Motor cables in small bend radii

Motor cables in small bend radii

Those looking for parking spaces in big cities today will quickly discover that space is often a problem. Cars are getting larger, and there are now significantly more vehicles than 20 or 30 years ago. If you compare modern cars’ interiors with those from the 1980s, you will find that modern cars, for example, have a much smaller boot. 

On one hand, this is because modern cars are significantly safer in their passenger compartments. A car now has stronger, thicker spars. It also has even more technology that must be incorporated into the vehicle. Additionally, the interiors are covered in more nice-looking materials to look good.

For machines and systems, the situation is similar. Today's machines are significantly more technologically advanced. In addition, the market demands compact machines, which affects energy chains' installation space. As a result, an increasing number of cables for sensors and bus transmission must also be placed in the energy chain together with motor cables, with the smallest possible bend radii.

Problems with motor cables in small radii

Particularly when producing display glass for large televisions, a bend radius of 175mm can be challenging, especially when using powerful motors. Shielded 4G16mm² motor cables typically have an outer diameter of 22mm to 25mm. Calculating the bending factor, you will find that with a 23mm outer diameter, the chain radius produces a bending factor of 7.6xd. 

Of course, there are cables that are designed for such bend radii. It should be noted, however, that straight cables with large cross sections are very stiff due to their high copper content. As a result, plastic materials are put under heavy stress when used in the energy chain, which can lead to jacket breaks. Long travels or soft jacket materials, such as PVC, can also cause corkscrewing.

Make sure you have the right outer jacket

igus offers chainflex motor cables with outer jacket materials made of PVC, PUR and TPE. The cables are designed for small bend radii, so they are subject to high mechanical stress. The most durable option are halogen-free TPE outer jacket cables which we recommend. It also has a longer service life than PVC or PUR cables. TPE cables offer high oil resistance and are resistant to a wide range of chemicals. In addition, they have a much better abrasion behavior than PVC or PUR cables. All halogen-free TPE cables from igus have UL approval and can therefore also be used in the USA. In our 3,800m² test laboratory, we tested a shielded 4G25mm² motor cable with a bend radius of 175mm to find out how long this cable would last with sagging. You can see the results here.

Another option is to switch from a four-core cable to four single-core cables. The benefit of this approach is that a smaller chain bend radius can be selected. In addition, this solution often offers cost savings. In the crane industry, this type of design can be found on STS cranes which they have been implementing for many years.

 

Calculate the service life

If you have a demanding application and would like to know how long a chainflex cable lasts, we offer a service life calculator to help you easily find out the service life of your application. We also offer a guaranteed service life of 36 months and up to 12.5 million double strokes for all chainflex cables.

Feel free to contact us to help you choose the right cable.