Technical Parameters Basic Information Brand: ALSTOM / Converteam Part Number: SIR4-S3-4-1-2 Form Factor: Standard 3U slide-in rack pluggable safety relay isolation module Matching peripheral boards: MVTU/MVTT traction master CPU, MVAJ/MVAX/MVUA high voltage auxiliary power supply, PRS12 series DC110V backup power, MPA157 digital I/O board, AP5427A/AT315MR IGBT gate drive boards, TTM211/IP166 TCMS communication gateway Application: European urban metro & light rail traction converter, redundant safety chain signal isolation, emergency stop hard blocking, high-voltage cabinet door interlock, earthing switch safety loop monitoring Control Power Supply Rated operating voltage: DC 24V vehicle control power Operating voltage range: 18 VDC ~ 30 VDC Max power consumption: 7.2 W Input protection: Reverse polarity blocking diode, multi-stage TVS surge absorption filter, input overcurrent fuse, undervoltage safety interlock lockout Safety Relay Channel Configuration (S3-4-1-2 Definition) Channel layout: 4 groups of dual redundant forced-guided safety relays Input signal type: DC24V contact safety chain signals Emergency stop loop feedback High voltage cabinet access door interlock contact Vehicle earthing switch position detection Pre-charge safety interlock feedback Dual redundant output functions Digital opto-isolated feedback signals transmitted to master CPU for software logic judgment Hardwired hardware blocking signal directly wired to all IGBT drive boards, cutting off gate drive power within microseconds once safety chain is broken Relay safety feature: Forced-guided contact safety relays, contact wear detection, short-circuit & open-circuit self-diagnosis for each safety loop Load specification per relay contact: DC24V / 3A resistive safety circuit load, built-in freewheeling surge suppression for inductive loads Internal Rack Communication High-speed proprietary backplane bus for bidirectional real-time data exchange with traction master CPU: upload all safety relay contact status, loop fault diagnosis flags and interlock trigger records; receive master control reset instructions for safety fault latch release. Mechanical Specifications Overall dimension: H130 mm × W98 mm × D220 mm PCB protection: Full acrylic conformal coating, anti-moisture, anti-corrosion, anti-dust, anti-mold Front panel LED indicators: 24V Logic Power OK, Rack Bus Communication Normal, Safety Loop Closed, Safety Fault Trigger, Each Group Relay Status Indicator Fastening structure: Anti-looseness lock buckle, stable electrical contact under long-term vehicle running vibration and shock Suffix S3-4-1-2 optimization: Reinforced insulation between safety field circuit and control logic, enhanced EMC filter for underground tunnel high-interference environment Railway Environmental & EU EN Compliance Operating ambient temperature: -25 ℃ ~ +70 ℃ Storage & transport temperature: -40 ℃ ~ +85 ℃ Relative humidity: 5% ~ 95% non-condensing Vibration test standard: IEC 61373 railway rolling stock Shock resistance: 12g half-sine wave impact test EMC standard: EN 50121-3-2 railway vehicle electromagnetic compatibility Fire safety grade: EN 45545-2 HL2 low smoke, low toxicity flame retardant material