Product Overview

The Allen-Bradley 1756-OC8 is a DC output module for ControlLogix systems. This module has 8 output points arranged in 4 points per group. It operates on 48V DC nominal voltage. The voltage range is 30 to 60V DC. This module has no internal fuses. Use external fused interface modules (IFM) for output protection. The recommended fuse is 5x20mm 4A quick acting type (SOC p/n MQ2-4A).

For inquiries, contact us at +86 158 8020 0923 (WhatsApp).

Part Number Breakdown (Tree Structure)

• 1756 → Series Family
  • ControlLogix platform
  • Allen-Bradley / Rockwell Automation
• OC → Product Type
  • DC Output Module
  • Higher voltage range (30-60V DC)
• 8 → Channel Count
  • 8 output points
  • 4 points per group

Key Specifications

• Brand: Allen-Bradley / Rockwell Automation
• Part Number: Allen-Bradley 1756-OC8
• Series: ControlLogix
• Module Type: DC Output Module
• Number of Outputs: 8 points (4 per group)
• Voltage Type: 48 Volts DC Source
• Operating Voltage Range: 30 to 60 Volts DC
• Enclosure: None (open-style)

Current Ratings

• Maximum Current per Point (60°C): 2 Amps
• Maximum Current per Module (60°C): 8 Amps
• Pilot Duty: 2 Amps
• Minimum Load Current: 2 mA per point
• Surge Current: 4 Amps for 10 ms per point (repeatable every second at 60°C)
• Maximum Off-State Leakage Current: 1 mA per point
• Maximum On-State Voltage Drop: 2V DC at 2 Amps

Power and Backplane

• Backplane Current (5.1 Volts): 165 milliamps
• Backplane Current (24 Volts): 2 milliamps
• Total Backplane Power: 0.89 Watts
• Power Dissipation (Max at 60°C): 4.9 Watts
• Thermal Dissipation: 16.71 BTU per hour
• Isolation Voltage: 50 Volts continuous

Output Timing

• Maximum Output Delay (Off to On): 1 ms
• Maximum Output Delay (On to Off): 2 ms

Fuse Recommendation

• Module has no internal fuses on outputs.
• Use external fused interface module (IFM) for protection.
• Recommended fuse: 5x20mm 4A quick acting type.
• Manufacturer SOC part number: MQ2-4A.
• Using external fuses prevents output circuit damage.

Compatible Removable Terminal Blocks (RTB)

• 1756-TBNH (screw terminal)
• 1756-TBSH (spring clamp terminal)
• Both are 20-pin RTB types.
• Module requires RTB for field wiring connections.

Communication Formats Available

• Rack optimization
• Scheduled output data
• Output data
• Listen-only rack optimization
• Listen-only output data

Fault Mode and Program Mode Settings

Each output point has independent configuration for:

• On - Output turns ON in fault or program mode
• Off - Output turns OFF in fault or program mode (default)
• Hold Last State - Output keeps its last value

Installation Guide

• Turn off all power before installation.
• Install and ground the chassis and power supply first.
• Connect compatible RTB (1756-TBNH or 1756-TBSH) to module.
• Insert the Allen-Bradley 1756-OC8 into any available chassis slot.
• Press firmly until the module seats in backplane.
• Secure the module with retaining screws.
• Connect external 30-60V DC power to outputs.
• Install external 4A fuses on each output for protection.
• Apply backplane power and check module status.
• Test each output before connecting to field loads.

Maintenance Tips

• Check external fuses periodically for blown condition.
• Inspect RTB connections for tightness every 6 months.
• Monitor output current (do not exceed 2A per point).
• Verify operating temperature stays below 60°C.
• Keep module free from dust and moisture.
• Replace module if outputs fail repeatedly.

Troubleshooting Tips

• If output does not turn on, check external fuse first.
• Check load current (must be above 2 mA minimum).
• Verify supply voltage is between 30-60V DC.
• Check off-state leakage (should be below 1 mA).
• Use Studio 5000 to view module fault codes.
• Check output delay timing (1 ms on, 2 ms off).

Typical Applications

• Industrial equipment running on 48V DC systems
• Telecom and datacom power applications
• Material handling equipment control
• Conveyor systems with 48V solenoids
• DC motor contactor control
• Machine tool power distribution
• Battery-backed industrial systems

Package Contents

• One Allen-Bradley 1756-OC8 DC output module
• Removable terminal block not included (order separately)
• One product label
• Fuses not included (order MQ2-4A separately)

Warranty and Shipping

• 12 months factory warranty from shipment date.
• Warranty covers manufacturing defects only.
• Overload or short circuit without external fuse voids warranty.
• Shipping options: FedEx, UPS, DHL.
• Tracking number provided after shipment.

Frequently Asked Questions (FAQ)

Q1: How many outputs does the 1756-OC8 have?

The Allen-Bradley 1756-OC8 has 8 output points. These are arranged as 4 points per group. Each output can handle up to 2 Amps at 60°C.

Q2: Does this module have internal fuses?

No, this module has no internal fuses on outputs. You must use external fused interface modules (IFM) for protection. The recommended fuse is 5x20mm 4A quick acting type (SOC MQ2-4A).

Q3: What voltage range does the 1756-OC8 accept?

This module operates from 30 to 60 Volts DC. Nominal voltage is 48 Volts DC. Do not apply voltages outside this range.

Q4: What RTB works with this module?

Use 1756-TBNH (screw terminal) or 1756-TBSH (spring clamp). Both are 20-pin removable terminal blocks. Order the RTB separately if needed.

Q5: What is the minimum load current for this module?

Minimum load current is 2 mA per output point. Loads below this may cause incorrect output operation. Use a shunt resistor if needed for very light loads.

Buying Guide

When you buy a Allen-Bradley 1756-OC8 output module, follow these tips. First, check your system voltage. This module works at 30-60V DC (48V nominal). Second, count your output needs. This module gives 8 points. Third, verify your current per output. Maximum is 2A at 60°C. Fourth, order external 4A fuses for each output (MQ2-4A). Fifth, order compatible RTB. Choose 1756-TBNH or 1756-TBSH. Sixth, calculate your power budget. Module draws 165 mA at 5.1V and 2 mA at 24V. Seventh, confirm your control voltage is above 2 mA minimum load. Eighth, consider fault mode behavior. Default is Off. Ninth, review warranty terms. We offer 12 months coverage. Tenth, choose your shipping method. We use FedEx, UPS, and DHL. Finally, test each output with a dummy load before connecting to field equipment.

Copyright © 2026 PLCDCS HUB Limited. All rights reserved.
Original Source: https://plcdcshub.com/
Partner: Powergear X Automation Limited
Oiltech Controls Limited