Allen-Bradley 1769-OA8 CompactLogix AC Output Module
The Allen-Bradley 1769-OA8, also cataloged as the 1769-OA8 AC Output Module, operates as a dedicated hardware component for solid-state AC load switching within CompactLogix and MicroLogix 1500 controller platforms. The unit converts internal controller logic signals into 8 solid-state AC outputs across 2 isolated channel groups, providing direct physical execution for field devices such as solenoid actuators, magnetic contactors, and motor starters. Operating across a voltage range of 85 to 265 VAC at 47 to 63 Hz, the module draws a maximum bus current of 145 mA at 5 VDC directly from the 1769 Compact I/O backplane interconnect.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1769-OA8 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 0.56 lbs (0.26 kg) |
| Dimensions | 4.65 in x 1.38 in x 3.43 in (11.8 cm x 3.5 cm x 8.7 cm) |
| Operating Temp | 0 to 60 deg C (32 to 140 deg F) |
| Power Consumption | 0.725 W (Bus Power: 145 mA @ 5 VDC) |
| Heat Dissipation | 2.12 W |
| Output Channels | 8 AC outputs (2 isolated groups of 4 channels) |
| Operating Voltage Range | 85 to 265 VAC (120/240 VAC nominal) |
| Operating Frequency | 47 to 63 Hz |
| Signal Delay | Turn-on: 1/2 cycle max; Turn-off: 1/2 cycle max |
| Power Supply Distance Rating | 8 modules |
| Mounting Style | DIN Rail or Panel Mount |
| Wire Size | 22 to 14 AWG solid, 22 to 16 AWG stranded |
Backplane Bus Communication & Deterministic Processing
The Allen-Bradley 1769-OA8 interfaces with the CompactLogix backplane via high-speed parallel bus connections, maintaining deterministic system execution and rapid output state updating. Firmware flash compatibility ensures seamless backplane timing synchronization with 1769-L2x, 1769-L3x, or MicroLogix 1500 processors, as well as 1769-ADN (DeviceNet) and 1769-AENTR (EtherNet/IP) bus adapters. High-density I/O channel scaling is achieved while observing the strictly enforced power supply distance rating limit of 8 modules from the primary 1769 system power supply (e.g., 1769-PA2, 1769-PB2, 1769-PA4, 1769-PB4). Onboard optocouplers isolate internal backplane logic circuitry from field-side AC voltage transients, preventing signal noise propagation back to the host CPU.
Frequently Asked Questions
Q: What is the significance of the 8-module power supply distance rating for the 1769-OA8?
A: The power supply distance rating dictates that the 1769-OA8 cannot be mounted more than 8 module slots away from the system power supply module. Exceeding this limit causes excessive backplane voltage drop and communication timing errors along the internal bus.
Q: Can the two output channel groups on the 1769-OA8 operate at different AC supply voltages?
A: Yes. Group 1 (outputs 0 to 3) and Group 2 (outputs 4 to 7) are galvanically separated with independent AC common connections. One group can operate on a 120 VAC supply line while the second group operates on a 240 VAC supply line simultaneously.
Field Installation Guidelines
- System Power Isolation: Remove all primary AC line power and backplane power before mounting, removing, or wiring the 1769-OA8 module to prevent hardware damage or electric shock.
- DIN Rail / Panel Mounting: Secure the module onto a 35 mm DIN rail or panel-mount via screws. Ensure the tongue-and-groove side connectors lock firmly into the adjacent module or power supply before tightening the panel-mounting feet or DIN rail latch.
- Power Supply Placement: Verify that the module is positioned within 8 slots of the system power supply (1769-PA2, 1769-PB2, 1769-PA4, or 1769-PB4) to meet backplane current distribution requirements.
- Field Wiring Termination: Strip conductors to recommended length and connect to the removable terminal block using 22 to 14 AWG solid or 22 to 16 AWG stranded copper wire. Route low-voltage communications and DC signals in separate conduits away from AC output load lines to prevent inductive noise coupling.
Allen-Bradley 1769-OA8 CompactLogix AC Output Module
Allen-Bradley 1769-OA8 CompactLogix AC Output Module
The Allen-Bradley 1769-OA8, also cataloged as the 1769-OA8 AC Output Module, operates as a dedicated hardware component for solid-state AC load switching within CompactLogix and MicroLogix 1500 controller platforms. The unit converts internal controller logic signals into 8 solid-state AC outputs across 2 isolated channel groups, providing direct physical execution for field devices such as solenoid actuators, magnetic contactors, and motor starters. Operating across a voltage range of 85 to 265 VAC at 47 to 63 Hz, the module draws a maximum bus current of 145 mA at 5 VDC directly from the 1769 Compact I/O backplane interconnect.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1769-OA8 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 0.56 lbs (0.26 kg) |
| Dimensions | 4.65 in x 1.38 in x 3.43 in (11.8 cm x 3.5 cm x 8.7 cm) |
| Operating Temp | 0 to 60 deg C (32 to 140 deg F) |
| Power Consumption | 0.725 W (Bus Power: 145 mA @ 5 VDC) |
| Heat Dissipation | 2.12 W |
| Output Channels | 8 AC outputs (2 isolated groups of 4 channels) |
| Operating Voltage Range | 85 to 265 VAC (120/240 VAC nominal) |
| Operating Frequency | 47 to 63 Hz |
| Signal Delay | Turn-on: 1/2 cycle max; Turn-off: 1/2 cycle max |
| Power Supply Distance Rating | 8 modules |
| Mounting Style | DIN Rail or Panel Mount |
| Wire Size | 22 to 14 AWG solid, 22 to 16 AWG stranded |
Backplane Bus Communication & Deterministic Processing
The Allen-Bradley 1769-OA8 interfaces with the CompactLogix backplane via high-speed parallel bus connections, maintaining deterministic system execution and rapid output state updating. Firmware flash compatibility ensures seamless backplane timing synchronization with 1769-L2x, 1769-L3x, or MicroLogix 1500 processors, as well as 1769-ADN (DeviceNet) and 1769-AENTR (EtherNet/IP) bus adapters. High-density I/O channel scaling is achieved while observing the strictly enforced power supply distance rating limit of 8 modules from the primary 1769 system power supply (e.g., 1769-PA2, 1769-PB2, 1769-PA4, 1769-PB4). Onboard optocouplers isolate internal backplane logic circuitry from field-side AC voltage transients, preventing signal noise propagation back to the host CPU.
Frequently Asked Questions
Q: What is the significance of the 8-module power supply distance rating for the 1769-OA8?
A: The power supply distance rating dictates that the 1769-OA8 cannot be mounted more than 8 module slots away from the system power supply module. Exceeding this limit causes excessive backplane voltage drop and communication timing errors along the internal bus.
Q: Can the two output channel groups on the 1769-OA8 operate at different AC supply voltages?
A: Yes. Group 1 (outputs 0 to 3) and Group 2 (outputs 4 to 7) are galvanically separated with independent AC common connections. One group can operate on a 120 VAC supply line while the second group operates on a 240 VAC supply line simultaneously.
Field Installation Guidelines
- System Power Isolation: Remove all primary AC line power and backplane power before mounting, removing, or wiring the 1769-OA8 module to prevent hardware damage or electric shock.
- DIN Rail / Panel Mounting: Secure the module onto a 35 mm DIN rail or panel-mount via screws. Ensure the tongue-and-groove side connectors lock firmly into the adjacent module or power supply before tightening the panel-mounting feet or DIN rail latch.
- Power Supply Placement: Verify that the module is positioned within 8 slots of the system power supply (1769-PA2, 1769-PB2, 1769-PA4, or 1769-PB4) to meet backplane current distribution requirements.
- Field Wiring Termination: Strip conductors to recommended length and connect to the removable terminal block using 22 to 14 AWG solid or 22 to 16 AWG stranded copper wire. Route low-voltage communications and DC signals in separate conduits away from AC output load lines to prevent inductive noise coupling.
