When your expensive electrical, electronic and communications equipment is connected up and you begin using it, you may find that the cabling undergoes high amounts of stretching, bending, twisting etc. which are known collectively as “strain.” In due course of time wires and cables get damaged due to abrasion and continuous flexing. To prevent such damage and also ensure the safety of your equipment, home or work-space, it’s essential to provide adequate strain-relief protection to your cables and wires. This accessory, which can provide such protection, is known as a strain relief bushing.
Cables and wires can bend, crack, split or break away from the plug or connector with repeated movement. The point where the wire/cable meets the connector is usually the point of highest strain and a device which can prevent such strain is to be attached at this spot.
Strain relief bushings are usually made of tough, heat and strain-resistant plastic or polyethylene material. They can be used to protect both round and flat wires. Since they absorb the strain felt at the connecting point, your power supply cable remains flexible and efficient.
The bushing holds the wires in place securely and can withstand bending, twisting and knotting of the cable, without passing the strain onto the connectors or the point where they meet the power source. If there are sharp surfaces or edges, the bushing prevents the wires or cables from getting damaged or split. Often cables can get strained or stretched when they are repeatedly pulled out of power sockets and the strain relief bushings can help to prevent such damage. Strain relief bushings can also have a locking facility to keep the cable in position.
Some manufacturers offer a kit with several bushes designed to fit various wire diameters and these may come with a list of specifications and also a pair of bushing pliers for easy assembly. Such bushings kits are also available for prototype designing and lab work in electronics and electrical design departments, educational institutions etc. and come with an array of different types of strain relief bushings for experimental work in laboratories.
Important factors to keep in mind while choosing the bushings are:
Wire/Cable type: whether round or flat type. The bushings for each one will differ. The thickness, gauge and dimensions of the wire are also important factors.
Function: How much strain do the wires or connectors have to take? The kind of strain should also be assessed, whether pulling, stretching, twisting or knotting. The panel thickness is also to be assessed before purchasing the bushings.