Product Overview
When redundant power supply is critical for system uptime, the ABB SS822 Power Voting Unit provides a reliable solution. This unit accepts dual 24V DC inputs, each rated at 20A, and delivers a single 24V DC output at 20A. It supervises each power input to ensure continuous operation even if one supply fails. Designed for use with ABB power supplies SD821, SD822, or SD823, the SS822 is a compact, DIN rail mounted module that simplifies building fault-tolerant DC power architectures.
Technical Specifications Breakdown
The SS822 operates with a nominal input voltage of 24V DC and a maximum input current of 10A per channel. It provides one output at 24V DC with a maximum output current of 20A. The unit weighs 0.5 kg and has a gross volume of 1.01 dm³. Its width is 50 mm, making it space-efficient for control panels. Each power input is supervised, meaning the unit monitors the health of both incoming supplies and switches seamlessly if one fails.
Industry Applications
- Process Control Systems: In chemical plants or refineries, the SS822 ensures that critical controllers and I/O modules receive uninterrupted 24V DC power, preventing costly process shutdowns.
- Manufacturing Automation: For assembly lines with redundant PLC power supplies, the voting unit guarantees that a single supply failure does not halt production.
- Safety Instrumented Systems: When paired with SIL-rated power supplies, the SS822 adds an extra layer of power redundancy for emergency shutdown systems.
Installation & Setup Guidance
Mount the SS822 on a standard DIN rail in a clean, dry enclosure. Connect two independent 24V DC power supplies to the dual inputs. Wire the load to the single output terminal. Ensure each supply can deliver at least 20A to support the full output current. The unit automatically selects the active input; no configuration is needed. Verify all connections are secure before powering up.
Maintenance & Reliability
The SS822 requires minimal maintenance. Periodically inspect the unit for dust accumulation and ensure ventilation around the DIN rail area remains unobstructed. Check that both input power supplies are functioning correctly. Because the unit supervises each input, any supply failure will be indicated. Replace faulty supplies promptly to maintain redundancy.
Compatibility & Integration
This voting unit is specifically designed for use with ABB power supply models SD821, SD822, and SD823. It integrates seamlessly into ABB control systems and any 24V DC power distribution network requiring redundancy. The DIN rail mounting allows easy installation alongside other ABB automation components.
Selection Guide & Purchasing Advice
Before purchasing the ABB SS822, verify that your system requires redundant 24V DC power with a maximum load of 20A. Confirm that your power supplies are compatible (SD821/822/823). The unit is available from SpareTechPLC, a trusted supplier of industrial automation parts. Check current lifecycle status and availability with SpareTechPLC before ordering.
Frequently Asked Questions
Q: Can the SS822 be used with power supplies other than SD821/822/823?
A: The SS822 is designed for use with ABB SD821, SD822, and SD823 power supplies. Using other models may affect performance or safety.
Q: What happens if one input power supply fails?
A: The SS822 supervises both inputs and automatically switches to the healthy supply, ensuring uninterrupted output.
Q: What is the maximum output current of the SS822?
A: The maximum output current is 20A at 24V DC.
Q: How is the SS822 mounted?
A: It is mounted on a standard DIN rail, with a width of 50 mm.
Q: Does the SS822 require configuration?
A: No, the unit operates automatically. No configuration is needed.
