Design and operating principle of the structure
The electric heating element, which is installed on the battery, has a specific device that every person who wants to install equipment for their radiators should know about.
In appearance, the product is represented by an ordinary metal tube, in which there is a special small spiral made of copper. Using a special filler, this spiral does not come into contact with the walls of the tube in any way. This entire element is built into a special protective housing, which ensures the reliability of the use of electrical products.
The operating principle of the heating element is as follows:
- cold and hot coolants have different weights, a unidirectional current is created;
- The heated liquid is directed upward, and the cooled coolant goes down.
It is believed that for heating radiators. on which an electric heating element is installed, transformer oil is considered an excellent choice as a coolant. It heats up very quickly and also takes a long time to cool down.
System installation features
Before starting work, it is important to decide. what power should the heating element have?
so that it can perfectly cope with the heating of a particular room. The comfort of using the equipment depends on this. Because if it does not cope with the task, then the room will not have the optimal temperature. Therefore, the performance of an electrical appliance must be chosen wisely.
It is best to choose a product with a thermostat. although it will have a higher cost compared to a design without this element. However, after the work is completed, it will be possible to set certain parameters, which will significantly improve the process of using the room.
The installation itself must be carried out in accordance with numerous safety requirements and regulations. If there are any errors or violations, this may lead to danger in the use of the housing itself or poor-quality operation of equipment that will not be able to cope with heating the room.
Therefore, it is advisable to additionally install a special protective box, which should be selected in accordance with the power of the heating element itself.
Carrying out calculations
At the first stage of work, you need to make certain calculations. which determine how many heating elements need to be produced and what power they should have
It is important to consider which batteries will be installed on, since some products are intended for an aluminum radiator. and others - for a cast iron battery
The power of the heating elements depends on the characteristics of the room itself, which requires the installation of electric heating. The fact is that there may be high-quality thermal insulation of various surfaces, or it may be absent. Additionally, the presence of modern and warm double-glazed windows and the material from which the walls of the building are made are taken into account.
It is important to know the thickness of the walls and the properties of the foundation, since it can be well insulated, so heat loss through the floor will be small
In accordance with correctly carried out calculations, it is possible to determine which heating elements should be purchased and in what quantity. Here it is decided where they will be installed, what additional elements they will be equipped with, and what the features of their installation will be, depending on the type.
Independent creation of an electric heating system
As a rule, any heating element is installed according to the same principle, regardless of its power, appearance and features. It is best to immediately equip it with a thermostat that ensures efficient and comfortable use of this product.
The entire installation process can be divided into the following steps:
Initially, the device in which the heating element will be installed is de-energized; the supply of coolant in the batteries stops, then the liquid must be completely drained from the radiator; in the place where there is a lower plug, the installation of the heating element itself begins, and it must completely go into the pipe, which is intended to supply coolant; then you can reintroduce liquid into the system, but it is important to make sure that the resulting structure is sealed; The heating element is equipped with a thermostat and other elements if necessary, after which it can be connected to the electrical network.
Schemes for connecting heating elements to a single-phase network.
Tubular electric heaters are designed for a specific power
and
voltage
, therefore, to ensure the nominal operating mode, they are connected to a supply network with the appropriate voltage.
According to GOST 13268-88, heaters are manufactured for rated voltages: 12
,
24
,
36
,
42
,
48
,
60
,
127
,
220
,
380 V
, however, heating elements designed for voltages of 127, 220 and 380 V are most widely used.
Let's consider possible options for including heating elements in a single-phase network.
2.1. Plugging in.
Heating elements with a power of no more than 1 kW (1000 W) can be safely plugged into an outlet through a regular plug, since the majority of electric kettles and boilers that we use to heat water have this power.
in parallel via a regular plug
two heating elements, but both heaters should have a power of no more than 1 kW (1000 W), since when connected in parallel their total power increases to 2 kW (2000 W). Thus, you can turn on several heaters, but their total power should be no more than 2 kW, and to plug into an outlet you must use a more powerful plug.
There may be a situation when you have several heaters lying around at home, designed for an operating voltage of 127 V, you can’t throw them away, and you can’t plug them into the home network. In this case, the heaters turn on sequentially
, which makes it possible to apply increased voltage to them. When two heaters with a voltage of 127 V are connected in series, their power remains the same, but the total resistance doubles. For example, when two 500 W heaters are turned on, their total power will be 1000 W.
However, this scheme has one drawback: if any of the heating elements fails, then both will not work, since the electrical circuit will break and the power supply will stop.
You must also remember that when two heaters with an operating voltage of 220 V are connected in series, their total power decreases
twice as much, since due to the increase in total resistance, each heater will receive about 110 V instead of the required 220 V.
2.2. Switching on via circuit breaker.
It will be much more convenient if voltage is supplied to the heating elements using a circuit breaker. To do this, it is necessary to provide a machine in the house panel, or install the machine directly next to the heating device. The voltage supply and shutdown will be carried out by turning on/off
circuit breaker.
The next option for turning on the heaters is carried out with a two-pole switch, which is the most preferable, since in this case the phase and zero are broken simultaneously and the heating element is completely disconnected from the general circuit. Voltage is supplied to the upper terminals of the switch, and the heater is connected to the lower terminals.
If an electric heater is used to heat water and the house is grounded
, then to protect against electric shock in the event of a breakdown of the heater insulation, it makes sense
to install an RCD
or a circuit breaker.
In this case, the grounding conductor
connected to the heating element body or connected to a special screw fixed to the container body. Next to such a screw there is a grounding sign. Let's consider a circuit with a difavtomat:
Protection with a difavtomat works as follows: when the heater insulation breaks down, a phase appears on its body, which, using the least resistance, will “go” along the PE
and will create
a leakage current
.
If this current exceeds the setting, the automatic circuit breaker will operate and turn off the voltage supply. If a short circuit
, then in this case the automatic circuit breaker will operate and de-energize the heating element.
When using an RCD, an additional single-pole circuit breaker must be installed between it and the heater, which, in the event of a short circuit, will cut off the voltage supply to the heater and protect the RCD from short circuit current. In the event of an insulation breakdown, the RCD will cut off the voltage supply.
Boiler heating element connection diagrams
Option 1. Connection diagram to a single-phase network
Typically, three single heating elements in such a design are placed so that the contacts from different heating elements are located opposite each other.
To connect a heating element to 220 Volts, you need to connect three contacts from different single spirals with a jumper and connect them to the working zero.
The three remaining contacts also need to be connected and connected to the working phase. This will ensure that all heating elements are turned on simultaneously for heating when power is applied.
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However, the connection is not made directly this way, and for every second contact the heating element is connected to a phase after its own machine or, what is done more often, it is connected from its own control line (automation).
Option 2. Three-phase connection
If we look at the heating elements for boilers sold, we will see that almost all of them are labeled as 220/380 Volt heating elements.
If you have this version of the heating element, and you have the opportunity to connect to a three-phase power supply of 220 Volts or 380 Volts, then you need to use connection diagrams called “star” and “delta”.
According to the "star" scheme
220 Volt three phases, you need to connect the three contacts of single heating elements with a perm and connect them to the working zero. Apply to the second free contacts via a phase wire. Each single heating element will operate from 220 Volts, independently of each other.
According to the "triangle" pattern
380 Volts, you need to connect contacts 1-6, 2-3, 4-5 with jumpers, for single heating elements 1-2.3-4.5-6 and supply phase wires to them. Each single heating element will operate at 380 Volts, independently of each other.
Therefore, the power of the 1st heating element may not correspond to the parameters for heating the vessel and may be more or less. In such cases, to obtain the required heating power, you can use several heating elements connected in series or series-parallel. By switching various combinations of connecting heating elements, a switch from a household electric. plates, you can get different power. For example, having eight embedded heating elements, 1.25 kW each, depending on the switching combination, you can get the following power.
- 625 W
- 933 W
- 1.25 kW
- 1.6 kW
- 1.8 kW
- 2.5 kW
This range is quite enough to adjust and maintain the desired temperature. But you can get other power by adding the number of switching modes and using different switching combinations.
A series connection of 2 heating elements of 1.25 kW each and connecting them to a 220V network gives a total of 625 W. A parallel connection gives a total of 2.5 kW.
We know the current voltage in the network, it is 220V. Next, we also know the power of the heating element, knocked out on its surface, let’s say it’s 1.25 kW, which means we need to know the current flowing in this circuit. Knowing the voltage and power, we find out the current strength from the following formula.
Current = power divided by line voltage.
It is written like this: I = P / U.
Where I is the current strength in amperes.
P is power in watts.
U is voltage in volts.
When calculating, you need to convert the power indicated on the heating element body in kW into watts.
1.25 kW = 1250W. We substitute the known values into this formula and get the current strength.
I = 1250W / 220 = 5.681 A
R = U / I, where
R - resistance in Ohms
U - voltage in volts
I - current in amperes
We substitute the known values into the formula and find out the resistance of 1 heating element.
R = 220 / 5.681 = 38.725 Ohms.
Rtotal = R1+ R2 + R3, etc.
Thus, two series-connected heating elements have a resistance of 77.45 Ohms. Now it is easy to calculate the power released by these two heating elements.
P = U2 / R where,
P - power in watts
R is the total resistance of all lines. conn. heating elements
P = 624.919 W, rounded to 625 W.
Table 1.1 shows the values for series connection of heating elements.
Table 1.1
| Number of heating elements | Power, W) | Resistance (Ohm) | Voltage (V) | Current (A) |
| Serial connection | ||||
| 2 heating elements = 77.45 | ||||
| 3 heating element =1 16.175 | ||||
| 5 heating element = 193.625 | ||||
| 7 heating element=271.075 | ||||
Table 1.2 shows the values for parallel connection of heating elements.
Table 1.2
| Number of heating elements | Power, W) | Resistance (Ohm) | Voltage (V) | Current (A) |
| Parallel connection | ||||
| 2 heating element = 19.3625 | ||||
| 3 heating element = 12.9083 | ||||
| 4 heating element=9.68125 | ||||
| 6 heating element = 6.45415 | ||||
(and how to decrypt it)
The optimal source of energy for heating the evaporation tank is a residential electrical network with a voltage of 220 V. You can simply use a household electric stove for these purposes. But, when heating on an electric stove, a lot of energy is spent on useless heating of the stove itself, and is also radiated into the external environment from the heating element, without doing any useful work. This wasted energy can reach decent values - up to 30-50% of the total power expended on heating the cube. Therefore, the use of conventional electric stoves is irrational from an economic point of view. After all, for every extra kilowatt of energy you have to pay. It is most effective to use elec- tronics embedded in the evaporation tank. Heating elements. With this design, all energy is spent only on heating the cube + radiation from its walls to the outside. The walls of the cube must be thermally insulated to reduce heat loss. After all, the cost of heat radiation from the walls of the cube itself can also amount to 20 percent or more of the total power expended, depending on its size. For use as heating elements embedded in a container, heating elements from household electric kettles or other suitable sizes are quite suitable. The power of such heating elements varies. The most commonly used heating elements with a power stamped on the body are 1.0 kW and 1.25 kW. But there are others.
Therefore, the power of the 1st heating element may not correspond to the parameters for heating the cube and may be more or less. In such cases, to obtain the required heating power, you can use several heating elements connected in series or series-parallel. By switching various combinations of connecting heating elements, a switch from a household electric. plates, you can get different power. For example, having eight embedded heating elements, 1.25 kW each, depending on the switching combination, you can get the following power.
- 625 W
- 933 W
- 1.25 kW
- 1.6 kW
- 1.8 kW
- 2.5 kW
This range is quite enough to adjust and maintain the required temperature during distillation and rectification. But you can get other power by adding the number of switching modes and using different switching combinations.
A series connection of 2 heating elements of 1.25 kW each and connecting them to a 220V network gives a total of 625 W. A parallel connection gives a total of 2.5 kW.
We know the current voltage in the network, it is 220V. Next, we also know the power of the heating element, knocked out on its surface, let’s say it’s 1.25 kW, which means we need to know the current flowing in this circuit. Knowing the voltage and power, we find out the current strength from the following formula.
Current = power divided by line voltage.
It is written like this: I = P / U.
Where I is the current in amperes.
P is power in watts.
U is the voltage in volts.
When calculating, you need to convert the power indicated on the heating element body in kW into watts.
1.25 kW = 1250W. We substitute the known values into this formula and get the current strength.
R = U / I, where
R - resistance in Ohms
U - voltage in volts
I - current in amperes
We substitute the known values into the formula and find out the resistance of 1 heating element.
Rtotal = R1+ R2 + R3, etc.
Thus, two series-connected heating elements have a resistance of 77.45 Ohms. Now it is easy to calculate the power released by these two heating elements.
P = U2 / R where,
P - power in watts
R is the total resistance of all sequences. conn. heating elements
P = 624.919 W, rounded to 625 W.
Table 1.1 shows the values for series connection of heating elements.
Table 1.1
| Number of heating elements | Power, W) | Resistance(Ohm) | Voltage(V) | Current(A) |
| 1 | 1250,000 | 38,725 | 220 | 5,68 |
| Serial connection | ||||
| 2 | 625 | 2 heating elements =77.45 | 220 | 2,84 |
| 3 | 416 | 3 heating element =1 16.175 | 220 | 1,89 |
| 4 | 312 | 4 heating element=154.9 | 220 | 1,42 |
| 5 | 250 | 5 heating element = 193.625 | 220 | 1,13 |
| 6 | 208 | 6 heating element = 232.35 | 220 | 0,94 |
| 7 | 178 | 7 heating element=271.075 | 220 | 0,81 |
| 8 | 156 | 8 heating element = 309.8 | 220 | 0,71 |
Table 1.2 shows the values for parallel connection of heating elements.
Table 1.2
| Number of heating elements | Power, W) | Resistance(Ohm) | Voltage(V) | Current(A) |
| Parallel connection | ||||
| 2 | 2500 | 2 heating element = 19.3625 | 220 | 11,36 |
| 3 | 3750 | 3 heating element = 12.9083 | 220 | 17,04 |
| 4 | 5000 | 4 heating element=9.68125 | 220 | 22,72 |
| 5 | 6250 | 5 heating element = 7.7450 | 220 | 28,40 |
| 6 | 7500 | 6 heating element = 6.45415 | 220 | 34,08 |
| 7 | 8750 | 7 heating element = 5.5321 | 220 | 39,76 |
| 8 | 10000 | 8 heating element = 4.840 | 220 | 45,45 |
Another important advantage that the series connection of heating elements gives is that the current flowing through them is reduced several times, and, accordingly, the heating element housing is low, thereby preventing the mash from burning during distillation and does not introduce an unpleasant additional taste and smell into the final product. Also, the operating life of the heating elements, with this inclusion, will be almost eternal.
Calculations were performed for heating elements with a power of 1.25 kW. For heating elements of other power, the total power must be recalculated according to Ohm’s law, using the above formulas.
Therefore, for such a “gluttonous” consumer of electricity as an electric boiler, on whose stable operation in winter a lot depends, it is important to make the correct electrical wiring, select reliable automatic protection and make the connection correctly.
To better understand the principle of connecting a boiler, you need to know what it usually consists of and how it works. We will talk about the most common heating element boilers, the heart of which is Tubular Electric Heaters (TEH).
An electric current passing through the heating element heats it up; this process is controlled by an electronic unit that monitors important indicators of the boiler’s operation using various sensors. The electric boiler may also include a circulation pump, control panel, etc.
Depending on the power consumption, electric boilers designed for a supply voltage of 220 V - single-phase or 380 V - three-phase are usually used in everyday life.
The difference between them is simple, 220V boilers are rarely more powerful than 8 kW
, most often in heating systems, devices of no more than 2-5 kW are used, this is due to limitations on the allocated power in single-phase supply lines of houses.
Accordingly, 380V electric boilers are more powerful and can effectively heat large houses
. Connection diagrams, rules for choosing cables and automatic protective equipment for 220V and 380V boilers are different, so we will consider them separately, starting with single-phase ones.
Criteria for selecting a device
Before you buy a seemingly simple Ariston device, you can take note of certain points:
- Equipment warranty. When selecting a heating element, warranty obligations cannot be ignored, because the device ensures normal and safe service of the water heater. Incorrect operation of the installed heating element is also manifested in the fact that the water unit will probably turn off continuously and even give an electric shock.
- Consumable materials for the heater. The standing magnesium anode used to protect the device must be changed once at least once a year. Therefore, when selecting, you need to choose modifications with available consumables.
- Power. It is necessary to take into account that the more powerful the boiler itself, the more powerful the water heating element must be. Productivity ranges from 2-9 kW.
- Types of thermostat. Particular preference is given to a thermostat with a heat-protective function.
- Temperature range. If the user knows what temperature he wants to achieve, then the heating element must be selected with the appropriate rating.
The length of the Ariston heating element and the tubes for the thermostat play a significant role in ensuring optimal power and heating speed. More famous are heating elements with a power of 2-5 kW. Also separately distinguished are those heating elements that are installed in instantaneous water heaters. Structurally, such devices do not take into account containers for storing water, so the purpose of the heating element is to heat the full flow passing through it to the desired temperature.
Heating elements with a regulator are used in everyday life and in various fields of industry. It, as well as the fitting - the fastening component - is made from different metals. More and more, a heating element is becoming a necessary component for obtaining warm water. And its use in conjunction with a thermostat will significantly reduce utility costs and increase the service life of the device.
How to connect a heating element with a thermostat
Now you know how and by what parameters heaters are selected. But how is the connection made? In order to connect a heating element with a thermostat, you must select a wire with reliable insulation
We also pay attention to the cross-section - it must be such that the wire can provide adequate power to the heater and not melt. For example, for a 3 kW heater, the wire cross-section must be at least 2.5 mm
We recommend choosing cables with copper conductors for connection.
Do not forget to pay attention to the presence of an RCD - it will instantly turn off the power in the event of an unexpected failure of the heating element or a short circuit. The RCD must be installed as close as possible to the heater itself
You should also ensure a reliable connection of the conductors with the contacts of the heating element (without “snot” and flimsy contacts that can spark).
Features of heating elements for cast iron batteries
Tubular electric heaters for conventional and cast iron radiators are practically no different. The only exception is the material of the plug - it must be made of cast iron or an equally heat-resistant material.
In addition, the shape of the outer part of the housing where the thermostat is installed may also differ. In this case, the length of the heating element should be 5-10 cm shorter than the length of the radiator. Otherwise, water circulation and heating cannot be achieved. Therefore, before purchasing, make sure that the heating element with a thermostat is designed for cast iron batteries.
Installation
Sometimes situations occur in which the heating element of the water heater is functioning properly, but the thermostat for some reason has already failed - it does not turn off or does not work correctly. In this case, you can postpone the purchase of a new water heater and limit yourself to replacing the thermostat yourself. To do this, you should take the technical passport of the boiler and, based on its operational properties and technical characteristics, select the appropriate model.
For a more accurate choice, you should rewrite all the data from the markings of the old device, and based on the data sheet and these data, you can purchase a new thermostat.
Installing a thermostat with your own hands requires certain skills and knowledge in the field of electrical installation work. It is very important to comply with safety regulations, without knowledge of which work cannot begin. The thermostat should only be replaced with a model similar in its technical characteristics; the use of a home-made device for installation in a factory-made boiler is not allowed.
At the first stage, you should turn off the power to the water heater and stop supplying water to it from the water supply system. Then you need to drain the existing liquid and remove the bottom panel of the device, thereby opening access to the heating element. After opening the cover, you need to remove the pressure ring and remove the old thermostat along with the control unit.
Next, you should install and connect the new thermostat, put the pressure ring in place and fix the bottom panel. After installation is complete, you need to fill the water heater tank with water, turn on the heating element and check the operation of the new device by setting it to the minimum temperature value.
If the thermostat turned off the heating element after the water had reached the desired temperature, then the installation was carried out correctly and the thermostat is functioning in operating mode. At the last stage, you should adjust the thermostat, giving it the necessary operating parameters.
Purpose of a thermostat for a water heater
In addition to all of the above, the thermostat is responsible for the safe operation of the boiler. To be more precise, as the water temperature rises, the pressure inside the sealed tank also increases, and if this growth is uncontrolled, an explosion will soon occur. This can be dangerous not only for equipment, but also for human health if you are nearby at that moment. A temperature regulator is a device through which the optimal temperature level is also maintained.
Starting with the hot water tank. When hot water is used, cold water enters the bottom of the tank at the same time. This will cool the lower thermostat and the lower element will heat up. If enough hot water is used to cool the top thermostat, the bottom element will turn off and the top element will heat up.
Electric Water Heater Repair Tools You May Need
Taking the above information, let's say that you have a normal amount of hot water, but when you use a lot, it takes a long time to heat the backup. Let's say you have hot water, but it's running out quickly. Garden hose - into the drainage tank Multimeter - for checking power, thermostats or elements.
- Elemental tool - for replacing elements.
- Screwdriver - for replacing elements or thermostats.
It is designed to cut off power to the water heater if the water temperature must rise to dangerous levels. This is a kind of thermal valve that prevents:
- Overheat;
- Explosion;
- I damage not only equipment, but also nearby property.
It is he who is responsible for controlling the heating of water at the moment when the device is connected, as well as for ensuring that the heating element is blocked in time. Almost every manufacturer strives to equip the boiler with a thermostat. The products come in different models, however, they all have the same operating principle. At the moment when you need to connect the equipment to the network, you need to immediately adjust the water heating level.
If the limit switch should stop, the reset button will pop out. When the water in the tank has cooled, the button can be pressed to reset the limit switch. When a limit switch trips, there is a reason. This could be a faulty thermostat, a grounded element, or the limit switch itself.
It is a kind of thermal valve that prevents
Water heater thermostats control the temperature of the water and act as switching relays, sending energy where it is needed. The elements will always be 120 volts, even when the thermostats are turned off. When the thermostat calls for heat, it will send another 120 volts to the element it controls. This will give the element 240 volts, causing it to heat up.
Next, controlled heating of the water is carried out, and the relay installed on the thermostat is responsible for opening the contacts of the heating element. When the tank cools completely, the temperature drops below normal, and the contacts of the heating element of the relay close, due to which the system starts up, and the liquid in the tank heats up again.
How to install your own electric heating system
Before using heating elements in heating radiators, it is worth deciding on the required heating power
It is also important to have information about the characteristics of the electric heating element, in particular its performance. This will avoid wiring burnout and unnecessary costs for purchasing a new cable.
You need to understand that independent installation of heating, if there are some errors, can lead to insufficiently efficient heating of the home or even incorrect operation of the system. In order for everything to function stably, it is recommended to acquire a thermostat. Additionally, it is worth installing a special protective box, the functioning of which is designed for the power of certain heating elements.
The number and performance of devices for heating a house based on an electric heating system is calculated taking into account the volume of the premises. To begin with, average power indicators are selected that are sufficient for high-quality heating of 1 m3 of living space.
Average values for premises:
- with reliable thermal insulation, equipped according to European standards - 20 W/m3;
- with modern double-glazed windows, effective insulation of floors and walls - 30 W/m3;
- with insufficiently reliable thermal insulation - 40 W/m3;
- with frankly poor insulation - 50 W/m3 or more.
Based on the above calculations, the required power for high-quality heating of a particular room is determined. Based on the same values, a sufficient number of heating elements is selected.
Doing the calculations correctly is extremely important. As practice shows, with proper selection of equipment and reliable installation, installing electric heating even in a wooden house becomes an absolutely safe solution.
Nuances of work
Two-pipe system with bottom distribution and forced circulation. What an electric boiler is can be seen in the photo.
It is better that it is slightly narrower than the main highway. To increase the efficiency of heating systems in everyday life, either heat accumulators or bypasses are used.
Mandatory piping elements An electrode or induction boiler for the safe operation of the water circuit requires the following set of additional equipment: Piping and connection diagram for an electric heating boiler Special offer!
The heating elements themselves are connected to the network as follows: one end of each of the tubular electric heaters is connected by a jumper, the remaining three free phases are alternately connected: L1, L2 and L3. Particular care should be taken when installing grounding: inexperienced owners often connect it to the zero phase of the wiring.
More on the topic: To connect electricity to the site you need
General features of electric boilers
Any heating system consists of three basic components: a heat source - this role can be played by a boiler, stove, or fireplace; heat transfer line - usually this is the pipeline through which the coolant circulates; heating element - in traditional systems this is a classic radiator that converts the energy of the coolant into thermal radiation. And this is not related to the costs of equipment and installation, it is related to the cost of electricity.
In one of the articles we said that the design of a solid fuel boiler may have design differences. There are different installation methods, which differ somewhat in their operating principles. After connecting the device to the heating system, they proceed to the implementation of the electrical part of the circuit, which includes an RCD and a circuit breaker of certain technical characteristics.
What does the wiring of an electric heating boiler look like?
If you install the device in a separate room, kW will be wasted every month. They run along the load-bearing walls of the house, from the boiler to the location of the outermost battery. The spark generator works in conjunction with the gas valve and is an integral part of it. Then, it enters a large circuit whose task is to heat the entire building. Naturally, there must be a connecting section between the inlet and outlet pipes of the coolant into the radiator.
Emergency piping scheme for boilers The supply of water from the water supply system to the system is used quite rarely, as it is ineffective. Over time, scale builds up on tubular heaters, which reduces the power of the equipment and increases the likelihood of heating elements overheating. If you don’t have enough time or you are not sure that you can do everything correctly yourself, it is better not to start tying, relying only on your intuition and videos on the Internet. How to connect correctly, what circuit to use? What is cheaper to heat? I installed 4 boilers!
Connecting heaters according to the STAR scheme for an electric boiler
In electric heating boilers, heating elements can be connected in various ways, but to demonstrate the STAR-type connection diagram, we will describe the option of installing dry heating elements to a 3-phase power supply network with a voltage of 220V.
The high power of dry water heating elements imposes certain requirements on the quality of connections. The reliability of the connections must be ensured by high quality heat-resistant wires and strict compliance of all actions with the diagram described in the instructions.
The first thing to do is to screw on the M4 nut when connecting the phase drives. Next, you need to apply the washer and install the ring terminal of the power wire. The next step is to apply another similar washer, on top of which another special Grover spring washer is placed. And all this needs to be securely fixed with an M4 nut.
The wires that lead to the neutral phase are secured using an M8 bolt. The neutral wire must be placed in a jumper, which is located between the contacts of the heating element holes.
Be sure to ground the body of the heating element and power wires after connecting all the wires to the supply and neutral contacts of the heating element. In most cases, in standard electric boilers, the grounding bolt is located on the left side near the block with heating elements. We must connect the grounding wire to it.
After connecting the wires, ground the heater body and the heating element connection wires. Typically, grounding boilers have a bolt on the left side of the electric heater block, to which the grounding conductor should be connected.
You can use either a separate potential equation wire or a wire from the grounding terminal block of the control unit for grounding.
You can clearly see all of the above described in the figure below in the form of a diagram and photo of connecting the heating element.
If you have done everything in strict accordance with the instructions, the connection of the heating element of the electric boiler can be considered complete. All that remains is to return the protective casing to the heating unit.
In electric boilers, heating is controlled based on data from temperature sensors. Thermostatic devices are located on the main control panel of the boiler. The thermostat will receive data on the temperature of the heating element and the temperature of the coolant. Based on these readings and the settings set on the thermostat, a decision is made automatically to supply or turn off power to the heating elements. While the temperature is below the set one, power will be supplied and the heating elements will produce heating, and when the threshold value is reached or exceeded, the power will be turned off and the heating elements will stop heating. When it cools down to the lower threshold, the heating element will turn on again.
The thermostat allows a person to set the temperature (upper and lower thresholds) just once, and then the electric boiler will operate automatically, and the temperature will be maintained at the desired level.
There is an option to use thermostats with several types of temperature sensors, which will not only control the heating of the heating element itself, but also the air temperature in the room. To do this, the temperature sensor must be installed at a distance from the boiler and coolant.
Electric boiler connection diagram
The general connection diagram for an electric boiler with heating elements is nothing more than a diagram for connecting one or more heating elements to the power supply.
To understand and understand the principle of connecting a heating element boiler, let’s look at the heating element.
In the photo you see the simplest heating element, consisting of one heating tube. As a result, such a heating element has only two contacts for connection. This heating element is connected directly. One contact per phase (usually 220 Volts), the second contact to working zero.
The power of such heating elements is small and they are not used in heating boilers. Their prerogative is kettles or washing machines, dishwashers.
In electric boilers, heating elements are “curled” from two, often three, tubes. The heating element for the boiler looks like this.
As you can see, such heating elements already have 6 (six) contacts for connection and this is the simplest option. The task of connecting the heating element of the boiler is to correctly connect the six contacts of the heating element to connect it to the power supply.
There is nothing complicated about this if you recall two classic connection diagrams from the electrical engineering course. You've probably heard of them, these are circuits called "star" and "triangle". I wrote about them in some detail in the article How a low-voltage consumer of 380 Volts receives electricity.
I will describe these schemes in simple language. So, we have 6 contacts divided into pairs. Only three pairs.
- The “star” circuit involves connecting one contact from three pairs and connecting it to the working “zero”. The remaining contacts of the heating element pairs are connected to phases L1, L2, L3 if the power is 380 V, or they are also connected and connected to phase L if the power is 220 V.
- According to the “triangle” circuit, all pairs of contacts are connected in series and connected to three phases of 380 V.
How to use it correctly
In addition to the banal failure to follow the operating instructions and safety regulations, heating elements can break due to:
- shell corrosion;
- its rupture as a result of overheating;
- constant changes in mains voltage;
- and just a general depressurization of the tube.
In order for the device to heat your home for as long as possible, you need to follow simple rules:
- When connecting the wires, you should not be too zealous and over-tighten the contact nuts of the output ends of the heating element - they may burst.
- The device must be connected to the network only when it is in water. Otherwise, lowering a heated spiral into water can result in a fairly strong explosion.
- The surface of the heating tube must be regularly descaled. It all depends on the quality of the water, but during constant operation, it is best to clean it once a quarter, avoiding scale build-up of more than 2 mm.
- If there are problems with the quality of the power supply, you should connect an uninterruptible power supply or stabilizer.
- For the coolant, it is best to pour distilled water into the system; the percentage of impurities in it is minimal. They are the reason for the appearance of scale on the shell of the heating element.
- Use residual power supply devices (RCDs) - if the heating element breaks down, it will be immediately disconnected from the network.
- Grounding is mandatory.
It's important to understand. Not every heating element can be mounted in a heating radiator. You need to select specialized models in strict accordance with the required diameter
You need to select specialized models in strict accordance with the required diameter.
Let's sum it up
Follow all these simple rules and instructions. They will help you carry out safe and efficient heating of premises with electric heating elements, which can be used to form local heat sources or complement a centralized heating system.
Heating element with thermostat for water heater
Today, modern household water heaters successfully cope with the problem of lack of hot water supply. The design of any such device necessarily includes a heating element - a tubular metal rod. It is he who converts electrical energy into thermal energy and then gives it to water, heating it to the desired temperature. The thermostat built into the heating element allows you to set the degree of water heating.
A heating element with a thermostat is a device of simple design. It consists of several elements, namely:
A metal tube, the material of which can be titanium, steel, brass or copper with a protective coating against corrosion.
Inside the tube there is a spiral of wire, which has a high resistivity, which means that when an electric current passes through it, it can become very hot.
Insulating filler is a material that is designed to prevent the spiral from coming into contact with the walls of the tube.
Contact rod, which serves to connect the heating element to the electrical network;
Porcelain insulators located at the ends of the tube;
Thermal sensor (temperature regulator), which turns off when the set temperature is reached, and turns on again when the water cools down to the lower mark, and so on all the time the water heater is in the on mode.
A water heating element with a thermostat has significant advantages that will ultimately help optimize the water heating process from a financial point of view:
- Thermostats for heating elements allow rational use of resources. When the water in the water heater reaches the set temperature, the heating element turns off and turns on when the water has cooled significantly.
- Simplicity and reliability of design. The water heating element with a thermostat is designed for continuous operation for several years.
- Easy installation. Each water heater model has a special mount for the heating element. Some models provide the ability to use several heating elements simultaneously.
- The low price of a heating element with a thermostat makes it the optimal solution.
Tubular metal heating elements have only a few significant disadvantages. One of them is that if the heating element burns out, it cannot be repaired; it will have to be completely replaced. In addition, with constant contact with water, scale forms on the metal surface of the heating element, which reduces the efficiency of heat transfer. Also, such heating elements often suffer from voltage surges.
Thermostats for heating elements can be of several varieties. First of all, they are divided into mechanical, their action is based on the properties of various metals when heated, and electronic, based on a sensor.
Water heaters with a thermostat are also available in various designs, differing from each other in the material of manufacture and the method of installation on the water heater.
You can buy a heating element with a thermostat in Moscow for installation in water heaters and other household appliances. In our catalog you will find different models of heating elements that are suitable for all types of modern water heaters, boilers, washing machine tanks, tanks, etc.
We supply heating elements directly from the manufacturer, which allows us to keep prices low and be able to quickly supply the necessary devices in the required quantity. Each large customer can count on individual terms for calculating costs.
Legal address: 117105, Moscow, Varshavskoe highway, no. 26, building 2, floor 2, office 86
Selecting a heating element
When choosing a heating element, you need to pay attention to some details. Only in this case can you count on a successful purchase, high-quality heating, long service life and compatibility of the selected model with a water heating tank, boiler or radiator
Shape and size
There are dozens of heating element models available for buyers to choose from. They have different shapes - straight, round, figure-eight or ear-shaped, double, triple and many others. When purchasing, you should focus on the use of the heater. For installation in sections of heating radiators, narrow and straight models are used, since there is quite little space inside
When assembling a storage water heater, you should pay attention to the volume and shape of the tank, and based on this, choose a suitable heating element. In principle, almost any model will fit here
If you need to replace a heating element in an existing water heater, you need to purchase an identical model - only in this case can you count on the fact that it will fit into the tank itself.
Power
If not everything, then a lot depends on power. For example, this could be the heating rate. If you are assembling a small-volume water heater, the recommended power will be 1.5 kW. The same heating element will be able to heat disproportionately large volumes, but it will do this for a very long time - with a power of 2 kW, heating 100-150 liters of water can take 3.5 - 4 hours (not to a boil, but on average by 40 degrees).
If you equip a water heater or water tank with a powerful 5-7 kW heating element, the water will heat up very quickly. But another problem will arise - the house electrical network will not withstand it. When the power of the connected equipment is above 2 kW, it is necessary to lay a separate line from the electrical panel.
Protection against corrosion and scale
When choosing heating elements for heating water with a thermostat, we recommend paying attention to modern models equipped with scale protection. Recently, models with enamel coating have begun to appear on the market.
It is this that protects the heaters from salt deposits. The warranty on such heating elements is 15 years. If you don’t find similar models in the store, then we recommend purchasing stainless steel electric heaters - they are more durable and reliable.
The presence of a thermostat
If you are assembling or repairing a boiler or want to equip a heating element with a heating element, choose a model with a built-in thermostat. It will save on electricity by turning on only when the water temperature drops below a set point. If there is no regulator, you will have to monitor the temperature yourself by turning the heating on or off - this is inconvenient, uneconomical and unsafe.
Heating element and single-phase network. What to screw to what
This case is typical for dachas and old-built village houses. First you need to generally understand what we are talking about and the easiest way to do this is by looking at the following figure:
So, a single-phase electrical network has two conductors - zero and phase. The picture itself shows two ways to turn on the load - parallel and serial. These methods differ in how the initial voltage is divided between the elements. In most cases, heating elements are connected in parallel so as not to lose useful power; a series circuit is suitable only for various specific cases. A block prepared for connection to one phase will look like this:
It is also worth paying attention to the choice of cable, but we will touch on this point a little later, and now let’s move on to the three phases
Device and connection diagrams of heating elements. Part 2
Hello, dear readers of the site sesaga.ru. We continue to get acquainted with tubular electric heaters ( TEH ). In the first part we looked at the design and inclusion of heaters in a single-phase electrical network, and in this part we will consider the inclusion of heaters in a three-phase network
.
Schemes for connecting heating elements to a three-phase network
For inclusion in a three-phase electrical network, heating elements with an operating voltage of 220 and 380 V are used. Heaters with an operating voltage of 220 V are switched on according to the star
", and heaters with a voltage of 380 V are switched on according to the "
star
" and "
delta
" circuits.
3.1. Star connection diagrams
Consider a star
, composed of three heaters.
to pin 2
of each heater.
Terminals 1
are connected together and form a common point, called
zero
or
neutral
, and this load connection circuit is called
three-wire
.
Three-wire switching on
The circuit is used when heaters or any other load are designed for an operating voltage of 380 V. The figure below shows a wiring diagram for three-wire connection of heaters to a three-phase electrical network, where the supply and shutdown of voltage is carried out by a three-pole circuit breaker.
In this circuit, the corresponding phases A
,
B
and
C
, and the left terminals are connected to
the zero point
. Between the zero point and the right terminals of the heaters, the voltage is 220 V.
In addition to the three-wire circuit, there is a four-wire circuit , which involves connecting a load with an operating voltage of 220 V to a three-phase network. With this connection, the zero point of the load is connected to the zero point of the voltage source.
In this circuit, the corresponding phase is supplied to the right terminals of the heaters, and the left terminals are connected to one point, which is connected to the zero bus
voltage source. Between the zero point and the heater terminals, the voltage is 220 V.
If it is necessary for the load to be completely disconnected from the electrical network, then “ 3+N”
"or "
3P+N
", in which all four power contacts are switched on and off.
3.2. Delta connection diagrams
When connecting in a triangle, the leads of the heaters are connected in series with each other.
Let's consider the circuit for connecting three heaters: output 1
heater
No. 1
is connected to terminal
1
of heater
No. 2
;
pin 2
of heater
No. 2
is connected to pin
2
of heater
No. 3
;
pin 2
of heater
No. 1
is connected to pin
1
of heater
No. 3
.
As a result, we got three shoulders - “ a
”, “
b
”, “
c
”.
Now we apply a phase to each shoulder: to shoulder “ a
"phase
A
, to arm "
b
" phase
B
, and to arm "
c "
phase
C.
3.3. Scheme “heater - thermal relay - contactor”
Let's look at an example of a temperature control circuit. This circuit is made up of a three-pole circuit breaker, a contactor, a thermal relay and three star-connected heaters.
Phases A
,
B
and
C
from the output terminals of the machine are supplied to the input of the power contacts of the contactor and are constantly on duty on them. The left terminals of the heating elements are connected to the output power contacts of the contactor, and the right terminals are connected together and form a zero point connected to the zero bus.
From the output terminal of the machine, phase A
is supplied to the power terminal of thermal relay
A1
and is transferred by a jumper to the left output of contact
K1
and is constantly on duty on it.
The right terminal of contact K1
is connected to terminal
A1
of the contactor coil.
Zero N
from the zero bus is supplied to terminal
A2
of the contactor coil and is transferred by a jumper to the supply terminal
A2
of the thermal relay.
The temperature sensor is connected to terminals T1
and
T2
of the thermal relay.
In the initial state, when the ambient temperature is above the set value, relay contact K1
is open, the contactor is de-energized and its power contacts are open.
When the temperature drops below the set value, a signal comes from the sensor and the relay closes contact K1
.
Through closed contact K1,
phase
A
is supplied to terminal
A1
of the contactor coil, the contactor is activated and its power contacts are closed.
Phases A
,
B
and
C
are sent to the corresponding terminals of the heaters and the heaters begin to heat up.
When the set temperature is reached, a signal comes from the sensor again and the relay gives a command to open contact K1
.
Contact K1
opens and the supply of phase
A
to terminal
A1
of the contactor coil is stopped. The power contacts open and the voltage supply to the heaters is stopped.
The next version of the heater switching circuit differs only in the use of a three-pole circuit breaker with three phase and zero power contacts that can be switched off.
In order not to load the power terminal of the machine, it is necessary to provide a zero bus on which all the zeros will be collected. The busbar is installed next to the circuit elements, and the neutral conductor is pulled from it to the fourth terminal of the circuit breaker.
When connecting heating elements to a three-phase network, in order to distribute the load evenly across phases, it is necessary to take into account the total load power for each phase, which must be the same
.
So we looked at two main connection diagrams for heaters used in a three-phase electrical network.
Now we just have to consider possible malfunctions
and
ways to check the heating element
. Let’s finish here for now.
Good luck!
Source: https://sesaga.ru/ustrojstvo-i-sxemy-podklyucheniya-ten-chast-2.html
Correct choice of heating element model
When going to purchase a heating element, the buyer needs to know a number of technical characteristics:
- required power of the device;
- length, diameter and shape of the tube;
- length of the insulating cap;
- overall length;
- connection type;
- method of fastening.
To calculate the power of a heating element intended for heating water of a certain volume, use the formula:
P – power of the heated element, measured in kW;
m is the mass of the heated coolant circulating in the device, in kilograms;
tH – initial temperature of water or liquid, in °C;
tK – final temperature of water or liquid, in °C;
T – heating time of water or liquid.
Heating element in a heating radiator - video review:
How to choose a heating element for a radiator
A relatively inexpensive heating element with a built-in thermostat; the sensor responds to the temperature of the coolant, not the air in the room
- Design. Heating elements for cast iron radiators are not fundamentally different from heaters for cast iron and steel; the difference may be in the material of the plug and the shape of the outer part of the housing with the thermostat. The instructions for the heating element must indicate the types of heating devices for which it is intended. The diameter of the plug in standard radiators is 1 1/4″ (40 mm), the thread can be right or left.
- The length of the heating tube is an important factor affecting the completeness of heating. The fact is that a short heating element will not be able to create normal liquid circulation in those sections where it does not reach. Therefore, ideally, the length of the heater should be 6-10 cm shorter than the battery.
When selecting a heater, you need to take into account not only the power, but also the length of the tube
Automatic control can be external or built into the heating element. In the first case, the water heater does not have a thermostat, but is connected through a thermostat that measures the air temperature in the room. In the second, the thermostat can be built into the outer part of its housing. The sensor usually measures the temperature of the coolant. The manufacturer is not that important. Famous European companies do not produce such devices, but Polish, Turkish and Ukrainian heating elements are quite similar in quality
Chinese heaters should be treated with caution, although there are decent models among them.
The “correct” heater - insulated safe housing, convenient thermostat
Purpose of heating elements
Why do we need heating elements with thermostats? Based on them, autonomous heating systems are designed, boilers and instantaneous water heaters are created. For example, heating elements are mounted directly into batteries, resulting in sections that can operate independently, without a heating boiler. Some models are focused on creating anti-freeze systems - they maintain a low positive temperature, preventing freezing and subsequent rupture of pipes and batteries.
Storage and instantaneous water heaters are created on the basis of heating elements. Purchasing a boiler is not affordable for every person, so many assemble them themselves using separate components. By installing a heating element with a thermostat into a suitable container, we will get an excellent storage-type water heater - the consumer will only have to equip it with good thermal insulation and connect it to the water supply.
Heating elements for heating water with a thermostat are necessary not only for creating water heating equipment, but also for repairing it - if the heater fails, we buy a new one and replace it. But before that, you need to understand the issues of choice.
