1791-8BR Block I/O Module | 8 Inputs 8 Relays | Allen‑Bradley RIO

1791-8BR Block I/O Module – Allen‑Bradley

Oiltech Controls presents the 1791-8BR, a compact combination I/O block. It delivers 8 digital inputs (24VDC) and 8 relay outputs (dry contact, AC/DC compatible). Built for Remote I/O (RIO) networks, it mounts directly on DIN rail or panel. No chassis required – ideal for distributed control near field devices.

Oiltech Controls’s Insight

• Rackless design cuts installation space and cabling costs.
• RIO protocol ensures smooth integration with PLC‑2, PLC‑3, PLC‑5/20, and PLC‑5 scanners.
• Built‑in power supply and signal conditioning reduce external components.
• Relay outputs handle AC or DC loads – versatile for motor starters, solenoids, and indicators.
• Critical note: No internal fusing – always add external fuses to protect external circuits from surge currents.

Technical Specifications (At a Glance)

Compatible Controllers & Scanners

• PLC‑2, PLC‑3, PLC‑5/20, and PLC‑5 families.
• Scanner modules: 1771‑SN, 1772‑SD / SD2, 1775‑S5, 1775‑SR5, and PLC‑5VME (6008‑LTV).
• Works with SLC automation products via RIO.

Wiring & Termination Guide

• Power terminals: +24 (1), RET +24 (3), GND (2).
• RIO connections: BLU (6), CLR (8), SHD (7).
• Use 14‑gauge stranded wire, 3/64″ max insulation thickness.
• Do not parallel outputs – reduces circuit resistance.

Typical Applications

• Discrete control for conveyor systems, packaging lines.
• Interface with proximity / limit / selector / float switches.
• Drive solenoid valves, motor starters, and indicator lamps.
• Distributed I/O for obsolete system upgrades.

Installation & Maintenance Tips

• Mount vertically or horizontally – no derating required.
• External surge protection recommended (module lacks internal fusing).
• Check input off‑state voltage ≤5V DC to avoid false triggers.
• Keep load current ≤1A resistive per output (20‑30V DC).

Why Buy From Oiltech Controls?

• Over 15 years in industrial automation spares.
• Global logistics – ship via FedEx, UPS, or DHL.
• Every unit tested (surplus / refurbished options).
• 12‑month warranty covers parts and workmanship.
• Pre‑shipment technical verification.
• Expert support for obsolete control systems.

Frequently Asked Questions (FAQ) – Expert Selection Guide

• Q: Can I use this module with 120V AC loads?
• A: Yes, relay outputs handle 20‑132V AC (resistive). Check surge current – external fusing is mandatory.
• Q: How do I protect the external circuit from surges?
• A: Install external fuses or surge suppressors. The internal protection only guards the module’s internal circuitry.
• Q: Is this module compatible with a PLC‑5/40?
• A: Yes, via RIO scanner (e.g., 1771‑SN). It works with all PLC‑5 family scanners.
• Q: What wire gauge should I use for power connections?
• A: 14‑gauge stranded copper, with 3/64″ max insulation thickness. Keep leads short to reduce resistance.
• Q: Can I mount this module in a high‑vibration area?
• A: Yes – DIN rail or panel mounting is secure. Use additional end clips for severe vibration.

Shipping & Support

• Same‑day dispatch (24‑28 hours).
• Carrier options: FedEx, UPS, DHL (tracked).
• Technical inquiries: info@oiltechcontrols.com
• WhatsApp: +86 158 8020 0923

Original Source: https://www.oiltechcontrols.com/
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