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Heating cable for sewerage: varieties, device, purposes and methods of application

In this article I want to talk about heating methods sewer pipes heating cable. We will get acquainted with the methods of its laying, fastening, with the restrictions that should be followed during installation, and with the types of cable for heating pipes.

When heating is needed

If we summarize all possible scenarios, they can be divided into two main categories:

1. When laying sewer pipes or installing a septic tank below the freezing level is for some reason impossible or undesirable;

This is true, in particular, when building a house on permafrost.
With a soil freezing depth of 6 - 10 meters, installing a septic tank below this level is, to put it mildly, difficult; the only way out is to organize insulation and heating.
Another possible scenario is rocky soil on the site, which makes it very difficult to dig trenches.

1. In addition, heating can be insurance in case of extreme, uncharacteristic cold weather for a given climatic zone. So, in Crimea, the winter temperature rarely drops below zero, and most of the gravity sewers are laid openly or with minimal depth. However, when the Arctic air front breaks through the Crimean Mountains, the temperature can drop to -10 and even -20C for several days.

Laying sewer on the facade of the building. Location - Sevastopol, Crimea.

Cable types

Cable for heating sewer pipes can be divided into two categories.

resistive

What happens when we pass current through a conductor with non-zero electrical resistance? Heat is generated on the conductor. Its temperature rises until the amount of heat generated by it is equal to that given off to the environment.

It follows from the law of conservation of energy that electric power of any direct heating appliance is exactly equal to the thermal power released on it. A relatively simple calculation allows, based on the resistivity of the conductor and the voltage applied to it, to select such a length at which heating will be effective against ice freezing, but safe for cable insulation and heated pipes.

This is how a resistive heating cable works.

The resistive cable can be single-core and two-core:

• In the first case, the heating cable forms closed loop, the beginning and end of which are connected to a power source;
• In the second case, the cable is powered from one side, and the second is completed with an end sleeve - a jumper between the cores.

A resistive cable, regardless of the number of cores, has a number of rather unpleasant drawbacks:

1. It consumes a constant amount of electricity regardless of the outside temperature. Need heating or not - as long as the cable is connected to the network, you will pay for the energy consumed by it in full;
2. It is sold in fixed length sections. The section size is selected according to your needs with a certain step depending on the specific resistance of the cable; however cut off extra plot You can not;
3. Overlapping the cable will most likely lead to overheating and melting of the insulation, and even the plastic sewer pipe.

The second problem has been successfully solved in the zonal heating cable.
It consists of two conductors with low resistance and heating elements connecting them.
The cable can be cut into fixed size sections.

self-adjusting

The self-regulating heating cable is a revolutionary solution, devoid of all the disadvantages of a resistive heater. How is it arranged?

Between two conductive copper wires with low resistivity a self-regulating matrix is ​​placed inside the polymer insulation. As a rule, it is a polymer with a high coefficient of thermal expansion, mixed with a finely dispersed conductive filler (for example, graphite particles).

How it works?

• When a section of the matrix is ​​heated, the polymer expands; in this case, the conductor particles move away from each other, losing electrical contact with each other. The resistance of the matrix increases, which leads to a drop in the current flowing through it, and to a decrease in heat generation in the corresponding area;
• When cooled, the matrix shrinks. This leads to the convergence of conductive particles and to the heating of the cable section.

What does it give?

1. The cable reduces energy consumption at high outdoor temperatures, saving electricity quite noticeably;
2. It can be cut into sections of any size; in this case, the end sleeve is not needed: it is enough to isolate the cut end;
3. If there is an overlap or if some area is thermally insulated, the corresponding section of the matrix will simply stop heating up. If so, the cable is not in danger of overheating.

It is a self-regulating cable that I strongly recommend using for heating pipes - both sewer and water pipes.
In what follows, we will focus on this solution.

Shielding

In the price lists of cable manufacturers, the list of options indicates "shielded" or "unshielded". What does this mean?

Copper twisted braid solves three problems at once:

1. Grounding. In case of mechanical damage to the shell, the current will flow between the phase current-carrying core and the braid. The situation in which a sewer, water pipe or drain is energized is completely excluded;

The braid, of course, must be grounded to the body of the electrical panel, dug into the ground a metal sheet or a contour welded from a bar.

1. The probability of mechanical damage itself will also noticeably decrease: the braid is not so easy to break through with an accidental blow;
2. Finally, ground shielding will protect nearby electronics from interference. With a certain laying configuration, the cable will be an inductor that induces currents in all adjacent circuits.

Power

On sale you can find cables with a specific power from 10 to 40 W / m. What power is optimal in each case?

• 10 W / m are optimal for heating water pipes with a diameter of 15 - 25 mm;
• 16-17 W / m are suitable for freezing protection of sewers with a diameter of 50 mm;

• 30 - 40 W / m - power sufficient to heat a sewer pipe with a diameter of 110 - 160 mm.

I used a 16 watt cable for a 50 mm sewer and 30 watt for a 110 mm pipe.

Sample study

The reader will certainly be interested in the price of a running meter and other characteristics of the solution so obsessively advertised by me. I hasten to satisfy his curiosity.

Fine SRL16-2

SST 30KSTM2-AT

Fine GRX-2CR 40W

In the specified range of operating voltages, the manufacturer guarantees that the actual power density corresponds to the declared values.
The cable will work at a significantly lower voltage; however, along with the voltage, heat transfer will decrease.

Assembly

Is it difficult to assemble a heating cable section with your own hands?

The instruction is extremely simple and does not require special skills. Of the tools and additional materials we need:

• Heat shrink tubing in three sizes;
• Sleeves and pliers for crimping current-carrying conductors (two for unshielded cable and three for shielded cable);
• Silicone sealant;
• Sharp knife and side cutters for stripping insulation;
• pliers;
• Hairdryer or regular lighter to warm up the heat shrink;
• The cold end is a cord with a plug. The ground wired on the plug and the third core are only needed to connect the shielding. If not, you can get by with a two-wire wire.

The procedure is as follows:

1. We remove the sheath from the heating cable and cord;
2. We clean the veins on both sides. In this case, the shielding braid and the earth must be stripped and twisted at a distance of 2–3 cm from the current-carrying conductors;
3. We put pieces of heat shrink on individual cores, on a cable without a screen / earth and on the outer sheath;
4. In pairs, we connect the current-carrying wires with sleeves;
5. We apply a little sealant to each of them, upset the heat shrink tube and heat it until the wires are completely crimped;
6. We repeat the operation with both current-carrying conductors assembled together;
7. We connect the screen and the ground with a sleeve, having previously put a heat shrink on the core;
8. We isolate the grounding separately, then we shrink the cable sheath and the cold end with heat shrink;
9. We clean the sheath at the end of the cable and cut off all the cores with a spread in length of 1 - 2 cm. They are bred in order to increase the resistance when water enters the termination;
10. Alternately we upset the tube with sealant on individual cores, on the conductive matrix and on the cable sheath;
11. We flatten the free end of each heat shrink with ordinary pliers.

Mounting

First, let's figure out how to warm up the sewer in a private house if it is already frozen.

The algorithm is extremely simple: the cable is laid under the pipe and is attracted to it in any way (adhesive tape, rags, bandages, etc.), after which the pipe is thermally insulated if possible (for example, wrapped in the same rags). The cable is plugged into the network and heated until it melts.

How to organize permanent sewer heating?

The cable can be installed both outside and inside the pipe.

Outer

1. The cable is attached under the pipe ( warm air goes up, remember?) with aluminum tape. Its surface should be as tightly pressed against the walls of the pipe as possible. It is aluminum tape that is used because the foil reflects infrared radiation, reducing non-target heat loss;

At sewer bends, the cable must be bent so that the wider plane is perpendicular to the bend radius.
Otherwise, there is a risk of damaging the current-carrying matrix or breaking the copper wires.

1. The pipe is thermally insulated from the outside with any roll insulation or, much better, with a foam shell. Thermal insulation not only reduces heat loss, but also fixes the cable: aluminum tape is not durable.

In my case, high-quality insulation was not required: in Crimea, heating is needed only a few days a year. In addition, with open sewerage, any thermal insulation would quickly become monstrously dirty.

I solved the heating problem like this:

1. The cable was pulled to the pipe ordinary tape, which is much stronger than aluminum;
2. On top of the tape was wrapped with aluminum tape;
3. Additional fixation was provided by polyethylene ties.

As it turned out, heating is needed, first of all, horizontal sections outdoor sewerage: The slow flow of the drains allows them to cool down to freezing point. A vertical riser laid along the facade does not freeze if its lower part is heated.

Interior

Heating of sewer pipes from the inside is possible with some restrictions.

• The heat shrink at the cold end connection and at the end must not come into contact with waste water. An aggressive environment destroys heat shrink tubes in one or two seasons, but the cable's own insulation can coexist with it indefinitely;

The end sleeve can be brought out of the sewer through a hole drilled in a corner or a tee.

• The cable should be easy to remove. When mechanically clearing the blockage (with a cable or wire), it is guaranteed to be damaged or at least wound around your tool.

I use internal cable heating for a septic tank sump installed outdoors under the porch of the house. For a volume of 1 m3, several turns with a total length of approximately 4 meters are sufficient. The tank is not insulated from the outside and successfully endured several days of frost at -10 without freezing the contents.

Conclusion

I hope that my recommendations will help the dear reader to solve the problem of heating sewer pipes. As always, the video in this article will suggest Additional information. Feel free to share your own experience in the comments. Good luck, comrades!

July 7, 2016

If you want to express gratitude, add a clarification or objection, ask the author something - add a comment or say thanks!

Sewer pipes need heating, outdoor and drain cleaning pipes, cleaning filter pipes leading to drainage wells. The heating cable is used for storm sewers, for drainage systems. The Avarit catalog contains solutions from European manufacturers and South Korean brands (Heatus, Lavita, Fine and other brands).

Insulate the sewer pipe with a special heating cable to prevent sewage from freezing during the cold season, so that ice plugs do not form inside the system during frost. A thermal cable with a polyolefin sheath is mounted outside the pipe. For installation inside the pipe, cable systems are produced, protected by a special sheath. The cable for the sewerage of Korean brands has proven itself perfectly in external heating.

External sewer heating with an ungrounded cable manufactured by Lavita, for example, is considered a budget option.

Sometimes the question arises: what type of heating wires function better and last longer. When answering, initial data are required: footage, width and type of sewer pipe that needs protection, climate zone in which the pipeline is laid. Tell the manager if the heating cable is needed only for the sewerage of your house or for the general sewerage system of the entire village. In the store "Avarit" they will help you decide on the choice of product for a specific request, calculate the price of a heating cable for sewerage in a particular case. On sale there are accessories for systems of heating of pipes, sensors, thermostats.

We will help you choose a sewer heating cable

Cable power outside the pipe:

Prices and delivery

Sale of cable for sewerage with delivery to the regions of Russia. Pickup points in Moscow, St. Petersburg and Orenburg (online store prices).

The performance of the sewer system in the winter season depends entirely on compliance with the recommendations regarding the deepening of the collector to a depth below the freezing mark. However, it is not always possible to adhere to such recommendations at the installation stage due to the characteristics of the soil on the site or other conditions. Common causes are:

• Wetlands that do not allow pipes to be lowered below the groundwater level;
• Part of the external collector, which is responsible for connecting the system to the septic tank;
• Pipes at the exit from the house;
• Piping from filters to drainage fields, etc.

In this case, the sewer cable will help to heat the collector.

It is important to know that the average depth of the sewer collector varies between 1-1.4 m. The pipeline laid above is prone to freezing. And this means that peculiar growths-icicles will form inside the pipe, which will subsequently gradually collect drains on themselves, thereby forming a large ice plug from the inside in the drainage system. As a result, the sewer will simply fail.

Important: a heater in the form of a special cable will prevent possible freezing of the pipeline of the sewer system.

Heating of sewer pipes can be carried out and equipped even at the stage of collector installation in two ways:

• Through the use of special heated pipes, which have a sandwich structure and are equipped inside with a special heating element. This collector is made of plastic. A heating element is placed on top of the plastic collector, and already on top the pipes are wrapped with a special heat-insulating material. The cost of such a sewer collector will be several times higher than the standard one.
• And you can heat the sewer pipeline with a special heat cord. Such a device is a sealed and waterproofed heating element, which in most cases is located outside the pipeline. It is not recommended to mount such an electrical cable from the inside. There are only a few situations when the heating cable is mounted inside. One of them is the insufficient cross section of the collector.

Benefits of Using Cable

Using a special cable for heating the sewer with your own hands, the master gets a lot of advantages from this solution:

• So, the sewer collector is in working order all the time, regardless of the temperature outside the window and the intensity of use of the sewerage system.
• The speed of transporting wastewater from the house to the septic tank (pit) increases significantly, which prevents stagnation in the pipes.
• The technological consistency of the aggressive environment remains in its original state, which accelerates the bacteriological treatment of wastewater in the septic tank in winter.
• In addition, there will be no condensation on the surface of the collector, which means that the risk of corrosion inside the collector is minimized.

Types of heating cable

You can use three types of cable to create pipe heating with your own hands. Each of them has its own advantages and disadvantages.

• Resistive heating element (heating cable). This type of device works on the principle of constant heating, regardless of the temperature outside. That is, installed temperature regime is constant, which means that the current consumption will also be constant. A resistive type heater needs constant monitoring.
• Zone cable. This type of heating element is identical to the principle of operation of a resistive one. But at the same time, it has a significant difference - the heating element works in zones, and not along its entire length. Most often, such a wire for heating the system is used in separate sections of the sewer network.
• Self heating cable. This type of heating element for heating the sewer is more productive and economical. The wire is able to regulate the collector heating temperature depending on ambient temperature. At the heart of the operation of such a wire is a semiconductor matrix, which regulates the amount of heat. Self-regulating cable consumes only 33 W of electricity per linear meter. At the same time, the installation of the wire is simplified due to the presence of an adhesive aluminum side on it. The convenience of using such an element is due to the fact that it can be easily cut into pieces and at the same time it will not lose its working properties. And the cable, which is 80 m long, can be plugged directly into a socket. Also, the self-heating cable can be adjusted according to temperature parameters at any desired section of the pipeline. That is, where the collector is located higher to the earth's surface, the temperature can be made higher and vice versa.

Important: during the initial connection of the heating system, a one-time consumption of electricity exceeding the nominal one may be observed. But already within 1-2 minutes, the heating system equalizes the current consumption and switches to normal operating mode.

Do-it-yourself heating cable installation

It is worth remembering that the installation of a heating element inside the system is not recommended. If there is an urgent need to mount the HPV inside the collector, then it is better to invite specialists for this. Outside of the system, it is quite possible to mount the wire with your own hands.

Work rules

If you decide to install a heating system with your own hands, then you should follow these important rules:

• It is forbidden to mount the heating element on any sharp and cutting surfaces;
• Before carrying out work, it is worth inspecting the collector for tightness and detection of possible leaks;
• It is forbidden to connect a cable wound into a ball to electricity;
• The finished heating system must be wrapped with hydro- and heat-insulating materials;
• If the collector is made of plastic, then it is recommended to first wrap it with foil material to increase the thermal conductivity of the collector;
• When laying the heating cable, it is necessary to make 3-4 loops 1.4 m long throughout the entire pipeline (depending on the length of the collector) in case of emergency disconnection of the pipeline. Loops are attached to the valves or neatly laid along the manifold;
• Depending on the diameter of the cable, it is possible to strengthen the heating system by winding the heating element outside the collector with a spiral in two steps in opposite directions relative to each other.
• Installation of the heating system for sewer pipes can also be carried out parallel to each other in a straight line. But in any of the cases, it is necessary to use additional clamps that will not allow the wire to move away from the collector in the future.
• To avoid possible damage to the heating element, a mark is placed outside the pipeline stating that the collector is equipped with electronic system heating.

Important: overlaying layer on layer or crossing a resistive type cable during the installation phase is not allowed, as the cable may burn out. The self-regulating wire can be twisted during installation.

Performing installation work

If you purchased a cable in a reel and are going to mount it yourself, you will have to make a plug to the wire. To do this, you need to perform the following stages of work:

• Measure 10 cm from the end of the cable and remove the outer sheath on this section of the wire. To do this, use a clerical or any other knife.
• Now carefully unwind the braid with an awl and twist it into a bundle. In the future, this harness will be connected to the ground wire.
• Again, remove the outer layer of thermal protection to the same length. Under it will be a conductive matrix. To easily remove it, you need to heat the material with a hair dryer to a state of plasticity. When the matrix becomes pliable, remove it.
• We will have two copper current conductors in our hands, which must be connected to the wires of the prepared plug.
• We reliably isolate all contacts of the heating cable after connection.

Important: if there is no grounding barrier in the plug circuit, then you can simply cut off the remaining braid braid.

We mount the prepared cable on the pipeline in the intended position and insulate the pipes.

Cable selection

In order to choose the right heating system, it is necessary to pay attention not only to the type of the wire itself (resistant, self-regulating), but also to the power of the wire. Since not always a more powerful element is needed in a particular case. Most likely, you just have to overpay for electricity.

• So, for water pipes with a diameter of 22 to 36 mm, a cable with a power of 16 W per one running meter.
• If the water pipe or sewer has a diameter of 50 to 110 mm, then a wire with a power of 24 W / linear meter will do.
• For pipes with a larger diameter, you will need electrical cable with a power of 33 W per linear meter and above.

Most of our country is located in a severe climatic zone. Therefore, the protection of sewer pipes from freezing has always been and will be an urgent task. Certainly, ideal option is laying pipes below the soil freezing limits, but this is not always possible.

Modern technologies come to the rescue, and now you don’t have to worry that drains will freeze, turning comfortable life into inconvenience. A heating cable for sewerage can well guarantee peace of mind during the onset of winter frosts.

How heating cable works

The principle of its operation is based on the heating of the core wire, which forms its basis. The heat created in the wire by the flow of electric current is transferred to the outside, and the liquid in the pipes to which the cable is attached is heated.

The cable is protected by seamless insulation. There are two wires inside it. Heating (hot) and electric (cold). They are connected by laser soldering, and the cold wire ends with a plug.

Any heating cable for sewers can be self-regulating or resistive.

Resistive

These cables are characterized by constant resistance. This means that when turned on, heat is constantly released from it, and the temperature range is 5-130 C. That is, the liquid in the pipes is heated continuously.

To make the operation of such a cable more efficient, apply additional devices. These include thermostats and temperature sensors. They are intended for automatic start and shutdown of the system when the specified temperature parameters are reached. But the minus of the thermal relay is that frequent turning it on and off reduces the service life of the cable.

Self-adjusting

Self-regulating heating cable for sewerage is more complicated. The change in cable resistance is affected by the temperature of the liquid in the pipes. Heat dissipation decreases as the resistance increases and increases as the resistance decreases.

This principle of self-regulation allows you to maintain the cable in optimal mode. The wire does not overheat, which prevents it from burning out.

The main feature of such a cable is the ability to heat up non-uniformly. On the different areas pipeline temperature can be different, so the cable in these sections will have a different heating temperature.

Rules for mounting heating cables

Specific types of sewer communications need to be heated:

• drains to a septic tank or to treatment plants;
• outlets of washing waters of cleaning filters;
• connecting septic tanks to filtration wells or drainage fields.

Most often, a self-regulating cable is used, because it is more reliable and durable. In order to get the correct heating of the sewer in a private house, it is necessary to comply with some requirements:

• it is unacceptable that the bending radius of the cable be less than its possible minimum value;
• do not lay the cable on sharp objects;
• before the pipes are inspected - they should not have any damage;
• do not connect a cable that is in a coiled state to the mains;
• after installing the cable, it is necessary to carry out the thermal insulation of the pipes.

There are two options for securing the cable.

1. Along the pipe. Installation is made on a pipe in one or several parallel threads. The number of threads is determined by the expected power.
2. around the pipe. Mounting occurs in the form of a spiral. But in this case, the length of the cable must be greater than the length of the pipe.

Mount process

The technology for properly mounting the cable on the pipe looks like this:

• to achieve uniform heating, pipes made of plastic and polyethylene are initially equipped with an aluminum layer, on which a layer of foil is wound;
• fixing the heating cable is carried out with aluminum or other heat-resistant tape;
• cable loops (up to one and a half meters) are fixed at flanges and valves for the possibility of subsequent separation of the latter;
• the resistive cable must not cross in turns;
• it is necessary to provide waterproofing of communications;
• fixing the temperature sensor to the pipe is similar to fixing a heating cable;
• we must not forget about the markup, which will give information about the placement of the cable.

If these rules are followed, freezing will not happen even in severe frosts.

Internal installation

To mount a heating cable for sewage inside a pipe, you must first install a tee through which it will be introduced into the system. The effectiveness of this option, especially when removing ice plugs, is very high. But there are some negative features:

• installing a tee somewhat reduces the reliability of the pipeline;
• the cable located inside the pipes makes the risk of blockages higher;
• the performance of pipes is somewhat reduced, since their working diameter decreases;
• if the sewer system has many bends and turns, then laying the heating cable becomes much more complicated.

Internal installation is much more complicated than external, so specialists will do it better.

How to buy the right cable

Heating cable for sewerage is sold in the form of ready-made kits various lengths or by size. It is more profitable to buy a cable according to the second option. But it must be remembered that maximum length wire intended for external fastening, should not be more than 100, and for the internal - 60 m.

Cables produced for domestic needs usually have a power of 9 to 24 watts per linear meter. For external installation, a cable is required that is more powerful than for internal installation, because the heating consumption is much higher.

When choosing a cable, you need to be especially careful. Even the smallest damage to it will lead to the electrification of the pipe. Right choice manufacturer and following the instructions that accompany the product will help to avoid this.

At correct installation sewerage heating will be uninterrupted for up to 20 years, and in some cases twice as much. But we must not forget about standard insulation pipes. The main purpose of the heating cable is to avoid emergency situations. Even the most powerful cable cannot completely replace the thermal insulation system!

Video with an example of installing a heating cable for sewerage:

In cases where the owners simply do not have the opportunity to lay pipes above the freezing level of the soil, there is an urgent need to organize the heating of sewer pipes from the inside or outside in the winter season.

Of course, it is more expedient to lay the pipeline still below this level, but if there are circumstances that do not allow this, then it is imperative to use additional heating elements.

Types of pipes that need heating

Often it is necessary to warm the sewer pipes of the following types:

• An external sewer pipeline used to divert sewage to a septic tank or to a local type treatment plant:
• Pipes used to drain wash water from filter cleaners;
• A pipeline that provides communication between sewer septic tank and drainage fields or filtration well.

Pipeline Heating Methods

The most popular and frequently used methods of heating sewers are the following:

1. Heated sewer system with a heating wire;
2. Laying a pipeline from elements equipped with their own heating system inside the pipe.

Sewer heating with a cable

While searching for an answer to the question of how to heat the sewer in a private house, each owner wants to use the most reliable and durable heating element, which is a self-regulating cable that works on the principle of a heating tape.

Features of using this method include:

• The power of this type of heater is about 33 W per 1 meter of pipe;
• When laying it, a reinforcing tape with an adhesive-based aluminum coating is used;
• It can be cut into pieces of any desired length;
• If the length of the pipeline requiring heating is less than 80 meters, then a cable of this length can be connected directly to a socket or to electrical panel without additional devices.

Connection process

Instructions for connecting a heating cable with your own hands consists of the following steps:

1. A heat-shrinkable tube is put on one end of the heating cable large diameter;
2. The end is stripped of insulation and to a length of about 5 cm, the braid is removed to a length of 1 cm;
3. The heating cable wires are separated and the insulation is removed from their ends for a length of 4 cm;
4. A medium-sized heat-shrinkable tube is put on the cable itself, and small-diameter shrink tubes are put on each wire;
5. Holding the shrink tube with tweezers, warm it up with a building hair dryer;

Advice. If a building hair dryer is not at hand, you can shrink with an open flame.
For example, an ordinary lighter.

1. We clean the ends of the wires by 0.6 cm;
2. We place the twisted braid in a metal tube, after which we clamp it;
3. We strip the electrical cable from insulation to a length of 8 cm;
4. We separate the wires of the electrical cable. We leave the ground wire of the same length; cut the rest by 3-4 cm;
5. We clean each power wire by 6 cm;
6. We make the connection of the wires of the electric cable and the heating:

1. After connecting, the sleeve is clamped, and the tube is seated with a hairdryer;
2. The connection points of the power wires must be insulated with insulating tape;


3. We make a connection of a metal braid, place its end in a metal sleeve, after connecting the sleeve must be clamped;
4. The junction of the braid must be insulated with electrical tape;
5. The junction is covered with a large diameter heat shrink tube, which then shrinks with a hair dryer;
6. The free end of the heating cable is stripped 0.6 cm, the metal braid is removed;
7. A heat-shrinkable cap is put on the end of the cable and also shrinks with a hair dryer.

Mounting the heating element

For high-quality operation of the system, it is necessary to ensure not only the connection, the cable for heating the sewer pipes must also be correctly installed.

The process of fastening the heating element to the pipeline must be carried out taking into account the following requirements:

• The bending radius must exceed the minimum allowable value specified in the instructions for each type of cable;
• It is forbidden to mount this element on sharp surfaces;
• Before starting installation, make sure that the pipeline is tight;
• It is impossible to connect a cable wound into a bay to the network;
• After installing the heating element, it is necessary to insulate the sewer pipeline.

Installation process

To date, it is possible to use one of 2 installation options:

1. The location of one or more heating elements along the pipe parallel to each other. The price of the heating system in this case directly depends on how many heating elements will be used;
2. Spiral winding of the pipeline.

Note!
The second type of installation is used when the length of the cable is several times greater than the length of the pipeline.

The installation itself is carried out as follows:

• For even heating plastic pipes it is recommended to pre-wrap them with adhesive foil;
• The heating element is also attached with foil tape;

Note!
Whichever mounting method you choose, remember that resistive heater suppression is simply unacceptable.

• Thermal insulation of the pipeline is made in such a way as to exclude the ingress of moisture. If necessary, wrap the pipes with additional waterproofing material;
  
• The temperature sensor is also attached to the pipe with foil tape.

Finally

By implementing all the tips, recommendations and instructions described above, you can provide your own sewer system with decent heating, and the pipes will not freeze even in the most severe frosts. And the video in this article will tell you even more about how to protect the sewer pipeline from winter frosts.

hydroguru.com

Heating sewer pipes with a cable

In order for the pipe not to freeze, you need to think about its insulation in advance. A cheap, but already outdated way is to wrap thermal insulation around it. However, at very low temperatures this may not help, therefore, for greater reliability, they began to use pipe heating with a cable.

Sewer heating occurs in the same way as heating any other plumbing system: a cable wrapped around or along a pipe generates heat that prevents it from freezing. Thermal insulation laid on top of the cable does not allow heat to escape into the air, making the system work more efficiently. The heat cable is connected to the electrical wire and connected to the mains.

In heating systems, the following types of cable can be used: resistive, having a constant power and heating level, and self-regulating, changing the level of heat release depending on the ambient temperature.

Resistive cable:

• Requires the installation of a thermostat (thermostat) to control heating
• May overheat and fail
• Suitable for systems with the same temperature throughout the area / length
• Sold in ready-made kits, can not be cut
• Cheaper than self-adjusting

Self-regulating cable:

• Adjusts to the temperature of the sewage system, changing its power in different areas
• Can be purchased as a set or cut
• Does not burn out, even if its threads overlap each other
• The use of a thermostat is optional
• More expensive than resistive

Due to the greater reliability, it is the self-regulating cable that is popular. The use of a thermostat here, although not necessary, is desirable if you want to save on electricity and manage the system yourself.

Heating cable laid on a pipe.

Features of sewer heating

When installing a sewer pipe heating system, a number of nuances must be taken into account.

1. When using cable system electricity will be consumed, which will also affect electricity bills. Therefore, it is advisable to use it in areas passing on the street, or if the pipe is laid at the level of possible freezing of the soil.

2. Especially carefully insulate pipe joints, bends, fittings, etc. - that is, the most "problematic" places prone to freezing.

3. The power of the cable is selected based on the diameter and type of pipe, the minimum temperatures in the area and the type of sewer system. So, for gravity sewer pipelines, you can use a cable of less power, and for pressure sewer pipes and with a constant accumulation of liquid, a more powerful one.

5. If plastic pipes are insulated, it is recommended to attach aluminum tape at the point of contact with the cable.

6. Heating can be laid in several parallel threads or in a spiral. To wind the pipe in a spiral, you will need a longer cable. The advantage of this method is the best contact of the heating section with the pipe.

On our website you can buy a cable for heating sewer pipes, self-regulating or resistive. We offer models different capacities, self-regulating cable cut or in ready-made kits.

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Can sewers freeze?

The situation with the freezing of the sewer pipe is quite rare, because. such a pipe has a slope from the device-consumer, and therefore, unlike РІРѕРґРѕРїСЂРѕРІРѕРґРРСРѕР№, most of the time it is empty, and portions of liquids periodically flowing through it are usually ... warm. However, if small water leaks occur, due to a malfunction of the descent assembly in the toilet bowl or due to a leaking faucet, then the water does not have time to fast walk to a warm septic tank and it freezes along the way.

Such smudges freeze layer by layer and eventually completely block the diameter of the sewer pipe.

In order to eliminate the ice plug, you need to melt it with boiling water and salt, or dig out the pipe and try to warm it up with a blowtorch or a building hair dryer.
After removing the ice block, it is necessary to check the pipeline for cracks, and if necessary, replace the damaged section.

Sewer cable heating

In its turn heating a sewer pipe with a heating cable prevents such problems and increases the life of the sewer system in your home.

The power of the heating cable is selected in such a way as to compensate for the heat loss of the pipe by 120-160% at minimum temperature according to MSN 2.04-01-98 "Construction climatology":

Considering that in most cases household sewerage pipes with an internal diameter of 5 0 before 110 mm and thermal insulation with a thickness of 20-50 mm (PPS, PPU, PPE), to solve the problem of protecting sewer pipes from freezing, you can use self-regulating heating cables of low-temperature class with linear power from 16 W/m to 32 W/m.

We list the most popular:

Samreg is sold by the cut, a multiple of meters. Due design features provides energy savings and prevents overheating of the pipe.
The resistive cable used in underfloor heating for heating pipes inside is not suitable, because. it is supplied in ready-made kits (from 20 m), the length of which cannot be changed and is not protected from local overheating (which is fraught with failure).

Installation of cable heating sewerage

At the first stage, it is necessary to determine the length of the heating cable, taking into account cold bridges (flanges, supports, valves, etc.) and the power cable. Then install the end and coupling with a building hair dryer.

In case of installation on the pipe the heating cable is fixed along it along its entire length. If the pipe is metal, then fiberglass tape is used for fasteners. Transverse fastenings are carried out every 30-40 cm. If the pipe is plastic, then to ensure thermal contact, the cable is glued along the entire length with aluminum self-adhesive tape and additionally across every 30-40 cm.

If it is not possible to install on the surface of the pipe, then it is allowed installation of the heating cable inside the pipe.
In this case, the external insulation must be resistant to aggressive environments.

Here is a list of fluoropolymer sheathed heating cables suitable for installation inside a sewer pipe:

The end sleeve and the coupling must be brought out of the pipe!
The PUE requires the adoption of measures to protect against fire and electric shock.

To save energy and extend the life of the system, you can install a thermostat, because. the cable, although it is called self-regulating, but, unfortunately, is not completely turned off. The temperature controller sensor must be mounted in the supposedly coldest place in the pipe. If it is difficult to determine the coldest place, then you can set a programmable on-off timer.

You can purchase a ready-made section of any length from us, including power cable, coupling, the actual heating cable and the termination.

You will only have to install the heating section on the pipe and connect it to the electrical panel.

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Purposes of application

The use of a heating cable for heating pipeline systems can be justified in the following situations:

• Large depth of soil freezing. If the ground freezes more than 4-6 meters, installing a pipeline below this level can be a very labor-intensive undertaking.
• Complex types of soils. Rocky rocks in the area where the sewerage is supposed to be laid.

Of course, all these phenomena should be discussed only in relation to regions in which there is a periodic or constant presence of negative air temperatures that can provoke damage to the sewer.

It is worth noting that the use of an internal heating cable for sewerage systems is not without some drawbacks.

So, due to the presence of an additional element, it decreases throughput pipeline. Also, the risk of blockages increases and the tightness indicators deteriorate, since it is necessary to additionally mount the tee. For extended sewer systems, this option may be unreasonably expensive.

But for private courtyards, where sewer systems of a sufficiently large cross section and short length are operated, an internal cable is the best fit.

For sewerage systems based on PVC, concrete or asbestos-cement pipes, internal heating of the pipeline may even be the only one available. These materials have very low thermal conductivity, so it is very difficult to effectively heat them from the outside.

Varieties

Industrial enterprises produce several types of heating cable:

The principle of operation of a self-regulating cable is based on the properties of certain polymers that can contract and expand with temperature changes. Placed between conductive wires, the polymer expands under the action of heat, moving away neighboring conductor particles and weakening their electrical contact. This leads to an increase in resistance, a drop in current strength and, accordingly, a decrease in heating of the corresponding section of the cable.

Note! The termination at the second end of the self-regulating cable is not required, its end can be easily insulated.

Resistive cable, in turn, can be classified by structure into two groups:

Features of assembly and installation of heating cable sections

Before proceeding with the installation of a heating cable, it is worth deciding on the choice of a specific product model, the use of which will be most appropriate in this case.

There are many types of cable available on the market. Their main characteristic - specific power - can vary in the range from 10 to 40 W/m.

• 10 W/m. Suitable for heating plumbing systems no more than 25 mm in diameter.
• 16-17 W/m. Can be used in sewer pipelines with a diameter of not more than 50 mm.
• 30-40 W/m. Such power will be enough to heat a large sewer pipeline with a diameter of 110-160 mm.

The assembly procedure itself is very simple and does not require any special skills from the master. Of the tools, you only need pliers for crimping the connecting sleeves, pliers, a building hair dryer for heating the shrink film, side cutters or a knife for stripping insulation, sealant.

The algorithm of actions can be represented as follows:

• The current-carrying cores, the shielding metal braid and the ground are cleaned (not present in all cable models).
• Segments are sequentially put on individual cores, a cable under a braid and its outer sheath heat shrink tubing appropriate length.
• The adjacent ends of the current-carrying conductors are connected in pairs with the help of sleeves.
• A small layer of sealant is applied to the junction, after which heat shrink is crimped.
• A similar procedure is performed with the ground and the screen, if any.
• At the end of the heating cable further actions depend on cable type. For a resistive two-core cable, the current-carrying conductors are connected, followed by sealing and insulation of the coupling with a jumper. In a self-regulating cable, all the cores at the far end are cut off and separated by a certain distance, to increase resistance in the event of a violation of the tightness of the coupling.
• The free ends of the shrink film are flattened with pliers.

Note! Since the heating cable can only perform its functions in the presence of electricity, such systems are often additionally equipped with a backup power source.

outdoor installation

The heating cable is fixed under the pipe with aluminum tape. To improve heat transfer, it should be pressed against the pipe as tightly as possible. Aluminum tape helps to further limit heat loss by partially reflecting infrared radiation.

The cable is fixed with short pieces of adhesive tape at regular intervals (at least 30 cm), after which it is also fixed with adhesive tape along its entire length. For additional reliability of fixation, plastic clamps are often used.

It is important! In places where the pipeline bends, the cable should be positioned so that its wide part is perpendicular to the direction of the bend radius.

It is allowed to place the cable under a layer of insulation, which will not only provide additional thermal insulation, but also help to fix it securely. It should also be borne in mind that, first of all, horizontal sewerage sections need heating, through which drains move much more slowly than vertical ones.

Internal installation

The laying of the heating cable inside the sewer pipes is allowed with some restrictions.

The ring coupling should not be in contact with wastewater passing through the pipes, since they are considered an aggressive environment that can destroy heat shrink in just a few seasons. At the same time, the cable's own insulation is resistant to such influences, and is able to stay inside the pipe for an arbitrarily long time.

Therefore, the ring coupling, as a rule, is taken out of the pipeline. To do this, use special holes in the tee or corner of the structure.

Another indispensable condition is that the cable should be easily removed. Otherwise, in the process of mechanical cleaning of pipes with wire or plumbing cable, the cable will almost certainly be damaged.

Of course, this method of heating sewers cannot be called cheap. However, given that the pipeline will be reliably protected from any temperature fluctuations and will be able to serve properly for many years, the use of a heating cable will be much more profitable than replacing frozen parts of the system.

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Features of freezing of the sewer system

The problem of freezing of the sewer pipe is not immediately detected. Unlike plumbing, here the fluid flow is not constant and does not completely fill the pipe section. In addition, sewage entering the sewer system usually has a higher temperature than, for example, water from a well. Therefore, the freezing of drains occurs gradually.

At first, only some small part of the contents of the sewer can freeze, then another layer of frozen sewage appears, etc. Gradually, the entire lumen of the pipe is filled with a dense frozen mass, after which the problem becomes apparent. Faulty plumbing, such as a leaking faucet or cistern, can aggravate the problem.

Small portions of water enter the sewer, quickly cool and freeze. Even correct styling sewer pipes and the presence of a layer of insulation do not always prevent the freezing of drains. Defrosting a frozen sewer is troublesome, in addition, this phenomenon can lead to damage to pipes, some of which will have to be replaced.

Therefore, it is recommended to lay the sewer below the level of soil freezing with the obligatory insulation of communications. If in the southern regions and middle lane digging a deep enough trench is usually not a problem, but in the north everything is a little more complicated. In this situation, the use of a special heating or hot cable is more than appropriate.

When using this type of system, the volume of excavation is significantly reduced, since the depth of the trench can be reduced to an acceptable level without worrying about soil freezing.

How it works

A heating or hot cable is a heating system for pipes laid in the ground. The electrical cable in the insulating sheath is fixed on the pipe and connected to the power supply. The pipe heats up wastewater acquire a consistently high temperature, which reliably protects them from freezing.

There is a cable for external heating of a pipe or internal. The first is placed outside the structure, and the second - inside. It is believed that outdoor installation easier to produce than domestic, so it is more in demand. In addition to the external cable, a heating film is also used.

This material is completely wrapped around the structure, then it is fixed. The film gives a more uniform heating of the pipe than the cable, it has less power, which allows you to somewhat reduce operating costs. Three types of cable can be used for heating pipes:

• resistive;
• zonal.

Self-regulating cable is considered exclusively convenient option, since it can automatically change the heating temperature depending on climatic conditions. Cable resistance decreases if the ground heats up more and increases as the temperature drops.

This change in operating mode reduces the overall power of the system, i.e. allows you to save energy. Moreover, the change in resistance may be different in individual sections of the pipeline. The result is more high quality heating, the cable itself will last longer, and there is no need to install thermostats.

A resistive cable does not have such abilities, but differs in comparison with self-regulating systems by a more reasonable price. When installing this type of cable, you will need to install a set of temperature sensors and thermostats to ensure that the operating mode of the system changes when the weather changes.

If this requirement is neglected, the risk of overheating of the cable and its breakage increases. The zonal cable also does not have the ability to regulate resistance, but this system does not generate heat along its entire length, but only in certain sections. Such a cable can be cut into separate fragments, which is convenient when installing pipelines of complex configuration.

It is also widely used in the installation metal sewer or for heating containers. It should be noted that the heating of structures buried in the ground is not the only area of ​​\u200b\u200buse of a heating cable. It is also used to heat pipes laid on the surface or in rooms that are not heated.

Sometimes the cable is used only for certain sections of the pipeline, for example, parts that go to the surface. Systems that are mounted inside the pipe are used relatively rarely. Most often they are used if the pipeline is already laid in the ground, and the installation of an external cable would require extensive excavation.

So installing an internal cable will be much cheaper. But such cables are usually recommended to be used only inside small diameter pipes, since their power is low. It varies between 9-13 W / m, which is usually not enough for large sewer pipes. The length of such a cable, for obvious reasons, should be equal to the length of the pipe. The internal heating cable is made only of a self-regulating type.

How to choose and calculate

When choosing a suitable hot cable, it is necessary to determine not only its type, but also to choose its power correctly. In this case, it is necessary to take into account parameters such as:

• the purpose of the structure (for sewerage and water supply, calculations are performed differently);
• the material from which the sewerage is made;
• pipeline diameter;
• features of the area to be heated;
• characteristics of the heat-insulating material used.

Based on this information, heat losses are calculated for each meter of the structure, the type of cable, its power are selected, and then the appropriate length of the kit is determined. Calculations can be performed using a special formula, according to calculation tables or using an online calculator.

The calculation formula looks like this:

When heat losses are calculated, the length of the system should be calculated. To do this, the resulting value must be divided by the specific power of the cable heating device. The result should be increased, taking into account the heating of additional elements. The power of the cable for sewerage starts from 17 W / m and can exceed 30 W / m.

If we are talking about sewer structures made of polyethylene and plastic, then 17 W / m is the maximum power. If you use a more productive cable, then there is a high probability of overheating and damage to the pipe. Information about the characteristics of the product can be found in its technical data sheet.

Use the table to select suitable option a little easier. To do this, you first need to find out the diameter of the pipe and the thickness of the thermal insulation, as well as the expected difference between the temperature of the air and the contents of the pipeline. The latter indicator can be found using reference data depending on the region.

At the intersection of the corresponding row and column, you can find the value of heat loss per meter of pipe. Then the total length of the cable should be calculated. To do this, the size of the specific heat loss obtained from the table must be multiplied by the length of the pipeline and by a factor of 1.3.

The result obtained should be divided by the specific power of the cable. Then you need to take into account the influence of additional elements, if any. On specialized sites you can find convenient online calculators. In the appropriate fields you need to enter the necessary data, for example, pipe diameter, insulation thickness, temperature environment and working fluid, region, etc.

Such programs usually offer the user additional features, for example, they help to calculate the required diameter of the sewer, the dimensions of the thermal insulation layer, the type of insulation, etc. Optionally, you can choose the type of laying, find out the appropriate step when installing the heating cable in a spiral, get a list and the number of components that will be needed for laying the system.

When choosing a self-regulating cable, it is important to correctly consider the diameter of the structure on which it will be installed. For example, for pipes with a diameter of 110 mm, it is recommended to take the Lavita GWS30-2 brand or a similar version from another manufacturer. For a 50 mm pipe, the Lavita GWS24-2 cable is suitable, for structures with a diameter of 32 mm - Lavita GWS16-2, etc.

Complicated calculations will not be needed for sewers that are not used often, for example, on summer cottage or in a house that is used only occasionally. In such a situation, they simply take a cable with a power of 17 W / m with a length corresponding to the size of the pipe. A cable of this power can be used both outside and inside the pipe, and it is not necessary to install a gland.

For laying a hot cable inside a pipe, a cable with special protection against aggressive effects, for example, DVU-13, is selected. In some cases, for installation inside, the brand Lavita RGS 30-2CR is used. This is not entirely correct, but a valid solution.

Such a cable is intended for heating a roof or storm sewer, so it is not provided with protection against corrosive substances. It can only be considered as a temporary option, since with prolonged use in inappropriate conditions, the Lavita RGS 30-2CR cable will inevitably break.

Features of installing heating for pipes

Laying the heating cable is a relatively simple process. It is simply fixed on the surface of the pipe, usually along, in one strip. Some projects provide for spiral installation. In this case, it is necessary to accurately maintain the calculated step between the turns of the spiral so that the pipe warms up evenly.

The intersection of individual sections of the heating cable is unacceptable. The cable, depending on the type, is fixed with heat-resistant adhesive tape or mounting ties. The step between the attachment points must be at least 200 mm. To fix the cable in the mineral sheath, metal fasteners are used: clamping bands or a special bandage.

But most often I still use heat-resistant tape. Fasteners must carry not only high temperatures, but also be resistant to the influence natural factors and chemical substances. Sometimes aluminum tape is used as fastening. But at the attachment points, the thermal power of the cable will increase.

This is not always useful, it can lead to overheating of communications. It is not recommended to use metal fasteners when installing a heating cable enclosed in a polymer insulating sheath. But in some cases, aluminum tape can even improve the situation.

When laid on polymer pipe metallized tape is placed both under the cable and above it. This raises a little thermal power and also promotes uniform heating of the pipeline. Inside the sewer, a heating cable is used extremely rarely. Usually it's heated small areas systems not located in the ground, such as pumps.

To install an indoor cable in a pipe that has been laid, you will first need to cut a tee into the system. This will make a hole for inserting the cable into the pipeline. In addition, a special nipple coupling may be required. Such a solution may slightly worsen the characteristics of the sewer system, for example, at the installation site of the tee, the pipe clearance will slightly decrease.

This increases the likelihood of debris buildup and blockages. Difficulties with internal cable are inevitable if the sewer has several turns, bends, etc. It is not easy to carry out internal work on the installation of a hot cable, as well as in sewer systems considerable length.

Of course, you should not connect the system to the power supply until the installation work is completed. Before covering the cable with insulation, you should carefully check all connections. If you use thermal sensors, it will be easier to determine the time to connect and disconnect the system.

You can automate the process using a relay. If the power of the cable laid in one line is not enough, you can install it in a spiral or lay two parallel lines. The main thing that separate sections did not intersect, and there was no overheating. To make the heating of the structure more uniform, sometimes the pipe is first wrapped with foil, then a cable is placed on top.

Temperature sensors are installed after the insulation is installed. From above, it is recommended to apply markings that reflect the position of the heating elements. To connect the cable to the mains, you will need a piece of heat-shrinkable pipe. Then about 50 mm of insulation and 10 mm of braid are removed from the edge of the cable.

The separated and stripped ends are protected with pieces of heat-shrinkable tubing of a suitable diameter and heated with a hair dryer. Now you need to strip about 6 mm of the wire, coil it and clamp it in metal tube. Similar manipulations will have to be done with the power cable.

About 80 mm must be stripped of insulation and sheath and divided into individual wires. The resulting ends are cut to 35 mm, but one wire should be left uncut for grounding. 6 mm wires are also stripped here. Now the ends of the cables of the heating elements and power are connected in a heat-shrinkable tube equipped with a metal sleeve. It is heated and clamped, the contact point is wrapped with thermal tape, and then closed with another protection tube.

Useful video on the topic

This video shows an option for laying sewers using an internal cable:

Here is an overview of the features of the functioning and installation of a self-regulating cable:

Hot cable solves the problem of freezing sewer pipes in winter much more effectively than other means. The power consumption is thus minimal. If the installation is done correctly, the cable will work for many years without any breakdowns.

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