Heating cable for water supply: types of wires, installation methods

When building a house without the help of specialists, not every owner takes into account climate changes throughout the year, so they forget to lay a heating cable for the water supply if it is installed above the freezing depth of the soil. To do this correctly, we will consider the types of wires, fastening methods, connection techniques and the procedure for thermal insulation. The article provides all this information, as well as a comparative analysis of cables, highlighting the advantages and disadvantages of each installation method.

Installation of cable along the pipe Source obustroeno.com

Features of the heating cable

The water supply cable is used to ensure that the water in the pipes remains in a liquid state even at subzero temperatures. In fact, it is a regular heating element that converts electrical energy into heat, taking into account the required temperature.

The design features that a heating cable for water supply must have are as follows:

1. Multilayer , has several layers of insulation (according to GOST, at least 2).
2. Increased flexibility . This allows installation of the cable on a pipeline of any configuration.
3. Resistance to external influences and temperature changes.
4. Immunity to aggressive conditions . Inside there should be a gasket in the form of a foil screen or copper braid. This avoids short circuits and neutralizes the magnetic field.

Internal filling of the cable Source koffkindom.ru
To choose the right heating cable, you should consider the main characteristics:

1. Sufficient conductivity power for indoor installation per linear meter is 10 W/m.
2. If the installation is carried out outdoors, then this figure should be increased to at least 20 W/m.

These nuances should be taken into account when choosing a wire in the same way as other indicators:

• Length . Not only the distance where the product will be laid is measured, but also the footage that will be required to insert the wires into the holes. A significant increase in length can lead to the fact that if the device is shorted or bent, the entire heating system will fail.
• Number of internal cores . Wires are produced in different thicknesses and have different conductor resistivities. The same diameter may differ in the internal filling, that is, in the number of cores.

Single-core and two-core cable Source sjevi.ru

• Section shape . Round – most often used for outer braiding. Flat - it is convenient to insert such a wire inside the pipe.

The maximum permissible temperature of the wire in the disconnected state should also be taken into account.

Design

Heating wire elements:

• The inner core is the main component. Made from alloys that have adequate electrical resistance.
• The protective shell is an insulating material that is equipped with a continuous aluminum screen.
• The general sheath is made of PVC, which is designed to protect all elements of the wire from the influence of external factors.

There are various types of heating wires available in the market. The cost will depend on the number of cores. The most budget ones - 1-core - have the simplest design. The downside will be the lack of protection against magnetic radiation present in 2- and 3-wire wires.

Cable device

Types of cable

Before installation, it is important to study what heating wires are available and how to install them.

There are two types of cables: resistive and self-regulating.

The difference between them is that when an electric current passes through the cable, the resistive one heats up evenly along the entire length, while the feature of the self-regulating one is that the electrical resistance changes depending on the temperature. This means that the higher the temperature of the section of the self-regulating cable, the lower the current strength will be on it. That is, different parts of such a cable can each be heated to the desired temperature.

In addition, many cables are available with a temperature sensor and automatic control, which significantly saves energy during operation.

A self-regulating cable is more difficult to manufacture and costs more. Therefore, if there are no special operating conditions, then a resistive heating cable is often purchased.

Resistive

A resistive type heating cable for water supply has a budget price.

Cable differences Source teplina.rus

It is divided into several varieties, depending on the design features. Each of them has its own advantages and disadvantages:

Resistive wires of different types Source yandex.net

Most buyers prefer to lay the wire “the old fashioned way” and purchase a wire with one or two cores.

Due to the fact that a cable with only two cores can be used to heat pipes, the single-core version of the resistive wire is not used. If the owner of the house unknowingly installed it, this threatens to short circuit the contacts. The fact is that one core needs to be looped, which is problematic when working with a heating cable.

If you install the heating cable on the pipe yourself, then experts advise choosing a zonal option for external installation. Despite the peculiarity of the design, its installation will not cause serious difficulties.

Additional features and advantages of zonal cables: stable power, you can cut the product and connect to the power source due to the presence of an end section. Another important nuance in single-core and double-core designs: on sale you can find already cut and insulated products, which eliminates the possibility of adjusting the cable to the optimal length. If the insulating layer is damaged, the wire will be useless, and if damage appears after installation, the entire system will need to be replaced. This disadvantage applies to all types of resistive products. Installation work of such wires is not convenient. It is also not possible to use them for laying inside the pipeline - the head of the temperature sensor gets in the way.

Wire design Source otdelkaexp.ru

See also: Catalog of companies that specialize in electrical engineering.

Another important nuance in single-core and double-core designs: on sale you can find already cut and insulated products, which eliminates the possibility of adjusting the cable to the optimal length. If the insulating layer is damaged, the wire will be useless, and if damage appears after installation, the entire system will need to be replaced. This disadvantage applies to all types of resistive products. Installation work of such wires is not convenient. It is also not possible to use them for laying inside the pipeline - the head of the temperature sensor gets in the way.

Self-regulating

Self-regulating heating cable for water supply with self-regulation has a more modern design, which affects the duration of operation and ease of installation.

The design provides:

• 2 copper cores in a thermoplastic matrix;
• 2 layers of internal insulating material;
• copper braid;
• external insulating element.

It is important that this wire works great without a thermostat. Self-regulating cables contain a polymer matrix. When turned on, carbon is activated, and when the temperature rises, the distance between its graphite components increases.

Self-regulating cable Source moydomik.net

On a note ! Self-regulating wire is more expensive, but these costs will pay off in the future. Pipes can be heated more intensely, using less electricity.

Installation methods

Installation work can be carried out in two main ways:

1. When the wire is attached to the outside of the pipe.
2. When - installed inside it.

Both methods have their own nuances. When choosing a cable laying method, you should also not forget about additional thermal insulation of the pipeline.

External cable installation

You can install the cable outside the pipe along it or around it using the ring (spiral) method.

Linear method

More often, wire installation is carried out linearly, when the cable for heating the water pipe is attached from below. Despite its simplicity, the method has its advantages, the main of which is protection. In this case, the risk of breaking the integrity of the wiring will be minimized, and the heating element will not suffer from mechanical damage from above. The electrical cable should be secured at the bottom. The fixation must be strong. Then the frost will not grab the water supply in case of a sharp drop in temperature.

Fastening along the pipe Source prom.st

On a note ! For fastening it is better to use: aluminum tape. It will increase heat transfer.

Ring method

The spiral method allows you to place the conductor along the outer radius of the pipe. This option is necessary for areas with low temperatures in winter. Due to the circular circulation, the water supply heats up better. The only downside of this method is that it requires a longer cable. To increase heating and properly secure the product, it is important to observe an intersection step no more than 5 cm.

On a note ! If there is a hard-to-reach area, then you can hug it with a small allowance. It is important to wrap the loops in the opposite direction.

Ring winding of heating cable Source www.dobroeteplo174.ru

Installation of individual components when laying cables outside the pipe

If you need to install the cable on separate metal supports, more material will be required to provide better thermal insulation. For this, only a self-regulating wire is used. Difficulty may arise from installing a temperature sensor, which will prevent the structure from overheating. It should be placed at the point where the heating rate is lowest. It is important to maintain the distance of the sensor from the cable line: no closer than a meter.

On a note ! The surface where the device will be installed is first glued with aluminum tape.

Areas of use

Heating cables are used for various needs:

• in construction - for heating the concrete solution;
• in industry - for the purpose of heating tanks with diesel fuel and chemical liquids;
• in everyday life - to prevent icing of roofs, stairs, paths.

It is possible to install it inside greenhouses - this way you can maintain a constant positive soil temperature. Pipelines are also often wrapped with heating wires, especially those parts that run outdoors - a little heating reduces heat loss.

In addition to cables, it is recommended to use insulation using mineral wool and other materials. In this case, the heating efficiency will be much higher. And the cost of paying for electricity is lower.

Connection and thermal insulation

The connection technique is universal, regardless of which wire is used, but there are nuances. The installation of the heating cable is completed by insulating the ends and connecting them to devices and sensors. To work you need to use the following equipment:

• knife;
• pliers;
• side cutter;
• construction hairdryer

First you need to prepare the cable. This will require additional terminals that come with the wire or pipe. Inside the sleeve has a special heat-shrinkable layer that improves the quality of the connection. Instead of a terminal, a special plug can be used. Only after this the end coupling is installed. To do this, first cut off a few centimeters of the outer insulation, then remove the braid, string the sleeve and heat it with a hair dryer so that shrinkage is successful. To be sure, the terminal should be clamped for a few seconds with pliers.

An example of cable installation inside a water supply system Source www.ingeneriya.ru

Results: how to choose the right one

To ensure efficient and economical heating of an object, you need to take into account its dimensions, the conditions under which the cable will operate, the power of the wire, and the operating temperature. The quality of the insulation should also be taken into account. For outdoor installation, be sure to use a cord with durable braiding. And in order to prevent interference with electrical appliances near residential premises, the cable must be equipped with a screen, which will also allow the system to be grounded.

All heating wires sold in the country must undergo mandatory certification.

Nuances of installation work

When the wire is securely fastened inside or outside, it is important to take care of the insulation of the end of the conductor. Experts recommend using heat shrink tubing. This product will perfectly protect the conductors from moisture, which will reduce the risk of short circuits and repair work. We must not forget that the heating part must be connected to the “cold” part.

Connecting wires Source termodar-64.ru

Tips and recommendations from experienced craftsmen:

• If you use two methods of laying wires inside and outside the pipe at once, you can increase the rate of water heating several times, but this will require additional installation costs.
• Heating water pipes with a self-regulating heating cable will allow you to ignore warm sections and direct the current to cold places. It is allowed to be cut, so there will be no problems in installation even in hard-to-reach places. The cable length does not affect heat transfer.
• Resistive wire is half the price, but its service life is much shorter. If a regular two-core cable was installed, you should prepare for the fact that in 5-6 years it will have to be replaced.
• The braid on the wire serves to ground it. You can skip this stage of work, but it is better to become familiar with grounding methods.

Life time

One of the most important qualities of a heating wire is the stability of the heating matrix. As time passes, the polymer ages, the matrix loses its own characteristics, and the power of the electrical cable decreases.

Budget products have a short service life - no more than 3-4 years. It is not uncommon for the power to be halved within 1-2 years, or for the wire to completely lose its qualities within 1 season of use. Products from such developers as Penair and Fujikura are distinguished by high stability of parameters and a long service life due to high-quality initial components and high-tech production processes.

Important! It is also necessary to take into account that a number of manufacturers of electrical cables, with an increased rate of aging, initially set too high powers in order to ensure proper service life of the wire. This leads to the appearance of a high initial and rated electric current.

Water pipes located at depth are subject to freezing at minimum temperatures. This leads to disruptions in the operation of the entire water supply system. In order to reduce the likelihood of such a risk, it is possible to install a heating electric cable for the plumbing system. A wire with a simple operating principle can save a lot of money and time for the owner.

Video description

How to ground a water supply is shown in the video:

• Most often, for self-installation, a linear cable laying method is chosen.
• The level of heat transfer directly depends on what pipes are installed in the room. For plastic pipes, this figure will not be high, which means that when installing a heating cable for a water supply system, you will need to wrap the pipes with aluminum foil.
• Before attaching a cable to the outside of a metal pipe, it is important to ensure that there is no rust. If there is one, it requires cleaning and treatment with a special antiseptic. If this is neglected, there is a risk of damage to the insulation in the future.
• If fastening is carried out from the outside, then the distance between the insulating bundles should not be more than 30 cm. If you take a wider step, then after a while the fastening elements will separate.
• In practice, some craftsmen pull two wires at once to increase the heating rate. It is important that there is a small distance between the cables.
• For fastening to plastic, it is better to use special clamps.

Fastening with clamps and thermal insulation in section Source yandex.net

• If you decide to twist the wire in a spiral, then initially the pipe is wrapped with metallized tape.
• To fix the insulation, it is better to use special ties. They can be purchased at any hardware store.
• It is necessary to completely isolate the temperature sensor from the electrical cable to eliminate the risk of short circuit and fire. To do this, it is necessary not only to maintain a distance between these devices, but also to make the insulating gasket with a special material.
• Heating the pipelines with a heating cable using a thermostat will ensure constant temperature maintenance. It is better to install this device next to the electrical panel or directly in it. It would not be superfluous to install an RCD.

Wire with thermostat Source www.elektrikaup.ee

Is it worth installing a thermostat?

Nowadays, issues of saving money in the family budget come to the fore, so no one will overpay, which means that without a thermostat, the operation of the heating system for water pipes will be ineffective and costly. The thermostat turns on the system at a temperature of +3 degrees and turns it off at a temperature of +13 degrees.

When water is supplied from a well, its temperature will not reach +13 degrees, so the system will operate all year round. In the summer, you can turn off the heating, but in spring and autumn, when there is a high probability of frost, this cannot be done.

Whatever one may say, in any case, a thermostat is simply necessary. If you set the shutdown temperature on it to about +5 degrees, then you will have to pay a pittance for electrical energy. In addition, the durability of the heating system increases noticeably, since the cables have a certain working life. The less they work, the more at maximum, the longer they will last.

Heating cable for water supply - connection diagram to the thermostat

Naturally, in this case you will have to correctly position the temperature sensor. It should fit snugly against the pipe, but at the same time it should be reliably isolated from the heating element itself.

As a rule, the thermostat is installed indoors. The device is connected to the house electrical panel via a circuit breaker, 6 amperes and an RCD, with a leakage current of no more than 30 mA.

The heating cable is connected to certain terminals located on the thermostat housing. If several cables are connected, they are connected in parallel. The temperature sensor is connected to other contacts. As a rule, there is a corresponding marking on the body of the device, and the connection diagram is in the passport, so it’s not at all difficult to figure it out. If there is no marking on the device, then it is better not to buy such a product, since it does not meet all the requirements. Most likely it was produced illegally.

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

Connecting the heating cable