ABB DO820 Digital Output Module

Description

ABB AWT200048 Transmitter

The ABB DO820 is a highly reliable 8-channel Digital Output Module designed for the S800 I/O distributed system. It is a core component within the ABB Ability™ System 800xA and Compact Product Suite architectures, built to interface safely with field devices.

Product Detailed Description

The DO820 is a 24V DC digital output module featuring 8 isolated relay outputs. Each channel consists of a robust, dry contact relay capable of switching both AC and DC loads. It provides optical isolation between the internal ModuleBus and the external process environment, protecting sensitive controller electronics from field disturbances and voltage spikes.

Technical Parameters

Product Advantages

• Galvanic Isolation: Features complete channel-to-channel isolation, meaning a fault or short circuit on one field device cannot propagate to another channel or damage the central controller.
• High Switching Capacity: Unlike solid-state outputs, the heavy-duty relay contacts can switch loads up to 3 A at 250 V AC, making it ideal for directly driving high-power field actuators.
• Flexible Voltage Handling: Because the outputs are dry contacts, a single module can simultaneously control a mix of different voltage levels (e.g., 24V DC on Channel 1 and 230V AC on Channel 2).
• Hot-Swapping (HCIR): Supports “Hot Configuration in Run.” The module can be safely replaced while the rest of the S800 I/O station remains powered and operating, minimizing system downtime.

Important Considerations & Precautions

• Inductive Loads: When switching inductive loads (such as solenoid valves or heavy contactor coils), external spark suppression/snubber networks (RC snubber for AC, flyback diode for DC) must be installed to protect the relay contacts from arcing and premature wear.
• Maximum Combined Current: While individual channels can handle up to 3 A, pay close attention to the maximum aggregate current limit specified for the entire termination unit to prevent overheating.
• Mechanical Lifespan: Because these are mechanical relays, their lifetime is finite and dependent on the switching frequency and load type. Avoid using this module for high-frequency pulse-width modulation (PWM) tasks.
• Derating: Operating the module at elevated ambient temperatures may require derating the maximum allowable current per channel. Consult the S800 I/O hardware manual for specific temperature curves.

Product Applications

The ABB DO820 is used anywhere robust switching of diverse electrical loads is required:

• Process Control Systems: Direct actuation of solenoid valves, motorized valves, and dampers in chemical or water treatment facilities.
• Electrical Substation Automation: Interfacing with external trip circuits, interlocks, and heavy-duty auxiliary contactors.
• Machine Automation: Controlling heating elements, large sirens, status beacons, and industrial fans.
• Interlocking Networks: Managing hardwired safety and process interlocks between independent machinery systems.

Shipping Port: Xiamen, China

Payment: Bank of Chicago, Bank of Singapore

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