Description
ABB DSSR122 (4899001-NK)
- Technical Specifications (typical for DSSR122 10 A version):
- Input Voltage: 85–264 V AC (47–63 Hz) or 120–300 V DC (model dependent)
- Output Voltage: 24 V DC ±1 % (adjustable ±5 % via potentiometer)
- Rated Output Current: 10 A (240 W) or 20 A (480 W) depending on exact sub-type
- Ripple & Noise: <50 mV pp
- Efficiency: >88 %
- Overload Protection: 105–130 % rated current; auto-recovery on fault removal
- Parallel Operation: Diode-OR capable for N+1 redundancy (external diodes or built-in ORing)
- Indicators: Green LED = Output OK; Red/Amber = Fault or Overtemp
- Hold-up Time: >20 ms @ full load (typical)
- Operating Temp.: 0 °C to +60 °C (derate above 50 °C)
- Mounting: Plug-in to dedicated PSU slot in S100 rack or DIN-rail with adapter; screw terminals for field wiring
- Dimensions: ≈120 × 75 × 130 mm (H × W × D) depending on frame
- Certifications: CE, UL 508, cULus, EN 61000 EMC
- Functional Features:
- Wide input voltage tolerance — suitable for global site mains (100–240 V AC auto-sensing)
- Short-circuit proof; automatic recovery avoids nuisance replacement
- Redundancy-ready — parallel two units for N+1 hot-standby
- Power-good contact / signal (on some versions) for external alarm
- Convection cooled (no fan on most versions — some high-current have temp-controlled fan)
- Application Scenarios:
- Powers S100 I/O modules (DI/DO/AI/AO) and controller CPU in compact process stations
- Primary or backup 24 V DC supply for S800 I/O rack (when used with appropriate TB820/TB807 base)
- Retrofit/replacement in existing ABB Advant / MasterPiece 200 cabinets
- Material & Structure:
- Chassis: Aluminum heat-sink with vent slots
- PCB: FR4 with through-hole power components; conformal coated on some versions
- Terminals: Screw-type for AC in / DC out / PE
- Working Principle:
AC mains is rectified and filtered, then switched through a high-frequency PWM converter. The secondary side is transformer-isolated, rectified, and regulated by a feedback loop maintaining 24 V DC at the output terminals despite load or input variations. A separate supervisory circuit monitors output current, voltage, and internal temperature — triggering shutdown or fold-back if limits are exceeded.
- Installation Requirements:
- Verify input voltage selector/jumper (if present) matches site mains BEFORE connecting AC
- Connect protective earth (PE) to the PSU earth terminal — mandatory for safety and EMC
- Tighten DC output terminals to specified torque (typically 0.5–0.8 N·m)
- For redundancy: ensure both units share equal load; use recommended OR-ing diode module or verify built-in ORing
- Leave ≥50 mm clearance above/below for convection cooling
- Precautions:
- Never connect AC and DC input simultaneously — module is AC or DC input only
- Confirm total rack current draw (all modules + contingency) < PSU rated output; for hot-standby size for N+1
- Disconnect mains before removing/inserting module
- Do NOT block ventilation openings; ambient >50 °C requires output derating per datasheet
