Product Description
The Allen-Bradley 1756-OC8 is an 8-point, 4-point-group ControlLogix DC output module requiring a fused IFM with a recommended 5x20mm 4A quick-acting fuse (SOC p/n MQ2-4A) for output protection due to its unfused design. Before installation in any chassis slot, the chassis and power supply must be grounded, and a compatible 20-pin RTB (1756-TBNH or 1756-TBSH) must be connected. This 48V DC source module operates between 30-60V DC, features a 2A pilot duty, 2mA minimum load current, 165mA/5.1V and 2mA/24V current draw (0.89W backplane power), and a 4A/10ms surge current per point (repeatable every second at 60C). It has a maximum module current of 8A and a maximum point current of 2A (both at 60C), a 1mA maximum off-state leakage current per point, and a 2V DC maximum on-state voltage drop at 2A. Output delay times are 1ms (off to on) and 2ms (on to off), with a thermal dissipation of 16.71 BTU/hr and a maximum power dissipation of 4.9W at 60C. Communication formats include rack optimization, scheduled output data, output data, listen-only rack optimization, and listen-only output data, and it allows configurable fault/program mode states (On, Off, Hold Last State, default Off) per point.
Is Your Device Showing These Signs?
The Allen Bradley 1756-OC8 output module commonly experiences failures due to blown output fuses, often caused by inductive load spikes or wiring shorts. Technicians frequently address issues stemming from damaged Triacs or MOV components within the output circuitry, leading to non-functional outputs. Corrosion on the backplane connector pins is a prevalent problem, resulting in communication errors and intermittent operation. Firmware corruption necessitates reflashing the module, and component degradation due to thermal stress requires replacement of capacitors or resistors to restore proper functionality. Field wiring issues, such as improper termination or incorrect voltage application, also contribute to module malfunctions.
Technical specifications
The Allen-Bradley 1756-OC8 is an 8-point ControlLogix DC output module that requires external fusing (4A quick-acting) for output protection. It operates on a 30-60V DC source, has specific current draw and load requirements, and features configurable output states and communication formats. Key specifications include current limits, voltage drop, delay times, and power dissipation, all detailed for optimal performance within a ControlLogix system. Proper grounding and a compatible RTB are essential for installation.
Our Repair Process for the
1756-OC8
Our repair process for the Allen Bradley 1756-OC8 output module begins with a thorough inspection for blown output fuses, which are replaced and tested under load. The output circuitry is then scrutinized for damaged Triacs or MOV components; these are replaced with new, high-quality components. Next, the backplane connector pins undergo meticulous cleaning and inspection for corrosion, with damaged pins receiving immediate repair or replacement. If firmware corruption is suspected, the module is reflashed to the latest revision. Component-level diagnostics are performed to identify and replace degraded capacitors or resistors affected by thermal stress. Finally, all field wiring connections are verified for proper termination and voltage application, ensuring adherence to specifications before the module undergoes rigorous functional testing to validate complete restoration of operational integrity.
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Your satisfaction is our top priority, and we confidently stand behind the quality of our repairs. That's why every repair service is covered by our comprehensive 24-month warranty. Furthermore, we offer lifetime phone support – if you have questions or need assistance related to our repair down the road, we're here to help. Our service commitment is straightforward: we guarantee our work, and if you're not satisfied, we will make it right. Learn More about our Repair process.
Comprehensive Repairs You Can Depend On
We take immense pride in the quality and reliability of our work. Our process goes beyond simply fixing the immediate problem. We perform a comprehensive inspection of your main board (or other equipment) and proactively replace components known to be failure-prone or showing signs of potential future failure. Before any item is returned, it undergoes rigorous functional testing to ensure it meets performance specifications and operates flawlessly. Visit our main Repair Services page to learn more.
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Our primary goal is to save you hundreds, or even thousands, of dollars compared to the cost of new equipment replacement. By repairing existing components, we provide an economical solution that is also eco-friendly. At Roc Industrial, our commitment to integrity and community drives our consistent growth and ensures you receive a reliable, cost-effective solution.
Please Note: Roc Industrial operates as an independent service provider and is not an authorized distributor for the manufacturers or brands mentioned. Consequently, the original manufacturer's warranty is not applicable to items repaired or sold by us. Roc Industrial provides its own 2-year warranty on all repair services performed.