We live in an era of connectivity and advancement. From entertainment to education, everything is dependent on an intricate mesh of hidden wires. We enjoy the conveniences brought to us not knowing about the hidden threat – heated wires.
Let’s study the causes and the remedies of overheating wires and protect commodities home appliances and our Cox Internet connections saving a lot of money and hassle in the long run.
What is Wire Heating?
Wire heating is a universal phenomenon in the world of electrical circuits. While the heating effect is the working principle behind a wide variety of appliances, from hair dryers to car air heaters, excessive, unintended heating can end up causing consumers and producers significant losses, especially when it leads to short-circuiting, which is the foremost cause of electrical fires today.
The real reason behind electrical circuits generating heat
The answer is simple high school physics: Electrical current is a form of energy transmitted via “waves” of elevated energy level. These waves are composed of “free” electrons which are usually the outermost electrons that become locally free due to the densely packed lattice structure of metals.
Upon application of a potential difference (measured in volts), these free electrons travel from the point of higher potential to that of lower potential. This can be thought of as a stream of water flowing downhill. The heating effect itself, on an atomic level, comes from these “free” electrons colliding with their parent lattice when passing along waves of electricity.
These collisions result in the dissipation of some of that energy into heat. Sure enough, the heat dissipated on the atomic level is tiny, but the effect scales with the conducting material’s size, which is why wires almost always feel warm to touch after prolonged usage.
Factors Causing Wires to Heat Up
Just like all 5 fingers aren’t the same, all conductors aren’t the same as well. You might have come across the puzzling phenomena where two wires of the same thickness (and sometimes even material) have different levels of heat when transmitting the same current.
Chances are, you’ve also seen the havoc these benign levels of warmth can inflict if left undetected or untreated. The golden question is, what causes the wires to heat?
Wire Size
This is a no-brainer. If you have to divert a stream carrying a thousand liters of water every minute, you’ll go for the biggest pipe you can find. Naturally, the smaller the pipe, the bigger the chance of the entire assembly failing, simply because there will be “too much pressure” on the pipe.
Wire Material
The heat dissipation in a conducting material is a direct product of its “resistance” i.e. the ability to inhibit the passage of current. This is inversely proportional to its cross-sectional area. Thus, increasing wire size (both, the number of cores and thickness of individual strands) will reduce losses and heat generation as a result.
Some materials, like copper, gold, etc have physical and atomic properties that enable them to conduct electricity well. This means, in comparison to other metals, they can carry a higher current without heating up.
Ambient Temperature & Current Load
In real life, regardless of the conductor, some electrical energy is always lost as heat to surroundings. When the rate of heat generation in your wire exceeds the rate, it seeps into the surroundings, heat gradually starts building up in the conductor.
This phenomenon is especially noticeable at higher current levels and compounds exponentially If the wires are placed in a heated area (say, next to a steam boiler in a constricted space)
Why is Wire heating Bad?
Well one of the main reasons, is evident from the problem itself. Fires due to short-circuiting are a leading cause of damage to life and property all over the world. The short-circuiting itself is often a result of prolonged wire heating.
Even if the heat isn’t enough to start a fire, repeated heating and cooling (when the circuit is switched off) can accelerate metal fatigue, which reduces its efficiency and results in increased wear & tear.
Reduced Efficiency
The heat given off by wires is wasted energy. Given the costs and overheads associated with the generation & supply of electricity, heat actually denotes a significant operational cost. Reducing the same not only eliminates risks but also reduces overheads.
How to minimize wire heating?
While it is impossible to make your circuits totally heatproof, here are a few steps you can take to minimize the menace of wire heating:
Material
You should always go for the purest material with a resistivity value as low as feasible for you. Upgrading from, say silver to copper strands, or from copper to gold strands will automatically reduce heat (and wire losses) for you, even if the rest of the parameters stay the same
Conductor Size
If it’s not possible to switch to a better material, a quick solution would be to increase the conductor size. Think of it like a road. If you can’t carpet it any better, adding more lanes is always a way of dealing with your “traffic jam”
Controlling Current
Even with the above factors, power surges are not uncommon and can spell doom for the unfamiliar user. Due to a wide number of reasons, your circuits can be flooded with current exponentially higher than the rated value. This can be prevented by the use of fuses and circuit breakers that cut off the power supply before the damage is done.
Controlling the external heat
Sensitive electrical equipment or installations consuming high levels of current should always be housed in a separate, air-conditioned enclosure. This has the added effect of safety, as access to unsusceptible bystanders is limited, and by maintaining a favorable temperature and humidity level in the space, one can ensure that no additional stress is placed on the system due to its surrounding environment.
With these steps, you can safeguard your home, appliances, and wired network from foreseeable damage. Timely and deliberate measures are better than a loss.
