What is the difference between HV and MV Cables?
One of the ways to specify electrical cables depends on their voltage. According to the voltage, there are low-voltage, medium-voltage, and high-voltage cables. Most residential, commercial, and industrial cables are low-voltage. Medium-voltage and high-voltage cables have a longer list of characteristics that set them apart, which often creates confusion. Read this blog by the popular cable distributor Nassau National Cable to learn what sets HV and MV cables apart.
Defining a Medium Voltage MV Cable
A medium-voltage cable, shortened as an MV cable, has a medium voltage of between 1kV to 100kV. This is an international standard defined by International Electrotechnical Commission (IEC), founded in London and headquartered in Geneva, Switzerland. The manufacturers always produce medium-voltage cables within this range. For instance, at Nassau National Cable, you may buy medium-voltage power cables with 2.4 Kv, 5 Kv/8Kv, 15 Kv, and 25 Kv/ 35 Kv voltages. These are the standard voltages of MV cables in the United States.
Construction and Applications of an MV Cable
MV cables have many applications, including power distribution in industry and mining, mobile substation tools used for repair and maintenance, and many others.
Aside from the standard construction that most cables have, including a conductor, insulation, and a jacket, an MV cable also has separate shieldings for its conductor and insulation. This is not the case with the medium-voltage jumper cables, as they follow the design characteristics that are typical for jumper cable construction.
What is a High-Voltage HV Cable?
For high-voltage cables, the factor that matters in defining them is not just the voltage limits but the specific role that they serve. As the name suggests, HV cables are used to transmit power at high voltage. A typical voltage of a high-voltage transmission line is 345,000 volts.
Construction and Applications of an HV Cable
High-voltage cables are always used in underground transmission power lines. HV cables are rated for direct burial, but otherwise, they are laid in ducts in underground transmission systems. Other than that, HV cables may be used for AC and DC power transmission, as an instrument cable, as a submarine cable, or as a cable for an ignition system.
The structure of a high-voltage cable is more complex than a medium power cable. Aside from conductor shielding and insulation shielding, an HV cable has additional means of cable protection, such as semi-con layers of insulation. The shieldings of an HV cable are always metallic, the insulation is fully-rated, and the jacket is extra-protective. The construction of the cable is equipped to be protected from the high stress of high-voltage applications. The cable may have additional grounding depending on the specifications of a circuit.
