ABB DO820 S800 I/O 8-Channel Digital Output Relay Module 3BSE008514R1

Product Overview

The 3BSE008514R1 (DO820) is a high-density, 8-channel digital output relay module within the ABB S800 I/O family. Engineered for maximum versatility in industrial automation, this module provides high-current switching capabilities for both AC and DC loads. Its primary strength lies in its individually galvanic isolated channels, making it an ideal choice for diverse control applications where different voltage potentials or electrical isolation between circuits are required.

Whether integrated into the Advant OCS, 800xA, or Compact Product Suite systems, the DO820 serves as a robust interface for driving solenoids, motor starters, and actuators. It enhances system reliability by protecting sensitive control electronics from field-side electrical noise and surges.

Technical Configuration

The DO820 is designed for seamless integration and rugged performance in demanding DCS and PLC environments:

• Switching Capacity: Supports 24 to 230 VAC/VDC, with a maximum current rating of 3 A per channel.
• Galvanic Isolation: Each channel is individually isolated, allowing mixed voltage types within a single module.
• Inductive Load Management: Optimized for switching loads with a power factor (cos φ) greater than 0.4 and a DC rating of 42 W.
• Termination Compatibility: Works with MTUs including TU811, TU813, TU831, TU836, TU837, and TU851.

Technical Specifications

Technical FAQs

Can the DO820 handle different voltage sources on the same module?

Yes. Because each channel is individually galvanic isolated, you can switch 230 VAC on one channel and 24 VDC on another without electrical interference.

What happens if I exceed the 3 A current rating?

Relay contacts may experience arcing or welding if overloaded. For loads exceeding 3 A, use an external interposing relay or apply proper surge suppression.

Which Module Termination Unit (MTU) should I use?

Selection depends on wiring density and safety requirements. TU811 is a standard compact MTU, while TU813 and TU831 provide alternative terminal configurations.

Engineering & Installation Guide

Arc Suppression:
Install a flyback diode for DC inductive loads. For AC loads, use an RC snubber to extend relay contact life.

Thermal Management:
If all eight channels operate at maximum current simultaneously, ensure adequate cabinet ventilation to prevent heat buildup.

Mounting Orientation:
Mount vertically on a DIN rail via the compatible MTU. Confirm the locking mechanism is fully engaged to avoid vibration-related contact issues.

Hot Swapping:
S800 I/O modules support HCIR, but always disconnect field power or ensure the process is in a safe state before removal.