Siemens SIMATIC ET 200SP Manual page 38

Product overview
3.7 Functions
Switching on
The inrush current in the case of motorized loads is conducted briefly via the
semiconductors.
Advantage: The relay contacts are protected. Longer service life is achieved thanks to
reduced wear and tear.
Current routing
The continuous current is routed via relay contacts.
Advantage: Relay contacts cause lower thermal losses than semiconductors.
Switching off
Switching off is implemented via the semiconductors.
Advantage: The contacts are not stressed with arcs when switching via the semiconductors.
This results in increased service life.
Schematic circuit diagram
The following diagrams show schematic circuit diagrams of the standard and fail-safe
versions of the ET 200SP motor starter:
Figure 3-3 Schematic circuit diagram
The ET 200SP motor starters do not possess any galvanic isolation of the switching
elements in the main circuits. The isolating function in compliance with EN 60947-1 is only
warranted in the parking position.
See also
Preface (Page 5)
38
Motor starter (3RK1308-0**00-0CP0)
Manual, 12/2016, A5E34821005002A/RS-AB/002