ABB PI726DO 099-1078-05

1. Product Overview

The ABB PI726DO 099-1078-05 is a robust digital output expansion module engineered for ABB industrial drive systems. Designed to convert low-level control signals from a PLC or motion controller into high-current switching outputs, this module directly activates actuators, contactors, solenoids, and indicator lamps. Its compact form factor and plug-and-play compatibility with ABB’s PI series backplane make it a preferred choice for system integrators requiring reliable field-side drive control.

2. Key Features

• 8 isolated digital output channels, each rated for 0.5A continuous
• Short-circuit and over-temperature protection per channel
• Built-in flyback diodes for inductive load handling
• Status LEDs for each output (green = ON, red = fault)
• Reverse polarity protection on power input
• Compatible with ABB ACS880, DCS800, and legacy ACS600 systems
• Operating humidity: 5% to 95% non-condensing

3. Technical Parameters 

The ABB PI726DO operates on a nominal 24V DC supply with a tolerance of 19.2V to 28.8V. Each of its eight digital output channels supports a maximum continuous current of 0.5A at 24V DC, with a peak inrush current of 1.0A for up to 100ms. The output type is open-collector NPN (sinking), with an ON-state voltage drop of less than 1.2V. Switching response time is 0.5ms typical for both turn-on and turn-off. Isolation between field outputs and the internal logic is rated at 2500Vrms for one minute. The module draws a maximum backplane current of 80mA plus up to 4A total from the external load supply. Physical dimensions are 45mm in width, 128mm in height, and 115mm in depth, with a weight of approximately 0.35kg. Protection class is IP20, suitable for installation in enclosed control cabinets.

4. Installation & Maintenance

Installation Steps:

1. Ensure the drive system is fully de-energized before installation.
2. Clip the PI726DO onto a standard 35mm DIN rail inside the drive cabinet.
3. Connect the external 24V DC load supply to terminals L+ and M.
4. Wire field devices (e.g., contactor coils, solenoid valves) between each output terminal (O1 to O8) and the common return (M).
5. Connect the ribbon cable or backplane connector to the adjacent PI series module.
6. Restore power and verify each output LED lights correctly when commanded.

Maintenance Guidelines:

• Periodically check terminal screws for loosening (torque to 0.5 Nm if applicable).
• Replace the module if any output channel remains shorted after a fault reset.
• Keep the ventilation slots free of dust using a soft brush or low-pressure air.
• No routine calibration is required; the module is maintenance-free under normal conditions.

5. Structure & Composition

The PI726DO 099-1078-05 consists of four functional layers:

• Input Interface Layer – A 16-pin backplane connector carrying logic signals and module power.
• Isolation Barrier – Digital isolators (capacitive type) separating the logic side from the field outputs.
• Output Driver Array – Eight MOSFET-based low-side switches, each with independent current sensing.
• Termination Area – A removable, cage-clamp terminal block accepting wire sizes 0.2–1.5 mm² (24–16 AWG).

The front bezel is molded from UL94 V-0 flame-retardant polycarbonate and includes a printed label with the model number 099-1078-05.

6. Application Fields

• Industrial oven heating element control
• Motor brake release circuits in hoists and cranes
• Solenoid valve banks in pneumatic sorting systems
• Warning beacon and alarm annunciator drivers
• Small DC motor forward/reverse control (with external H-bridge)
• Automated guided vehicle (AGV) drive enable signals

7. Additional Information

• Certifications: CE marked, UKCA, cULus listed for hazardous locations Class I, Division 2
• MTBF: 420,000 hours (calculated per IEC 61709)
• Storage temperature: –40°C to +85°C
• Vibration resistance: 5g @ 10–500 Hz (operational)
• Replaces older part numbers: PI726AO, PI726BO
• Warranty: 24 months from date of manufacture

The ABB PI726DO 099-1078-05 is an ideal output expansion solution when you need to drive real-world actuators directly from an ABB drive controller, eliminating the need for intermediate relay banks.