Fail-safe DOL starter with integrated safety logic
The Siemens SIMATIC 3RK1308-0CE00-0CP0 is a fail-safe direct-on-line starter that integrates a 4 via 3DI/LC module — meaning it handles up to four safety-related inputs via three digital inputs and a load-circuit channel, all in a single 30 mm-wide housing that plugs into a BaseUnit on the DIN rail. Rated for 55 kA at 400 V, this starter safely interrupts fault currents up to that level without cascading upstream — critical for SCCR compliance in a panel feeding motor loads. The adjustable trip class (CLASS OFF / 5 / 10) lets you match the overload curve to the motor's starting profile: CLASS OFF for solid-state or soft-start applications, CLASS 5 for fast-cycling loads like conveyors, CLASS 10 for standard induction motors.
Safety-rated switching with B10d data
With a B10d value of 910 000 cycles, this starter is suited for safety circuits where the probability of dangerous failure per demand must be quantified — the figure represents the number of cycles until 10% of the population fails dangerously, used in SIL/PL calculations per IEC 61508 and EN ISO 13849. The safe state is load circuit open, and the ON-delay time is 35 ms with OFF-delay adjustable from 35 to 50 ms, giving the control system predictable response timing for guarding applications.
Network-ready for PROFINET and PROFIBUS
Both PROFINET and PROFIBUS DP protocols are supported natively, so this module drops into either an IO-controller or a classic DP master architecture without a gateway. The input process data is 4 bytes and output data is 2 bytes, mapping directly to the safety-related I/O and status words in the controller's address space.
Environmental and mounting constraints
Operating temperature range is -25 to +60 °C with derating required above that — the manual specifies the thermal curve. Storage and transport range is -40 to +70 °C. Mounting position can be vertical or horizontal, but derating applies for horizontal orientation. Vibration resistance is 15 mm at 6 Hz and 2g up to 500 Hz; shock resistance is 6g for 11 ms. Overvoltage category III and pollution degree 2 mean it's rated for fixed installation in industrial panels where transient overvoltages from the mains supply are expected.