ABB AI825 Analog Input Module – 4-Channel Isolated Bipolar Input

Product Overview

When your process demands precise analog signal acquisition with robust channel isolation, the ABB AI825 analog input module delivers. This 4-channel module offers individually galvanic isolated inputs for both current and voltage signals, including ±20 mA, 0…20 mA, 4…20 mA, ±10 V, 0…10 V, and 2…10 V ranges. Designed for the S800 I/O family, it withstands HART communication and provides 14-bit resolution plus sign for accurate measurement.

Technical Specifications

Channels: 4, individually galvanic isolated

Signal Ranges: -20…+20 mA, 0(4)…20 mA, -10…+10 V, 0(2)…10 V

Resolution: 14 bit plus sign

Input Impedance: 10 MΩ (voltage input), 50 Ω (current input)

Isolation: Individual channel-to-channel and to circuit common

Under/Over Range: ±15%

Error: Max. 0.1%

Update Cycle Time: <10 ms

Maximum Field Cable Length: 600 meters (656 yards)

CMRR, 50Hz, 60Hz: 120 dB

Power Dissipation: Typ. 2.5 W, Max. 3.2 W

Current Consumption +5 V Modulebus: Typ. 70 mA, Max. 100 mA

Current Consumption +24 V Modulebus: Typ. 90 mA, Max. 110 mA

Dimensions: 45 mm width, 102 mm depth, 119 mm height

Weight: 0.22 kg (0.49 lbs)

Industry Applications

The AI825 excels in applications requiring high accuracy and isolation, such as process control in chemical plants, oil and gas refineries, and power generation. Its ability to handle HART communication makes it ideal for smart transmitter integration. The ±15% under/over range capability ensures reliable readings even during signal excursions, reducing false alarms and downtime.

Installation & Setup Guidance

Mount the AI825 in an S800 I/O system using compatible MTUs like TU811, TU813, or TU831. Ensure the ModuleBus provides 24 V power. The module supports field cable lengths up to 600 meters, allowing flexible placement in large plants. Use the keying code DA for correct insertion. Always follow the manufacturer's guidelines for wiring and grounding to maintain isolation integrity.

Maintenance & Reliability

With a temperature drift as low as 34 ppm/°C (±10 V) and 57 ppm/°C (±20 mA), the AI825 maintains stable performance across its operating range of 0 to +55 °C. The module features front LEDs for fault, run, and warning status, enabling quick diagnostics. Regular inspection of the PTC resistor protection and input shunt resistors ensures long-term reliability. The corrosion protection meets ISA-S71.04: G3, suitable for harsh environments.

Compatibility & Integration

The AI825 integrates seamlessly with ABB S800 I/O systems and is compatible with MTUs TU811, TU813, and TU831. It supports HART communication for smart field devices. The module provides internal power supply supervision and status indication for module error, module warning, and channel error, simplifying system diagnostics.

Selection Guide & Purchasing Advice

Before purchasing the AI825 (3BSE036456R1), verify your system's compatibility with the S800 I/O family and required MTU. This module is not intrinsically safe and does not support redundancy or SOE. For current availability and lifecycle status, contact BluePLC Industrial. We stock genuine ABB modules and can help you find the right solution for your automation needs.