PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1791-8AC is an I/O Module in the Block I/O 1791 series. This distributed device provides eight 120V AC discrete inputs and eight 120V AC discrete outputs. It operates as a remote node on the proprietary Allen-Bradley Remote I/O network. Communication uses a three-wire Belden 9463 cable arranged in a daisy-chain topology.
The module interfaces with legacy PLC-2, PLC-3, and PLC-5 controller systems. It also connects to SLC 500 processors using the 1747-SN Remote I/O scanner module. The unit requires an external power supply operating between 85 and 132 Volts AC. Total power dissipation reaches 12.9 Watts with thermal output measured at 43.99 BTU per hour.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| UPC | 612598127061 |
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| Weight | 1.31 lbs (0.60 kg) |
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| Output Voltage Range | 20-123VAC |
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| No. of Inputs | Eight (8) |
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| No. of Groups | 1 group of 8 |
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| On-state Voltage range | 79-132VAC |
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| No of outputs | Eight (8 |
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| External Power, Voltage | 85-132VAC |
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| External Power, Current | 150 mA |
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| Mounting | Vertical / Horizontal |
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| Power Dissipation, maximum | 12.9 Watts |
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| Thermal Dissipation, maximum | 43.99 BTU/Hr |
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| Voltage | 120 Volts AC |
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| Inputs per Block | 8 |
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| Input On-state Voltage Range | 79 to 132 Volts AC |
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| Input On-state Current | 5mA at 79 Volts min. |
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| Input Off-state Voltage | 35 Volts max. |
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| Input Off-state Current | 2.3 mA min. |
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| Outputs per Block | 8 |
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| External Power | 85 to 132 Volts AC |
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| Product Lifecycle Status* | Discontinued/Obsolete |
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TECHNICAL INFORMATION
Features
- Provides eight 120V AC inputs and eight 120V AC outputs on one block.
- Communicates across Allen-Bradley Remote I/O networks using Belden 9463 cable.
- Supports distributed daisy-chain network topology for remote station connectivity.
- Allows panel mounting in either horizontal or vertical orientations.
- Dissipates a maximum of 12.9 Watts and 43.99 BTU per hour.
TECHNICAL INFORMATION
Applications
- Distributed AC input and output control in legacy Allen-Bradley PLC architectures.
- Remote machine monitoring and field control using 120V AC discrete devices.
- I/O expansion for SLC 500 controllers through 1747-SN scanner links.
TECHNICAL INFORMATION
Connections / Interfaces
- Remote I/O communications interface connects via three-wire Belden 9463 shielded cable.
- Input terminals accept eight field connections rated for 120V AC nominal operation.
- Output terminals accommodate eight discrete circuits between 20 and 132 Volts AC.
- External power terminals accept a voltage range from 85 to 132 Volts AC.
TECHNICAL INFORMATION
Installation Guidelines
- Mount the unit horizontally or vertically inside an industrial enclosure.
- Maintain space around the housing for convection cooling of up to 43.99 BTU/hour.
- Wire the Remote I/O communication line in a daisy chain using Belden 9463.
TECHNICAL INFORMATION
Compatibility
- Allen-Bradley PLC-2, PLC-3, and PLC-5 programmable logic controller systems.
- Allen-Bradley SLC 500 processors operating with a 1747-SN Remote I/O scanner.
TECHNICAL INFORMATION
Lifecycle / Replacement Information
- The Allen-Bradley 1791-8AC is classified as discontinued and obsolete by the manufacturer.
- Units can be sourced from surplus, refurbished, and maintenance inventory stocks.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSAllen-Bradley PLC-2, PLC-3, and PLC-5 programmable logic controller systems. Allen-Bradley SLC 500 processors operating with a 1747-SN Remote I/O scanner.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
What is the primary function of the Allen-Bradley 1791-8AC?
The module provides eight 120V AC inputs and eight 120V AC outputs on a Remote I/O link.
Which controller platforms support the 1791-8AC module?
It works with PLC-2, PLC-3, PLC-5, and SLC 500 processors using 1747-SN scanners.
What external power supply does the 1791-8AC require?
The unit requires an external supply of 85 to 132 Volts AC at 150 mA.
What is the indicative market reference price for the 1791-8AC?
Observed market reference pricing spans $2,559.51 to $7,901.25. These figures are indicative market reference pricing only and are not a final quotation.
