How power and control cables form the backbone of industrial automation
Power cables are vital to industrial and automation processes. Without power, electrical machinery stops functioning, and unwanted downtime ensues. Once a machine is powered on, control cables can then assist in telling it what to do.
In 1959, Oskar Lapp — the founder of LAPP — developed the first flexible, industrially manufactured control cable with colour-coded wires. Since then, LAPP’s ÖLFLEX cables have gained a reputation for durability and versatility, and are used across a wide range of industries.
Suitable for demanding applications, these cables are used in mechanical and system engineering, measurement, control, heating and climate technology, renewable energy sectors including wind and solar power, public infrastructure such as airports and railway stations, medical technology and chemical industries, food and beverage processing, robotics and automation, mobile electrical equipment, power tools, and stage engineering.
“LAPP has continued to evolve the ÖLFLEX range to meet the growing needs of industry. LAPP Australia has continued to expand its local stock, with service, support, technical expertise, and no minimum order quantities nationwide to assist Australian industry with minimising downtime,” said LAPP Australia Managing Director Simon Pullinger.
What are power cables used for?
LAPP’s ÖLFLEX power cables supply devices, machines and plants with energy. They also connect the power supply in buildings, and distribute energy (such as in power stations and converter stations).
A power cable has at least one core and a maximum of five cores. A variant with more than two cores usually consists of a neutral conductor, a protective conductor, and one to three current-carrying outer conductors (phases, L1–L3), depending on the single-phase or three-phase alternating current.
The conductor cross-section is generally ≥0.5 mm2, with the individual cores colour-coded according to VDE 0293-308/HD 308 (core identification code for colour-coded low-voltage cables and wires).
“LAPP offers power cables for the low-voltage range up to 1 kV and for the medium-voltage range up to 30 kV, with certifications to comply with a range of global and local Standards,” Pullinger said.
What are control cables used for?
LAPP’s ÖLFLEX control cables transmit signals within a control circuit and control machine components with these control signals.
Control cables are used to establish wiring within and across machines between electrical devices, machines, switchboards, sensors and actuators. The control cables transmit simple signals used to control machines and their components. The signal receivers execute an action based on the control signals.
A control cable can contain two to typically 25 or, in rare cases, up to 100 numbered cores. The conductor cross-section is usually between 0.5 and 2.5 mm2, but can also be up to 35 mm2 depending on the application. Control cables should be flexible and space-saving and have the smallest possible bending radii.
“Power and control cables are often used in the same applications, but have different functions. For example, a power cable provides the power supply to a machine control cabinet, and the control cables pass on commands to the machine,” Pullinger explained.
Standards compliance
“When specifying electrical cables, one of the most important considerations is whether they comply with the relevant Standards and guidelines,” Pullinger said.
For electrical cables, international standard DIN EN 60204-1:2019-06 regulates the safety and electrical equipment of machinery and, in Part 1, defines the requirements for cables and wires as well as their usage conditions.
“It’s also important to check whether there is a specific product standard with other or extended requirements that take precedence. These could be, for example, the application instructions of the IEC publication 62440:2008 for electrical cables with nominal voltages up to 450/750 V,” Pullinger added.
The nominal voltage is the reference voltage for which cables and wires are constructed and tested. It is expressed by the ratio U0/U in volts, whereby:
- U0 is the effective voltage between a phase conductor and earth; and
- U is the effective voltage between two phase conductors of a multi-core cable or a system of single core cables.
Cable selection: performance characteristics
Industrial cables must meet stringent requirements to perform reliably in demanding conditions. Some of the essential properties include:
- Flexibility: Allows for easy installation and movement, particularly in dynamic applications.
- Oil and chemical resistance: Ensures durability in environments where exposure to oils, chemicals and other substances is common.
- Temperature resistance: Designed to withstand extreme temperatures, from freezing conditions to high-heat applications.
- Mechanical strength: Withstands bending, torsion and other mechanical stresses.
- Electromagnetic compatibility (EMC): Shielded variants help prevent interference with sensitive electronic equipment.
Cable selection: application
“With such a broad range of functions that power and control cables can provide, it’s important to consider where they will be used, how they will be used, and what else they will need to interact with,” Pullinger said.
LAPP’s ÖLFLEX range includes:
- halogen-free cables, which offer suitable properties in the event of a fire;
- drag chain cables, which are made of fine and extra-fine wire conductors for maximum mobility;
- robot and torsion cables, which feature a special core stranding that allows simultaneous bending and twisting;
- spiral cables, which have a spiral cable shape for tight spaces;
- cables for industry-specific use, eg, direct current applications, SOLAR, TRUCK and TRAIN applications;
- cables for lift and conveyor technology, which have additional support stranding and/or reinforcements;
- temperature-resistant cables, which are made of cross-linked PE, silicone, FEP, PTFE or glass fibre;
- single cores: single core and no sheath, for universal and simple wiring;
- infrastructure cables: for building connection and energy distribution.
The future of cable technology
With industries rapidly advancing, cable technology continues to evolve to meet new challenges. Developments in materials, shielding techniques and smart cable monitoring systems are enhancing the durability, efficiency and safety of industrial power and control cables.
Understanding the selection, classification and performance of cables is essential for ensuring the safe and reliable operation of modern industrial systems.
“LAPP continues to innovate, ensuring that ÖLFLEX remains a trusted solution for industries worldwide,” Pullinger concluded.
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