Allen-Bradley 1746-NO4I SLC 500 Relay Module | 4-Channel, 5-250V AC/DC, 2A, 6-240V Isolated Specs

Allen-Bradley 1746-NO4I SLC 500 Relay Module | 4-Channel, 5-250V AC/DC, 2A, 6-240V Isolated Specs

Allen-Bradley 1746-NO4I SLC 500 relay output module specifications. 4-channel isolated relay output, 5-250V AC/DC, 2A per channel, IP20 protection. For industrial automation and control.

Product Overview

The Allen-Bradley 1746-NO4I​ is a 4-channel isolated relay output module​ from the SLC 500 series, designed for industrial automation and control applications. This module provides 4 Form A (SPST-NO) relay outputs​ with individual channel isolation up to 240V, capable of switching 5-250V AC or DC loads at 2A per channel. The "1746" designation indicates the SLC 500 I/O module series, "NO4I" specifies the 4-channel normally open isolated relay configuration. This module interfaces SLC 500 controllers to various AC/DC loads such as contactors, solenoids, and indicators, providing flexible output switching for machine control, process automation, and manufacturing systems.

Technical Specifications

Note: Specifications are based on Allen-Bradley 1746 series technical documentation. The "1746-NO4I" model specifically indicates 4-channel isolated normally open relay configuration. Actual specifications may vary slightly depending on production batch.

Model Number Decoding (1746-NO4I)

• 1746:​ Series designation (SLC 500 I/O module series 1746)

• NO4I:​ Module type (NO = Normally Open relay, 4 = 4 channels, I = Isolated)

Note:​ The "NO" prefix indicates Normally Open relay contacts. The "4" specifies 4 output channels. The "I" suffix indicates isolated channels (each relay isolated from others and from backplane). This module is designed for use in SLC 500 chassis (1746-A4, A7, A10, A13) and requires an SLC 500 processor for operation.

Key Features

• 4 Isolated Relay Outputs:​ Four Form A (SPST-NO) relay contacts

• Individual Channel Isolation:​ 240V AC isolation between channels and backplane

• Wide Voltage Range:​ Switches 5-250V AC or DC loads

• Status Indicators:​ Individual LED indicators for each output channel

• Removable Terminals:​ Screw terminal blocks for easy wiring and maintenance

• Flexible Load Switching:​ Compatible with AC and DC loads up to 250V

• Industrial Grade:​ Designed for harsh industrial environments

• Compact Design:​ Single-slot module for space-efficient installation

• SLC 500 Compatibility:​ Direct integration with SLC 500 controller systems

• High Reliability:​ Proven relay technology with long mechanical life

Load Ratings and Characteristics

Typical Applications

• Machine Control:​ Contactor and starter coil control

• Process Automation:​ Solenoid valve and actuator control

• Material Handling:​ Conveyor motor control and diverter actuation

• Packaging Machinery:​ Heater, sealer, and glue valve control

• HVAC Control:​ Fan, pump, and damper motor control

• Building Automation:​ Lighting control and equipment sequencing

• Water/Wastewater:​ Pump control and valve actuation

• Automotive Manufacturing:​ Production line equipment control

• Test Equipment:​ Load switching and circuit control

Important Technical Notes

1. System Requirements:​ Requires SLC 500 chassis (1746-A4, A7, A10, A13) and SLC 500 processor. Not compatible with CompactLogix or ControlLogix systems.

2. Load Ratings:​ Ratings are for resistive loads. Derate for inductive, capacitive, or lamp loads. See manufacturer's derating curves.

3. Inductive Load Suppression:​ Use appropriate suppression (RC snubbers, varistors, or diodes) for inductive loads to protect relay contacts and extend life.

4. Inrush Current:​ Limit inrush current to 10A maximum for 20 ms. Use inrush current limiters for high inrush loads.

5. Isolation:​ Each channel is isolated from others and from backplane. Maximum continuous isolation voltage is 240V AC.

6. Wiring:​ Use proper wire size (12-24 AWG) and follow NEC/IEC standards. Separate high-voltage and low-voltage wiring.

7. Fusing:​ External fusing required for each output circuit as per local electrical codes and safety standards.

8. Environmental Conditions:​ Install in appropriate enclosure for protection against dust, moisture, and contaminants. IP20 provides limited protection.

9. Maintenance:​ Periodically check connections, LED status, and relay operation. Monitor relay contact wear for high-cycle applications.

Note: For complete installation guidelines, wiring diagrams, configuration instructions, and detailed technical data, consult the official Allen-Bradley 1746 Series Technical Manual. Always verify the exact model number configuration with the manufacturer, as notation variations may occur.