Which machine to install on an air conditioner in an apartment: selection, installation and connection of a protective device

You've probably thought about which machine to install on the air conditioner in your apartment if you decide to get such an air conditioning system. The circuit breaker protects electrical wiring from overloads and possible fire. Errors made during its selection and installation can lead to electrical wiring failure or fire.

You can choose and install the right machine for your split system yourself. We will help you figure out how best to do this.

Why does the air conditioner need a separate machine?

Owners of household air conditioners often wonder about the need to install a separate machine for their device and lay a separate line to it from the apartment or floor distribution board. Low-power split systems are often equipped with a wire with a standard plug for connecting to a household outlet, which adds even more questions.

The first thing you need to do to find out whether you need to install a separate circuit breaker and lines for your device, please read the operating instructions. The instructions for absolutely any air conditioner have a section dedicated to connecting to the electrical network.

If the requirement for a separate line and machine is clearly stated in the manual, then it must be fulfilled unconditionally. Otherwise, you may lose the warranty on the device and face other troubles.

The air conditioner manufacturer specifically stated in its instructions that it is not permissible to connect other devices to the air conditioner switch. If your instructions include a similar requirement, then connect the split system via a separate line with a separate machine

If there is no such requirement, then you have to make the choice yourself. To do this, you need to know what advantages and disadvantages a connection via a separate line has.

Advantages of installing a separate line with a machine:

• You can use powerful air conditioners even in apartments with old, including aluminum, electrical wiring without replacing it;
• Reducing the negative impact of the air conditioner on the operation of other devices: the air conditioner is equipped with a compressor and fans that have significant starting currents that cause voltage fluctuations in the network when it is turned on. Such vibrations, if the wiring is weak, can harm other household appliances;
• Eliminating the possibility of overload during simultaneous operation of the air conditioner and other devices connected to the same line;
• There is no need to test existing electrical wiring for functionality and safety;
• The ability to turn off the air conditioner for maintenance or repair without interrupting the operation of other devices in the apartment;
• You don’t have to install a socket to connect the air conditioner, but run the wire directly into the terminal block of the device, which will look more aesthetically pleasing.

The more powerful the air conditioner and, accordingly, the more current it consumes, the more your choice should lean towards laying a separate line and installing a separate machine for the air conditioner.

If the air conditioner is installed after finishing work has been completed, then a separate line can be connected to it in a cable channel. If the device is equipped with a factory cord and plug, then you need to install a socket with grounding contacts

The list of disadvantages of constructing a separate branch includes only:

• It is necessary to carry out electrical installation work to lay a line from the panel to the device, which can damage the finishing of the apartment;
• It is not always possible to install another machine in an existing switchboard, which may require its replacement or modification.

Do not install a separate machine and a separate line for climate system, and you can get by by connecting the device to an existing household outlet only if there is a direct indication of this in the instructions.

In this case, the socket must have protective grounding contacts, and the electrical wiring and circuit breaker installed in the switchboard must withstand the total load from the air conditioner and other household devices connected to this line.

In order to find out which devices are connected to the line into which the air conditioner is supposed to be turned on, you need to turn off the circuit breakers in the apartment or floor panel one by one. This makes it easier to check which household appliances are left without power, that is, they do not turn on.

Before connecting the air conditioner to an existing outlet, check what material the electrical wiring is made of and what its cross-section is. If the wiring is old aluminum, it is better not to connect the air conditioner to it

Also, do not plug the air conditioner into an existing outlet if it is connected to the line that powers a microwave, electric kettle, washing machine or other devices with high power consumption.

If you have a low-power split system, and the choice fell on connecting to an existing outlet, then be sure to inspect the electrical wiring. Make sure that the wire connections in the branch boxes are not oxidized or loose, the bolt clamps in the socket and the machine in the panel are not loose, and the air conditioner plug is tightly inserted into the socket, ensuring reliable contact.

Choosing an air conditioner machine

Connecting an air conditioner via a separate line requires the installation of a separate circuit breaker to protect it from overloads.

The choice of a machine comes down to the selection of a device that will simultaneously ensure the fulfillment of several basic conditions:

• It will calmly pass through itself the electric current from the operation of the air conditioner in normal mode (rated current);
• Will withstand a short-term increase in the current of the split system by 3-5 times the rated value at the moment of starting the device;
• It will de-energize the air conditioner line as quickly as possible if a malfunction occurs in the device, leading to a short circuit, as well as a long-term excess of currents above the rated values.

It is important to remember that even it is correct selected machine gun is able to ensure safety only if the supply voltage parameters comply with the established requirements.

When installing a circuit breaker for an air conditioner, remember that it only protects the electrical wiring from overloads, but not the split system itself.If the voltage in your home is not of high quality, then only installing a stabilizer will help protect the equipment

Compact modular switches are most widely used for installation in residential buildings and apartments. They are small in size, easy to install and reliable.

Also, modular machines have a wide range of rated currents, which allows you to select the device that is most suitable for a specific air conditioner. For use in apartments, switches with rated currents from 10 to 40 A are most often used.

The choice of manufacturers of protective devices is also quite large. There are two segments here:

• Budget, which includes products from IEK, EKF, TDM and others;
• Expensive. These include: ABB, SIEMENS, Legrand and Schneider—Electric.

Despite the difference in cost between cheap and expensive machines from 2.5 to 5 times, it is better to opt for devices from more famous manufacturers, as they will provide greater reliability. Even in this case, the cost of the machine will not exceed 3% of the total cost of the split system.

Characteristics of circuit breakers

The housing of the modular circuit breaker contains two types of protection, one of which is thermal, and the second is electromagnetic.

The externally small device hides several types of protection inside, a device for extinguishing an arc in case of a short circuit and clamps for connecting wires

An electromagnetic release is a coil that instantly draws in the armature, breaking the contact, in the event of a large current flowing through the circuit breaker caused by a short circuit.

To operate air conditioners, select switches with characteristics of electromagnetic release B or C.Such machines operate when currents flowing through them are equal to 3 to 5 and 5 to 10 rated currents, respectively.

Such a “reserve” of breaking capacity is needed so that the machine does not operate due to the starting current of the air conditioner.

The thermal release will disconnect the line if the current values ​​exceed the nominal value by 1.14 times or more. The higher this value, the faster the protection will work. If the current exceeds 1.45 times, the modular circuit breakers for household use will turn off within 1 hour.

Such protection allows you to protect the line from currents that are close in value to the starting currents of the air conditioner, but significantly exceed them in time.

All parameters of circuit breakers are observed at an ambient temperature of +25^OWith and installation of the machine separately. When the temperature deviates and several machines are installed in parallel, correction coefficients are applied that take into account the heating of the machine by ambient air or from neighboring switches.

The more machines are located next to each other, the lower their operation current. An increase in ambient temperature also reduces the operating current. Cold air on the contrary will slow down the response time

Another characteristic of the machines is the number of poles, which can be from 1 to 4. This characteristic reflects how many wires can be simultaneously connected to the machine for protection.

For conventional air conditioners, single-pole circuit breakers are used, and they are installed in the phase conductor gap. However, the split system manufacturer's instructions may indicate installation of a two-pole device. In this case, the phase and neutral conductors are connected through the machine.

The machine will measure the values ​​of currents flowing in each wire, and if the specified value is exceeded in at least one of them, it will turn off the power in all wires of the line

The greater the number of poles, the more space will be required in the panel for installing the switch and wiring.

Subtleties of selecting a current switch

Since the safe operation of electrical equipment directly depends on the correct operation of the protective device, it is better to entrust the choice of a circuit breaker to electricians who have the necessary qualifications for this. If you still decide to do it yourself, then start by reading the manual for your air conditioner.

Manufacturers of climate control equipment indicate how many amperes the machine should have for a specific model of air conditioner.

For each model of its air conditioner, this manufacturer indicated in the instructions the required circuit breaker current. The owner of such a split system only needs to focus on these values ​​when choosing an automatic

If the instructions for your device say that the connection must be made through a circuit breaker rated 20A, then you only need to purchase the appropriate switch with characteristic B or C. However, often in their instructions, manufacturers do not indicate specific parameters of the machines, but only report requirements for their selection .

For example, the instructions may indicate that the machine should turn off at a current 1.5 times higher than the maximum operating current of the split system. In this case, in the table with the characteristics of the air conditioner, you need to find the maximum current value that the device consumes. Then select the machine with the closest shutdown current value.

It is necessary to take into account that the rated current marked on the machine is not its shutdown current. The characteristic that you should focus on is the operation of the machine at a current of 1.45 of its rated value. According to GOST, with such a current, the machine must turn off the line no later than in an hour.

For the air conditioner indicated in the left column, the maximum current consumed in heating mode is 12.5+10 = 22.5A. The closest IEK circuit breakers of the BA 47-29 series have ratings of 20 and 25A, while the currents that will turn them off within an hour are 1.45 times higher and amount to 29 and 36.25A, respectively

According to the air conditioner manufacturer's instructions, the shutdown current of the machine should be 1.5 times the maximum current of the device, that is, 22.5 × 1.5 = 33.75 A. This condition is met by a machine with a nominal value of 25A.

The same rule for choosing a machine should be followed if the instructions do not formulate requirements for its selection at all. This most often occurs if the air conditioner has low power and is equipped with a plug for plugging into a regular outlet, and you decide to connect the device via a separate line.

Sometimes information about which machine needs to be installed on a split system is not indicated in the instructions. This information is in the electrical connection diagram located on the split system unit itself or on the inside of the terminal block cover.

Additionally, you can check the current of the circuit breaker if you know the cross-section of the wire that connects the air conditioner. Often this parameter is indicated in the manual for the split system. As a rule, in apartments, wires with a cross-section of 1.5 are used for these purposes; 2.5 and 4 mm².

For each cross-section of wires, the collection of PUE (Rules for the Construction of Electrical Installations) indicates the permissible long-term currents at which the electrical wiring will operate without disturbances.

When choosing a circuit breaker for your air conditioner, compare its current characteristics with the permissible continuous currents of the existing wiring. When choosing the type of cable, do not take into account the presence of a protective grounding wire in its composition, since in operating mode it does not affect heating, because no current flows through it

For two-core wires of the specified cross-sections when laid hidden (in a groove, in a corrugation or in a cable duct), these currents are:

• For 1.5 mm2 – 18A;
• For 2.5 mm2 – 25A;
• For 4 mm2 – 32A.

To reliably protect the line, the machine must ensure that the wires are disconnected if these values ​​are exceeded. In accordance with GOST, any machine can turn off only if the current flowing through it exceeds 13% above the rated one. Until this value is reached, the machine will not turn off.

Thus, the following machines are suitable for protecting wires:

• For 1.5 mm² – 16A (16×1.13 = 18A ≤1 8A);
• For 2.5mm² – 20A (20×1.13 = 22.6A ≤ 25A);
• For 4 mm² – 25A (25×1.13 = 28.3A ≤ 32A).

In practice, cases arise when the current values ​​of switches specified in the installation manuals for split systems exceed the permissible currents for conductors determined in accordance with the PUE. In these cases, it is necessary to follow the requirements of the rules, and also contact the manufacturer for clarification.

Machine installation process

Despite the apparent simplicity of installing a circuit breaker, it is a responsible procedure, the quality of which determines the reliability of the equipment and your safety. This is especially true for performing work in existing electrical installations, where there is a risk of electric shock.

In accordance with current regulations, work on installing a circuit breaker may only be carried out by appropriate electrical personnel.

Electrical installation rules indicate that the circuit breaker must be installed directly on the branch of the protected line from the supply line (clause 3.1.16). That is, the best place to install the machine is apartment or floor panel.

You can install and connect the machine in your apartment panel yourself. To do this, completely de-energize the panel by turning off the input circuit breaker and make sure there is no voltage using a multimeter. Install the machine in the free space and connect it. Sign the machine so you know what it turns off

Before installing a safety switch, you need to make sure that there is enough space in the existing panel to accommodate it, as well as to install and route additional wires. The machine is mounted on a DIN rail. The power wire from the input or group circuit breaker is connected to its upper terminal, and the line wire to the air conditioner is connected to the lower terminal.

When installing the machine, you need to connect the wires in accordance with their color designation. This is necessary for the correct operation of the device and the performance of protective grounding and disconnection functions.

A phase wire is connected to the machine. In most cables it is white, less often red or brown.The neutral conductor is clamped into the neutral busbar in the shield and has a blue designation, less often black. The third required wire is the protective ground. It must be connected to the grounding bus or to the grounded panel body. The color of such a conductor is yellow-green.

During installation, you need to ensure that the rating of the air conditioner circuit breaker is not equal to or exceeds the rating of the input or group circuit breaker in the panel. Otherwise, it will be the group switch that will trip first, cutting off power to the entire apartment, including its lighting.

If it is impossible to fulfill this condition with an existing group machine, then it must be replaced with a more powerful one.

Since incorrect installation of the machine in the floor panel of an apartment building can lead to failure of electrical equipment not only in yours, but also in neighboring apartments, in this case, be sure to contact your management company or partnership to install and connect the machine

If it is not possible to install an air conditioner in floor or apartment panels, then the rules allow it to be installed at a distance from them. In this case, the length of the wire from the shield to the machine should be no more than 6 m, and installation of the protective device will require the installation of an additional shield or box.

Installing the machine in a separate box is not difficult. This box is equipped with a built-in DIN rail and can be equipped with a zero bus. Install the box on the wall using suitable fasteners, fix the switch, connect the wires and close the lid

In the case of such an installation, the cross-section of the wire from the panel to the machine must be no less than the cross-section of the wire from the machine to the air conditioner.Also, before installing a separate circuit breaker and supply line to the air conditioner, you should make sure that the cross-section of the supply line wires in the switchboard will withstand the additional load created by the split system.

Typical mistakes when installing a machine

The most common mistake when choosing and installing a machine to protect purchased split systems is an overestimation of its current characteristics. Most often this happens due to the desire to insure against a “false” positive.

This approach is really justified if the machine is installed in a room with a high temperature or is subject to some kind of heating. In this case, the thermal release may operate at lower currents, and the heating factor must be taken into account when selecting a circuit breaker by applying an adjustment factor.

In all other cases, overstating the machine is unacceptable, as it can lead to a delay in disconnecting the line and its failure, even to the point of fire. The second mistake is installing the machine on a split system with a rated current equal to or greater than the current of the main machine in the panel. Such a discrepancy threatens to completely cut off the power supply in the apartment.

A common mistake during installation is insufficient stripping, partial insertion of wires into the terminal of the machine, or loose tightening. This is especially true for wires with a small cross-section. Such a violation will lead to great heating of the connection point, as a result of which the insulation of the wire and switch will melt, which may lead to a fire.

A similar mistake when connecting wires is getting a stripped wire into the terminal space. In this case, there is no tightening of the wire at all, and the contact disappears when the load increases.This process may be accompanied by sparking and burning of the wire when the air conditioner is running.

When installing the machine, strip the wires to a sufficient length, make sure the wire is inserted into the clamp correctly and tighten it. After tightening, check if the wire is loose in the clamp.

Sometimes there is an error with the choice of location for installing the machine. As a result, it is installed not on a branch near the supply line, as prescribed by the rules, but in close proximity to the air conditioner. Such an installation does not at all protect the line from the panel to the circuit breaker from overloads, and the switch does not have a protective function and only allows you to turn the air conditioner on and off.

Conclusions and useful video on the topic

Video about laying your own line to the air conditioner and connecting it to a separate machine in the panel:

The video explains how to install additional differential circuit breakers in the floor panel:

Video about the device and features of the machines:

It is better to connect the air conditioner in the apartment via a separate line with the installation of a circuit breaker. This will help protect you from a number of problems when operating electrical equipment and will make using the air conditioner safer.

The selection and installation of circuit breakers is a rather complex process, on which the reliability of electrical equipment and the safety of people depend. Therefore, it is better to entrust these works to electricians and installers with appropriate education and experience.

If you decide to do everything yourself, then the first thing you should start with is to study the instructions for installing the split system. Often it contains direct instructions on choosing a machine and wire.