How do you define the specification "Minimum bending radius: occasional flexing" in the technical data on our catalogue pages?
The bending radii of cables are defined according to their installation type. In the case of fixed or static installation, a smaller bending radius can be chosen than would be required for flexible applications since the cable is only bent once in the former case. In the cable industry, we generally distinguish between three installation types:
The cables are installed statically, in cable ducts for instance, where they are fixed and immovable. In this case, there should be no movement or vibrations during operation. The cables can therefore be bent more sharply and usually subjected to somewhat higher or lower ambient temperatures than in the case of flexible applications.
Highly flexible application (e.g. permanent bending in drag chain):
The bending radii specified for ÖLFLEX® and UNITRONIC® FD cables are always based on continuous flexible use in the energy supply chain. Even though all drag chains vary and have different parameters, it is possible to use the relevant bending radius, acceleration and travel to make an educated assessment as to a cable's suitability for the intended application. These specifications provide a relatively clear impression of the exact application planned by the customer.
Flexible application (occasional flexing):
Unfortunately, no exact definitions exist for this installation type, unlike for the fixed and highly flexible options. How often and how sharply a cable is bent in the customer's application varies from case to case. In order to reflect as many applications as possible, a relatively high bending radius is specified for this installation type. It is then largely irrelevant whether the cable is bent just once per day or moved more often, e.g. in the case of a connecting cable for a portable device that is unplugged/plugged in multiple times over the course of a day. However, to avoid situations where cables that are not designed for highly flexible drag chain use are subjected to permanent bending outside the energy supply chain, the property "occasional flexing" is used on many of our catalogue pages. This reduces the danger of cables being used in continuous flexible applications for which they are not intended.