Product Overview
The Allen-Bradley 1756-OA16I is a 16-channel discrete AC output module from the ControlLogix family. Designed for demanding industrial environments, this module delivers reliable switching for AC loads up to 265V. With individually isolated outputs, it provides excellent electrical separation and fault containment, making it a trusted choice for PLC and DCS systems.
Part of the Rockwell Automation 1756 series, the 1756-OA16I offers a nominal output of 120/240 VAC and operates across a wide voltage range of 74-265 VAC at 47-63 Hz. Its robust design ensures stable performance in high-vibration or high-temperature settings, reducing downtime and maintenance costs.
Key Features & Benefits
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16 individually isolated outputs – Each channel is electrically isolated, preventing cross-talk and improving system safety.
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Wide operating voltage range (74-265 VAC) – Compatible with global power standards, simplifying integration.
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High output current – Supports up to 2 A per point at 30 °C and 1 A at 60 °C, with linear derating.
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Fast switching – Output delay of 9.3 ms at 60 Hz and 11 ms at 50 Hz ensures responsive control.
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Low leakage current – Only 3 mA per point in the OFF state, minimizing unwanted load activation.
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Flexible configuration – Fault and program mode states can be set to Hold Last State, On, or Off, with Off as default.
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number |
1756-OA16I |
| Series |
1756 ControlLogix |
| Module Type |
Digital AC Output Module |
| Number of Outputs |
16 (individually isolated) |
| Operating Voltage Range |
74-265 VAC |
| Output Voltage |
120/240 VAC nominal |
| Output Delay Time (OFF to ON) |
9.3 ms @ 60 Hz; 11 ms @ 50 Hz |
| OFF-State Leakage Current |
3 mA per point |
| Backplane Current at 5.1 V |
225 mA |
| Backplane Current at 5 V |
300 mA |
| Backplane Current at 24 V |
3 mA |
| Continuous Current per Point |
2 A @ 30 °C; 1 A @ 60 °C (linear derating) |
| Continuous Current per Module (Max) |
5 A @ 30 °C; 4 A @ 60 °C (linear derating) |
| Power Dissipation (Max) |
5.5 W @ 60 °C |
| Removable Terminal Blocks |
1756-TBCH, 1756-TBS6H |
| Isolation Voltage |
50 V continuous |
| Enclosure |
None (open style) |
| UPC |
10612598164513 |
Industry Applications
The 1756-OA16I excels in applications requiring reliable AC switching, such as:
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Motor contactor control – Switching contactor coils in conveyor systems and packaging lines.
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Valve actuation – Operating solenoid valves in process control and water treatment plants.
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Heater control – Managing AC heaters in plastic molding and food processing equipment.
With its wide voltage range and isolated channels, the module is ideal for mixed-voltage panels, reducing the need for additional interposing relays.
Installation & Setup
Mount the 1756-OA16I in any 1756 chassis (e.g., 1756-A4, A7, A10, A13, A17). Install it in the local rack with a ControlLogix controller or in a remote I/O rack using a communication adapter. Use a compatible removable terminal block (1756-TBCH or 1756-TBS6H) for wiring. Ensure the backplane current (300 mA at 5 V, 3 mA at 24 V) is within your system's power budget. Configure fault and program mode states via the controller software; the default is Off.
Maintenance & Reliability
This module's open-style enclosure requires periodic inspection for dust and debris, especially in harsh environments. Check that all wiring connections are tight and terminal blocks are seated correctly. The module operates between 0 and 60 °C with 5-95% non-condensing humidity; ensure adequate ventilation. With no internal fusing, external fusing is recommended for each output circuit to protect against overcurrent.
Compatibility & Integration
The 1756-OA16I integrates seamlessly with ControlLogix controllers and 1756 I/O chassis. It supports fault-mode configuration per point and is compatible with the 1756-TBCH and 1756-TBS6H terminal blocks. The module is a direct replacement for earlier 1756-OA16 models, offering the same form factor and improved isolation.
Selection Guide & Purchasing Advice
Before purchasing, verify your system's backplane power capacity and the required output current. Confirm that your controller supports 1756 series modules. For reliable supply and genuine parts, choose PLC Source PRO – your trusted source for industrial automation spares.