ABB SD831 3BSC610064R1 S800 Series Power Supply Unit

The ABB SD831 3BSC610064R1, also cataloged as the SD831 Power Supply Unit, operates as a dedicated hardware component for 24 VDC output conversion and distribution within System 800xA and S800 I/O control racks. Converting wide-range mains inputs (100-240 VAC / 110-300 VDC) to a regulated 24 VDC secondary output, it delivers 3 A continuous current for non-redundant and redundant control system topologies without requiring external mains filtering.

Hardware Specifications

Backplane Bus Communication Velocity and Power Distribution

The SD831 power supply module incorporates an integrated soft-start control circuit that suppresses initial inrush current, preventing unwanted tripping of upstream fuses or earth-fault circuit breakers upon energization. Designed for seamless SELV and PELV secondary circuit integration, the unit provides clean, low-ripple voltage (< 50 mV peak-to-peak) to power adjacent S800 I/O modules, local control processors, and field transmitters. When integrated alongside SS823 or SS832 diode voting units, multiple SD831 modules operate in dual-redundant power configurations, ensuring uninterrupted backplane bus communication velocity and power bus stability during individual supply line blackouts.

Frequently Asked Questions

Q: Can the SD831 power supply be deployed directly in redundant power configurations? A: For redundant applications, the SD831 must be paired with external ABB diode voting units (such as the SS823 or SS832) to decouple the 24 VDC output buses and prevent fault propagation between redundant power rails.

Q: Does the SD831 require an external line filter to comply with electrical safety standards? A: No. The internal filter design of the SD831 meets the electrical safety and functional criteria of EN 50178, EN 61131-2, and UL 508 without the installation of external mains line filters.

Field Installation Guidelines

Mount the SD831 vertically onto a standard 35 mm DIN rail inside the enclosure. Maintain a minimum horizontal mounting clearance of 15 mm between adjacent hardware units and a vertical clearance of at least 40 mm above and below the module housing to enable unhindered convective cooling during high-ambient operation.

Route incoming mains supply cables and secondary 24 VDC distribution wiring through dedicated, separated wire channels to eliminate capacitive coupling. Strip insulation back to the manufacturer specification, ensuring all terminal block screws tighten firmly without exposing bare wire conductors. Ground the DIN rail structure to the central cabinet earth bar using a heavy-gauge, low-impedance ground strap to ensure optimal noise suppression.