Fail-safe reversing starter with integrated safety logic
The Siemens 3RK1308-0DE00-0CP0 is a SIMATIC fail-safe reversing starter that integrates a 4 via 3DI/LC module — four safe digital inputs and a load circuit monitoring channel — into a single 30 mm-wide housing that plugs onto a base unit. It handles reversing motor control with integrated safety functions, so you can wire a Category 3 / PL d safety circuit without a separate safety relay. The B10d value of 910,000 cycles gives a mean time to dangerous failure you can plug into your SIL calculation per IEC 62061. Supply is 24 V DC nominal, with a permissible range of 20.4 V to 28.8 V. The trip class is adjustable to OFF (instantaneous), 5, or 10, matching the motor thermal characteristic. Minimum load is 50 % of the smallest adjustable rated current — so if you set the overload to 1 A, the starter needs at least 0.5 A load current to trip correctly.
PROFINET and PROFIBUS DP onboard
Both PROFINET and PROFIBUS DP protocols are supported natively. The module maps 4 bytes of input data and 2 bytes of output data onto the fieldbus, so the PLC sees the starter's status and can command start, stop, and direction without hardwired control wires. ON-delay is 35 ms; OFF-delay ranges from 35 to 50 ms, which matters when coordinating with downstream contactors in a reversing pair. Mounting position is vertical or horizontal with derating observed per the manual. The pluggable base unit lets you pre-wire the power and PROFINET/PROFIBUS drop cables, then snap the electronics module on during commissioning — saves panel space and wiring time on a multi-starter line.
Environmental and mechanical limits
Operating temperature is -25 °C to +60 °C with derating above 40 °C per the manual; storage and transport range is -40 °C to +70 °C. Shock resistance is 6 g for 11 ms; vibration resistance is 15 mm amplitude up to 6 Hz and 2 g up to 500 Hz. Pollution degree 2 and overvoltage category III — suitable for industrial control panels connected to the mains supply. Dimensions are 150 mm depth, 30 mm width, 142 mm height. The 30 mm width fits standard DIN-rail spacing; a row of four starters occupies 120 mm of rail. Clearance above and below is 50 mm each for airflow and cable bending radius.