Criteria for Cable and Wire Selection

Cable and wire design today is far more than a simple component decision. At its core is overall system thinking, which combines installation type – static or dynamic – electrical and mechanical stresses, as well as cost-effectiveness and sustainability. Ignoring this approach risks failures, energy losses, and unnecessarily high costs.

In times of electrification, increasing data transmission, and growing sustainability pressure, cables quickly become critical components. It is no longer just the parameters listed on a datasheet that determine failures, performance, and service life. A lack of system-level consideration can also prevent manufacturers’ latest technical innovations from being fully utilized. Renowned companies such as LAPP, Igus, HELUKABEL, and Belden have aligned their business models accordingly, treating cables and wires as integral parts of the overall system while taking current technological trends into account.

New fields of application, new requirements

A key development affecting cables and wires is the ongoing electrification of industrial applications from production and intralogistics to charging infrastructure. As a result, requirements for current-carrying capacity, temperature resistance, and service life are increasing significantly. At the same time, direct current (DC) applications are gaining importance, for example in industrial DC grids and high-power charging and drive concepts.

Another trend is functional densification: today, cables often perform multiple tasks simultaneously, including the combined transmission of power and data in hybrid cables. In addition, there is a growing demand for simplified installation and higher system availability.

Requirements are also rising in dynamic applications. Higher speeds, greater acceleration, tighter bending radii, and longer travel distances make cable design in moving systems increasingly demanding. At the same time, the proportion of data-intensive cables continues to grow. Bus systems such as Industrial Ethernet or PROFINET have long since found their way into cable carrier systems.

Sustainability is also becoming increasingly relevant. More users and purchasers are deliberately seeking cables with long service life, transparent CO₂ accounting, and products made from recycled materials. Cables and wires are therefore no longer evaluated solely based on standards compliance, but also on their contribution to the efficiency and sustainability of the overall system.

Selecting the right cable requires considering multiple criteria: installation type–static or dynamic–conductor cross-section, number of bending cycles, stranded versus solid conductors, insulation material, and jacket material. EMC behavior, voltage type (AC/DC), and data transmission requirements must also be factored into the decision-making process. Rather than addressing each parameter in isolation, a holistic system-level view is essential.

Common mistakes in cable selection

According to experts at LAPP, one of the most common pitfalls is addressing cable selection too late in the development process. Often, only the minimum cross-section permitted by standards is chosen without considering actual operating conditions over the entire lifecycle. This can have serious consequences.

To avoid risks from the outset, it is advisable to consistently design from the application perspective. Key questions include: What is the actual current load? How long does the system operate? How flexible must the cable be? What environmental conditions act on it continuously? Energy losses and temperature rise must also be evaluated to ensure a technically and economically sound decision.

In this context, a slightly larger conductor cross-section can provide economic advantages through reduced ohmic losses and lower heat generation. Over the system’s lifetime, the additional investment often pays for itself. Conversely, undersized cables may save costs in the short term but lead to higher energy losses and operating expenses in the long run.

Another observed issue is the uncritical transfer of proven solutions to new fields of application. For example, experience from AC applications is sometimes applied to DC systems without proper verification. Early, application-specific design helps prevent such errors.

A characteristic of LAPP products is that they are not considered in isolation. Especially in high-performance applications, combinations of cable and connector enable more stable long-term connections. This systemic understanding also allows electrical, mechanical, and thermal requirements to be better integrated - benefiting the development of highly flexible power and data cables.

A concrete example is the motor connection cable ÖLFLEX FD Servo (Figure 1 – Left) with integrated zeroCM technology, whose innovative design reduces leakage currents. Another innovation is the single-pair Ethernet cable ETHERLINE T1 FD (Figure 1 – Right), featuring just one twisted pair and enabling seamless network infrastructure down to the field level.

Figure 1: Examples of LAPP’s ÖLFLEX FD Servo (left) and ETHERLINE T1 FD (right) cables. (Image source: LAPP)

A special challenge: moving cables in cable carriers

Selecting suitable cables for cable carrier systems is particularly complex, as experts from Igus explain. Cables designed for continuous movement in cable carriers are not subject to specific standardized requirements. Standards can only be created for clearly defined and limited applications, such as cables for photovoltaic systems. For cable carriers, however, the application scenarios are too diverse for a single unified standard. Nor is there a single “one-size-fits-all” cable for cable carrier applications.

Customers face the challenge of navigating a wide selection of so-called “chainflex-compatible” products, which are difficult to compare directly.

A frequent mistake is selecting the wrong jacket material. A common misconception is that PUR is generally the best jacket material for cable carriers. While PUR is an excellent choice in oil- or lubricant-heavy environments, it often exhibits significantly higher abrasion in dry applications compared to specially formulated PVC compounds designed for continuous motion.

There is also an economic aspect: as a raw material, PUR is approximately three to four times more expensive than high-quality PVC variants. Misjudgment here can therefore cause both technical issues and unnecessary costs. Jacket material selection should always be tailored to the specific application. PUR is ideal for oil-rich environments, whereas PVC is often the better and more cost-effective option in low- or no-oil environments.

Another underestimated problem is selecting cables without verifiable test results. Datasheets may promise a service life of “up to 5 million cycles,” but such statements lack clarity. Under what conditions was this tested? Moving applications in cable carriers vary greatly, and cables do not perform equally under all conditions. Reliable, transparent lifetime data is therefore essential.

With more than 30 years of continuous research and development and extensive testing of cable designs and materials, Igus can now provide guaranteed service life statements for moving cables – calculated and confirmed on an application-specific basis.

Among the company’s key products is the CFCLEAN cable series (Figure 2), designed for highly dynamic applications in extremely space-constrained environments. The series stands out due to its low weight and compact design. Specifically, it is 30 percent lighter and features a 35 percent smaller diameter compared to conventional jacketed cables. Laboratory tests have demonstrated a service life of 20 million cycles–guaranteed by the manufacturer.

Figure 2: An example of the Igus CFCLEAN series. (Image source: Igus)

The system approach simplifies complexity

Many manufacturers confirm a clear shift from pure component purchasing toward integrated, ready-to-function solutions. Especially in mechanical and plant engineering, customers seek fewer interfaces, reduced coordination efforts, and lower project and operational risk.

HELUKABEL recommends a structured approach: first clearly define the application as static or dynamic; then analyze movement profiles, bending radius, travel distance, and dynamics; evaluate environmental conditions; define electrical requirements for power, signal, and data transmission; and finally verify relevant standards and target markets. This systematic process quickly reveals whether a component-only approach is sufficient or whether an integrated system solution reduces effort and risk.

Installation conditions are critical. Even high-quality drag chain cables can suffer damage if bending radii are exceeded, cables are improperly arranged, or separators and strain relief elements are incorrectly designed. Assembly is often underestimated; faulty shield connections, unsuitable connectors, or poor workmanship can quickly lead to EMC problems and failures.

One consistent system solution from HELUKABEL is the HELUCHAIN SYSTEM (Figure 3). It combines cable carriers, matched highly flexible cables, accessories, and optionally pre-assembled, ready-to-connect variants into an integrated package – providing a coordinated, reliable solution rather than separate components.

Figure 3: An example of HELUKABEL’s HELUCHAIN SYSTEM combination cable carrier, cable, and accessories. (Image source: HELUKABEL)

Network infrastructure

With rising data rates and increasing connectivity in industrial plants, the physical network infrastructure is gaining importance. Belden addresses this development with industrial Ethernet solutions (Figure 4) for modern automation architectures. Real-time-capable switches supporting TSN mechanisms enable deterministic communication in harsh industrial environments.

Figure 4: Belden's industrial Ethernet solutions. (Image source: Belden)

The new Belden Industrial Access Point provides deterministic Wi-Fi 7 with low latency for robotics, logistics, and automation applications. Its 5 GHz/6 GHz dual-band design, fast roaming, and integrated diagnostic functions ensure smooth interaction between different systems. System thinking therefore extends beyond the cable itself to include the associated infrastructure.

Sustainability

Sustainability has become significantly more important in the market. Cable manufacturers are increasing transparency and providing documentation on materials and efficient production processes.

However, the most important sustainability lever remains service life: the longer a system operates reliably and the fewer replacement cycles are required, the better the overall economic and ecological balance. Manufacturers are also working on alternative materials, such as bio-based or partially recyclable plastics.

Once again, sustainability should not be evaluated in isolation at the individual cable level, but in the interplay of materials, service life, and energy efficiency within the overall system.