Product Details
Product Overview
The Allen Bradley 1797-OB4D functions as a high-performance, intrinsically safe digital output module specifically engineered for the FLEX Ex I/O platform. This module controls field devices located in hazardous areas by providing four non-isolated sourcing outputs. It integrates advanced hardware diagnostics and electronic protection to maintain system integrity in volatile environments. We provide this unit as 100% Brand New and Original, ensuring your hazardous area installation meets all regulatory safety standards and operational requirements.
Technical Specifications
The 1797-OB4D delivers precise control and monitoring via the following technical parameters:
| Feature | Specification |
| Manufacturer | Allen Bradley |
| Product Line | FLEX Ex I/O (1797) |
| Number of Outputs | 4 Non-isolated Sourcing |
| Load Range | 30 to 5000 Ohms |
| Power Supply | 9.5V DC |
| Electronic Protection | Lead Break, Overload, and Short Circuit |
| Field-side Power Consumption | 7.5 Watts |
| Power Dissipation | 5.0 Watts |
| Thermal Dissipation | 17.07 BTU/hr |
| Conductor Wire Size | Up to 4 $mm^2$ |
| Weight | 1.00 lbs (0.45 kg) |
Engineering Advantages
The 1797-OB4D addresses the specialized challenges of hazardous location automation through targeted electronic design:
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Intrinsically Safe Architecture: This module eliminates the need for expensive explosion-proof enclosures or external safety barriers. It limits the energy discharged to the field, preventing the ignition of flammable atmospheres in Zone 1 or Zone 2 environments.
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Comprehensive Diagnostic Coverage: The hardware actively monitors the health of the output loop. It detects "Lead Break" (open circuit) and "Short Circuit" conditions instantly, reporting these faults to the controller to prevent process deviations and reduce troubleshooting time.
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Enhanced Load Versatility: A wide load range of 30 to 5000 Ohms allows the module to drive a broad variety of intrinsically safe solenoids, indicators, and actuators without requiring impedance matching components.
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Integrated Electronic Protection: The module features rapid-response electronic protection that shuts down individual channels during an overload. This localized response prevents a single field fault from compromising the entire I/O rack's power supply or backplane.
FAQs
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Can I use the 1797-OB4D with standard 1794 FLEX I/O terminal bases?
No. The 1797-OB4D requires a 1797-series terminal base. The 1797 FLEX Ex system uses a specialized backplane and power distribution architecture to maintain intrinsic safety ratings, making it incompatible with standard 1794 hardware.
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What type of field wiring do you recommend for this module?
The module terminals accommodate wire sizes up to 4 $mm^2$. We recommend using blue-jacketed cable to clearly identify intrinsically safe circuits within your control cabinets and field runs, adhering to international safety standards.
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How does the "Lead Break" detection benefit my operation?
Lead Break detection alerts the control system if a wire becomes disconnected or a solenoid coil fails open. This allows the PLC to trigger a safety interlock or maintenance alarm immediately, rather than waiting for a process failure to reveal the hardware issue.
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What power source does the 1797-OB4D require?
The module draws power from the 1797-PS series intrinsically safe power supply via the FLEX Ex backplane. You must calculate the total power consumption (7.5W field-side for this module) to ensure your power supply module has sufficient capacity for the entire rack.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Redundant Automation Systems: Ensuring Continuous Uptime in Critical Control Infrastructure
System reliability directly determines operational profitability across high stakes process industries. Modern industrial automation platforms must eliminate single points of failure to prevent catastrophic shutdowns. Deploying fault tolerant architecture safeguards complex facilities against unexpected hardware glitches, network disruptions, and maintenance outages.
Understanding Types of Noise in Electronic Circuits and Control Systems
Signal integrity directly determines measurement accuracy and loop stability across industrial automation environments. Electronic noise introduces unwanted stochastic interference into analog loops, sensor feedback lines, and digital fieldbus networks. Understanding how intrinsic electronic noise and external electromagnetic interference manifest allows control engineers to optimize signal conditioning and shield sensitive instrumentation effectively.
Why 24V DC Power Supplies Standardize Modern Industrial Automation
Industrial control cabinets worldwide rely on 24V DC as the universal power standard for field instrumentation, sensors, and controllers. Walk into any manufacturing plant, and you will find PLCs, human-machine interfaces (HMIs), and smart actuators running on extra-low voltage DC. Standardizing on 24V DC enhances operational safety, lowers cabinet footprint, and maintains steady control performance across factory networks.