Which heating cable to buy: heating or self-regulating. Comparison of heating cables

If you want to protect your pipeline from freezing, then you should pay attention to various heating methods. The best solution in this area is a self-regulating heating cable for water supply. There are several types of self-regulating cables. And each of them has its own advantages and disadvantages. In this article we will help you make a choice for any situation.

Self-regulating technology

According to the type of cable adjustment, they are divided into self-regulating and thermostatically controlled. With a thermostat, everything is quite simple - using a sensor on the cable or air temperature, the device controls whether the power to the cable is turned on or off. At first, the self-regulating cable causes surprise and skepticism. But in fact, its design is simple and really knows how to maintain temperature, without any sensors or thermostats.

The temperature in the self-regulating cable is maintained by the heating element itself. The fact is that the material used has so-called thermoresistive properties. As you know, the resistance of any metal changes depending on its temperature. As the temperature rises, due to the activity of electrons, the resistance increases, and when cooled, on the contrary, it decreases. But if for copper the resistance at -15 and at +20 degrees Celsius is almost the same, then the heater material in the cable at our winter temperature becomes a conductor, and in the summer heat it becomes an insulator. Selfreg, as professionals call it, has the following design:

Number one is regular, copper wires. The second layer is a self-regulating matrix. The third is isolation, the fourth is a screen. Last comes general isolation. Two copper conductors carry phase and neutral along the entire length of the cable, and a self-regulating material closes them. Depending on the ambient temperature, the cable resistance varies over wide ranges, and thereby regulates the current flowing between the wires. According to Ohm's law, with high resistance the current is low, and with low resistance the current is high:

The higher the current, the higher the power:

Quote: The screen may seem like an unnecessary element that increases the cost of the design. In fact, he has a very important role. The heating cable is always laid in places with a risk of mechanical damage. Installation work, sharp edges of fasteners, pipes can damage the insulation, and the screen adds additional mechanical protection. But this is not the main function. During a fault, there is a chance that live wires will touch the metal structure and the entire plumbing or gutter will become energized. And the screen will allow you to instantly discharge voltage into the ground, without harm to human health. The screen also provides an additional reduction in risks when contacting water.

Application of self-regulating cable

Due to easy installation, simple design and high reliability, the heating cable is used in various areas:

Plumbing on the street;

Sewerage;

Stormwater runoff;

Heating pipes;

Pipeline for diesel fuel;

Pipeline in unheated rooms.

We are interested in the use of a self-regulating heating cable for water supply.

Self-regulating cable laid in a pipe

According to the type of cable installation, they are divided into those laid in a pipe and along a pipe. The self-regulating cable laid in the pipe is easy to replace, if necessary. For easy replacement, it is necessary to ensure a minimum number of angles, and the shortest possible distance. Actually, the advantages end with an easy replacement. There are a lot of disadvantages to this type of gasket:

Cannot be installed through a crane. More precisely, it is possible through a ball valve, but the valve will not work.

High risk of damage during installation due to high tightening force.

During installation, the cable can be damaged by sharp edges of pipes or scale. Damage cannot be verified.

An obstacle to future repair work, since a pipe with a cable laid inside is very difficult to cut without damaging the cable.

Due to contact with water, there is a high probability of the pipeline becoming energized, even from the slightest damage.

Over time, the place where the cable exits the water supply may leak.

Reduces the diameter of the pipeline.

Collects all debris, rust and bacteria around itself.

Self-regulating cable laid through a pipe

In contrast, a pipeline-mounted cable has the following advantages:

Easily mounted on any pipe, it is possible to heat the fittings (for example, faucet, valve, filter).

During installation it does not require any physical effort, thereby reducing the risk of damage.

It has a lower risk of damage, since there are practically no sharp elements on the pipe, unlike the internal part. The cable is accessible for visual inspection of damage during installation.

Easily dismantled in the area required for repair or modification, and subsequent installation is no less easy.

Since there is no direct contact with water, the risk of the pipeline becoming energized is reduced.

There are no unreliable nodes for cable entry into the pipeline.

Does not affect the internal diameter of the pipe and does not collect debris.

There is no limit on the number of corners and turns, allowing laying over longer distances.

Among the disadvantages, we can note longer installation and a slight increase in price.

Features of installing a self-regulating cable on a water supply system

There are three types of cable installation on a pipe. Along, spiral and combined method:

The first two methods can be used for both round and flat cables. The third method is difficult to use for a flat cable. The second and third types increase cable consumption, but provide higher protection. The first, linear method can be used for a pipeline of small diameter, up to 32 mm. The second and third methods are suitable for larger diameter water pipes. A cable for laying along a pipe is often drawn from the side of the pipe. This is done for clarity only. In accordance with the laws of physics, it is necessary to lay the cable evenly along the bottom for better heating. It is recommended to use a flat cable for better contact:

Quote: On some sites it is not recommended to lay two cables linearly, preferring a spiral or combined method. In fact, there are still situations when a large cross-section pipe can only be heated in this way. More on this below.

Self-regulating cables come in fixed and arbitrary lengths. Standard length cables have factory-installed plugs and couplings. Their maximum power and current are fixed. Cable of any length is sold in a coil or by the meter. Requires manual installation of plugs and couplings, which are purchased separately.

If a standard length cable does not suit you, then pay attention to the following nuances:

The power increases with the length of the cable; therefore, depending on the manufacturer, different circuit breakers will be required for different lengths. Typically, power is indicated per meter of cable.

The maximum cable length is limited by the cross-section of the copper conductors and the nonlinear decrease in the matrix resistance with each meter. See maximum cable length.

Consult your dealer to select the required cable power density and spiral spacing.

It is highly undesirable to connect the cable. If this is necessary, the connection must be of the highest quality and made in a junction box with tightness in the appropriate environment. The same applies to the end coupling connection.

Since the cable is limited in length, on long sections it may sometimes not be enough for spiral laying. In such cases, it is recommended to lay two heating cables along a large diameter pipe. The cable must be placed on both sides of the bottom. If the length is not enough, you can send heating from two opposite sides. If this is not enough, or it is not possible to supply voltage from the opposite side, then you can run a regular cable along the pipe along with a self-regulating device, and install a distribution box for the next line at the maximum length.

The cable is installed on the pipe using aluminum tape. It is not allowed to use ordinary tape, since due to moisture, temperature and other factors it will fall off after a couple of months and will worsen the contact of the cable with the pipe. In addition, the aluminum tape serves as a kind of heat sink for the cable. It is better to glue along the entire length. Transitions through plumbing fixtures and fasteners can be reinforced with plastic or metal ties. A layer of thermal insulation must be placed on top of the pipe with the cable. The thickness of the insulation depends on the ambient temperature, the temperature of the water in the pipe, the diameter of the pipe, the material and a bunch of other factors. For the appropriate calculations and requirements, we recommend visiting the websites of thermal insulation manufacturers.

Conclusion

A self-regulating cable will help you protect your water supply from freezing. With the help of our instructions, you will be able to understand all the intricacies of its selection and installation. We advise you to buy a cable not on the market, but from specialized companies, where they will help you choose the required design and power.

Video of installation of a self-regulating heating cable

Sectional view of the cable

In the classical concept, a cable is a device for transporting electricity or an electrical signal from point “A” to point “B”, but with heating cables everything is a little different. Their main task is to radiate heat throughout their entire length or in certain areas. There are currently three types of heating cables on the market: resistive, zonal and self-regulating heating cables. Of these options, the last one is the most expensive, but often the most promising in terms of use in almost all areas.

Principle of operation

The difference between a self-regulating cable and a resistive and zonal cable lies in its design and operating principle. In short, a resistive cable is a long boiler, without the ability to shorten it. In this case, the current conductors are heating elements.

Resistive cable.

The zone heating cable can be cut, because The current in it is supplied through parallel conductors, between which a heating element made of high-resistance wire is wound. Through certain sections, this wire touches one of the current-carrying cores and ensures heating of a section of the “zone”

Installation of zonal heating cable

Self-regulating heating cable is a smarter design. Inside the braids and screens (depending on the modification) there is the main element of the cable - two copper conductors, between which there is heating matrix. It looks like ordinary dense polyethylene, but it has qualities that take cable heating to a completely new level. This matrix is a semiconductor, and it changes its properties when the temperature changes.

Self-regulating cable. What is inside

Example with heated floors

Let's say you make heated floors using such a cable. But different rooms usually have different initial floor temperatures, for example, in the bathroom it is one, and in the hallway it is different. Moreover, in the same room, the initial floor temperature can vary significantly, and if you use a resistive or zoned cable, you can achieve a comfortable floor balance, but only by dividing the rooms into “cold” and “warm” zones. To do this, you will need to install additional thermostats and heat sensors... Not a very pleasant prospect, especially taking into account the shortcomings that we will write about below.

Installation of a heated floor using a cable

A self-regulating cable allows you to exclude a thermostat from the circuit altogether. It itself regulates where it needs to be heated more strongly and where less so due to its matrix. Let's say you came home from the cold and left your snow-covered boots on the floor with a self-adjusting cable. So, the area with the boots will heat up more than all other areas exactly until it heats your boots to the set temperature.

This significantly saves energy due to the fact that it heats up only the area that needs heating.

Plumbing example

Using a heating cable to heat a water supply

To prevent the water in the water supply from freezing in severe frost, you wrapped it. Any valve (water meter, coarse filter, etc.) has a complex geometric shape that does not allow the cable to touch the metal directly. If you use a self-regulating heating cable, then the main consumption of electricity will go to heating exactly those areas that touch the metal, because there the heat transfer will be most pronounced. At the same time, the cable efficiency increases several times compared to other cable heating systems

Example with roof heating

When heating a roof against icing, you will almost never be able to guess which area will be the most dangerous for icicles to form. By using this semiconductor matrix cable, you can be sure that the area that had the most ice/water will be warmed.

Roof heating with self-regulating cable

Helpful advice: if you are going to use a cable for heating the roof, you should choose a type that is resistant to ultraviolet radiation and can easily withstand high temperatures, because The roof temperature in summer rises to 50-60 degrees. For example, Raychem ETL-10 can withstand temperatures of 65 degrees.

Advantages

In addition to the main ones listed, there are several more “chips” that complement the picture

The cable can be cut to any length, starting from 20 cm. This will not affect its properties in any way. There will be no unheated areas, as well as areas with elevated temperatures
You can cross them during installation. This is especially true when warming water supply units. The cable at the crossing point does not overheat and does not fail
Remains operational in the event of a break. If for some reason the current-carrying core inside the cable breaks, then it will still heat up to this point
In the case of heating pipes with a self-regulating cable, there are modifications for placement inside the pipe, which significantly increases efficiency
Does not require a heat sensor or thermostat. Plugs directly into an outlet or switch
Easy to connect, there are special kits for connecting to electricity, inside the pipe, and sealing the end of the cable.

Flaws

Well, where would we be without them? The main one is, of course, the price. Depending on the modification, it can be 2-3 times more expensive than the same power/length for resistive and zone heating cables.

The second significant drawback is that a self-regulating cable cannot quickly heat/thaw a particular area. It simply will not heat up above the rated temperature. This cable is designed rather to be turned on all the time, fortunately, low power consumption allows you to experience this painlessly for your wallet

The third drawback, or rather a feature of this heating element, is the increased starting load. Let’s say your cable is marked 50W m.p. (50 watts per linear meter) - this means that when the cable is connected to the network, the load will be 80-100 watts per meter until the cable warms up for the first time (1-5 minutes) - this feature should be taken into account when laying wiring of the appropriate section.

Connection

Some models of self-regulating heating cables have additional braids and protective screens. We will look at connecting a cable with two insulating braids.

We cut and remove the first insulation to a length of 40 mm;
Underneath there is a copper braid (ground) - we twist it into a bundle;
Under the braid there is internal insulation - it needs to be stripped down to the internal matrix (it is black) to a length of 30 mm;
After this, the matrix itself is carefully cut off, exposing the current-carrying wires, to the same length of 30 mm;
Heat-shrinkable tubes, 25 mm long, are put on the wires (current-carrying and ground) and shrinked with a hairdryer, but most often with a J lighter;
The current-carrying wires can then be combined with another heat-shrinkable tube and seated together;
The cable is ready for connection.

Cable cutting procedure

As you can see, there is no fundamental difference in connecting this cable from a conventional power cable with grounding. There are differences in the termination of such cables. Because The heating cable is a final element and is not connected to anything - its end must be properly terminated. Manufacturers of self-regulating heating cables sell special kits for cutting and terminating them. The work boils down to the following:

The first layer of insulation is stripped to a length of 20 mm;
A heat-shrinkable tube is put on the copper braid with a length 10 mm longer;
After shrinking, until the tube has cooled, the free end is clamped with pliers;
After cooling, all this is coated with a layer of silicone sealant.
Another heat-shrinkable tube of a larger diameter is put on this entire structure to overlap the inner tube by 20 mm in both directions
Shrink it with a hairdryer until silicone appears at the end.
The tube is bent and clamped with pliers until it cools down.

Procedure for cable termination

After such manipulations, the cable can safely be sent to the most dangerous and wet places. Moisture is no longer scary for him.

Electric heating systems for various objects are quite in demand today. They are fashionable to use both indoors and outdoors. Self-regulating cables are of particular interest. They are less demanding on the installation process and consume less energy resources.

Their design and principle of use differ from conventional ones. Consumer reviews will help you choose the appropriate product option. Experts will tell you how to properly install such a system. This guarantees a long and productive service life.

general characteristics

In appearance, self-regulating cables are very similar to their usual varieties, but only slightly flattened. This is due to the design of the presented product. This shape allows it to fit more tightly to the heated surface.

Most often, such products are used for heating pipes, tanks, drains and roof gutters. There are systems designed for indoor heating, as well as outdoor installation in the ground or screed. They are laid on steps or roadways.

The range of applications for such products is extremely wide. The advantage of such a cable is that the heating intensity and energy consumption vary depending on the ambient temperature. Therefore, such a system does not need a thermostat: it adapts itself to existing conditions.

Wire design

Self-regulating has a special design. Between two conductive cores there is a matrix made of a special polymer material. It is made from carbon.

When the temperature in a certain area decreases, the conductivity increases, as does the heating itself. If it is quite warm around the cable, the material changes its properties and begins to somewhat restrain the flow of electricity, and accordingly, the heating decreases.

The internal structure is protected by several shells. The metal screen is necessary for grounding and protects the heating element from mechanical damage. The PVC top shell also increases the durability of the product. The conditions under which the system can be used depends on its strength class.

Advantages

Self-regulating wire has a number of advantages. If we compare it with resistive varieties, it is easier to operate. It is not afraid of local overheating and does not need to maintain the same temperature along the entire length of the product.

It should also be noted that the presented system is not afraid of power surges. It can be crossed, unlike a constant heating wire. This is especially important when arranging the heating of pipeline systems and their valves.

Due to the design features, such products can be cut into small pieces. The minimum length is 10-15 cm. Paying attention to the scope of their application, we can say that in the near future self-regulating systems may supplant resistive ones.

System installation

You can install the presented product yourself. It is necessary to follow the manufacturer's instructions and expert recommendations. Installation of a self-regulating heating cable can be of two types: internal and external. If the pipe is already laid underground, but needs to be routed, you should purchase a system with the appropriate insulation class. Its length must correspond to the size of the pipe.

The diameter of communications should not exceed 50 mm. The cable is pushed into the pipe and connected to the network.

In case of external installation, the system is attached to the surface. Then it is insulated with special insulation. If the diameter of the communications is small, the wire is laid evenly and corresponds to the length of the pipe. For fairly wide products, the cable is wrapped around them. The length of the system exceeds the size of communications.

Heating of open areas

Self-regulating pipe cable is quite often used in snow melting systems. They are mounted inside the gutters on the roof. In addition, some systems of this operating principle can be mounted on steps and ramps. They are filled with a solution and turned on to remove snow and ice from surfaces.

Quite large areas can be heated with such a system. Car access paths and asphalt areas near houses are also arranged in a similar way. The soil in the greenhouse is heated by self-regulating systems. Their price is higher than that of a regular cable, but the operating costs will be much lower.

Types of cable power

For each type of conditions, it is necessary to select self-regulating cables that are appropriate in terms of power. Low temperature systems are suitable for indoor installation. Their maximum heating is 65 degrees. Moreover, their maximum power is 15 W/m.

For anti-icing systems, heating of medium-diameter pipes, gutters, it is necessary to purchase products with a maximum heating of 120 degrees. Their power reaches 30 W/m.

For industrial facilities, heating large-diameter pipes, and tanks, the heating of the wire reaches 190 degrees. The maximum power is 95 W/m. The price also depends on the power of the cable. By choosing the wrong type of cable, you can get a completely different result than what was required. Therefore, the choice must be approached as responsibly as possible.

Price

To purchase a system of the presented type, you will have to spend more of the family budget than when purchasing a regular cable. But in operation the price pays for itself quite quickly.

A self-regulating cable, the price of which was studied within our country, depends on the cross-section, power and manufacturer. The most expensive are Denmark. Their cost can reach 700 rubles. per 1 m. Domestic manufacturers produce systems whose starting price is 100 rubles. for 1 m.

The longer the wire is purchased, the cheaper each wire will cost; it must be taken into account before purchasing the product.

In winter cold conditions, you may encounter the problem of pipes freezing, which can cause the water supply to stop completely. This is felt especially acutely by owners of private houses who installed their own water supply and did not have the opportunity to lay pipes deep enough in the ground. To avoid such unpleasant situations, it is necessary to consider a heating system. A self-regulating heating cable for water supply is the best option for saving you from ice jams in winter.

Frozen pipes

Types of heating cable and advantages of the self-regulating option

City services have long been using additional heating when laying a sewer system, which is a cable with adjustable resistance to electricity, which allows you to control the temperature of the wire itself, and with it the pipe.

Moreover, a heating system is added before the onset of cold weather, thereby extending the life of the water supply system itself. There are two types:

Resistive;
Self-regulating.

By design, it is one or more copper wires (maybe another metal), which generate heat when electricity passes through them. They are tightly packed into a thermal insulation layer and covered with foamed polyethylene on top. The resistive option requires connection to electricity at both ends of the wire, which is why the self-regulating option is chosen for private needs.

Another advantage of using a self-regulating system is its ability to change the temperature regime in certain areas. As the external temperature increases, the resistance to polymers increases and heat generation decreases. This option can also be cut into small pieces, unlike the resistive one, which is more often used on an industrial scale.

Self-regulating heating cable for water supply: the advantages of such heating

This system for protecting pipes from frost has its advantages:

The ability to change temperature conditions in response to weather conditions in certain areas.
Electricity consumption is automatically reduced when the outside temperature rises or there is no water in the pipe.
Does not respond to voltage changes in the network.
It is possible to cut the cable into small pieces.
Simple installation, which boils down to fixing and connecting to the network.
Long service life (up to 15 years).

Thus, for private use it is better to purchase a self-regulating version, which can be purchased in the required length for your pipes.

Related article:

In a separate publication we will talk about the criteria for choosing a device, its price and proper installation. Read!

Options for installing a self-regulating heating cable for heating pipes

To install a heating cable for water supply (self-regulating) there are two main options:

External fastening;
Placement inside the pipe.

Let's look at each option in more detail.

External mounting of the pipe heater

To secure from the outside, you can also use two methods:

Linear;

In a spiral.

In the first case, you will need the same amount of cable along the length of your pipe. This method is usually chosen for pipes with a small diameter. In the second case, the communication branch is wrapped with a heating wire, distributing heat evenly on all sides.

Note! The highest permissible power when administered internally is 10 W/m.

Internal connection

If you plan to place the heating system inside, then do not forget to wrap the wire with an additional layer of aluminum tape, and when choosing a model, pay attention to its approval for contact with food.

The cable should be inserted using a gland. This option does not require fixing, however, if you are supplying heating from below, it is better to fix the wire.

Note! To connect to the network you will need a special coupling!

When laying a heating cable, how to connect it to the network correctly

To turn on the heating cable for the water supply inside the pipe or outside, access to a 220 W network is required. It is also necessary to insulate the second end of the wire so that there is no contact between the current-carrying wires.

However, the connection diagram is the same, to make it clearer for you, we suggest watching the video.

Self-regulating heating cable (video)

And here are some tips for connecting to the network yourself:

If the model is without braid, you can simply power it from the network, but it is important to insulate the other end of the wire. Check that there is no contact between the wires.
If you have the option with a grounded screen, then connect it to the ground; if there is nowhere to connect it, you can simply cut it off.
Connect it to the regular one and you're done.

Having considered how you can install and connect a self-regulating cable, let’s pay attention to the features of choice.

Review of self-regulating cable manufacturers

If you have already decided on the length, and all that remains is to buy a self-heating cable for the water supply, the price of which may vary, the main parameters will be the required power.

Professionals have a complex calculation scheme that can provide an accurate indicator of the required power. If you count on your own, you can use a simpler method. It is enough to focus on several indicators:

For internal heating, 10 W/m is sufficient;
When calculating the power outside, you can use the formula or simply use one of the popular options - 17 or 27 W/m.

In stores, the price will vary depending on the material used and the supplier. The table below shows several options from one of the Russian manufacturers (“Special Systems and Technologies”).

Name	Highest heating temperature	Power	price, rub.
Freezstop-25-1	65	25	1500
Freezstop Inside 10-2	65	10	1800
Freezstop Lite-15-4	65	15	2000

Note! Along with self-regulating cables, manufacturers recommend purchasing cables that allow you to control electricity consumption.

Thus, when you come to a store or visit the website of a certain company, you should also pay attention to the thermostats for the heating cable. First of all, they are needed to save money. Choose the optimal safety factor of 1.6. Here are some popular models.

Name	Description	price, rub.
OJ ETI-1551	Equipped with a switching relay. When the temperature at the sensor exceeds the set value, the thermostat disconnects the circuit. It has a single-band switch and supports temperatures from minus 10 to plus 50 degrees Celsius.	4400
ETI-1221	Temperature measurement range from 10 degrees to 110. One measurement channel and maximum current load 16 A.	4300
OJ ELECTRONICS ETN4 1999	Measurements from minus 19 to plus 70 degrees Celsius, maximum current load - 16 A, degree of protection - 20.	6100

When you buy a self-regulating heating cable for water supply, all the necessary equipment and materials, you can safely proceed to self-installation or call specialists.

There is no difficulty in installing a self-regulating heating cable for a water supply system, however, it is recommended to additionally purchase a thermostat so that you can save energy and reduce costs. And also do not forget about the thermal insulation layer, which is important for both internal and external installation.

If you choose the option of internal heating, then it is enough to use aluminum tape. However, do not forget that to enter the cable you need to accurately calculate its length. But the power is 10 W/m.

For external heating, it is necessary to install thermal insulation that will protect against moisture. It is also better to make a junction box if the network connection is too far from the cable.

You might also be interested in:

How to make heating in a private house from polypropylene pipes with your own hands How to choose and install a cable for heating a water pipe Bypass in a heating system: what is it and is it necessary at all?