Control cables are cables created specifically to positively and precisely transmit mechanical motion. In other words, they connect moving machinery or equipment parts and control their interaction with one another. Made of high-strength stranded metal wire, control cables are nonetheless flexible and bendable. They are important to the success of applications in a number of industries, including oil and gas, manufacturing, marine, electrical, automation and aerospace.
Like all wire rope products, control cables are made up of individual wire filaments, braided or twisted into wire strands and a core around which the strands are wrapped. To accommodate their various applications, control cables may are typically also outfitted with the trappings of entire wire rope assemblies, such as rubber or metal housings, wire fittings and terminals like handles, forks, pins, eyes, studs and various other mounting apparati. To protect them and/or improve their function, housings can be treated with oil resistant coatings, flame retardant and the like. Wire fittings can be attached to one or both ends of the cable. For added security, they can be hardwired into the cables. Conversely, for added versatility, they may be offered with change tool kits. The latter is particularly true of instrumentation control cables.
Under the large heading of control cables are many specific types. The most widely used control cable types, however, are push-pull cables and pull-pull cables. Pull-pull cables apply motion in only one direction, and do so through the application of tension, while push-pull cables apply motion in two directions, or multi-directionally, through the application of compression and tension. Note that, to return the cable to its starting point, pull-pull cables use spring actuation. Both of these control cable types are popular in mechanical motion and precision transmission and both must be durable, strong and able to bend in different directions multiple times without breaking. Of the two, though, push-pull control cables are the most flexible and versatile. Thus, pull-pull control cables are typically used only when transmission forces require tension, while push-pull cables are used with a variety of electrical, pneumatic and hydraulic systems.
Some control cables are used specifically in the area of process automation, which is a field in which software engineering and computer technology are used to ensure that factories and power plants run properly and efficiently. In generally, control cables used for automation applications are highly flexible and fabricated with a transparent PVC sheath, PVC bedding and PVC insulation. Control cables used in the field of automation can be divided into the groups of screened flexible (CY) cables, shielded flex (SY) cables and unshielded control (YY) cables. They are all quite similar to one another, but they do have some differences. First, CY cables are those cables that have a PETP separator, multi-core flex and a tinned copper wire braid. All of these parts work as a team to keep the cable isolated and protected from mechanical stress and external electromechanical interferences. They are selected for use in settings that require interference-free transmission. Next, the wire braids of SY cables are made up of galvanized steel. Of CY, SY and YY cables, SY cables are the strongest. They are chosen for applications that require dependable mechanical protection. Finally, YY cables are quite versatile and can be used both inside and outside and both in dry and wet environments. They, however, do not have the mechanical protection provided by steel wire, so they are only really suitable for work with light mechanical stress. More generally, CY, SY and YY cables can be as a group referred to as: instrumentation cables, multi-core cables, motor cables, robotic cables or control flex cables.
When installed and used correctly, control cables can revolutionize system functions and movements. However, it is of the utmost importance that floor supervisors instruct their workers in proper safety protocol. Also, to increase safety, potential customers should consider requesting cables with remote-access latch releases and safety brakes. Furthermore, they should make sure that the length, thickness, diameter, working life and maximum load of the cable they intend to purchase is sufficient for their application. If these safety precautions are observed, operators can expect their control cables to serve them well for years to come. For the best advice, reach out to an experienced cable manufacturer with questions, concerns and specifications.
More Control Cables
Control Cables – Bergen Cable Technology, LLC
Custom Push-Pull Controls – Tyler Madison, Inc.