Safety power module for motor starter circuits
The Siemens 3RK1903-1BB00 PM-D F2 is a fail-safe power module designed for motor starter applications, rated to safety category 4 per EN 954-1 with auto-start protection. It mounts onto the TM-PF30 S47-B0 or -B1 base unit in a 30 mm wide form factor — a compact drop-in for distributed safety zones on conveyor or machine lines. Safety integrity is SIL Claim Limit 3 per IEC 61508 and Category 4 per EN ISO 13849-1, with a PFHd of 9E-9 1/h in high-demand mode — low enough that a single module covers the safety function for most industrial cells without redundancy overhead. The safe failure fraction (SFF) sits at 99 %, and hardware fault tolerance is 1 (Type B device per IEC 61508-2). Control supply is 20.4 to 28.8 V DC, and the safe state is load circuit open — the module drops its output contacts when the safety chain demands it. Bus communication is built in, so it talks directly to the upstream safety controller without an extra gateway.
The module measures 30 mm wide by 196.5 mm high by 117.5 mm deep — a standard 30 mm footprint that clips onto the TM-PF30 base. Mechanical service life is rated at 10,000,000 operating cycles typical; electrical endurance at 200,000 cycles typical under rated load. No short-circuit protection is built into the module.