dark motor starter BaseUnit without potential infeed may only follow an empty slot if a
motor starter or a 24-V I/O module is plugged in to the left of the empty slot. You can
always plug in a light motor starter after an empty slot. The empty slot adopts the
potential of the BaseUnit on the left. An empty slot is an unpopulated slot of the same
potential group.
Motor starter
System Manual, 04/2016, A5E35582704002A/RS-AA/001
Application planning
3.5 Selecting the BaseUnit
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