How to choose industrial cable for automated systems
Industrial cables are the “nervous system” of automated systems—powering motors, transmitting sensor data, and enabling communication between controllers. Poor cable selection can lead to system malfunctions, unplanned downtime, or even safety hazards. Below is a step-by-step, practical framework to choose cables that match your automated system’s requirements.
1. First: Assess the core application requirements
Before evaluating cable specifications, clarify the cable’s primary function and the system it serves—this eliminates unnecessary options and narrows focus:
- Power cables: For driving motors, actuators, or power supplies. Prioritize current-carrying capacity and voltage rating (e.g., 480V for industrial motors vs. 24V for low-power sensors).
- Signal cables: For transmitting data from proximity sensors, encoders, or vision systems. Prioritize signal integrity (low attenuation, anti-interference) and bandwidth (e.g., Cat6 for Ethernet-based PLCs, coaxial for high-frequency sensors).
- Hybrid cables: Combine power and signal conductors (common in compact systems like robotic arms). Ensure separation between power and signal cores to avoid cross-interference.
Also, note the system’s criticality: For high-precision applications (e.g., semiconductor manufacturing), prioritize cables with tight tolerance and stable performance; for harsh but low-precision systems (e.g., material handling), focus on durability over ultra-high specs.
2. Evaluate environmental conditions (the most overlooked factor)
Automated systems operate in diverse environments—cables must resist external stressors to avoid premature failure. Key environmental factors to consider:
Temperature range
- Low-temperature environments (e.g., cold storage, outdoor winter operations): Choose cables with flexible insulation (e.g., TPE or silicone rubber) that remain pliable below -40°C. Avoid PVC, which becomes brittle at low temperatures.
- High-temperature environments (e.g., near furnaces, welding stations): Select cables with high-temperature rated materials—PTFE insulation (up to 260°C) for extreme heat, or XLPE (up to 125°C) for moderate heat.
Chemical exposure
- Oil/grease: Common in automotive or machinery automation. Use cables with oil-resistant jackets (e.g., nitrile rubber, polyurethane (PUR)).
- Chemicals/solvents: For pharmaceutical or chemical plants, opt for chemically inert materials like PTFE or ETFE.
- Moisture/humidity: In washdown areas (e.g., food processing), choose water-resistant cables with IP67/IP68-rated jackets (e.g., PUR or chlorosulfonated polyethylene (CSP)).
Mechanical stress
- Abrasion: Cables in conveyor systems or floor-mounted robots need wear-resistant jackets (PUR is ideal—3x more abrasion-resistant than PVC).
- Flexing/torsion: For moving parts (e.g., robotic arms, linear actuators), use “flexible” or “continuous-flex” cables. Look for:
- Stranded conductors (instead of solid) to withstand bending.
- Minimum bending radius (e.g., 5x cable diameter for static use, 10x for dynamic flexing).
- Tested flex cycles (e.g., 1 million+ cycles for 24/7 operations).
- Impact/crushing: In heavy-industry settings, choose cables with reinforced jackets (e.g., steel-reinforced PUR) or armoring (galvanized steel for mechanical protection).
3. Prioritize electrical performance to avoid signal/power issues
Electrical mismatches are a top cause of automated system errors (e.g., sensor lag, motor tripping). Focus on these specs:
Voltage and current rating
- For power cables: Select a voltage rating higher than the system’s operating voltage (e.g., 600V cable for a 480V motor) to prevent insulation breakdown.
- Current capacity: Match the cable’s ampacity (e.g., 12AWG copper cable carries ~20A) to the load—undersized cables overheat; oversized cables waste cost.
Anti-interference (critical for signal cables)
Automated systems have noisy components (e.g., inverters, motors) that disrupt signals. Choose cables with:
- Shielding: Foil shields (for high-frequency interference) or braided shields (for mechanical strength + low-frequency interference). For severe noise, use double-shielded (foil + braid) cables.
- Twisted pairs: Unshielded twisted pair (UTP) cables reduce crosstalk between conductors—use for Ethernet or encoder signals.
Impedance matching
For high-speed data (e.g., PROFINET, EtherCAT), ensure the cable’s impedance matches the system’s (typically 100Ω for Ethernet-based protocols). Mismatched impedance causes signal reflection and data loss.
4. Verify compliance and long-term reliability
Industry standards
Cables must meet regional or industry-specific standards to ensure safety and compatibility:
- Global: IEC 60228 (conductor size), IEC 60332 (fire resistance).
- North America: UL 1015 (power cables), UL 2464 (multi-conductor cables).
- Europe: CE marking (low-voltage directive).
- Special industries: ATEX (explosive environments), FDA (food contact areas—use non-toxic, easy-to-clean jackets like PUR).
Lifespan and maintenance
- Avoid “cheaper” cables with low-quality insulation—they degrade faster (e.g., PVC in UV light) and require frequent replacement.
- For hard-to-access areas (e.g., inside machinery), choose cables with a 10+ year lifespan (e.g., silicone-insulated cables) to reduce maintenance costs.
5. Final selection checklist
- Confirm the cable’s function (power/signal/hybrid) and system load.
- Match environmental specs (temperature, chemicals, mechanical stress) to cable materials.
- Validate electrical specs (voltage, current, shielding, impedance) against system requirements.
- Ensure compliance with industry standards (UL, IEC, ATEX, etc.).
- Compare total cost of ownership (not just upfront price—include lifespan and maintenance).
Conclusion
Choosing industrial cables for automated systems is not about selecting the “best” cable, but the “right” cable for your specific application. By prioritizing environmental adaptability, electrical performance, and compliance, you can minimize downtime, reduce maintenance costs, and ensure your automated system operates reliably long-term. When in doubt, consult cable manufacturers with experience in your industry—they can provide custom solutions for unique challenges (e.g., extreme temperatures or high-flex applications).