Are self-regulating electric heating cables energy-saving? Why?

Are self-regulating heating cables energy-saving? Why? Beijing Zhonghai Huaguang's answer: Self-regulating conductive plastic heating cables are not energy-saving.

Our electric heat tracing industry has entered a new era, from the 1.0 era of steam heat tracing, to the 2.0 era of market-accepted electric heat tracing, and now to the 3.0 era of energy-saving electric heat tracing.

There is a biased understanding of self-regulating and self-controlling heating cables. In the past decade or so, people only recognized self-regulating heating cables made primarily of conductive plastic. They didn't realize that self-regulating heating cables made of alloy wire, now called alloy wire self-regulating constant-power heating cables, were also emerging. The heating cables that were widely used and purchased in the past were conductive plastic variable-power heating cables. These so-called self-regulating heating cables are energy-saving, but they are actually power-consuming. We need to correct this misconception. This will prevent the large-scale use of electric heat tracing for insulation in my country from becoming energy-intensive and detrimental to energy conservation and emission reduction. We have repeatedly called for this. Let's explain why.

1. Under what conditions should electric heating cables be energized and started? They are used in low-temperature environments. Let's look at the working principle of self-regulating conductive plastic electric heating cables: simply put, electrical energy is converted into heat energy.

The general consensus is that the working principle of self-regulating electric heating cables is that the number of circuits between the busbars within each heating cable changes with temperature. When the temperature around the heating cable cools, the conductive plastic contracts, causing the carbon particles to connect and form circuits. Current flows through these circuits, causing the heating cable to heat up. When the temperature rises, the conductive plastic expands, the carbon particles gradually break, causing circuit interruption, increased resistance, and the heating cable automatically reduces its power output. When the ambient temperature cools, the plastic returns to its contracted state, the carbon particles connect again to form circuits, and the heating power of the heating cable automatically increases again.

Let's analyze its advantages and disadvantages. The advantages are fast low-temperature start-up, high power, and low resistance. Have you noticed the disadvantages? Many technicians have been misled, and this is one of the main reasons, and a major reason, for the increasing occurrence of conductive plastic failure and lack of heating in outdoor and extremely cold regions with these conductive plastic electric heating cables in recent years.

Because starting at low temperatures in extremely cold winters causes the heating cable to operate at full capacity, it doesn't allow for the proper cycle of thermal expansion and contraction. Even if some heat is stored within the insulation layer, it's still affected by surrounding heat dissipation. This simple low-temperature operation leads to: high power consumption and high starting current, resulting in high cost of power cables and inefficiency. Of course, manually adjusting the temperature using a temperature control device can improve this somewhat.

Furthermore, because self-regulating conductive plastic cannot withstand high external temperatures, exceeding its tolerance temperature further restricts the thermal expansion and contraction cycle, leading to overheating. Those who have used it may have noticed that this type of self-regulating conductive plastic heating cable performs relatively well when used for freeze protection and heating of fire-fighting pipes in indoor basements. While it's better suited for this environment because indoor temperatures are higher and the tolerance temperature is lower, many problems arise when it's moved to outdoor pipe heating. Through the above analysis, you should now understand the reasons.

Therefore, we now need to find energy-saving and power-efficient electric heating cables. After comparing two types of electric heating cables, it has been found that alloy wire self-regulating temperature and power electric heating cables are the future energy-saving type. They will be widely used in various industrial applications such as fire-fighting pipeline heating, snow melting electric heating insulation, etc. This is the matter of product segmentation into different types, which will not be discussed here.

This is why some people always say they can't clearly distinguish between conductive plastic variable power electric heating cables and alloy wire self-regulating constant power electric heating cables.

Of course, in the future, the installation and use of alloy wire self-regulating temperature and constant power electric heating cables will require continuous communication with manufacturers. Future installations will have some basic electrical engineering requirements and some restrictive technical requirements compared to conductive plastic heating cables. This is not complicated; it requires an updated mindset. If you need to replace an old or faulty electric heating insulation, which type of electric heating cable will you choose again? Have you thought about it?