Medium Voltage Power Cablemedium voltage cable

Medium voltage power cables are designed for tough elements and a reliable power connection. Whether for temporary power or for permanent function, medium voltage power cable is often required for various applications, including power for instruments, ignition systems, and building structures.

What is Medium Voltage Cable?

What is medium voltage cable? Most simply, medium voltage cables carry a range of electrical current labeled as “medium.” While there is no general census on what definitively constitutes “medium voltage,” NEMA (National Electrical Manufacturers Association) has ratings for medium voltage cables between 600 V and 69 kV. See this link to NEMA’s website for detailed information.

From a contractor’s perspective, however, medium voltage wire is generally thought to range from 2,500 to 35,000 volts of electrical current carrying capacity. Medium voltage cables are used to provide power to a site requiring such a range of electricity.  Medium voltage power cables contain:

Each medium voltage wire component serves a specific function to ensure that the voltage carried by the cable safely conveys the necessary power to its application.

How is Medium Voltage Cable Used?

Medium voltage cables are used to provide power for specific environments and applications. Some applications for medium voltage power cable are:

Depending on the particular type of cable selected, medium voltage power cable can be installed in wet or dry locations, indoors or outdoors, and in raceways or underground ducts.

Types of Medium Voltage Cable

Medium voltage cables are required to provide power in a wide variety of applications. As a result, medium voltage wire requires various construction features, an array of sizes, and materials to safely conduct high voltages of electricity. Medium voltage wire’s construction features include various:

Each of the differences between specification selections is due to the specific needs of the application.

For additional information about choosing the appropriate medium voltage cable for your application refer to Okonite’s engineering handbook linked here.

The Importance of Insulation

The insulation of the cable provides strength and durability for the life of the MV cable.  Insulation is often the conductor’s first line of protection.

In partnership with Okonite, Colorado Wire and Cable provides MV cables with a superior insulation system. Utilizing EPR (Ethylene Propylene Rubber) in direct contact with semiconducting shields, Okonite’s EPR insulation offers arguably the best options for insulated medium voltage power cable in the industry. For an in depth look at Okonite’s EPR insulation system take a peek at this article.

Non-shielded vs. Shielded Medium Voltage Cable

Generally shielded cables provide superior safety, noise reduction, and protection for the cable. For safety purposes, in 2005 the NEC made a change to their regulations concerning non-shielded medium voltage cables. Consequently, any medium voltage cable, with limited exceptions, must have a shield.  See this article outlining the changes to shielding for medium voltage wire.

Medium Voltage Cable Durability

Medium voltage power cable is the most durable power cable for the widest array of applications in commercial, industrial and utility industries. Due to the high voltage stress on the cable, it is essential that the cable is equipped with proper insulation, shielding, and jacketing to both contain the current and protect the cable from the particularities of the environment.