March 11, 2015 Leave a comment
Recently I read an article in Machine Design called “When Flexible Cables Doesn’t Flex for Long” by Leland Teschler which talks about different aspects of flexible cable terms, causes of breakage and testing.
The article touches on different lingo between flexible, high-flex and high-flex-life. Flexible and high-flex mean the same thing. Google’s definition of flexible is the capability of bending easily without breaking. High-flex-life is described by Northwire as a cable designed to survive 10 million to 20 million flexing cycles. Those are just the common terms used to describe flexing of a cable, but there are manufacturers that use their own flexing name to describe their cables.
Teschler also describes the feel of a cable, whether the cable bends easily or not, based on different degrees of limpness or stiffness. “All in all, cable makers say the stiffness or limpness of the cable has nothing to do with its flex life.” The article goes on to describe a limp cable as a jacket that is made from soft materials, or finely stranded conductors, that allow the cable to move easily but is not meant to be used in applications with repeated flexing.
The last part of the article mentions how cables are tested for flexing. There is not a standard in the industry so different manufacturers can use differernt tests. The 3 most common tests are twist and flex test, tick-tock cable test, and UL test setup. Teschler pointed out the main focus for UL and CSA is to test for fire safety and UL test the cables for runs of 15,000 cycles.
Overall, I really enjoyed the article and highly suggest giving it a read to understand more about raw cable and testing requirements.
To see Balluff’s offering of UL listed cables click here.