Allen-Bradley 1771-OD16 Isolated 120V AC Output Module

Product Overview

The Allen-Bradley 1771-OD16 is a 16-point isolated AC output module for PLC-5 1771 I/O systems. It provides individual 120V AC output channels capable of driving up to 2A per point and 8A total per module, with built-in fuse protection and status indicators for reliable AC load control in industrial automation applications.

Key Specifications

• Output Channels: 16 isolated AC outputs
• Voltage Category: 120V AC
• AC Operating Range: 74–138V AC
• Operating Frequency: 47–63 Hz
• Max Continuous Current per Output: 2 A
• Max Current per Module: 8 A
• Backplane Current: 200 mA
• Signal Delay (AC Off): 45 ± 15 ms typical
• Signal Delay (DC Off): 50 ms typical
• Data Format: BCD or natural binary
• Wiring Arm: 1771-WN or 1771-WH
• Operating Temperature: 0–60 °C (32–140 °F)
• Coating: Conformal-coated electronics
• Certifications: UL, CE, CSA

Features & Benefits

• High Current Capacity: 2A per point and 8A per module support demanding AC load applications
• Individual Output Isolation: Each channel is electrically isolated for safe multi-phase control
• Built-in Diagnostics: Green active LED, red fuse-blown indicator, and 16 red status LEDs for rapid troubleshooting
• Conformal Coating: Environmental protection for harsh industrial conditions
• Flexible Data Format: Supports both BCD and natural binary programming
• RIUP Compatible: Supports Removal and Insertion Under Power for reduced downtime

Applications

• AC motor starter and contactor control
• Solenoid valve and actuator switching
• Indicator light and annunciator control
• Heater and HVAC load management
• Pump and fan motor control

Installation Guide

1. Chassis Installation: Insert the 1771-OD16 into a compatible 1771-series I/O chassis slot. Ensure adequate backplane power capacity (200 mA per module).
2. Wiring Arm Attachment: Install the 1771-WN or 1771-WH wiring arm before field wiring. The wiring arm provides screw-terminal access for all 16 outputs.
3. Load Wiring: Connect AC loads (74–138V AC, 47–63 Hz) to the output terminals. Ensure load current does not exceed 2A per point or 8A total.
4. Fuse Verification: Check fuse status indicators after power-up. Replace blown fuses with correct ratings per the installation manual.
5. Environmental Protection: Install in NEMA-rated enclosures with proper ventilation. Maintain 0–60 °C operating temperature.

FAQ

Q: Can the 1771-OD16 drive DC loads?
A: No. The 1771-OD16 is designed exclusively for AC loads (74–138V AC). For DC output applications, use the 1771-ODD or 1771-OBD module.

Q: What is the maximum inrush current per output?
A: The module supports 2A continuous per output. For inductive loads with high inrush, verify the load profile stays within module specifications or use external contactors.

Q: How do I know if a fuse has blown?
A: The module features a dedicated red fuse-blown indicator LED. Individual output status LEDs also show channel state for quick diagnostics.

Q: Is this module still manufactured?
A: The 1771-OD16 is a discontinued legacy product. It is available through surplus and refurbishment channels for existing PLC-5 system maintenance.

Selection Tips

• Calculate total AC load current and verify it does not exceed 8A module limit
• For inductive loads (motors, solenoids), consider inrush current and use external protection if necessary
• Specify 1771-WH wiring arm if higher terminal density is required
• Ensure chassis power supply has sufficient 5VDC capacity for all installed modules
• For new designs, evaluate migration to ControlLogix 1756-OA16I or CompactLogix alternatives