Standards for static cable applications are well established and internationally recognized. However, the historic lack of standards for automation cables has resulted in cable performance criteria being defined according to the needs of specific industrial automation applications.
As the European market leader in automation cables, Nexans has responded by taking the lead in defining standards that provide a scientific means of comparing the relative merits of different cable designs, resulting in a clear and transparent way for customers to guarantee that the cables they specify will deliver the required performance and lifetime.
Trailing chain cables
The initial results of this programme are a series of standards for trailing chain cables that classify them as ‘basic’, ‘advanced’ or ‘premium’ according to a set of four main mechanical criteria: bending radius; acceleration, travel length; minimum number of bending cycles, together with other properties such as chemical and temperature resistance.
It is also important that cable conductor and insulation materials provide the appropriate level of fire, heat and abrasion resistance demanded for safety and performance, as well as offering the resistance to attack by oils and other chemicals essential for a long service life. Important developments in new material technologies are being made in this area such as TPM (Thermoplastic Modified) insulation and flame retardant PUR Medoxprotect-S jacket material. There may also be a requirement for cables to offer resistance to EMI (Electromagnetic Interference).
These standards have now been applied directly to the Motionline range, but the main intention is that they will be adopted as international standards recognized throughout the automation industry.
The standardization process is ongoing and Nexans is currently working to develop similar standards for robotic applications that will need to consider additional criteria such as torsional strength.
Dedicated Motion Application Centre (MAC)
Playing a key role in the standardization project is Nexans’ own dedicated Motion Application Centre (MAC), which is part of the Nexans Research Centre (NRC) in Nuremberg, Germany. This facility, unique in the industry, enables cables to be exposed to dynamic operating loads that simulate realistic, in-service, conditions, thus ensuring that they offer the ideal combination of bending, tension and torsional strength and vibration resistance required for their intended application. It provides clear proof that an automation cable will perform throughout its expected lifecycle as described in the relevant standard.
Nexans has been testing automation cables for 20 years. The MAC was established around 5 years ago and is the subject of considerable ongoing investment to reflect the changing needs of the automation industry, resulting in a current roster of 12 different machines designed to test cables to their limits. A key advantage of the facility is that it enables the electrical and data performance of the automation cables to be monitored under dynamic loading conditions. In addition to the mechanical tests, environmental chambers also allow the cables to be subjected to varying environmental conditions.
The Motionline brand covers a very wide scope of automation cable products. However, the catalogue range is sometimes only a starting point, since there is a frequent need for Nexans to design and engineer a special cable to deliver the vital combination of high-performance, reliability and long life required for a specific application.
The development process starts with an in-depth analysis of the customer requirements for the cable, such as a miniaturized cable tailor made to fit the available space envelope or a hybrid cable combining power and data transmission. The MAC will then test the cables used currently and work with the NRC to surpass the existing performance in terms of durability and environmental resistance. This seamless interface between benchmarking and design theory and then back to practical implementation results in the rapid and effective development of the ideal customized solution.
Source: Nexans, Celine.Revillon@nexans.com