How cable choices shape automation reliability

WITH AUTOMATION systems becoming ever more more advanced, expectations around performance continue to rise. High-speed drives, precise motion control and data-rich feedback systems all rely on stable, predictable behaviour across the whole installation. When something falls short, attention quite naturally turns to the active elements in the system. Drive parameters are checked, control loops reviewed and sensors recalibrated. After all, those are the areas where performance is most visible.

In my experience, though, when teams begin to work back through persistent or difficult-to-explain issues, cable specification often becomes part of the conversation. Not as the sole cause, but as a factor that influences how the system behaves under real operating conditions. That influence tends to appear at the margins, where systems are expected to operate consistently rather than simply function.

Specification in a changing environment

The demands placed on cables have shifted as automation has evolved. Higher switching frequencies, increased data transmission and more compact installations have all changed the electrical environment. Power, control and data cables are routed more closely together, often through tighter spaces, and are exposed to more dynamic operating conditions.

Specification choices that would have been sufficient in less demanding environments do not always translate directly. Small differences in construction, shielding or material properties can begin to affect how signals behave and how systems perform over time. This is where some of the more common blind spots tend to sit.

Flex rating is one example. A cable that performs well during installation can give the impression it is suitable for continuous movement, but dynamic applications place much more specific demands on conductor design. Where those demands are not fully matched, fatigue develops gradually. The result is rarely an immediate failure, but more often an intermittent issue that becomes increasingly disruptive.

Signal integrity and control performance

In controls and drives applications, signal quality is closely linked to overall system stability.

Electromagnetic compatibility has become more relevant as installations have grown denser and more electrically active. Power and signal cables frequently share routes, and the effectiveness of screening, combined with correct termination, plays a direct role in how much interference reaches sensitive circuits.

Where that combination is not aligned with the environment, noise can begin to affect signal quality. The effect may not be severe enough to stop the system, but it can influence how accurately feedback is interpreted and how stable control loops remain.

In practice, this often leads to systems that are slightly harder to tune or maintain within tight tolerances. The cable is not usually the root cause of the issue, but it can influence how stable and consistent the system is in operation.

Efficiency and load behaviour

Cable specification also has a role in how efficiently systems operate, although this is not always immediately visible. Many automated processes involve non linear loads, where current draw fluctuates rather than remaining steady. Where conductor sizing or thermal performance has not been aligned with that reality, operating temperatures can rise beyond what was anticipated at design stage.

As temperature increases, resistance changes, and with it the efficiency of power transmission. These effects are incremental, but across continuous operation they become more significant.

It is not simply a question of energy loss. Variations in thermal behaviour can also influence adjacent circuits, particularly in tightly routed installations, which adds another layer to how systems perform in practice.

Material choice and operating conditions

Environmental factors introduce further variation. Oils, cleaning agents, vibration and mechanical wear all interact differently with cable materials, and conditions can vary significantly within a single facility. A sheath that performs well in one area may not respond in the same way elsewhere, particularly where exposure is more demanding. These changes tend to develop over time, which is why they often escape attention during commissioning. By the point performance is affected, the cause is less obvious.

One of the consistent themes across these scenarios is that cable specification is often finalised later in the design process. By that stage, routing decisions and space constraints are already set, which limits how closely the specification can be aligned to the realities of the application. The result is usually a series of small compromises rather than a single critical issue.

Addressing specification earlier, alongside system design, allows those variables to be considered together. Movement, electrical environment and operating conditions can be factored in before constraints are fixed. In most cases, that leads to more predictable performance and fewer issues that need to be resolved once the system is live.

A supporting role with a measurable impact

Cables are not the primary driver of performance, but they contribute to how stable and predictable the system is over time. In highly optimised environments, where systems are expected to run efficiently and remain stable under varying conditions, those influences become more noticeable. Signal quality, thermal behaviour and mechanical durability all play a part in how closely real-world performance aligns with design expectations.

Taking a more considered approach to specification helps reduce the number of variables at play. It does not eliminate the need for careful control system design, but it supports it by creating a more stable foundation to work from.

Mark Froggatt is head of training, learning and development at Eland Cables

www.elandcables.com