DC vs. AC Cable: Is this a legitimate distinction?
With different types of current existing, AC and DC, we often hear about DC and AC cables designed to sustain a specific type of current. This is especially common when talking about solar panels, as However, there is actually no such distinction as AC vs. DC cable. A cable with the same type of conductor and insulation can easily be used both for AC and DC current. Aluminum and copper conductors alike are suitable for AC and DC currents. In fact, AC and DC currents can at times fly through the exact same wire. In this case, what is the distinction, and where does the confusion come from? Read this blog to find out.
AC vs. DC Current: How Do They Compare?
The first thing that needs to be understood in this context is the distinction between AC current and DC current. Those are two types of electrical current found in the electrical circuit.
AC current translates as an alternating current. The term "alternating current" means that it flows in different directions. AC is a more common type of electrical current in power generation and high-voltage power transmission. The standard AC voltage in the United States and Canada is 120 volts, while in Europe, India, and Australia, it is 220 volts.
DC current is a direct current. It flows exclusively in a single direction. This type of current is typically found in batteries, including photovoltaic cells for solar power. In PV cells, DC is converted into AC with the power inverter. Another thing that makes the two different is that a cable's power loss during the DC transmission is smaller than during AC transmission. The typical battery voltage in many countries across the world is 12 volts.
"Skin Effect" and Cross-Sectional Area Of The Cable
"Skin effect" is the phenomenon based on how DC and AC flow differently in a cable. Thus, a DC current flows through a cable in an even way. As for the AC, it flows through the outer corner of the cable only, spreading unevenly. Basically, the current moves close to the skin of the cable, which allows calling this phenomenon "skin effect." Because of the said effect, the cable in the DC is the most effective when single-stranded, whereas the cable in the AC is best when multi-strand. Multi Stranded cables are less resistant to AC currents because of their structure. It is worth noting that the skin effect is only really noticeable at high frequencies. Therefore, this distinguishment applies only to thick cables with large diameters. In most circumstances, the differences between AC and DC currents are not felt.
Things to Note When Choosing Cables For AC and DC Current
Therefore, the cable that transmits the AC current has a more extensive cross-sectional area than the cable that transmits the DC. The cable that transforms DC must be thicker than the current that transmits AC because DC is transmitted at a low voltage, and the load must be sustained because the current becomes higher. The wider the cable, the higher current capacity it has. As a standard, the cable that transmits AC power will have three conductors. For DC power, two conductors are just enough.