
Introduction
The Allen Bradley 1771-OAN is a reliable AC output module designed for the classic PLC-5 I/O platform. Despite being part of an earlier generation, it remains widely deployed in legacy industrial systems where robust AC load switching and long-term stability are required. Field engineers often use the 1771-OAN in applications where inductive or resistive loads need dependable control with predictable electrical behavior. Its construction and operating envelope make it suitable for demanding facilities that continue to rely on PLC-5 infrastructure.
Technical Specifications
| Parameter |
Value |
| Model |
1771-OAN |
| Module Type |
AC Output Module |
| Output Channels |
8 points |
| Output Voltage Range |
120 VAC nominal |
| Output Current per Channel |
2 A max (resistive) |
| Total Module Current |
12 A max (sum of all outputs) |
| Isolation |
Optical isolation between field side and backplane |
| Operating Frequency |
47–63 Hz |
| Backplane Current Draw |
Approx. 450 mA at 5 V DC |
| Operating Temperature |
0 °C to +60 °C |
| Storage Temperature |
–40 °C to +85 °C |
| Dimensions |
290 mm × 37 mm × 175 mm (H × W × D) — standard 1771 chassis size |
| Weight |
≈ 1.0 kg |
| Mounting |
1771 I/O chassis (PLC-5 system) |
Applications / Use Scenarios
-
Switching of AC solenoids, small motors, lamps, and resistive loads
-
Legacy facility automation in water treatment, steel mills, and power plants
-
Large PLC-5 control systems requiring durable AC output control
-
Retrofit and life-extension projects where existing 1771 racks must stay operational
-
Equipment requiring galvanic isolation from control electronics
Advantages / Engineering Benefits
-
Proven reliability in long-running PLC-5 installations
-
Optically isolated outputs provide enhanced noise immunity
-
High current capacity suitable for small industrial AC loads
-
Well-documented wiring and diagnostics simplify field maintenance
-
Direct integration with all 1771 I/O chassis without additional hardware
-
Extended temperature operation allows deployment in older control rooms and industrial cabinets
Technical FAQs
-
How many AC output channels are available?
The module provides eight independent AC output channels.
-
What type of loads can it drive?
Resistive, inductive, and small motor loads within the rated current.
-
Is there output isolation?
Yes, each output group is optically isolated from the backplane.
-
What is the rated output voltage?
120 VAC nominal at industrial frequency ranges.
-
Can the module handle simultaneous full-load operation?
Up to a maximum combined current of 12 A.
-
Does it support DC loads?
No, it is designed for AC loads only.
-
What chassis is required?
Any standard Allen Bradley 1771 I/O chassis.
-
Is the module hot-swappable?
No, power must be removed before insertion or removal.
-
How is field wiring connected?
Through the removable terminal block on the chassis front connector.
-
Does it require external fusing?
Yes, individual load circuits should be protected according to system design practices.
Recommended Related Models
| Model |
Description |
| 1771-OAD |
120 VAC digital output module (similar family) |
| 1771-OAJ |
High-current AC output module |
| 1771-OA |
8-point AC output, alternative version |
| 1771-OBD |
5 V DC/12–24 V DC digital output module |
Popular Allen Bradley Models
| Model |
Description |
| 1771-OAN |
8-point AC output module |
| 1771-IA |
AC input module (PLC-5 series) |
| 1756-OB16E |
16-pt digital output module (ControlLogix) |
| 1769-IF4 |
CompactLogix analog input module |
| 1794-IA16 |
FLEX I/O AC input module |
Excellent PLC Co., Ltd. has a large number of brand new and original PLC and DCS spare parts, with more than 60 cooperative countries. All products are guaranteed for 1 year and delivered to you by high-quality express.
We are committed to using the best products and the most favorable prices to meet the needs and friendship of our customers. We have won the trust of thousands of customers, including these excellent customers.
As for the delivery time, when we receive your order requirements, we will arrange for warehouse personnel to test and verify the products. After you place the order, we will send it to you within 24 hours.