Allen-Bradley 1756-CP3 ControlLogix Chassis Power Cable, 0.914 m (3 ft)

Description

Application Scenarios

Picture a ControlLogix panel where the 1756 chassis sits at the top of the enclosure and the 1756-PB75 power supply is mounted on a DIN rail below, exactly 0.9 m away. The 3 ft 1756-CP3​ is the correct length: long enough to route neatly along the panel channel, short enough that there is no excess cable to bundle, kink or couple noise into. Using a longer cable here would add inductance and a dangling loop; using a field-made cable would risk a pin-out error that can damage the power supply or the backplane. The 1756-CP3​ arrives with the correct 4-pin female connector and the correct polarity, so the installer makes one connection at each end and the backplane powers up. For a panel builder or a maintenance electrician, that predictability is the product’s real value — a few dollars spent on the right cable prevents a very expensive mistake.

Parameter

Technical Principles and Innovative Values

Innovation Point 1 — A defined length instead of a field-made cable.​ The 1756-CP3​ is 0.914 m (3 ft) by design, which is deliberately short. Chassis power is unregulated 24V DC at several amps, so a long, unshielded, field-made cable adds inductance and becomes an antenna for the VFD and contactor noise that fills a ControlLogix panel. Rockwell’s answer is a family of three fixed lengths — the 1756-CP3​ at 3 ft, the 1756-CP10​ at 6 ft and the 1756-CP15​ at 14 ft — so the installer picks the length that fits the panel instead of coiling excess cable. In a rack with a redundant power supply, the short cable also prevents the two supply leads from becoming a tangled, hard-to-trace pair during a fault.Innovation Point 2 — Correct polarity and pin-out, factory-terminated.​ The 4-pin female connector is terminated at the factory to the ControlLogix power-supply and chassis-backplane pin-out, with the polarity fixed. A reversed or mis-pinned connection can damage the power supply or the backplane, and the symptom is often a dead chassis with no obvious cause. Using the 1756-CP3​ removes that failure mode entirely — there is only one way to seat the connector, and it is the right way.Innovation Point 3 — Part of a redundant and distributed power strategy.​ In a ControlLogix chassis, the power supply can be mounted locally or remotely, and the 1756-CP3​ is the link that makes both layouts possible. In a redundant configuration, the same cable family carries power from the redundant supplies to the chassis, so a failed supply is replaced without rewiring. For a panel builder, that means one cable part number per layout and a wiring plan that is identical across every panel in the plant.Innovation Point 4 — The unglamorous component that decides uptime.​ A power cable is rarely specified with care, yet it is the single point through which every module in the chassis draws its 24V DC. The 1756-CP3​ is built to the same UL/CSA/CE/C-Tick standards as the modules around it, with a 300V AC / 24V DC rating and a 0…60 °C operating range. That consistency matters during an unplanned outage: a verified spare of the correct length is the difference between a 20-minute repair and a day lost to a makeshift cable.

Application Cases and Industry Value

Case 1 — Skid-mounted ControlLogix panel, local power supply.​ A system integrator building a skid-mounted ControlLogix panel placed the 1756-A10 chassis at the top of the enclosure and the 1756-PB75 power supply on a DIN rail 0.9 m below. The 1756-CP3​ was the correct length: it routed along the panel channel without excess, and the factory-terminated 4-pin female connector meant the electrician made two connections and moved on. During commissioning, the backplane powered up cleanly on the first attempt — no polarity check, no voltage drop, no re-termination. The integrator now specifies the 1756-CP3​ for every local-supply panel and keeps a verified spare in the skid’s spare-parts kit.Case 2 — Remote power supply in a high-temperature cabinet.​ A steel-mill application mounted the ControlLogix chassis in an air-conditioned section of the panel and the power supply in a cooler compartment 0.9 m away, to keep the supply out of the worst heat. The 1756-CP3​ carried the 24V DC between the two sections without adding a cable loop that could couple mill noise into the backplane. When the supply failed during a scheduled shutdown, the maintenance team swapped it in minutes using the spare 1756-CP3​ and the chassis was back online before the next heat. The plant now treats the cable as a consumable spare rather than an afterthought.In both cases the 1756-CP3​ raised the automation level by making the power connection predictable and repeatable, cut maintenance cost by eliminating field-terminated cables and polarity errors, and strengthened operational reliability by keeping the backplane supply clean and the spare-parts list short.