Allen Bradley 1756 ControlLogix Chassis Specifications

Product Overview

The 1756 ControlLogix chassis is a modular system designed for horizontal back-panel mounting. It provides a high-speed communication path between installed modules and distributes power to each module within the chassis. The system supports various configurations, including standard, XT (extreme temperature), and ZXT (corrosion-resistant) versions to suit diverse industrial environments.

Technical Specifications

The chassis are available in 4, 7, 10, 13, and 17-slot configurations. Key electrical specifications include:

• Backplane current: 1.5 A at 1.2V DC, 4 A at 3.3V DC, 15 A at 5.1V DC, and 2.8 A at 24V DC.
• Isolation voltage: Determined by the installed power supply and modules.
• Mounting: Horizontal panel mounting only.
• Enclosure rating: Open-style.

Environmental specifications vary by series and model, with operating temperatures ranging from -25 to +70 degrees Celsius for XT models. All units are designed to withstand significant vibration and shock, with specific models featuring conformal coating for enhanced protection against corrosive atmospheres.

Installation and Spacing

Proper installation requires adherence to strict spacing requirements to ensure adequate airflow and cable management. A minimum clearance of 12.7 cm (5.0 in.) is required on the left side of the chassis to route and connect the 1756-CPR2 cable. When using redundant power supplies, a minimum clearance of 12.7 cm (5.0 in.) must be maintained below the supply for cable routing.

Safety and Maintenance

The chassis must be grounded using functional earth ground (8.3 mm2 / 8 AWG) and protective earth ground (2.1 mm2 / 14 AWG) copper wire rated at 90 degrees Celsius or greater. For maintenance, use slot filler modules (1756-N2 or 1756-N2XT) to cover any empty slots. Ensure that port plugs remain installed in unused ports to maintain the corrosive atmosphere rating for XT and ZXT models.