Introduction
Plant floors have changed dramatically over the past three decades. Pneumatic relays and manual pushbuttons once ruled the line, but today’s automated cells demand fast, repeatable DC switching. The Allen-Bradley 1746-OBP8 emerged from that shift as a practical answer for engineers who needed high-current outputs without adding external relay banks.
What Is the 1746-OBP8?
The 1746-OBP8 is an SLC 500 digital DC output module from Allen-Bradley. It provides eight sourcing output channels arranged in two groups of four. Each point handles up to 2.0 A at 60 degrees Celsius, and the module supports a total of 8.0 A across all channels. The output voltage range is 20.4-26.4 Volts DC source, making it a natural fit for 24 VDC control circuits. It installs in either fixed or modular SLC 500 hardware and occupies a single chassis slot.
Key Specifications That Matter
Output Current and Grouping
Eight outputs split into two isolated groups of four give you flexible load distribution. With 2.0 A per point and 8.0 A per module, the 1746-OBP8 drives pilot lamps, horns, solenoids, and small actuators directly. That eliminates the cost and wiring of interposing relays in many high-current applications.
Switching Speed
Signal delay is 1.0 ms on and 2.0 ms off. The step response is 60 milliseconds in and 2.5 milliseconds out. These figures suit packaging, material handling, and automotive lines where timing consistency keeps production rates steady.
Power and Thermal Profile
Backplane current draw is 0.135 A at 5 Volts DC. Power dissipation is 0.3 W, with heat dissipation of 0.300 watts per point. The module operates from 0 to 60 degrees Celsius and stores safely from -40 to 85 degrees Celsius. Non-condensing humidity of 5-95% covers most industrial environments.
Where the 1746-OBP8 Fits
Automotive assembly lines use this module to energize solenoid valves and motorized actuators on indexing conveyors. Packaging equipment relies on its fast turn-off for precise glue and seal cycles. Material handling systems use the eight outputs to drive diverter arms, alarm annunciators, and indicator stacks. If a load runs on AC voltage, you can still use the 1746-OBP8 by adding interposing relays whose coil voltage matches the module output.
Installation and Compatibility
The 1746-OBP8 works with SLC 500 processors in stand-alone, expanded, or Remote I/O topology. It fits fixed-style or modular-style SLC 500 platforms. The module needs an external DC power supply to generate output power, and recommended signal wires are max 2 mm sq. (14 AWG). It carries a 1500 V isolation rating and NEMA standard ICS 2-230 noise immunity. Note that the module does not include electronic protection, so verify load characteristics before commissioning.
Maintenance and Reliability
The e-fuse LED indicators let you monitor channel state at a glance during routine inspections. Check for off-state leakage and minimum load current, both rated at 1 mA. Keep the chassis slot free of conductive dust and confirm the surrounding air temperature stays within the 0-60 degrees Celsius operating range. Periodic inspection of wiring terminations helps prevent intermittent faults.
Selection Checklist
Before ordering, confirm your load voltage falls within 20.4-26.4 Volts DC, total current stays under 8.0 A, and your SLC 500 chassis has an open slot. For AC loads, plan for interposing relays with matching coil voltage. Oil AutoTech offers hands-on technical selection help and fast dispatch, worldwide. Contact Oil AutoTech today for pricing and availability.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
