ABB SS823 Voting Unit 20A Redundant Power

ABB SS823 (3BSE038226R1) Voting Unit

Product Introduction

The SS823, also known as 3BSE038226R1, separates and supervises two redundant power supply units. It connects the output from both power supplies and votes which one delivers correct voltage. Green LEDs on the front panel provide visual confirmation of proper output. When a green LED lights up, a voltage-free contact closes the corresponding OK connector path. All trip levels come factory preset. Additionally, the SS823 includes a double overvoltage protection circuit on both inputs.

Technical Specifications

The SS823 accepts a nominal input voltage of 24 V DC. Rated output current is 20 A, with a maximum overload capacity of 35 A. Rated input power reaches 500 W. Heat dissipation measures 24 W at 20 A and drops to 6 W at 5 A. Output voltage regulation sits 1.2 V lower than the input voltage at maximum current.

Key parameters include:

• Rated output current: 20 A

• Maximum output current: 35 A (overload)

• Input voltage: 24 V DC nominal

• Output overvoltage protection: < 30 V

• High integrity: Yes

• Load sharing: Yes

• Supervision relay: Yes

The SS823 also detects both short circuits and open circuits in the voting element. This feature enhances diagnostic capabilities for critical systems.

Mechanical and Environmental Data

The SS823 measures 116 mm wide, 132 mm high, and 145 mm deep (including connector). Weight is 870 g. Mounting spacing requires 15 mm on the sides and 30 mm above/below. Maximum ambient operating temperature reaches 55°C. Protection rating is IP20 according to IEC 60529.

For harsh environments, the 3BSE038226R1 carries ISA-S71.04 G3 certification for corrosive atmospheres. Pollution degree is rated at Degree 2 per IEC 60664-1. EMC compliance includes EN 61000-6-4 (emission) and EN 61000-6-2 (immunity).

Safety and Certifications

The SS823 holds multiple important certifications. It is certified for SIL3 according to IEC 61508. The unit carries CE mark and meets electrical safety standards IEC 61131-2 and EN 50178. Hazardous location approval includes ATEX Zone 2. Marine certifications cover ABS, BV, DNV-GL, and LR.

Furthermore, the SS823 complies with RoHS DIRECTIVE 2011/65/EU (EN 50581:2012) and WEEE DIRECTIVE 2012/19/EU. Equipment class is Class 1 according to EN 50718. The unit also supports SELV and PELV applications.

Frequently Asked Questions (FAQ)

1. Can the SS823 be used with non-redundant power supplies?

Yes, but that defeats its main purpose. The SS823 is designed for redundant configurations. Using a single power supply will not trigger the voting logic, but the unit will still pass power and supervision signals.

2. What happens if both power supplies fail?

The SS823 will de-energize both OK relay contacts. Green LEDs will turn off. The output voltage will drop to zero. Your connected system will then shut down safely.

3. Is the SS823 compatible with the S800 I/O system?

The SS823 is specifically intended for AC 800M High Integrity and S880 High Integrity I/O. For standard S800 I/O, please check other voting unit models like SS822Z or SS833.

4. How do I know if the double overvoltage protection has activated?

The 3BSE038226R1 does not have a dedicated indicator for OVP activation. You must measure the output voltage. If it stays below 30 V even when input exceeds that level, the OVP circuit is working.

5. Can I replace the SS823 while the system is powered?

No. The SS823 does not support hot swap. You must shut down input power from both redundant power supplies before removing or replacing the unit.