PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1771-A3B is a 12-slot I/O chassis in the PLC-5 series. This modular chassis provides physical mounting slots for 1771 digital, analog, and intelligent modules. It accepts processor modules or remote I/O adapter modules across the 1771 product line. The backplane provides communication pathways between installed modules and the host controller. It supplies internal distribution with a maximum rating of 24 Amperes at 5 Volts DC.
Industrial installations support standard panel subpanel mounting or standard 19-inch rack mounting. The open-style enclosure allows natural air cooling within industrial control enclosures. Modules connect with 1771 wiring arms and remote termination panels for servicing without rewiring. Operating temperature ranges from 0 to 60 degrees Celsius. Noncondensing relative humidity tolerance spans 5 to 95 percent during active operation.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Category | PLCs |
|---|
| Weight | 21.75 lbs (9.87 kg) |
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| Vibration | 2 g (at 10-500 Hertz) |
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| Operating Shock | 15 g |
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| Enclosure Type | Open Style |
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| Mount Type | Panel mount; Rack mount |
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| Max Backplane Current (at 5 Volts DC) | 24 Amperes |
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| Number of Module I/O Slots | 12 Slots |
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| Module Type | I/O Chassis |
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| Operating Temperature | 0 - 60 °C (32 - 140 °F) |
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| Relative Humidity | 5-95% non-condensing |
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| Nonoperating Shock | 30 g |
|---|
| Location | Stand-Alone |
|---|
TECHNICAL INFORMATION
Features
- Provides twelve slots for 1771 I/O, processor, and adapter modules.
- Delivers up to 24 Amperes backplane current at 5 Volts DC.
- Supports both 19-inch rack mounting and enclosure panel mounting.
- Employs an open-style chassis frame for natural convection cooling.
- Accommodates 1771 wiring arms to allow module replacement without disconnecting field wiring.
TECHNICAL INFORMATION
Applications
- Central chassis assemblies in modular Allen-Bradley PLC-5 control systems.
- Distributed remote I/O stations using 1771 I/O adapter modules.
- Industrial control cabinets requiring panel or 19-inch rack mounting.
TECHNICAL INFORMATION
Connections / Interfaces
- Backplane connectors provide data and power distribution across twelve module slots.
- Mechanical mounting areas support 1771 field wiring arms directly.
TECHNICAL INFORMATION
Installation Guidelines
- Mount the chassis to the subpanel using 1/4-20 or M6 x 10 mounting bolts.
- Maintain 102 millimeters clearance between major components and enclosure sides.
- Allow 153 millimeters vertical separation between major components and the chassis.
- Ensure at least 102 millimeters horizontal clearance for cooling airflow.
- Verify that operational shock does not exceed 15g and vibration remains below 2g.
TECHNICAL INFORMATION
Configuration Guidelines
- Verify that total module load does not exceed 24 Amperes at 5 Volts DC.
TECHNICAL INFORMATION
Compatibility
- Compatible with Allen-Bradley 1771 digital, analog, and intelligent I/O modules.
- Accepts 1771 PLC-5 processor modules and 1771 I/O adapter modules.
- Supports standard 1771 removable wiring arms and remote termination panels.
TECHNICAL INFORMATION
Compliance and Certifications
- Certified for use in Class 1, Division 2, Groups A, B, C, and D hazardous locations.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSCompatible with Allen-Bradley 1771 digital, analog, and intelligent I/O modules. Accepts 1771 PLC-5 processor modules and 1771 I/O adapter modules. Supports standard 1771 removable wiring arms and remote termination panels.
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
How many module slots does the 1771-A3B chassis provide?
The 1771-A3B provides twelve module slots for 1771 I/O, processor, or adapter modules.
What is the maximum backplane current rating for the 1771-A3B?
The backplane delivers a maximum current rating of 24 Amperes at 5 Volts DC.
What mounting methods are supported by the 1771-A3B?
The chassis supports both back-panel subpanel mounting and standard 19-inch rack mounting.
What installation clearances are required for the 1771-A3B chassis?
Maintain 102 millimeters side clearance, 153 millimeters vertical clearance, and 102 millimeters horizontal clearance.
