Strain relief: The essential protection for every cable

Strain relief is important for cables and hoses that are being tightened. Logical. Everyone actually knows that you shouldn’t do this, as cables aren’t handles for holding onto. However, this is not the only reason why cables are exposed to mechanical stress and should be protected with strain relief. A lot of cables are bent or even constantly moved back and forth. The cable is then stretched over the outer radius and pulled out of the opening of the housing, the connector or the cable gland, while on the inner radius it is inserted and pushed in. If the bending radius is very small, the cable can even kink. If the cable is inserted into a plug, this can lead to the cores being torn off the contacts in the long term.

A cable duct with strain relief prevents this. It secures the cable in the cable gland or connector and ensures that the tensile and bending forces that occur on the outside don’t continue to the other side, but are absorbed by the structure on which the strain relief is mounted. Ideally, the forces at the contacts in the plug or in the cable inside the control cabinet are zero. No matter how the cable moves on the outside, it stays still inside. This saves the contacts and sensitive electronics. However, strain relief starts even before this. A bending protection spiral is a good idea for cables that are constantly being bent. It prevents too tight bending radii which in turn prevents the cores from breaking and the shielding braid from spreading.

LAPP offers a wide range of strain relief solutions. Including the simplest one, of course: cable ties. They secure cables or cable bundles to sockets and provide basic protection against cables that aren’t moved being pulled out, for instance in a control cabinet. If cables need to move, more complex solutions are called for. One is SKINTOP® GRIP, a brass cable gland available in versions up to M 32x1.5. It’s equipped with a double saddle that provides ten times higher strain relief than the standard. This cable bushing is primarily intended for use in machine and system parts that are moved, such as foot switches and push-button control units.

A real innovation is SKINTOP® MULTI, a practical multi-cable bushing system for control cabinets and automation technology. In the space-saving multi-cable bushing, you can simply feed up to 30 unassembled round cables with different diameters and AS-I cables through an elastic gel membrane. The gel seals firmly around the cable insulation over a wide clamping range and hermetically seals the opening, while also acting as the optimum strain relief for the entire cable bundle.

LAPP also offers a wide portfolio of strain relief solutions for its cable range, such as the SILVYN® conduit gland for protective conduits. There are also numerous types in HYGIENIC variants for the food industry. Strain relief is also an important topic in energy chains. The ÖLFLEX® CONNECT CHAIN range includes fully equipped power chains in which the assembled cables are optimally strain relieved in the factory. The configuration is simplified by the ÖLFLEX® CONNECT CHAIN configurator, where an energy chain can be engineered with just a few mouse clicks.

The answer: all of them. Or almost all of them. Wherever cables are subjected to mechanical stress, whether it’s by pulling, bending or frequent movement, strain relief is essential. But there isn’t a single solution that can do everything. It always depends on the intended use. If you don’t have much experience with this topic or you’ve got a specific problem, LAPP certainly has the solution and will be happy to help and advise you. Simply get in touch with us.