Description

The B&R 7DO138.70 is a high-density 16-channel relay output module designed for universal load switching in industrial automation systems. As part of B&R Automation’s (ABB Group) X20 System, this module bridges the gap between low-voltage control systems and high-power AC/DC loads through robust electromechanical relays. Each channel features Form C (SPDT) contacts rated for 250 V AC/30 V DC at 2 A – enabling simultaneous control of diverse devices like motor starters, solenoid valves, lighting systems, and three-position actuators without external interposing relays. The B&R 7DO138.70 combines the flexibility of mixed-voltage switching with deterministic performance, leveraging B&R’s X2X Link technology for synchronized operation within 10 ms.

Engineered for reliability in harsh environments, the module integrates arc suppression for inductive loads and offers a mechanical lifespan of 10 million operations. Integrated diagnostics monitor contact welding, coil status, and load conditions, feeding real-time health data to B&R’s Automation Studio platform. With hot-swap capability, front-accessible connectors, and a compact 25 mm width, the B&R 7DO138.70 simplifies cabinet design while providing industrial-grade durability (-40°C to +60°C operation, 50g shock resistance). This versatility makes it indispensable for applications requiring safe isolation between control circuits and power loads.

7DO138.70 B&R

Technical Specifications

Parameter Name	Parameter Value
Product Model	7DO138.70
Manufacturer	B&R Automation (ABB Group)
Product Type	Relay Output Module
Number of Channels	16
Contact Configuration	Form C (SPDT) per Channel
Max. Switching Voltage	250 V AC / 30 V DC
Max. Switching Current	2 A (Resistive)
Inrush Capacity	15 A (20 ms)
Contact Resistance	< 100 mΩ
Isolation (Contact to System)	1500 V AC
Mechanical Life	10 Million Operations
Electrical Life	100,000 Operations @ 2 A
Response Time	≤ 10 ms
Connection Interface	X2X Link (Front-Mountable)
Operating Temperature	-40°C to +60°C
Certifications	CE, UL, cULus, IEC 61131-2

Main Features and Advantages

Universal Load Flexibility: The B&R 7DO138.70 eliminates external relays by handling mixed AC/DC loads directly. Each SPDT contact allows NO/NC configurations – ideal for safety interlocks or fail-safe circuits. Integrated RC snubbers suppress voltage spikes from inductive loads (solenoids, contactors), extending contact life 5× compared to unprotected relays.

Advanced Diagnostics & Predictive Maintenance: Real-time monitoring detects contact welding, open coils, and abnormal load currents. Automation Studio estimates contact wear based on switching cycles and load profiles, enabling proactive replacement before failure. Hot-swap capability allows module replacement without process interruption.

Space-Optimized Design: At just 25 mm wide, the module delivers 16 isolated relays – 50% denser than conventional solutions. Front-accessible terminals accept wires up to 2.5 mm², while screw-clamp technology ensures vibration-resistant connections. Conformal coating options protect against humidity and corrosive atmospheres in pulp/paper or chemical plants.

Application Field

The B&R 7DO138.70 excels in applications requiring voltage-agnostic switching. In building automation, it controls HVAC dampers (24 V AC), lighting circuits (230 V AC), and elevator call buttons (48 V DC) within a single panel. Water treatment plants deploy it for chemical dosing pumps (120 V AC) and tank level alarms (24 V DC).

Manufacturing lines leverage its SPDT contacts for dual-control of pneumatic cylinders (advance/retract) and machine status indicators. In energy distribution, the module switches capacitor banks for power factor correction. Its 1500 V isolation prevents ground loops when controlling sensors and actuators across different electrical systems. The B&R 7DO138.70 also enables safe retrofit of legacy equipment – replacing hardwired relay panels with programmable control while maintaining existing 110-230 V AC loads.

7DO138.70 B&R

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