Allen-Bradley 1756-A10 ControlLogix 10-Slot Chassis

A ten-slot ControlLogix backplane

The Allen-Bradley 1756-A10 is a ten-slot standard ControlLogix chassis. It gives room for a controller, several communication modules and a broad set of I/O modules while keeping one backplane and a single power supply. Any module can be placed in any slot, as stated in the Rockwell Automation documentation.

The data sheet lists a weight of 1.45 kg and a power dissipation of 5 W, and a minimum cabinet width of 71.1 cm.

Technical specifications

Installation notes

Mount the chassis horizontally only. A cabinet of at least 50.8 x 71.1 x 20.3 cm is specified, so check the panel width before choosing the ten-slot size. Use 8.3 mm² (8 AWG) wire for the functional earth ground and 2.1 mm² (14 AWG) wire for the protective earth ground.

The power supply sits at the left side of the chassis and is ordered separately. Match its 5.1V output to the total backplane draw of the modules you plan to fit; the chassis itself is rated 15 A at 5.1V DC.

Series and related chassis

Series B and series C are listed, with a series C operating range of -25 to +60 °C. The 1756-A10K is the conformal-coated variant and the installation instructions add XT versions. The 1756-A7 has seven slots and the 1756-A13 thirteen, with the same current ratings per slot.

When you plan the panel, note that the ten-slot chassis weighs about 1.45 kg without modules or a power supply, so mount it on a rigid back panel. Rockwell also lists series C with a wider operating range of -25 to +60 °C, so choose series C if the cabinet can see cold start-up conditions, and keep the clearances around the chassis that the installation instructions specify.

Key features of the 1756-A10

• Ten slots on one backplane – enough for a controller, communication modules such as EtherNet/IP or ControlNet bridges, and a medium I/O count in a single rack.
• Any module in any slot – controllers, communication and I/O modules can be arranged freely, which simplifies layout and later expansion.
• Multiple controllers in one chassis – ControlLogix allows more than one controller to share the backplane, useful when separating process and safety-related or packaged-unit logic.
• Removal and insertion under power – ControlLogix I/O modules support RIUP, so a faulty module can be replaced while the system runs, taking the usual precautions for the field wiring.
• Passive backplane – the chassis itself has no active electronics, which is why its dissipation is only 5 W.

Planning the power budget

The chassis carries no power supply of its own. A 1756 power supply, standard or redundant, must be selected so its output covers the sum of the backplane currents drawn by every module at 1.2 V, 3.3 V, 5.1 V and 24 V DC. The table above gives the chassis limits per voltage. In practice, add up the backplane current figures from each module’s data sheet and compare them with both the power supply rating and these chassis limits. Leaving spare capacity allows future modules to be added without changing the power supply.

Choosing the chassis size

Where fewer modules are needed, the four, seven or thirteen slot chassis may fit better; where more are needed, the 1756-A17 offers seventeen slots.

Applications in Oman and GCC facilities

ControlLogix racks are found across oil and gas, power, water and desalination and process industries in the region. In plants near the coast or in sour gas environments, the conformal-coated version is often preferred because it adds protection against corrosive gases and humidity. Control rooms are normally air conditioned, but remote instrument shelters can run hot, so the chassis operating temperature and that of every installed module should be checked against the shelter design temperature.

What to include in your RFQ

• Catalog number 1756-A10 or 1756-A10K and the required series, if a specific one is needed for an existing system.
• Power supply, slot filler modules and any other ControlLogix components to be quoted together.
• Quantity, delivery location and documentation requirements.

Documents and quotation

The Rockwell Automation ControlLogix chassis installation instructions are attached; the full technical data sheet, publication 1756-TD006, is on the Rockwell Automation literature library. See our PLC and I/O cards catalogue for compatible controllers and I/O. Confirm the exact catalog number, series letter and firmware or hardware revision on the product label, and the compatibility with your existing system, before ordering. Stock and lead time are confirmed at quotation.