ABB SS823 Voting Unit Redundant Power Supply Control

ABB SS823 Voting Unit for Redundant Power Systems

The SS823 is a critical control unit designed to manage and supervise redundant power supply configurations in high-integrity control systems. It ensures continuous, reliable power to essential automation hardware like the AC 800M High Integrity controller and S880 I/O.

Core System Specifications

• Brand & Article Number: ABB, 3BSE038226R1
• Model: SS823
• Product Type: Voter and Over Voltage Protection Unit
• Rated Input Voltage: 1x 24 V DC (Nominal)
• Rated Input Power: 500 W
• Rated Output Current: 20 A
• Maximum Output Current (Overload): 35 A
• Output Voltage Drop (at max current): 1.2 V lower than input
• Output Overvoltage Protection (OVP) Trip: < 30 V
• Heat Dissipation: 24 W @ 20 A, 6 W @ 5 A
• Load Sharing: Yes
• Supervision Relay: Yes (Voltage-free "OK" contact per channel)
• High Integrity Design: Yes, for SIL 3 applications

Electrical & Protection Features

• Manages two redundant 24V DC power supplies, separating and supervising each input.
• Double overvoltage protection circuit on both inputs safeguards connected equipment.
• Detects short and open circuits within the voting element itself for maximum reliability.
• Output protected against overcurrent (current limiting) and overvoltage (OVP).
• Input designed for SELV (Safety Extra Low Voltage) or PELV (Protective Extra Low Voltage) power supplies.
• Green LED per channel on front panel provides instant visual confirmation of correct output voltage.
• Simultaneous with LED illumination, a voltage-free "OK" relay contact closes for remote monitoring.

Certifications & Environmental Ratings

• Safety Integrity: Certified for SIL 3 according to IEC 61508.
• Electrical Safety: Compliant with IEC 61131-2, EN 50178.
• Hazardous Areas: ATEX Zone 2 certified.
• Environmental: G3 compliance for corrosive atmospheres (ISA-S71.04).
• EMC: Complies with EN 61000-6-4 (Emissions) and EN 61000-6-2 (Immunity).
• Marine: Certified by ABS, BV, DNV-GL, LR.
• Enclosure: IP20 protection rating (IEC 60529).
• RoHS/WEEE: Compliant with EU directives.
• Equipment Class: Class I (requires Protective Earth connection).

Mechanical & Installation Data

• Mounting: Simple DIN-rail mounting (35mm).
• Dimensions (W x H x D): 116 mm x 132 mm x 145 mm (4.6" x 5.3" x 5.8")
• Weight: 870 g (1.9 lbs.)
• Mounting Spacing: 15 mm side-to-side, 30 mm above/below for ventilation.
• Maximum Ambient Temperature: 55 °C
• Pollution Degree: 2 (IEC 60664-1)

Installation & Application Guidelines

• Install on a standard DIN rail within the control cabinet, observing required spacing for cooling.
• Connect the outputs of two redundant 24V DC power supplies (e.g., ABB SD83x series) to the voter inputs.
• Connect the voter's output to the power distribution for the AC 800M High Integrity controller and S880 I/O system.
• Wire the voltage-free "OK" supervision relay contacts to the controller or monitoring system for alarm/status.
• Ensure proper protective earth (PE) connection as this is a Class I device.
• Do not exceed the maximum ambient temperature of 55°C to ensure rated performance.
• This unit is a key component in safety instrumented systems (SIS) requiring SIL 3 power redundancy.

For system integration support or to order the ABB SS823 Voting Unit (3BSE038226R1), contact our engineering team.

Contact: Email sales@nex-auto.com or WhatsApp +86 153 9242 9628.

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