Product Overview
When an output module fails on a live ControlLogix line, every hour of downtime hits production hard. The Allen-Bradley 1756-ON8 is an 8-point output module built for the ControlLogix platform, and it is a practical drop-in spare for oil, gas and industrial automation cabinets that cannot wait on long lead times.
This module provides On/Off actuation and detection for output devices such as motor starters in industrial environments. It uses a producer and consumer network model, so it can generate information when needed while adding system functionality. The 1756-ON8 supports direct and rack-optimized connections, and its integral status indicators make I/O status and module health easy to monitor.
Key Parameters
Operating Voltage Range
The 1756-ON8 operates on a 10-30 Volts AC range. That wide band gives you headroom in real-world cabinets where supply levels drift, and it simplifies matching the module to existing AC output circuits.
Output Configuration
The module carries 8 outputs arranged as 4 points per group. Grouping matters during troubleshooting: a fault in one group does not automatically take down the other, so you can isolate problems faster and keep more of the process running.
Power Dissipation
Maximum power dissipation is 5.1 Watts at 60 degrees Celsius. Plan panel airflow accordingly, especially in densely packed enclosures where heat builds up over a shift.
Isolation
Isolation voltage is 50 Volts continuous, which helps protect backplane electronics from field-side disturbances.
Physical
The module weighs 0.363 kilograms and uses an open-type enclosure, so it must be installed inside an enclosure designed for the surrounding environmental conditions.
Where the 1756-ON8 Fits
Oil and gas facilities often run ControlLogix racks in pump stations, compressor control panels and pipeline valve skids. The 1756-ON8 handles AC output switching for motor starters and similar devices in those cabinets.
In food, water and general manufacturing plants, the same module drives AC output loads where a compact 8-point block keeps spare-part inventory simple. Because it is a component of a ControlLogix system, it works alongside controllers, removable terminal blocks and adapters.
Installation Notes
Shutting off power to the ControlLogix system is not necessary to remove or install the module, since the operation does not disrupt other processes in the system. Even so, do not disconnect equipment unless power has been shut off.
Secure the mating external connection using screws, shear hooks, threaded connectors or other means provided with the product. Exceeding the surge and power rating while applying the module to network devices can damage it, so verify load ratings before commissioning.
Compatibility and Sourcing
The 1756-ON8 accepts removable terminal blocks 1756-TBNH and 1756-TBSH. Confirm which terminal block style your rack uses before ordering, because the module alone will not complete the field wiring.
As a component of a ControlLogix system, this module depends on the controller, adapters and RTBs around it. If you are replacing a failed unit mid-shift, having the right terminal block on the shelf matters as much as the module itself. Oil AutoTech offers hands-on technical selection help and fast dispatch, worldwide, so you get spares when you need them.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
Selection Checklist
Before you buy, confirm the module type, output count, operating voltage range, terminal block part number and enclosure requirements against your existing installation. Matching these details prevents a second order and a second delay.
Contact Oil AutoTech today for pricing and availability.
