Choosing the right type of cable is important. There are many different types of cable, some of which are designed for specific applications. Twisted-pair cable, such as RJ11 and RJ45, are is used in data and networking applications, whereas solar cable is used in photovoltaic (PV) systems. A lesser-known type of cable, however, is control and instrument. It’s used to send signals for controlling and monitoring applications. Here are five facts about control and instrument cable.
#1) Multiple Conductors
Control and instrument cable features multiple conductors. Conductors consist of strands of electrically conductive metal wire. In control and instrument cable, multiple wire strands are bundled together. These conductor bundles are encased in a protective outer shell or “sheath,” which protects them from abrasion and environmental damage.
#2) Aluminum or Copper Conductors
You can find control and instrument cable in different conductor materials. Some types have aluminum conductors, whereas others have copper conductors. Copper is the most popular material for cable conductors. It’s highly conductive and offers a superior level of protection against corrosion. Aluminum, though, typically costs less while still offering sufficient electrical conductivity for many applications.
#3) Used in Low-Voltage Applications
Control and instrument cable is commonly used in low-voltage applications. It’s still able to carry electrical signals to equipment and devices, but it leverages a lower voltage than other types of cable. Common voltage ratings for control and instrument cable include 300V, 600V, 1000V. For power transmission applications, other types of cable with higher voltage ratings are typically preferred. Control and instrument cable, in comparison, is used in low-voltage applications
#4) Features an Insulative Sheath
All types of control and instrument cable feature an insulative sheath. It acts as an outer shell, separating the bundled conductors and preventing electrical leakage. Common sheath materials used for control and instrument cable include polyvinyl chloride (PVC), polyethylene and cross-linked polyethylene (XLPE). Each material has its own unique characteristics, but they are all excellent electrical insulators.
#5) Requires Shielding
Control and instrument cable needs shielding. Even though it’s a type of low-voltage cable, it’s still carries electrical signals. Electromagnetic interference or “noise” can bleed into control and instrument cable, thereby weakening or disrupting its signal. Fortunately, shielding is available to prevent this from happening. Shielding for control and instrument cable may consist of foil or braided wire that blocks out external noise.