The Allen-Bradley 1756-OA8D serves as a high-performance digital output module for the ControlLogix platform. This unit provides eight independent AC output points featuring advanced diagnostic functions. It specifically detects blown fuses, no-load conditions, and short circuits during operation. These smart features help maintenance teams identify field-side wiring issues immediately. Consequently, the module significantly reduces troubleshooting time and improves overall system reliability.
Output Performance and Voltage Regulation
This module operates within an AC voltage range of 74V to 132V. It supports a frequency range of 47Hz to 63Hz for global industrial compatibility. Each point manages up to 1A of continuous current at 30°C. However, this capacity decreases as the ambient temperature rises toward the 60°C limit. The circuitry also handles high-demand startup loads with an 8A peak surge rating. Furthermore, signal transition delays remain consistent at approximately 11ms for 60Hz systems.
Technical Specifications and Power Ratings
- Backplane Current (5.1V DC): 175 mA
- Backplane Current (24V DC): 250 mA
- Peak Surge Current: 8 Amps per point (43 ms)
- Maximum Leakage Current: 3 mA per point
- On-State Voltage Drop: 3.0V at 1.0 Amp
- Power Dissipation: 5.6 Watts (General)
- Thermal Dissipation: 18.0 BTU per hour
- Chassis Slot Width: 1 (Single Slot)
Installation and Environmental Safety
The 1756-OA8D installs into any available slot within a standard 1756 chassis. It utilizes a Removable Terminal Block (RTB) for simplified field wiring and maintenance. This design allows for module replacement without disconnecting individual wires from the process. Regarding electrical safety, the unit offers 125V continuous isolation between outputs and the backplane. This protection ensures that field-side electrical noise does not interfere with the controller logic. The module functions reliably in non-condensing environments with humidity levels up to 95%.
Reviews
There are no reviews yet.