Heating cable is like a warm floor. Zone cable General requirements for underfloor heating cables
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Heating cable- this is a cable special type, whose main task is to transform electrical energy in the warmth. Suitable for both industrial and residential sites apartment buildings. Widely used for laying underfloor heating systems.
Heating cable: brief description
Heating cables are widely used in many fields of activity. It is used for laying heated floors and heating systems. Correct installation allows you to maintain a certain temperature regime not only in residential premises, but also in open areas.
Action heating cable associated with the transformation process electric current into a thermal element. Using this method allows you to maintain the set temperature. Characteristic feature product is not the transfer of energy itself, but only its reception and transformation, without the use of an oxidizer or fuel.
The versatility and ease of use, as well as the special operating principle, determine the widespread use of:
- for heating open areas;
- for heating pipes and drains;
- for heating pipes located on the roof;
- for heating underfloor heating;
- for use in industrial and high-temperature facilities.
Proper use of a heating cable ensures comfort and coziness in a living space, and also guarantees safety in industrial facilities and open areas.
Main types of heating cable
The heating cable is conventionally divided into three types. Each of which is characterized by certain features and properties. According to technical data, there are:
. resistive heating cable;
. self-regulating heating cable;
. zone heating cable.
The resistive type product is a classic design, created under the guidance of modern technical process. It is characterized by fixed power and length parameters and cannot be divided into segments. The main advantages of the resistive type are:
Affordable price;
. simple circuit installations;
. stable characteristics;
. high level reliability.
Resistive cable, in turn, is available in three main variations: single-core, two-core and zonal. The first type is ideal for creating closed circuits, the two-core product is characterized by the availability of the system, and the zone cable is one of the standard structures. The resistive type of product is widely used for open areas, industrial organizations, residential premises, warehouses and hangars.
A self-regulating cable is distinguished by the presence of a matrix in the structure of the product, which is created from a semiconductor elastic material. The resistance level directly depends on the temperature indicator environment. The advantages of a self-regulating product include:
minimal energy costs;
- easy installation;
- possibility of length adjustment;
- flexibility;
- elasticity;
- long service life.
A zone cable is a complete analogue of a resistive cable; it is widely used in industry and other areas. The main advantage of the model is the ability to adjust the length without loss of resistance and power. Characteristic difference zonal product - connection of one end, with complete sealing of the second.
Where to buy heating cable
Buy heating cable in Moscow You can contact the ONClimate company. The main activity of the organization is the sale of goods for the installation of climate control systems, as well as floor heating systems. The site presents a wide range of products from the world's leading manufacturers.
The main advantage of ONClimate is high-quality products at reasonable prices. One more key feature company is to provide partners for installing systems climate control equipment and floor heating systems.
Behind detailed information about the activities of the organization, and to order professional services, call the indicated phone numbers.
Warm floor Caleo
Warm floor under laminate
Warm floor under tiles
Warm floor in screed
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;
- Under it 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.
Currently, heating cables are widely used to create high-quality electric heating systems. Its main function is to convert the electrical current flowing through it into ordinary heat. The advantages of systems based on heating cables include savings on maintenance, simplicity and ease of installation. Modern heating systems based on heating cables are widely used in industry and for household needs.
Heating cables are mainly used for heating pipes and pipelines, various containers, tanks and other technological objects; heating areas in front of houses or cottages, preventing icing of roofs, for creating “warm floor” systems.
There are three types of heating cable: resistive, zone and self-regulating cable. Each of these two types has its own advantages and disadvantages. However, it is the self-regulating one that is most widespread in modern electric heating systems. heating cable capabilities regulate heat transfer and significantly save energy.
Resistive heating cable
The principle of operation of a resistive heating cable, as the name suggests, depends solely on a constant resistance that is unchanged along the entire length. Heat in a resistive cable is generated by the metal core. The safety of the cable is ensured by reliable insulation.
A distinctive feature of this type of cable is its increased elasticity, which allows it to take the desired shape. Its elasticity makes it possible to lay it on surfaces of any configuration. Resistive heating cable provides increased linear power and, if necessary, can be laid in several layers. Such a cable is usually cut at factories in the form of finished cable sections of a certain length, equipped with special couplings. The disadvantages of this type of cable include the inability to regulate heat transfer. This means that there is a high probability of over-consumption of electricity. Plus, the resistive cable requires maintenance: removal of debris to avoid overheating.
Zone heating cable
WITH contains two parallel insulated conductors. A spiral of wire with high ohmic resistance is placed on top of the current-carrying wires, which through contact windows alternately closes with one or the other current-carrying wire, forming parallel heating elements - “zones”. Each “zone” represents an independent heater about 1 m long.
The thermal power of resistive and zone cables is practically independent of temperature. To ensure long-term and reliable operation of these types of cables, it is very important to ensure the design heat transfer conditions so as not to cause unacceptable overheating.
Self-regulating heating cable
As opposed to a resistive heating cable, a self-regulating heating cable ensures economical energy consumption; has high maximum power; it can be cut into pieces of any length, which saves material and installation costs.
Self-regulating cable can change the generated power in each of its sections depending on the ambient temperature. The main element of this cable is a special plastic matrix. Specific heat release - from 6 to 100 W/m - can vary along the length of the section depending on the actual heat loss. Thus, each section of the cable adapts to external conditions. Heat dissipation is standardized under strictly defined conditions and is usually included in the name of the cable.
A self-regulating cable has two parallel conductors. The conductors are surrounded by conductive plastic, in which heat is generated. Plastics are characterized by a dependence of conductivity on temperature, and the temperature coefficient of resistance of conductive plastics is an order of magnitude greater than that of copper or steel. This is what allows the cable to self-regulate thermal power. Also, this type of cable is capable of changing its power locally, only in the overheating zone. This property makes it possible to make heating systems for pipelines and tanks safe, including those with variable heat transfer conditions along the length of the pipeline.
A self-regulating cable is more expensive than a resistive cable, and this is perhaps its only drawback. However, with proper design, the cost of systems based on it exceeds the cost of a system based on resistive cables by only 15-25%, since fewer distribution cables are required. But the main thing is that such systems are more reliable and economical.
There is no need to be afraid that the self-regulating cable will burn out, even if it overlaps or is covered with leaves. The cable itself automatically regulates the allocated power according to the optimal algorithm. Electricity is not wasted. This self-regulating cable is significantly more expensive, but it is also more durable and reliable in operation.
Comparison of heating cable characteristics
If there is a danger of pipes freezing, experts recommend using a cable to heat them. When the pipes are in the open air, or at a depth of up to one and a half meters, or in unheated rooms, first of all, you need to use a heating cable.
Heating cables are often used to prevent solid precipitation, maintain a certain temperature, and ensure a specific speed of liquid passage through the pipe.
Two types of cables are used for heating pipes: resistive and self-regulating.
Resistive cable
Has high constant resistance. It is distinguished by its simplicity and low cost. This pipe heating cable consists of an inner core, which is made from a material with high resistance. The core is capable of generating heat only when current passes.
The core is completely insulated with plastic and has a copper braid on top. It is not possible to cut such a cable, since it is made to a standard length. Its power is constant and equals 10-20 W per meter of cable.
The main disadvantages of a resistive cable: low wear resistance and the possibility of overheating, due to which it quickly fails. To prevent overheating, you should use temperature sensors that will turn off the heating when the set temperature is reached.
There are two types of resistive cable - linear and zonal. A linear cable for heating pipes has heat that is released due to the Joule-Lenz effect during the passage of current. The cable design has some peculiarity when the heating core experiences a complete drop in the applied voltage, however, it does not overheat.
Can be more than several hundred meters long. There is single-core, double-core or with several cores in the form of lines or spirals. It is not possible to cut such a cable arbitrarily.
A zone cable differs from a linear cable in its design. The zone cable has two conductive parallel conductors. The insulation of the current-carrying core has “windows” offset relative to each other by a set distance. The cores are covered on top with a thin wire spiral made from a high-resistance alloy.
Cutting the zonal cable is possible into certain sections with a minimum length of 1.5-2 meters. A zone cable is called a high-power cable due to the fact that there is no dependence of power on temperature.
Self-regulating cable for heating
It has variable resistance, that is, there is a dependence on temperature. An increase in heat transfer occurs when the temperature decreases, and vice versa, when the temperature rises, a decrease in heat transfer occurs.
Just like a resistive cable, a self-regulating pipe heating cable consists of two parallel conductors, however, the conductors are not insulated from each other. They are located in a polymer matrix or are connected by spiral polymer threads. The self-regulation process is carried out due to a significant increase in resistance during heating of the heat-generating device of the cable, which is made of a conductive polymer material.
Features that the self-regulating cable for tap heating has:
Thanks to two parallel conductors, constant voltage is ensured along the entire length;
The thermoplastic shell provides insulation and protection against moisture and abrasion;
Thanks to the braiding, grounding and additional protection from mechanical influence occur.
When the outside temperature drops, the heating cable for the water pipes independently copes with the decrease in thermal output, thus reducing the consumption of electrical energy or eliminating the need for the use of temperature sensors. You can immediately connect the cable to the network.
Even despite the fact that a self-regulating cable is more expensive than a resistive cable, it is not worth saving, since the use of a self-regulating cable will be fully justified due to the reduction in costs during the service life.
Advantages:
For a resistive cable, a uniform environment along its entire length is important, which is very difficult to ensure. This is why such a cable often overheats and fails. As for the self-regulating cable, the temperature decrease in areas with a small heat sink occurs independently, while the temperature in other areas is maintained;
High resistance to sudden voltage changes, even when the increased voltage persists for a long period of time;
It is possible to overlap the cable;
The cable can be cut to the required length.
If heating system devices are ignored, ice will constantly form in the gutters due to temperature changes, which can significantly increase the mechanical load on the gutter and drain fastening mechanisms. The ice formed in this way significantly shortens the period of operation of the drain, and if taken to the maximum, it can lead to the destruction of some facade devices.
The purpose of installing a heating drainage system is the continuous drainage of melt water, for which non-freezing flow channels are provided. Installing a heating cable makes it possible to completely eliminate the formation of ice on drainage devices and other areas where there is a high probability of its occurrence. This ensures that the drain is operational throughout the winter period.
The operation of heating systems occurs during the thaw period - autumn and spring, when the temperature ranges from -5 to +3 degrees. As a rule, the heating system is equipped with temperature sensors, with the help of which the operation of the entire system is independently controlled.
Engineering areas where heating cables are most often laid:
Gutters;
Funnels and areas around funnels;
Drainage and catchment trays;
Cornices;
Storm sewer pipes.
Roof heating cable
This cable completely prevents the formation of ice on the roof. However, it is worth noting that effective operation of the roof heating cable is possible only in autumn and spring, as well as during thaws. This is explained by the fact that at temperatures below minus 15 degrees such a heating system is useless. Moreover, there is a possibility of damaging the roof.
One of the difficult tasks is the uninterrupted water supply of residential buildings and other facilities, especially in winter. To prevent pipes from freezing, they must be laid below a certain freezing level. However, there is no absolute guarantee that the water supply will not freeze and the water supply will not stop.
This is due to the following reasons:
- Abnormal frosts, which are no longer uncommon lately.
- The place where pipes enter the house most often freezes.
- Occurrence of accidents on the pipeline route.
Conventional pipe insulation does not give the desired effect during prolonged and severe frosts. The solution to this issue is to use a heating cable to warm the water supply. With its help, you can maintain the required temperature and prevent the formation of condensation on the pipes. In this case, the pipes will still have to be laid in the ground, but to a much shallower depth. At the entrance to the house, you can install a more powerful heating cable and apply high-quality insulation.
The heating cable comes with instructions, after studying which you can easily install and connect it yourself. Heating cables are used not only for plumbing, but also in other areas.
Types and design features
Heating cable is classified into two types:
- Resistive.
- Self-regulating.
Resistive heating cable
This model is the most affordable for the buyer, since its production does not require the use of complex technologies and expensive materials. The power and cable length are kept constant. It is not allowed to cut a resistive cable into several parts, as the resistance will decrease and the core temperature will increase above the permissible value. This may cause the circuit to break.
The resistive cable heats up evenly along its entire length. When creating a project, it is necessary to accurately determine the cable length.
The heating cable can be connected in various ways. The easiest way is to connect it to an electrical outlet. With more complex options, the circuits use various sensors and electronic equipment with a power regulator to maintain a certain temperature.
Resistive cable is in turn divided into several types:
- Single-core . This is a simple design with an outer heat-resistant shell, under which there is a copper shielding braided with fluoroplastic insulation. Inside this insulation is a heating conductor. Such a cable is laid taking into account the possibility of connecting both ends on one terminal block. To do this, it is necessary to calculate the cable length to obtain the required temperature. You can do this simple connection yourself.
- Two-core the cable is laid over its entire length. Then one end of the cable with two cores is connected to the power supply, and the other end is closed with a special sealed coupling. This cable greatly simplifies the installation process.
- Zone cable is also a resistive heating cable model. Its structure is similar to a two-core cable with the addition of heating coils between the two main cores at equal lengths with equal power. This allows sections of the cable to be cut at a specific pitch. A malfunction in the form of burnout of spiral conductors in some areas leads to the appearance of a cold zone in the faulty area.
Features of installing a resistive cable
- Carefully calculate the required power and heat costs. When calculating, it is necessary to take into account the material of the heated surface and its area, temperature, and humidity. If heat removal is insufficient, the service life of the heating system will be significantly reduced.
- Cables that are used for heated floors in an apartment cannot be used to heat water pipes, since their insulation is not protected from moisture.
- When laying the heating cable, do not allow it to cross.
The main advantages of a resistive heating cable are:
- Increased reliability.
- Stability of characteristics throughout the entire service life.
- Low current when turned on.
- Easy installation.
- Simple device.
- Low cost.
Self-regulating cable
This type of cable works differently. The device of the self-regulating heating element is made in the form of a matrix located between the current-carrying conductors. This matrix is made of elastic semiconductor material. The resistance value of the matrix semiconductor depends on the temperature of the environment surrounding the cable. This changes the power consumption and heating efficiency.
The principle of self-regulation is that the necessary heat is released only in a certain area where it is needed. As the temperature decreases, the cable resistance increases and more heat is generated. Conversely, if the temperature rises, the cable resistance and the amount of heat decreases. With this effect, the cable will not overheat, even if there is an overlap during its installation. Electricity during operation of a self-regulating cable is consumed optimally.
Self-regulating heating is effective for underground pipes and anti-icing systems. During installation, the cable can be cut into pieces of any length, without the help of specialists, and without compromising its working properties. It is not necessary to heat the entire pipeline. It is enough to lay the heating cable only in places with a higher probability of freezing.
Self-regulating cable is expensive, but is very popular. Purchase and installation costs are quickly recouped during operation due to electrical energy savings.
Advantages
- Elasticity and flexibility make it possible to lay the heating cable for any pipe network, in structures of different geometric shapes.
- The operation and installation process does not harm the environment.
- Possibility of self-installation of the system, subject to proper calculation and fulfillment of all heating installation requirements.
- Simple work that does not require professional skills.
Application
The versatility and ease of use, as well as the operating principle of the heating cable, determine its wide application:
- Heating of garden paths, steps and sidewalks. This eliminates injuries and falls of pedestrians on a frozen surface.
- In industrial buildings and residential premises, a heating cable is used to maintain the required water supply temperature, as well as heating pipelines located in the ground and in the open.
- Heating the floor covering provides comfort and warmth in the room on frosty days.
- Heating of pipes located on the roofs of houses, drainage systems, roofing coverings. The wire is fixed inside or outside the pipe. When the heating system is working, destruction of the pipeline, falling ice and icing of the roof edge are eliminated. This ensures safety for people.
Installation methods
The heating cable for heating the water supply system is laid inside or outside the pipe. Each method involves the use of a different type of cable.
Installation inside a pipe
Requirements for indoor installation of heating cable:
- Sealed end coupling.
- no less than IP
- No harmful substances when heated.
To install the wire inside the pipe, a tee is installed at its end. The wire is inserted into one of the branches of the tee with a gland seal.
The coupling located at the transition between the electrical supply cable and the heating cable must be located behind the gland and pipe, since it is not protected from moisture.
The mounting tee can be designed with different angles. With this method, the cable is not secured, but tucked inside.
External installation
The heating cable for the water pipe is fixed from the outside tightly, using the entire surface of the cable. Before installation on metal pipes, it is necessary to clean them from rust, dirt and dust, as well as traces of welding. The surface of the pipes should not have elements that could damage the heating wire.
The heating cable is laid on a clean surface, secured after 30 cm with adhesive metallized tape or special clamps. When laying two cables, they are installed in the lower cold part of the pipe parallel to each other, without touching. If more than three cable threads are laid, then most of them are placed below, also without touching.
Another installation method is spiral installation. Be careful when doing this, as repeated and sharp bends can damage the cable. You can gradually unwind the coupling by winding the freed cable around the pipe. You can also fix the cable with slack, which is wound and fixed with adhesive tape.
To heat a plastic pipe, metallized tape is first glued, which increases heat conductivity and heating efficiency. A feature of the installation is the following factor: valves, tees and other plumbing devices require more heat. Therefore, when installing on each such device, it is necessary to make several loops without bending the heating cable too much.
For this, special types of insulation are used: polystyrene foam, made in the form of pipe elements, and called shell. It has good insulation properties and does not absorb moisture.