Which heating cable to choose? Self-regulating or resistive?

As an advertisement

Freezing of the soil, and with it water and sewer pipes, can paralyze the activity of vital communications. Sometimes the only remedy for such troubles is the installation of a heating cable.

We will introduce you to unique technical solutions that, at a reasonable price, ensure the operational safety of utilities during the winter cold season. We are talking about the self-regulating heating cable Heatus - a product of the South Korean manufacturer Young Chang Silicone.

The manufacturer has its own history, a good name, it has been known on the world market since 1986. The company concentrated its production capacity and resources in its homeland. Considering that its competitors have long since moved factories to the territory of friendly powers (for example, China), then this fact in itself deserves trust in the product.

Why do you need a heating cable?

It is reasonable to argue that you can easily do without heating the water supply. It is enough to find out the level of soil freezing in the area, and then, based on the indicators, dig a trench of the required depth. Usually this is 1.5-1.7 m for the middle strip, depending on the type of soil.

Pipes buried at such a depth and insulated do not freeze, since the surrounding soil has a positive temperature (let's say + 2-4 ° C).

However, not all so simple. In wetlands or areas close to water bodies, high groundwater levels are a common occurrence. This means that during floods or snow melting, communications will be flooded, which will negatively affect their functional properties.

If you bury the pipes only half a meter, but at the same time connect the electrical cable and provide proper thermal insulation, then you will not have to dig deep ditches.

It happens that in severe winters even deep-rooted areas freeze. Living in a house without automatic water supply from a well becomes less comfortable and sometimes even impossible. We have to carry out emergency repair work

Let's not forget about the critical areas that are most susceptible to the effects of cold - the places where the pipeline enters the house. If the building is built on a pile-screw foundation, then underneath there is an open section of the pipeline, which is easiest to insulate with a heating cable.

Conclusion: if it is technically possible to install a heating system for a water supply system, you should definitely use it, at least for the sake of insurance against freezing.

When contacting a specialized company, you may encounter some variety of offers. Let's look at the assortment.

How to choose a cable according to power?

To put it simply, for each degree below 0, 1 W of power is taken. That is, if a sewer pipe must operate at a temperature of -10°C, then the cable power must be at least 10 W/m (meaning that the pipe temperature will not be 0°C, but positive, for example, +3 - +5° WITH). However, these are fairly average indicators and for a more accurate calculation you need to use special calculators that take into account the heat loss of the pipe material (metal or plastic), the length of the pipeline, whether there is additional thermal insulation, the installation of the wire and the temperature it generates. Cables from different manufacturers with the same output power can produce different temperatures. For example, one wire at a power of 10 W/m produces a maximum operating temperature of 65°C, and the other at the same power produces 75°C.

The product data sheet usually indicates the rated output power of the cable, as well as the maximum heating (exposure) temperature. Above you can see a clipping of the characteristics of self-regulating cables from one of the manufacturers. From it you can find out which wire can be used for what purposes. Almost every manufacturer provides similar data.

Some “tricks” used when selling self-regulating cables

Currently on the market there is a self-regulating cable without a screen (copper braid) and an external protective layer. This is contrary to generally accepted safety cable design and leads to reduced reliability and safety. The letters CT, CF or CR in the cable marking indicate the presence of a copper screen and outer insulation (thermoplastic or fluoropolymer), and their absence indicates that this is a semi-finished cable.

Examples of full-fledged self-regulating cables

HS-FSR2-CT 31W – self-regulating cable “Heat Systems” brand FSR for voltage 220-240 V (2) with tinned copper screen (C) and thermoplastic sheath (T) with a power of 31 W/m.

10BTV2-CR

– self-regulating cable “Raychem” brand BTV for voltage 220-240 V with a tinned copper screen and a shell made of modified polyolefin with a power of 10 W/m.

SRL 30-2-CR

– self-regulating cable “WUHU” brand SRL for voltage 220-240 V (2) with tinned copper screen (C) and thermoplastic sheath (R) with a power of 30 W/m.

Example of the name of a semi-finished product (blanks for cable production)

SRL 30-2 is a self-regulating cable of the SRL brand for a voltage of 220 V (2) with a power of 30 W/m, without a protective screen and without a sheath (the letters CR are missing).

Such a semi-finished cable product has protection class “0” from electric shock to humans (GOST 12.2.007.0-75 C. Electrical devices of protection class “0” can only be used in fenced areas or premises, as well as in premises without increased electrical danger (there is no dampness or conductive dust; conductive floors; high temperature; the possibility of simultaneous human contact with metal structures of buildings connected to the ground, technological devices, mechanisms, etc., on the one hand, and metal housings of electrical equipment on the other) (clause 1.1.13 PUE).

In addition, the International Electrotechnical Commission recommends that electrical equipment of protection class “0” be excluded from international standardization (GOST R IEC 61140-2000).

Be careful when ordering self-regulating heating cables, understand the cable markings, and make sure that the cable design is suitable for your application.

Make sure that the manufacturer has certificates of conformity for the heating cable (when using a heating cable in hazardous areas, the manufacturer must have an explosion-proof certificate for this cable), also ask whether the cable has been tested for aging, since the absence of this data can lead to a waste of your money.

Self-regulating heating cables without a screen, for example, HS-FSM2, SRL 30-2 and the like should be used only in closed technological processes where human access is limited.

The use of a self-regulating cable without a screen for the installation of heating systems in the home is strictly prohibited!!!

Design and scope of application

Depending on the type and technical characteristics, heating cables are used to heat drains, water and sewer pipes, and tanks. The main purpose is to protect liquids from freezing by increasing the temperature.

Heating systems are relevant for external communications, that is, for use in the ground or in the open air.

The basis of its operation is the ability of the cable to convert electricity into heat. The wire itself cannot transmit energy, as power analogues do. He only accepts it, and then gives off heat to the pipe (tray, gutter, tank, etc.)

Heating systems have one useful ability - zonal application. This means that you can take a set of elements and assemble a mini-system from it for heating a separate area, without connecting to the entire network.

This results in savings in materials and energy. In practice, you can find miniature “heaters” of 15-20 cm, and 200-meter windings.

The main components of the heating cable are the following elements:

• Inner core - one or more. It is made using alloys with high electrical resistance. The higher it is, the greater the specific heat release value.
• Polymer protective shell. Together with plastic insulation, an aluminum screen or copper wire mesh is used.
• Durable PVC outer shell covering all internal elements.

Offers from different manufacturers may differ in nuances - the alloy of the core or the method of protection.

Shielded types are considered more reliable, equipped with foil protection and containing 2-3 cores instead of one. Single-core products are a budget option, which is good for assembling systems for short sections of water supply (+)

To improve the characteristics, the copper braid is nickel-plated, and the thickness of the outer layer is increased. In addition, the PVC material must be moisture resistant and not susceptible to ultraviolet radiation.

Completeness and footage

Agree that any system looks much more profitable and practical if it is delivered to the consumer fully equipped. If we talk about heating systems, then this is better than buying a separate cable, and separately couplings and seals, which are not always of good quality, and which then have to be adjusted to the size of your communications.

Cable products based on the Heatus heating matrix are initially equipped with everything necessary for quick and easy installation. Thus, PerfectJet heating cable kits, designed for installation inside pipes (sewage, water, etc.), in addition to heating elements, are equipped with a cable gland.

A cable gland is a set of parts and elements that ensure hermetically sealed cable fixation in the pipeline. One hundred percent tightness of Heatus kits is ensured by a special form of seal, as well as a large contact area between the cuff and the cable.

And a couple more important points: Heatus installation kits include cables of different lengths (a total of 65 standard sizes, multiples of one meter). For the buyer, such an assortment means the availability of optimal solutions for all occasions. Now, as for safe transportation: neat cardboard packaging will protect the product from damage during transportation, which is very important, because the consequences of mechanical shocks and invisible scratches will certainly manifest themselves during operation.

What characteristics are important for choosing a warm cable?

Before choosing a heating wire, you need to pay attention to the following factors:

• on the diameter of the main line and the length of the area that needs heating;
• to the minimum soil temperature at the depth of the water main.

To correctly calculate the cable power, study the video materials:

When selecting a cable, the type of external insulation and the temperature class of the product are taken into account. For example, to heat sewer drains, a wire with a polyolefin insulator is used. When arranging external protection for water pipes, a cord coated with materials based on fluoropolymer (resistant to ultraviolet radiation) is used.

The heating cable inside the pipe is covered with fluoroplastic protection. It is also recommended to pay attention to the power consumption and the name of the company that manufactured the product.

Cable selection criteria

Selecting a heating cable according to all the rules involves taking into account several criteria:

• design features;
• type of external insulation;
• temperature class;
• water pipe cross-section;
• power;
• manufacturer.

Externally, this type of product differs little from each other, but different brands of cable have their own individual characteristics. They are different, which can be clearly seen by examining each criterion in detail.

Criterion #1 - cable design features

First of all, when choosing, you should pay attention to the design features of the heating cord. Thus, a self-regulating cable, in addition to two copper conductors and a matrix, can have insulation, braiding, and an outer sheath.

Braiding increases the mechanical strength of the product. If it is not on the thermal cable, it is an economy class product.

The functioning of a self-regulating cable is carried out due to the fact that the value of the electrical resistance of the matrix adapts to the ambient temperature. When it's cold, it decreases and the current increases

The presence on the market of a self-regulating cable that is not equipped with copper braiding or external insulation is not uncommon. This reduces product safety, reliability and is contrary to generally accepted standards. In fact, this is not a cable, but only a blank.

Criterion #2 - external wire insulation

The type of external insulation is also of great importance. To protect your home water supply, an insulating layer made of polyolefin is quite suitable.

For industrial environments, fluoropolymer is more suitable as external insulation. To lay the cable in a pipe, fluoroplastic insulation is required.

To improve the characteristics of the heating cable, the thickness of the outer insulation is increased and the copper braid is nickel-plated. The insulation material must be highly resistant to moisture and ultraviolet radiation

There are also recommendations regarding the thickness of insulation depending on the diameter of the pipe. With its value of 15 or 20 mm, the optimal thickness of the insulating layer is 20 mm. For cross-sections of 25 and 32 mm, the optimal insulation thickness is 30 mm. For water pipes with a cross-section of 40, 50, 65 mm, the thickness of the insulation must be equal to the diameter of the product.

Criterion #3 - cable temperature class

Temperature class is the next most important evaluation indicator when choosing a heating cable. A low-temperature product can warm up to 65 °C with a specific heating power of a maximum of 15 W/m. This product is more suitable for a pipeline with a small cross-section.

The thermal cable, heating up to 120 °C, with a maximum power of 33 W/m is classified as medium temperature. It is used for medium diameter pipes.

It is better not to use a cable that heats up to 190 °C, with a power of 15 to 95 W/m, for home plumbing at all. It is used in industrial environments where large diameter water pipes are installed.

Criterion #4 - choice by power

It is important when choosing a thermal cable to proceed from the cross-sectional area of ​​the water pipe and select the appropriate power according to it.

Experts recommend focusing on the following parameters:

• pipeline diameter 1.5-2.5 cm - power 10 W/m;
• 2.5-4 cm - 16 W/m;
• 4-6 cm - 24 W/m;
• 6-8 cm - 30 W/m;
• More than 8 cm - 40 W/m.

The choice of power is impossible without taking into account the pipe material. If it is made of polymers, then the power of the cable should not exceed 17 W/m. Otherwise, the water supply may fail due to overheating.

The last criterion is the cable manufacturer. It’s better to pay a little more, but the system will work like a clock.

You will learn how to choose a heating cable to protect sewer pipelines from the following article, which we strongly recommend reading.

Types of heating cable

All heating systems are divided into 2 large categories: resistive and self-regulating. Each type has its own area of ​​application.

Suppose resistive cables are good for heating short sections of pipes with a small cross-section - up to 40 mm, and for long sections of water supply it is better to use a self-regulating cable (in other words, self-regulating, “samreg”).

Type #1 – resistive

The principle of operation of the cable is simple: a current passes through one or two cores located in the insulating winding, heating it. Maximum current and high resistance add up to a high heat dissipation coefficient.

Pieces of resistive cable of a certain length that have a constant resistance are available for sale. During operation, they give off the same amount of heat along their entire length. A single-core cable, as the name suggests, has one core, double insulation and external protection. The single core acts as a heating element

When installing the system, you must remember that a single-core cable is connected at both ends, as in the following diagram: Schematically, a single-core connection resembles a loop: first it is connected to an energy source, then it is pulled (wound) along the entire length of the pipe and returns back

Closed heating circuits are more often used for heating roof drainage systems or for installing “warm floors”, but an option applicable to plumbing also exists. A special feature of installing a single-core cable on a water pipe is that it is laid on both sides. In this case, only the external connection type is used

For internal installation, one core is not suitable, since laying the “loop” will take up a lot of internal space, and accidental crossing of wires can lead to overheating.

A two-core cable is distinguished by the separation of the functions of the cores: one is responsible for heating, the second is for supplying energy.

The connection diagram is also different. In “loop-shaped” installation there is no need: as a result, the cable is connected at one end to the power source, the other is pulled along the pipe

Two-core resistive cables are used for plumbing systems as actively as samregs. They can be mounted inside pipes using tees and seals.

The main advantage of a resistive cable is its low cost. Many note reliability, long service life (up to 10-15 years), and ease of installation.

But there are also disadvantages:

• high probability of overheating at the intersection or close location of two cables;
• fixed length – can neither be increased nor shortened;
• the impossibility of replacing a burnt-out section - it will have to be completely replaced;
• no power adjustment - it is always the same along the entire length.

In order not to spend money on constantly connecting the cable (which is impractical), install a thermostat with sensors. As soon as the temperature drops to + 2-3°C, it automatically starts heating; when the temperature rises to + 6-7°C, the energy is turned off.

Type #2 – self-regulating

This type of cable is universal and can be used for various applications: heating roofing elements and water supply systems, sewer lines and liquid containers.

Its feature is independent regulation of power and intensity of heat supply. As soon as the temperature drops below the control point (assuming +3°C), the cable begins to heat up without outside intervention. Self-regulating cable diagram. The main difference from its resistive counterpart is the conductive heating matrix, which is responsible for regulating the heating temperature. The insulating layers are no different

The principle of operation of the samreg is based on the property of the conductor to reduce/increase the current depending on the resistance. As the resistance increases, the current decreases, which leads to a decrease in power.

What happens to the cable during cooling? The resistance drops - the current increases - the heating process begins.

The advantage of self-regulating models is the “zoning” of work. The cable itself distributes its “labor power”: it carefully warms up the cooling areas and maintains an optimal temperature where strong heating is not needed.

The self-regulating cable works constantly, and this is welcome in the cold season. However, during a thaw or in the spring, when frosts stop, it is irrational to keep it on (+)

To fully automate the process of turning the cable on/off, you can equip the system with a thermostat that is “linked” to the outside temperature.

Heating cable for roof and gutter: how to choose and install correctly?

Drainage systems are especially unstable during thaws and off-seasons. Blocks of ice can form in pipes and gutters, causing numerous problems. Because of them, the drainage system suffers greatly. Also, ice formations greatly weigh down structures, which increases the risk of their breakage. To eliminate these aspects of cold climates, it is necessary to use anti-icing systems, of which this cable is a key element.

What is it for?

It is important to spell out the definition and answer the question “what is it?” This device is a conductor of electricity that converts it into heat. The amount of heat depends on the size and volume of electricity passing through. If you have studied physics well, you know that any conductor has this function. However, for an ordinary device that simply conducts electricity, such an effect is very undesirable, and therefore they are trying to minimize it due to the design of the structure. As you might guess, the situation is the opposite with a heating cable. It is necessary to heat the roof and gutters, which makes it impossible for ice to form there.

This wiring can eliminate:

• Icicles;
• Ice in gutters;
• Breakage of gutters due to ice accumulation;
• Pipe failure due to ice formation inside.

Parameters and important aspects.

Heating cables for roofs and gutters can operate in a variety of conditions: frost, high humidity, mechanical stress. Therefore, you need to check the presence of these parameters in such devices:

• Moisture tolerance and tightness;
• Ability to tolerate UV radiation;
• Maintains properties regardless of changes in temperature;
• Good strength, able to protect against ice, snow and mechanical stress;
• Safety, which is based on electrical insulation parameters.

The devices come in the form of ready-made sections and bays; they have a special length and wire for power. Sections would be a more suitable option for installation. Wire in coils is used mainly for roofs and ebbs with a very complex structure, where the use of conventional sections is impossible.

Types of heating cables:

There are two varieties: self-regulating and resistive. Below we will discuss in detail the key aspects of each type.

Type #1. Resistive

A fairly ordinary representative, having the same heat generation and output power along the entire length. To heat gutters, wires with a rating of 15-30 W/m and an operating temperature of up to 250°C are perfect. This option works the same along the entire length. The heating level depends solely on the incoming electricity, without environmental factors. And the factors for different parts can vary greatly.

For example, one part may be located in a drain, another in the open air, and the third may even be covered with something. Of course, each of these parts requires a different amount of current to generate heat, but the wire cannot automatically adjust to these external factors. Due to this, you will use electricity the same for any part, which leads to the fact that a certain amount of current will go to waste, since the same wire in a shelter requires less electricity than its other part in the open air. Based on the parameters of their structure, resistive devices are divided into series and zonal.

Consecutive

These representatives are very quite simple in their design. Inside there is a current conductor - a copper wire, which is covered with insulation on the outside. To eliminate electromagnetic radiation, a shielding braid is also installed on the wire. A special sheath is used as the outer layer on the wiring to prevent short circuits and environmental factors. The key aspect of this type is that the sum of the resistance of all its parts of the wiring equals the total resistance. In this connection, its power changes when adjusting the length. Since heat transfer is difficult to control, it needs to be monitored regularly, including cleaning. Due to various leaves or branches, the wiring can easily deteriorate and burn out. In this case, it will no longer be possible to restore it. The series differ in the number of cores. In wires with two cores, the flow of electricity runs through the wires parallel to each other, unlike single-core wires, which is why this type is considered more reliable and safe.

Series resistive have the following advantages:

• Good value;
• Flexibility, which allows installation anywhere;
• Simple and easy installation.

Among the disadvantages of this type are the same heat generation in all areas, as well as low strength, due to which it may break if overheated in one place.

Zonal

In addition to the ordinary resistive representative, there is also its updated version - zonal. The wire structure has 2 insulated cores that transmit electricity. Near them is a special heating spiral wire with high resistance.

Advantages of using a zone cable:

• Low cost;
• The presence of several zones, which makes it possible to eliminate the possibility of overheating;
• Easy installation.

The disadvantages include the stable heat release, the dependence of the heating area on the size of the pieces for installation.

Type #2. Self-regulating

This variety has a much wider range of capabilities. Here the structure differs significantly from resistive analogues. Inside there are 2 conductors that transmit electricity, which are connected by a special matrix. The layers are arranged in the following order: photopolymer insulation inside, shielding shell, outer plastic insulation. The presence of two layers of insulation makes the cable reliable and durable. The key detail of this cable is the presence of a matrix that changes the temperature based on external factors. Thanks to it, the higher the external temperature, the lower the heat level, exactly as well as vice versa. This makes it possible to regulate the heat level in the cable based on external factors. Thus, the heat inside is automatically adjusted. Each section operates independently of other sections and selects the optimal power for itself.

This type is several times more expensive than the resistive type. However, it has many positive aspects, which include:

• Changing heating based on external factors;
• Energy is spent more economically;
• Low power consumption (approximately 15-20 W/m);
• Long service life;
• Easy installation;
• Possibility to divide the cable into different pieces at the installation site.

In addition to the high cost, one of the disadvantages is the need for high current consumption at the start of work.

How does the anti-icing system work?

It has already been mentioned that the cable is a key component of the anti-icing system, but not the only one. The system has other components:

1. The wire itself;
2. Supply wiring;
3. Fasteners;
4. Couplings;
5. Power unit;
6. Temperature regulator.

How well the complex will work depends on the temperature controller. This device makes it possible to set the desired temperature based on external factors. The correct parameters can be set based on external sensors. An ordinary temperature controller has a special sensor. For small systems, a dual-range thermostat is used. A temperature controller called a weather station better controls the external environment. It has several sensors that, in addition to temperature, record the moisture content of the sediment and other important parameters. The presence of such a sensor makes it possible to save up to 80% of electricity consumption.

Heating cable installation

To install the entire complex, the wiring is installed:

• From the edge of the roof;
• In the valleys;
• At the junction of walls and roof;
• In gutters;
• In the drain.

At each location, laying the wire has its own key points.

From the edge of the roof

Here the installation is carried out with a snake, so that it is 30 cm higher than the wall. The required height is 0.6, 0.9 or 1.2 m. When laying on metal tiles, the coil is installed at the bottom of the wave. Installation on a standing seam metal roof is significantly different. The wire goes up the initial seam to the required height, then goes along the gutter on the opposite side. When he reaches another seam, the whole circle goes in a new way. When the roof does not have gutters, icicles and ice build-ups can form on the edges. To avoid this phenomenon, it is necessary to lay it according to plan: a “dripping” loop or edge. The loop means that moisture drains from the wiring. Here it is installed with a snake in such a way that it hangs from the roof by 5-8 cm. The edge is made according to a similar plan. The wiring is also laid with a snake, but is fixed on the edge of the roof.

At the junction of walls and roof and in valleys

Ice can form very easily in these areas. Here you need to lay the wire in 2 threads, along the joint, 2/3 of its length. This creates a special passage for moisture to drain. Approximately the same method is used for the area where the wall and roof meet. The wiring is laid according to the same pattern, and the distance from it to the wall is 5-8 cm, the distance between the threads is 10-15 cm.

In gutters

Here the wiring is installed along the entire length in one or two threads. Based on the width of the gutter, you choose how many threads there will be. You need to install it in such a way that there is a distance of 10-15 cm. To install the wiring in the gutters, use plastic clips or a special tape. You can also create these fastenings yourself - using steel tape, make the necessary clamps. Then secure everything to the gutters using self-tapping screws. The distance between fastenings should be 0.3-0.5 m.

Gutter

Ice can often form in place of the drains, preventing the passage of water from the roof of the building through the drain. In this regard, it is simply necessary to lay a heating cable in this area. One thread is installed in a pipe with a diameter of up to 10 cm, and if the diameter is 10-30 cm, then two are already used. At the entrance to the pipe, the cable must be attached to the walls using steel brackets. Good heating is required at the bottom and top of the pipe, which is achieved by installing other strands of the heating cable - according to the “dripping” loop pattern or a pair of spiral turns. In the case where the pipe is more than three meters in length, you need to use a chain or cable to lower the wiring and its subsequent installation. The cable or chain is suspended from a specially installed hook or metal rod, which is tightly attached to the gutter. It turns out that there shouldn’t be any particular difficulties in terms of installing such wiring. Having learned about the most key points and having figured out how to work with certain types of cable and its installation locations, you can understand what you need to do and what kind of installation is required.

Using minimal energy costs, the anti-icing system will help you avoid the formation of ice and snow in the most inappropriate places. By choosing such a system, you can avoid any problems in drainage systems during the cold season, and the heating cable will give you the opportunity not to worry about frost, and therefore, this kit helps keep your drains in good condition for the longest time, regardless of the weather conditions. weather conditions and time of year.

Installation methods for water supply

There are two ways to install a heating cable - external and internal. In the first case, it is attached along the pipe (or wound around it), in the second, it is wound inside. Both options have active practical applications, so let’s take a closer look at them.

Option #1 – external

Linear installation of cable along a water pipe is easy. The wire is fixed on one side using heat-resistant plastic clamps or fiberglass self-adhesive.

The holders are fastened at intervals of 0.3 m. Metal fasteners cannot be used. It is not difficult to calculate the length of the cable - it is equal to the length of the pipe that needs to be heated.

Line installation instructions:

For pipes buried in the ground, the cable is not placed strictly at the bottom or at the top, but slightly offset, which can be called the “8 (4) o’clock position.”

In addition to linear installation, spiral installation is used - the cable is wound along the entire length of the pipe with a uniform pitch. Plus – maximum contact with the pipe surface, minus – increased material consumption.

The pitch between turns can be changed depending on conditions. For example, for areas subject to severe freezing, it is reduced - thus, the entire surface of the pipe will be heated to the maximum

The wound method is relevant for pipes of medium and large diameter - sewer, drainage, but is also used for heating water pipes.

Option #2 – internal

The internal installation method is not suitable for all pipes, but only for water pipes with a cross-section of more than 40 mm. In pipelines with a smaller diameter, the cable will partially block the flow of water. It is difficult to equip a long pipe with internal heating, but for sections several meters long this is one of the best ways.

It is easiest to pull the cable in vertical sections - from top to bottom. The procedure takes place using a tee and a sealing coupling, which prevents the cord from slipping.

In some cases, internal cable installation is more rational than external installation - for example, for repairs or replacement of elements. It is not difficult to insert and connect a finished system; it is much more difficult to assemble it.

You can learn how to properly prepare the wires for insertion into the pipe from the following instructions.

Thermal insulation of heating cables

Regardless of the type of cable, it is necessary to carry out insulation. Thermal insulation is mounted on top of the heating system and water pipe. If the water supply along with the heating cable is not placed in a sealed “cocoon”, the heating will go in all directions, that is, mostly into the air.

The thickness of the thermal insulation layer is selected depending on external factors. Let’s assume that for installation in the ground, a 20-30 mm layer is sufficient, while for above-ground installation, insulation of at least 50 mm in thickness will be required

Expanded polystyrene or foamed polyethylene act as reliable and effective insulation materials. They are moisture resistant and provide some protective cushioning for the pipe, but also need protection.

For this reason, the “pipe-in-pipe” design is often used, when water pipes located in the ground or in the air, together with insulation, are placed inside another pipe of a larger diameter.

“Smart” matrix as a guarantee of efficient energy consumption

Experts know that the main element of a self-regulating heating cable is its matrix. This material, made on the basis of semiconductors, is capable of changing its resistance depending on the temperature in a specific section of the electrical circuit.

The Heatus matrix is ​​made using the most advanced technologies. The manufacturer, of course, does not reveal their secret, but proudly reports the results of their implementation into production practice. Thanks to its technological features, the Heatus matrix demonstrates minimal resistance precisely at low temperatures. As a result, the Heatus cable is ideal for working in low temperature environments where there are power limitations. It consumes a relatively small starting current, so even at the moment of starting, the energy consumption level is very low.

As the temperature rises, the working matrix automatically reduces power consumption. This guarantees energy savings without loss of functionality, and also allows you to equip the system with protective automatics of a lower rating.

Food and non-food - 3 differences

Self-regulating cables are divided into food-grade cables, which can be laid directly into the pipe, and non-food-grade cables, which can be laid on top.

How do they differ from each other structurally? Firstly, the size.

Food grades, with fairly similar characteristics, have a smaller cross-section so as not to occupy useful space inside the water supply. Compare, the most common dimensions for external ones are 7*14mm, 7*15mm, and for internal ones – 5*7mm.

Mistake No. 4 If you get the size wrong, such a cable can actually reduce the water pressure.

At the same time, do not forget about the end coupling, which has a cross-section 1.5-2 times larger than the wire itself.

The second difference is the mandatory presence of a screen. External ones may not have it.

And thirdly, and most importantly, the external insulation material.

Here, for example, is a food option.

On the outside we have:

• fluoropolymer shell

This shell is chemically inert to aggressive environments and does not decompose inside the water supply.

Next come:

• armored, protective screen or braid

Error No. 5 Without such a grounding screen, the cable cannot be used inside the pipe.

• insulation layer

• two copper strands with a polymer between them

For the non-food model, the shell consists of ultraviolet-resistant polyolefin.

Tips for choosing

When choosing a self-regulating cable, you don’t always need to focus on price. You need to consider what you will use it for and under what conditions it will be used. Here are some points you need to know before purchasing:

• Cable power. To heat pipes from the outside, cables of 16-30 W/m are usually used; if the cable heats the pipe from the inside, then 10-15 W of linear power is quite enough. For roofs and gutters, samregs with a power of 30-40 W/linear m are usually used;
• UV protective shell. If the cable will lie in the open sun and will be exposed to UV radiation, then you need to buy a cable with UV protection;
• Grounding braid. Self-regulating cables are sold both with and without a grounding braid (screen). The price of a cable without ground is about 1.5-2 times cheaper. It is advisable to use it for heating pipes going into the ground, wells, and on roofs. The most important thing is to seal this cable with a reliable adhesive seal to ensure protection against water penetration. A cable with a screen is safer, however, but much more expensive, which is not always justified, especially since they have the same self-regulating heating matrix. It determines the durability of the cable and in this regard, a cable with the same service life will significantly differ in price;

• Starting power. When any self-regulating cable is turned on, its power consumption is higher than the rated one. With a good quality self-regulating wire, the power increases by 20-50%; with a low-quality samreg (usually made in China), the starting power can “soar” significantly. This indicates the instability of the matrix and its fragility. Also, low-grade cable requires more powerful power supply machines;

• Air cavities. When purchasing, you need to squeeze the cable with your fingers and run them along its length. A low-quality cable is not manufactured according to standards and air cavities will be felt inside it. There will be a feeling that the outer sheath is lagging behind the internal parts of the cable. And, conversely, if the production process is streamlined and the technology is followed, then the outer sheath sits tightly on the cable and forms a single whole with it;
• Thickness. Self-regulating cables usually have a width of about 1 cm and a thickness of 3-4 mm. In the markets of Minsk and in the regions, sellers, trying to attract buyers with a “red” price, slip in Chinese cable. It comes to the point that its width is a little more than 0.5 cm. With such a thickness, the area of ​​heat generated is much lower and such a samreg is much less efficient. And if a matrix, which is 2 times smaller in size, generates similar heat, then its service life is short-lived. In addition, there is a possibility that over time the supply wires may close with each other due to the fact that in some places the heating matrix melts or collapses.

Determining the power of a heating self-regulating cable

The use of heating cables for heating water pipes is associated with the following circumstances:

1. When laying the system outdoors. This method is used very rarely today and requires careful thermal insulation even when heaters are used.
2. Heating is necessary at the area where the pipeline enters the house.
3. If the pipelines are located in an unheated and uninsulated attic or basement.

Internal self-regulating cables are installed in cases where an external heater was not used when laying the network. At the same time, the size of the pipes is limited; such insulation is used up to a size of 32 millimeters. This is due to the limited power of such devices - 9-13 W/m. The pipe is heated only in the area where the conductor is located.

External heating cables come in higher power ratings - 17, 23 and 30 W/m in resistive or self-regulating versions.

Some caution should be exercised when installing heaters on plastic water pipes. The limitation here is the properties of the pipe material itself.

IMPORTANT! The maximum permissible temperature for most plastics is a maximum of 95 degrees, which corresponds to a maximum heating cable power of 17 W/m.

This must be taken into account when planning water supply works. It should be noted that plastic pipes do not defrost when frozen and emergency measures do not need to be taken in winter.

The level of heat transfer and energy consumption directly depends on such indicators as cable power. The higher it is, the stronger the heating and the amount of electricity consumed. The power of the wires has a wide range, the minimum is 5, and the average maximum is 150 W/m. Therefore, it is difficult for a specialist who is poorly versed in thermal wires to select a product with the required characteristics.

To facilitate the process of calculating power, there are special tables that take into account all operating features that may affect efficiency:

• application area;
• ambient temperature level;
• material of the heating object, its size, diameter;
• placement features;
• length of cable.

For your information! The use of a cable heating system together with a programming thermostat will significantly reduce power consumption, thereby saving the family budget.

When purchasing a self-regulating cable, its power should be given special attention, since:

• excessive power will lead to overheating of the cable, and this in turn will cause damage and premature failure of the heating system;
• the use of a cable with a reduced value will contribute to freezing of the structure, since the system will not provide the necessary heating.

Correctly calculated power - efficiency, economy, safety and durability of your heating system.

Life time

The standard service life declared by manufacturers for self-regulating heating cables ranges from 10 to 40 years. They are made on the basis of semiconductor matrices, which is precisely due to the mistrust of users in the possibility of such long-term operation.

It is worth saying that this is not unreasonable, since the matrix can wear out up to 15% over a year of operation. Experts recommend several options to solve this problem:

• if the installation is underground, then a 100% reserve should be made, that is, laying a rubber thread of the heating cable;
• use a cable channel and place the heating wire in it; in case of a malfunction, you will not need to open the entire pipe, but only the area where the junction box is located;
• install the cable inside the pipe - an industrial certified product for food-grade water supply is suitable;
• laying the pipeline on the ground, with an increase in the thickness of the thermal insulation, this will reduce heat loss.

In addition, there are several rules that should be followed to extend the life of the self-regulating cable:

1. When purchasing a thermal cable, you need to focus on well-known manufacturers. Naturally, the cost of such products is much higher, but repairing or redoing the entire structure will be much more expensive.
2. In terms of type and power, the selected cable must correspond to the load that will be placed on it during operation.
3. A thermoregulation system and protective automation should be installed.
4. It is necessary to ring the self-heating system before installing it.
5. Strictly follow the conditions of the technological process during installation and the operating instructions.

Important! The key condition under which a warranty replacement of a product is made is if the temperature conditions during use are observed.

Since manufacturers conduct an examination to evaluate the wire remaining in the outer sheath of the stabilizer. This study makes it possible to establish the temperature at which the thermal cable operated.

Self-regulating heating cable - do-it-yourself installation inside a pipe

Watch the video

How to install a self-regulating heating cable inside a water pipe

Above we have already paid attention to the circumstances under which the internal device is installed. It should also be noted that such heaters are manufactured specifically for this installation method. They must meet certain requirements:

1. The outer sheath of a self-regulating cable should not emit harmful substances. Such heaters are used on small pipes through which drinking water is supplied.
2. Due to the use of electricity in an aquatic environment, the degree of electrical protection must be at least IP.
3. The end coupling must be sealed, therefore, before installing a self-regulating cable, you must carefully study the technical documentation and fully follow the recommendations.

To ensure the cable is inserted into the pipe at its end, you need to install a tee with the required outlet angle and then proceed as follows:

1. Shut off the water supply to the water supply system.
2. Measure the required cable length, having previously made the necessary measurements on the pipeline.
3. Cut a piece of the heater at the nearest mark on the cable sheath.
4. Install the end coupling.
5. Place the heater inside the pipe.
6. Place the sealing sleeve, rubber washer, conical metal clamping washer and clamping sleeve onto it.

• Assemble the oil seal in the order listed and carefully tighten the connection.
• Connect a coupling with an installation wire and a Euro plug to the rear end of the heating cable.

If tapping is necessary, heaters can be installed in several places in the water supply network.

DIY installation on the outer surface of the pipeline

When installing such a device on an external surface, the main condition for success is its tight fit. Therefore, before installing the coolant, the surface of the pipe (especially metal) must be thoroughly cleaned of dirt and traces of corrosion. This can be done efficiently using a wire brush in the form of an attachment to an electric drill.

Watch the video

Heating cable on a pipe. Installation rules

The heating element is laid in the direction of the pipe axis. Every 30 centimeters it should be secured using construction plastic clamps or metallized tape. The second option is preferable, since the heat transfer area increases significantly and the system will work more efficiently.

If several heating elements are installed, they should be located at the bottom of the pipe, where the coldest water is located.

You can run the heater in a spiral while simultaneously fastening it with metallized tape; in this case, the contact surface between the cable and the pipe increases and heating is more intense.

If it is necessary to heat plastic pipes, it is advisable to wrap a layer of metallized adhesive tape under the coolant. Having good thermal conductivity, it will distribute heat more evenly throughout the pipe, eliminating local heating at contact points. In this case, local overheating is eliminated, which can cause a breakdown of the water supply system.

During the operation of the water supply system in winter conditions, the fittings are subject to greater cooling. Therefore, when laying the heater along these elements, it must be placed like a snake, while simultaneously controlling the permissible bending radius so that there are no creases.

The best heating cable manufacturers

Heating cables are produced by many companies, both domestic and foreign.

The most popular products among manufacturers are:

• Nelson;
• Lavita;
• Ensto;
• Devi;
• Veria;
• Raychem;
• CTK.

Let's take a closer look at the features of these companies' products.

Place #1 - NELSON LIMITRACE

The company, part of the Emerson concern (USA), specializes in the production of self-regulating thermal cables. The products are known for their high quality, because... During the production process it is subjected to multi-stage control. At the final stage, aging testing is carried out.

The service life of NELSON cable without loss of power is about 20 years. To protect water pipes from frost, a brand of cord such as NELSON LIMITRACE HLT210-J is used.

It has the following characteristics:

• operating temperature limited to 120 °C;
• maximum length - up to 115 m;
• power supply - 220-240 V;
• power - 32 W/m.

NELSON LIMITRACE HLT212-J can also be used to heat water pipes. It differs from the previous one with slightly greater power (37 t/m) and length - a maximum of 105 m.

Nelson Limitrace cables are available in two versions. If the designation contains the symbols JT, the outer insulation is made of polyolefin. The letter J in the designation indicates fluoropolymer insulation

The shorter the Nelson cable, the greater the power. Thus, the power of NELSON LIMITRACE HLT215-J is 46 W/m, but the length is only 95 m. NELSON LIMITRACE HLT218-J has a length of 80 m and a power of 56 W/m.

Place #2 – DEVI and Veria

The Danish company Danfoss, which produces products under the DEVI brand, supplies the market with several options for heating wires - single- and double-core, as well as self-regulating. Each type has its own purpose.

They are plastic, have a long service life, are reliable, and environmentally friendly. The products have a fixed length, so it is impossible to cut or increase their heating area. All these manipulations can only be carried out with a “cold end”. The Devi cable has reliable insulation and sufficient power for use in any conditions.

Products in the Devi-Pipeguard 10 line are equipped with food-grade plastic insulation, so they can be installed inside a pipe for transporting drinking water

Products from Veria, a subsidiary of the Danish company Danfoss, have the same high quality characteristics as DEVI products, but their price is lower. Cable power is 20 W/m, length from 10 to 125 m. The manufacturer provides a guarantee for its heating cable for at least 12 years.

Place #3 - Lavita company

Lavita is a South Korean company. Self-regulating cables from this manufacturer are used both in everyday life and for protecting pipelines at industrial facilities. The company always fulfills its contractual obligations and strictly adheres to the quality system, so its products are in great demand on the market.

For internal heating of pipelines transporting drinking water, Lavita HPI 13-2 CT food cable is used. It is highly flexible, which guarantees easy installation. The fluoropolymer from which the external insulation is made is completely environmentally safe.

Laser marking is also harmless; it does not dissolve in water. Long service life and economical energy consumption ensure flexible power changes.

The Lavita cable differs from similar products in its high resistance to mechanical and temperature influences. The declared power is still valid even after many years of operation.

Rated cable power is 13 W/m, maximum temperature 65 °C. The length of the heating circuit depends on the switching temperature and is 51 – 108 m maximum.

Place #4 - manufacturer Ensto

Ensto heating wires, produced by the international concern Ensto, created in Finland, are distinguished by their high quality.

They provide safety and energy efficiency, and guarantee protection of water pipes from freezing. The products are easy to install, convenient to use, durable, because... High quality components are used in production.

The photo shows the Ensto EFPPH2 cable. It saves water pipes from freezing by connecting them to a power cable and plug. It is not necessary to connect it to the thermostat. Suitable for installation in drinking water pipe

For domestic use, the Ensto Plug'n Heat cable set is most often used. This is a self-regulating cable with a power of 90 W, a length of 10 m. The maximum operating temperature is 65 ° C. Installation is possible both inside and outside the pipe.

Place #5 - Raychem company

To protect a water pipe of a relatively small cross-section from freezing, the most suitable option is the Raychem ETL cable. It is equipped with a Teflon shell, suitable for both external and internal installation.

The cable regulates heat transfer based on the ambient temperature. In water at 5 °C it has a power of 20 W/m; when installed on top of a metal pipe at the same temperature, the power is halved. The cable is certified for use in drinking water supply systems.

The main advantage of Raychem cables is their length. Due to the wide selection for this parameter, you can always choose the one you need. There are also two power options: 230 and 400

Raychem FroStop Blask cable is suitable for outdoor use. In this case it has a power of 18 W/m at 0 °C. When installed in cold water, its power increases to 28 W/m.

Self-regulating FroStop Green with a rated power of 10 W/m, GM-2X (18 W/m) is also used to protect water pipes.

Place #6 - domestic manufacturers

Chuvashteplokabel is a domestic company established 18 years ago. ChTK brand . Heating cables are created taking into account all the advanced developments of European companies. Their quality is not inferior to foreign ones, and their price is lower.

Ekkotec HBS brand , also produces a large range of heating cables.

"Thermal Systems" the TS-HEAT trademark .

The company has installed the latest equipment, allowing it to produce a wide range of high-quality heating cables. The basis of self-regulating products is a high-tech semiconductor matrix.

Self-regulating heater

There is no exaggeration in this name. Engineers have actually managed to create products that do not require external control.

Design of self-regulating heating cable for water supply

The diagram shows the usual elements: copper conductors, shielding, fluoroplastic insulation resistant to high temperatures. But here the main useful function is performed by a special matrix. Its conductivity changes with increasing/decreasing temperature. At the same time, the heating decreases/increases.

These products are more expensive than their resistive counterparts. However, they are much more economical to operate. When using them, the temperature will increase only where it is really needed.

Self-regulating and resistive heaters

Creation of a heating system

The implementation of plans will be easier if you divide the entire project into stages:

• Preparation of drawings and list of components, tools, consumables.
• Connecting heating elements to power wires.
• Installation inside (outside) of the pipeline.
• Additional activities.

Connecting the heater and power cable: instructions

Below is an algorithm of actions and features that will be useful in practice:

Using the same technology, working devices are created using other types of self-regulating cables

Installation outside the pipe

With this option for placing the heater, the following table is used to approximately calculate the required power:

For more precise actions, you can use free calculator programs that are offered on the official websites of cable product sellers. In this case, specific operating conditions, liquid temperature, and installation features are taken into account. Experts do not recommend installing heaters with a power of more than 17 W per 1 m length on plastic pipes. But in reality, it is necessary to take into account the heat resistance of a certain type of polymer. Such restrictions do not apply to metal products.

Flat cables are better suited for this option. They adhere well to the surface and are easier to fix.

Typical installation of a cable for heating an outdoor water pipe

The cable is secured with clamps that are resistant to high temperatures. The pitch is chosen in such a way as to eliminate sagging. A protective casing is installed on top of the thermal insulation layer made of porous material to prevent mechanical damage.

If necessary, increase the heating by adding the required number of cables. It is advisable to place them in the lower part of the pipe, since this is where unwanted icing processes begin.

In this option, the insulation and heating element are protected by special metal shells

Attaching heating wires to water pipes with metalized tape reduces heat loss

Spiral installation

For your information! In some places you can reduce the winding pitch and make a reverse turn to increase the heating area.

During installation, special allowances are made around flanges, valves and fastening points.

Installing a heating cable inside a water pipe

This option looks preferable. Inside the pipe, the product is well protected from mechanical influences. The heater is located inside the liquid, so it performs its functions with maximum efficiency. The numbers confirm this. To maintain a positive temperature, 8-10 W per 1 m of route is sufficient. This figure is almost two times less than the previous (external) installation method.

But this technology can only be used on straight sections where there are no shut-off valves.

You can purchase a ready-made kit, or connect the heater and power cable according to the above algorithm src=»https://ventkam.ru/images/wp-content/uploads/2017/01/26-1.jpg» class=»aligncenter» width =»800″ height=»644″[/img] Manufacturers include bushings and sealing elements in such kits

When designing the pipeline, allow for a 90° turn and install a tee with the appropriate dimensions to accommodate the gland assembly.

Temperature control

A thermostat is used to automate work processes. The device itself is installed in an electrical panel. The temperature sensor is fixed to the pipe at the control point. It should be remembered that this element may fail over time, so it is installed in a place convenient for maintenance. The thermostat of a self-regulating heating cable for heating pipes is used in accordance with the instructions src=»https://ventkam.ru/images/wp-content/uploads/2017/01/28-1.jpg» class=»aligncenter» width=»850 ″ height=”286″[/img] Different electrical circuits are used to connect single- and double-core cables

In separate sets, a compact thermostat (with temperature sensor) is installed in the power supply circuit

Important! The disadvantage of compact thermostats is the lack of adjustment and remoteness from the work area.

Connecting pipeline heating to the electrical network using a heating cable

The total power of the heating system can be significant. Therefore, it is connected to a 220 V network through a separate machine. It is also recommended to install a specialized protection device (RCD) in this circuit. It constantly measures the current. When losses caused by insulation breakdown or touching a bare wire are detected, the heater quickly turns off.

Connecting the heater to the electrical network

Thermal insulation

This operation is required. It will prevent heat loss and prevent cold penetration. The best insulator is air, so porous materials that are resistant to humidity are used.

Special split tubes made of foamed polymers

The water supply is installed in a special channel, which is formed by Penoplex slabs.

Self-regulating cable - operating principle

Self-regulating, there is no closed loop or loop.

Error No. 2 There is no need to short the cores together at the end of the cable!

Between them, along the entire length, there is a cunning polymer, which, when cooled to a certain temperature, forms different conductivity bridges.

That is, at the cooling point, the loop of two wires closes on its own, current begins to flow between them and the cable heats up. In this case, you will have different temperatures along the entire length of the cable.

The hottest point will be in the coldest place. But at no point will the temperature exceed 85C. The nominal heating is 65 degrees.

This cable is completely fireproof. Even if it is overlapped on itself, it will still not burn.

Error No. 3 Make no mistake, when the weather is warm enough outside, it does not completely turn off on its own.

He simply reduces his consumption several times. There is no such option for its consumption to be zero when switched on.

Self-regs from different manufacturers differ in the quality of the so-called matrix. This is the same miracle polymer that transmits electricity through itself.

The vast majority of specialists use self-regulating types of cable to heat pipes. This is explained by their simpler operation and simplified installation.

You don't have to buy and connect a thermostat.

All you have to do is plug it into a power outlet, and it will immediately start working as it should.

Types of heating cables for water supply

There are two types of heating cables - resistive and self-regulating. Resistive ones use the property of metals to heat up when passing an electric current. In this type of heating cables, a metal conductor is heated. Their characteristic feature is that they always emit the same amount of heat. It doesn’t matter whether it’s +3°C or -20°C outside, they will heat up the same way - at full power, therefore, they will consume the same amount of electricity. To reduce costs in relatively warm times, temperature sensors and a thermostat are installed in the system (the same as those used for electric heated floors).

Structure of a resistive cable

When laid, resistive heating wires should not intersect or be located next to each other (close to each other). In this case, they overheat and quickly fail. Pay close attention to this point during the installation process.

It is also worth saying that resistive heating cables for water supply (and not only) can be single-core or double-core. Two-core ones are more often used, although they are more expensive. The difference is in the connection: for single-core ones, both ends must be connected to the mains, which is not always convenient. The two-core ones have a plug at one end, and at the other end there is a fixed ordinary electrical cord with a plug, which is connected to a 220 V network. What else do you need to know? Resistive conductors cannot be cut - they will not work. If you bought a coil with a section longer than necessary, lay it in its entirety.

This is approximately how heating cables for plumbing are sold.

Self-regulating cables are made of a metal-polymer matrix. In this system, the wires only conduct current, and the polymer, which is located between the two conductors, heats up. This polymer has an interesting property - the higher its temperature, the less heat it releases, and vice versa, as it cools down, it begins to release more heat. These changes occur regardless of the condition of adjacent sections of the cable. So it turns out that it regulates its own temperature, which is why it is called self-regulating.

Structure of a self-regulating cable

Self-regulating (self-heating) cables have many advantages:

• they can intersect and will not burn out;
• they can be cut (there are markings with cutting lines), but then you need to make an end coupling.

They have one drawback - the high price, but the service life (subject to the operating rules) is about 10 years. So these expenses are reasonable.

When using a heating cable for any type of water supply system, it is advisable to insulate the pipeline. Otherwise, heating will require too much power, which means high costs, and it’s not a fact that heating will cope with particularly severe frosts.

What kind of outer insulation should the wire have?

Internal insulation of conductors is not as important as external insulation. The external conditions determine the conditions in which the product can be used. For example, if it is necessary to run a wire inside a water pipe, then the insulation should be made of food-grade fluoroplastic, which will not affect the taste of the water or change its chemical composition. Moreover, dust and moisture protection must be according to the IP68 standard.

For roof or gutter installations, it is important that the insulation can withstand prolonged exposure to ultraviolet rays. It is usually made from fluoropolymer. The product may not indicate the shell material, but only the phrase “protection from UF rays.” But for sewerage, a cable with a polyolefin sheath is intended. Although this information is usually written in the specifications for each product, it is better to check with the seller so as not to make a mistake and buy the right wire.

Sources

• https://sovet-ingenera.com/santeh/trubodel/greyushhij-kabel-dlya-vodoprovoda.html
• https://ichip.ru/sovety/pokupka/kakoj-greyushchij-kabel-luchshe-vzyat-dlya-vodoprovoda-711692
• https://vodatyt.ru/uteplenie-truby/vybiraem-greyuschiy-kabel.html
• https://domikelectrica.ru/montazh-greyushhego-kabelya-dlya-obogreva-trub/
• https://TrubaNet.ru/kanalizacionnye-truby/greyushhijj-samoreguliruyushhijjsya-kabel-dlya-obogreva-trub.html
• https://HouseChief.ru/kabel-dlya-obogreva-vodoprovodnojj-truby.html

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