SIMATIC BaseUnit for ET 200SP remote I/O
The 3RK1908-0AP00-0GP0 is a SIMATIC BaseUnit from Siemens, designed as the mechanical and electrical backbone for ET 200SP remote I/O modules. This BaseUnit variant includes an AC infeed and an F-DI infeed, meaning it carries both the main supply voltage and the fail-safe digital input power bus to the module above it.
DIN rail footprint and wiring
The mounting position is flexible — vertical or horizontal — so it fits both wall-mount enclosures and back-panel layouts. Wiring uses push-in spring-loaded terminals on both the main current circuit and the auxiliary/control circuit. A standard 0.6 mm x 3.5 mm slot screwdriver is the tool for release.
Supply voltage and current limits
The DC supply operates between 20.4 V and 28.8 V, with a rated value of 24 V. The maximum ampacity through the BaseUnit is 7 A — this is the total current the bus can carry to the modules and field devices stacked on it. Pollution degree 2 applies, which is typical for clean industrial control panels.
Environmental and mechanical ratings
Storage and transport tolerances are wider, from -40 to +70 °C. Relative humidity during operation can run from 10 to 95 %, non-condensing. Shock resistance is 6 g for 11 ms, and vibration resistance is 15 mm at 6 Hz, then 2 g up to 500 Hz. This covers most industrial machinery and conveyor applications without needing additional damping.
Substance prohibitance date is April 15, 2016, which aligns with the RoHS exemption sunset for certain materials — the BaseUnit complies with the current RoHS and REACH requirements for industrial equipment.