Strain relief: The indispensable protection for every cable
What is a strain relief?
Strain relief is important for cables and protective conduits that are pulled. Logical. Everyone knows that you shouldn't do that, after all, cables are not handled to hold on to. But that is not the only reason why cables are exposed to mechanical stress and should be protected with strain relief. Many cables are bent or even constantly moved back and forth. Then the cable is stretched on the outer radius and pulled out of the housing opening, out of the connector or the cable gland. On the inner radius, it is compressed and pushed in. If the bending radius is very small, the cable may even kink. If the cable leads into a connector, in the long run, this can cause the wires to be torn from the contacts.
A cable bushing with strain relief prevents this. It fixes the cable in the cable gland or the connector and ensures that tensile and bending forces that occur externally do not continue to the other side, but are absorbed by the structure on which the strain relief is mounted. At the contacts in the connector or the cable inside the control cabinet, the forces are then ideally zero. No matter how much the cable moves on the outside, it is at rest on the inside. This protects the contacts and sensitive electronics. But strain relief starts before that. For cables that are constantly bent, a bending protection spiral is useful. It prevents bending radii that are too tight and thus prevents the cores from breaking and the shielding braid from spreading.
What strain relief does LAPP offer?
LAPP offers various solutions for strain relief. Of course, also the simplest one: cable ties. They fix cables or cable bundles to bases and provide basic protection against pulling out for cables that are not moved - for example in a control cabinet. Where cables have to move, more complex solutions are required. One is SKINTOP® GRIP, a cable gland made of brass, which is available in versions up to M 32x1.5. It is equipped with a double clamp which provides ten times more strain relief than the standard one. The cable gland is primarily intended for machine and system parts that are moved, such as footswitches or control bulbs.
A real innovation is SKINTOP® MULTI, a practical multiple cable gland for control cabinets, and in automation technology. You can easily pierce up to 30 unassembled round cables with different diameters as well as AS-I cables through an elastic gel membrane into the space-saving multi-feed-through. The gel nestles tightly around the cable sheath over a wide clamping range and hermetically seals the opening. At the same time, the gel serves as an optimal strain relief for the entire cable bundle.
Also, LAPP offers a wide range of strain relief solutions for its cable range, such as the SILVYN® conduit fitting for protective conduits. There are also several types in HYGIENIC versions for the food and beverage industry.
Strain relief is also an important topic in power chains. The ÖLFLEX® CONNECT CHAIN range includes fully assembled power chains, in which the assembled cables are already optimally strain-relieved ex-works. The configuration is facilitated by the ÖLFLEX® CONNECT CHAIN configurator, where the engineering of a power chain takes only a few mouse clicks.
Which industries and applications require strain relief?
The answer: all of them. Or at least almost all of them. Wherever cables are subjected to mechanical stress, whether by pulling, bending or frequent movement, strain relief is essential. But there is not a single solution that can do everything. Rather, it always depends on the intended use. If you have little experience with this topic or have a special problem: LAPP certainly has the solution and is ready to help you with advice and support. Please contact us!