Allen-Bradley 1756-OB16EK – ControlLogix Electronically Fused Output Module

The Allen-Bradley 1756-OB16EK is a ControlLogix electronically fused output module. Specifically, this module provides 16 output points with electronic fusing. It belongs to the ControlLogix series from Rockwell Automation. Furthermore, it features conformal coating for enhanced environmental protection. The voltage category is 12/24V DC source. Consequently, this module suits applications requiring overcurrent protection without physical fuse replacement.

Ordering Configuration and Product Identification

• Manufacturer: Rockwell Automation.

• Brand: Allen-Bradley.

• Part Number: 1756-OB16EK.

• Series: ControlLogix.

• Module Type: Electronic Fused DC Output Module.

• Outputs: 16-point electronically fused.

• Voltage Category: 12/24V DC source.

• Operating Voltage Range: 10-31.2 Volts DC.

• Removable Terminal Block Housing: 1756-TBNH or 1756-TBSH.

• Enclosure Type: None (open-style).

• Coating: Conformally coated (EK suffix).

• Therefore, the Allen-Bradley 1756-OB16EK offers advanced electronic fusing in a compact form factor.

Output Current Ratings

• Maximum Output Current (Per Point): 1 Amp at 60° Celsius.

• Maximum Output Current (Per Module): 8 Amps at 60° Celsius.

• Current Rating Condition: At 60°C ambient temperature.

• Derating: Required for higher temperatures.

• Output Type: Source output (current sourcing).

• Electronic Fusing: Individual channel protection.

• Fuse Reset: No physical replacement needed.

• Fault Indication: Electronic detection and reporting.

• Thus, the 1756-OB16EK protects each channel independently without fuse replacement.

Power and Thermal Specifications

• Power Dissipation (Maximum): 4.1 Watts at 60° Celsius.

• Backplane Current (5 Volts): 250 milliamps.

• Backplane Current (24 Volts): Not specified (field power separate).

• Isolation Voltage (Continuous): 50 Volts.

• Thermal Dissipation: Contained within power dissipation.

• Field Power Supply: External 10-31.2V DC required.

• Efficiency: Electronic fusing minimizes power loss.

• Consequently, the Allen-Bradley 1756-OB16EK consumes moderate backplane power.

Conformal Coating Feature

• Coating Type: Conformal coating on circuit board.

• EK Suffix: Indicates conformally coated version.

• Purpose: Protects against moisture, dust, and chemicals.

• Environment: Suitable for harsh and corrosive conditions.

• Benefit: Extends module lifespan in challenging environments.

• Application: Chemical plants, food processing, outdoor installations.

• Standard Version: Non-coated version available (1756-OB16).

• XT Compatibility: Works with ControlLogix-XT systems.

• Therefore, the 1756-OB16EK is ideal for applications with environmental exposure risks.

Electronic Fusing Features

• Fuse Type: Electronic (solid-state) per channel.

• Advantage: No physical fuse replacement required.

• Reset Method: Software reset or power cycle.

• Trip Indication: Diagnostic feedback via backplane.

• Coordination: Can be monitored by controller logic.

• Recovery Time: Fast recovery after fault clearance.

• Reliability: No fuse wear or fatigue.

• Maintenance: Reduced compared to fused modules.

• Thus, the 1756-OB16EK eliminates fuse inventory and replacement downtime.

Removable Terminal Block Options

• Terminal Block Housing 1: 1756-TBNH (standard housing).

• Terminal Block Housing 2: 1756-TBSH (standard housing).

• Terminal Type: Removable for easy wiring.

• Connection Count: 20-pin configuration.

• Wire Size: Accepts standard industrial wiring.

• Replacement Benefit: No rewiring during module exchange.

• Securing Method: Screw or latch mechanism.

• Field Wiring: Convenient access from front of module.

• Consequently, the Allen-Bradley 1756-OB16EK simplifies installation and maintenance.

Installation Guide

First, verify that all system power sources are completely disconnected. Then, select an available slot in your ControlLogix chassis. The 1756-OB16EK occupies a single slot. After that, slide the module into the chosen slot. Push firmly until the backplane connector is fully seated. Next, select either the 1756-TBNH or 1756-TBSH removable terminal block. Attach the terminal block to the module front. Then, connect your external 10-31.2V DC field power supply to the appropriate terminals. After that, connect your field devices (solenoids, relays, indicators) to the 16 output channels. Each channel can source up to 1 Amp at 60°C. Then, apply backplane power to the ControlLogix chassis. The module will begin its power-up sequence. After that, configure the electronic fusing parameters in your control program. Set fault monitoring and reset behavior as needed. Then, test each output channel for proper operation. Finally, monitor diagnostic feedback for any fuse trip conditions. As a result, the Allen-Bradley 1756-OB16EK will provide reliable electronically fused DC outputs.

Packaging List

• One Allen-Bradley 1756-OB16EK electronically fused output module

• One removable terminal block (1756-TBNH or 1756-TBSH, order separately)

• One product identification label

• One installation and wiring guide

• Conformal coating (applied at factory)

Common FAQs

Q1: How many outputs does the Allen-Bradley 1756-OB16EK provide?
A: This module provides 16 electronically fused output points. Each output is individually protected. Therefore, a fault on one channel does not affect the other channels.

Q2: What is the operating voltage range of the 1756-OB16EK?
A: The operating voltage range is 10 to 31.2 Volts DC. The voltage category is 12/24V DC source. Therefore, it works with standard 12V or 24V DC control systems.

Q3: What does the "EK" suffix mean on the 1756-OB16EK?
A: The "EK" suffix indicates conformal coating on the circuit board. This coating protects against moisture, dust, and chemical exposure. Consequently, this module is ideal for harsh industrial environments.

Q4: What is the maximum current per output on the 1756-OB16EK?
A: The maximum current per output is 1 Amp at 60° Celsius. The maximum module current is 8 Amps at 60° Celsius. Therefore, derating applies at higher temperatures.

Q5: What removable terminal blocks work with the Allen-Bradley 1756-OB16EK?
A: This module works with 1756-TBNH or 1756-TBSH terminal block housings. Both are removable for easy wiring. Therefore, order the terminal block separately if not already owned.