You probably thought about what kind of automatic machine to put on the air conditioner in the apartment, if you decide to acquire such an air conditioner. The circuit breaker protects the electrical wiring from overload and possible fire. Mistakes in its selection and installation can lead to failure of electrical wiring or fire.
You can choose and install the right machine for the split system yourself. We will help you figure out how best to do this.
The content of the article:
- Why does an air conditioner need a separate machine?
-
Choosing a vending machine for an air conditioner
- Circuit breaker characteristics
- The subtleties of selecting a current switch
- The process of installing the machine
- Typical mistakes when installing the machine
- Conclusions and useful video on the topic
Why does an air conditioner need a separate machine?
Owners of household air conditioners often wonder about the need to install for their device a separate machine and laying a separate line to it from the apartment or storey distribution shield. Low power split systems are often equipped with a standard plug wire for connecting to a household outlet, which adds further questions.
The first thing to do is to figure out if you need to install a separate circuit breaker and lines for your device, read the instruction manual. The instructions for absolutely any air conditioner have a section on connecting to the mains.
If the requirement for a separate line and machine is clearly spelled out in the manual, then it must be unconditionally fulfilled. Otherwise, you may lose the warranty for the device and face other troubles.
The manufacturer of the air conditioner in its instructions specifically indicated that it is unacceptable to connect other devices to the air conditioner switch. If your instruction contains a similar requirement, then connect the split system on 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 the advantages and disadvantages of a separate line connection.
Advantages of a separate line device with an automatic machine:
- You can use powerful air conditioners even in apartments with old, including aluminum, electrical wiring without replacing it;
- Reducing the negative effect of the air conditioner on the operation of other devices: the air conditioner is equipped with a compressor and fans that have significant inrush currents that cause voltage fluctuations in the network when it inclusion. Such vibrations with weak wiring can harm other household appliances;
- Elimination of the possibility of overload during the simultaneous operation of the air conditioner and other devices connected to the same line;
- There is no need to test the existing electrical wiring for its performance 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 do not have to install an outlet for connecting the air conditioner, but lead 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 the cable channel. If the device is equipped with a factory cable with a plug, then you need to install a socket with earthing contacts.
The list of disadvantages of the construction of a separate branch includes only:
- It is necessary to carry out electrical work to lay a line from the panel to the device, which can damage the decoration of the apartment;
- It is not always possible to install another machine in an existing switchboard, which may require its replacement or revision.
Do not install a separate machine and a separate line for climate system, and it is possible to manage 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 a protective circuit breaker, installed in the switchboard, 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 machines in the apartment or floor panel one by one. This makes it easier to check which household appliances were left without power supply, 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 is its section. 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 a line from which powered by a microwave oven, electric kettle, washing machine or other devices with a large consumption power.
If you have a low-power split system, and the choice fell on connecting to an existing outlet, then be sure to revise the wiring. Make sure that the junction boxes are not oxidized or loosened wire connections, bolt clamps in the socket and the vending machine in the dashboard are not unscrewed, and the air conditioner plug is tightly inserted into the outlet, providing reliable contact.
Choosing a vending machine for an air conditioner
Connecting the air conditioner via an independent line requires the installation of a separate machine to protect it from overloads.
The choice of the machine comes down to the selection of such a device that will simultaneously ensure the fulfillment of several basic conditions:
- It will calmly pass through itself an electric current from the operation of the air conditioner in normal mode (rated current);
- Withstands a short-term increase in the current of the split system by 3-5 times from the nominal value at the time of device start-up;
- As quickly as possible, it will de-energize the air conditioner line in the event of faults in the device that lead to a short circuit, as well as a prolonged excess of currents over the nominal values.
It is important to remember that even the right matched machine is able to ensure safety only if the parameters of the supply voltage comply with the established requirements.
When installing a circuit breaker for an air conditioner, remember that it protects only the electrical wiring from overloads, but not the split system itself. If the voltage in your house is not of high quality, then only installing a stabilizer will help protect the equipment.
For installation in residential buildings and apartments, compact modular switches are most widely used. They are small, easy to install and reliable.
Also, modular machines have a wide range of selection of rated currents, which allows you to select the device that is most suitable for a specific air conditioner. For use in apartments, circuit breakers with rated currents from 10 to 40 A are most often used.
The choice of manufacturers of protective devices is also quite large. Two segments can be distinguished here:
- Budgetary, 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, since they will provide greater reliability. Even in this case, the cost of the slot machine will not exceed 3% of the total cost of the split system.
Circuit breaker characteristics
In the case of the modular circuit breaker there are two types of protection, one of which is thermal, and the second is electromagnetic.
A small external device hides several types of protections 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, the opening contact, in the event of a large current flowing through the circuit breaker, caused by a short circuit.
To work with air conditioners, you should select switches with the characteristics of an electromagnetic release B or C. Such machines operate when currents flowing through them equal from 3 to 5 and from 5 to 10 rated currents, respectively.
Such a "reserve" of breaking capacity is needed so that the machine does not work on the starting current of the air conditioner.
The thermal release will cut off the line if the current values have exceeded the rating by 1.14 times or more. The larger this value, the faster the protection will work. If the current is exceeded by 1.45 times, the disconnection of modular automatic machines for domestic use will occur within 1 hour.
Such protection allows you to protect the line from currents close in value to the starting currents of the air conditioner, but significantly exceeding them in time.
All parameters of the circuit breakers are observed at an ambient temperature of +25OC and installing the machine separately. In case of temperature deviation and parallel installation of several machines, correction factors are applied, taking into account the heating of the machine by ambient air or from neighboring switches.
The more machines are located with each other, the lower their operating current. Also reduces the pick-up current by the rise in ambient temperature. Cold air on the contrary will slow down the response time
Another characteristic of 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 circuit breaker for protection.
For conventional air conditioners, single-pole machines are used, while they are installed in the phase conductor break. However, the manufacturer's instructions for the split system may contain an indication of the 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 the 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 switchboard for installing the switch and wiring.
The subtleties of selecting a current switch
Since the safety of operation directly depends on the correct operation of the protective device electrical equipment, then it is better to entrust the choice of a circuit breaker to electricians who have the necessary qualifications. If you do decide to do it yourself, then start by studying the manual for your air conditioner.
Manufacturers of climatic equipment indicate how many amperes an automatic device should be for a specific air conditioner model.
For each model of its air conditioner, this manufacturer indicated in the instructions the required current of the circuit breaker. The owner of such a split system only needs to be guided by these values, choosing a machine
If the instructions for your device say that the connection must be made through an automatic circuit breaker with a rating of 20A, then you only need to purchase the corresponding circuit breaker with characteristic B or with. However, manufacturers often do not indicate specific parameters of the machines in their instructions, but only report the requirements for their choice.
For example, the instructions may indicate that the machine should be turned off at a current 1.5 times the maximum operating current of the split system. In this case, in the table with the characteristics of the air conditioner, it is necessary to find the maximum value of the current that the device consumes. Then select the machine with the closest shutdown current value.
It should be borne in mind that the rated current applied to the machine is not its shutdown current. The characteristic that is worth focusing on is the operation of the machine at a current of 1.45 of its nominal value. According to GOST, with such a current, the machine must turn off the line no later than one hour later.
For the air conditioner indicated in the left column, the maximum current is consumed in heating mode and is 12.5 + 10 = 22.5A. The nearest IEK machines of the VA 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 instructions of the air conditioner manufacturer, the cut-off current of the machine must be 1.5 of the maximum current of the device, that is, 22.5 × 1.5 = 33.75A. According to this condition, an automatic machine with a nominal value of 25A passes.
The same rule for choosing a machine should be followed if the instructions do not formulate requirements for its choice at all. Most often this occurs if the air conditioner has a 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 slot machine needs to be put on a split system is not indicated in the instructions. This information is in the wiring 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, knowing the cross-section of the wire to which the air conditioner is connected. Often this parameter is indicated in the manual for the split system. As a rule, in apartments for these purposes, wires with a cross section of 1.5 are used; 2.5 and 4 mm2.
For each section of wires, the collection of PUE (Rules for the Arrangement of Electrical Installations) indicates the permissible continuous currents at which the wiring will work without violations.
When choosing a circuit breaker for your air conditioner, check 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 indicated cross-sections with hidden laying (in a groove, in a corrugation or in a cable channel), these currents are:
- For 1.5 mm2 - 18A;
- For 2.5 mm2 - 25A;
- For 4 mm2 - 32A.
For reliable protection of 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 when the current flowing through it exceeds 13% above the nominal. Until this value is reached, the machine will not shut down.
Thus, the following machines are suitable for protecting the wires:
- For 1.5 mm2 - 16A (16 × 1.13 = 18A ≤1 8A);
- For 2.5 mm2 - 20A (20 × 1.13 = 22.6A ≤ 25A);
- For 4 mm2 - 25A (25 × 1.13 = 28.3A ≤ 32A).
In practice, there are cases when the values of the circuit breakers' currents 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 be guided by the requirements of the rules, and also contact the manufacturer for clarifications.
The process of installing the machine
Despite the seeming simplicity of the installation of the circuit breaker, this is a responsible procedure, the quality of which depends on the reliability of the equipment and your safety. This is especially true for the performance of work in existing electrical installations, where there is a threat of electric shock.
In accordance with the current regulations, installation of the 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 (clause 3.1.16). That is, the best place to install the machine is apartment or floor board.
The installation and connection of the machine in the apartment switchboard can be done independently. To do this, completely de-energize the shield by turning off the input circuit breaker, and make sure that there is no voltage using a multimeter. Install the vending machine in a free space and connect it. Sign the machine so you know what it turns off
Before installing the safety switch, make sure that there is enough room in the existing switchboard to accommodate it, as well as to insert and route additional wires. The machine is mounted on a DIN rail. The power wire from the input or group machine is connected to its upper terminal, and the line wire to the air conditioner is connected to the lower terminal.
When installing the machine, the wires must be connected in accordance with their color designation. This is necessary for the device to function properly and to perform the protective grounding and shutdown functions.
A phase wire is connected to the machine. In most cables, it is white, less often red or brown. The zero conductor is clamped in the zero bus in the shield and has a blue designation, less often black. The third obligatory wire is the protective earth. It must be connected to a grounding bus or to a grounded shield frame. The color of such a conductor is yellow-green.
During installation, it is necessary to ensure that the rating of the machine for the air conditioner is not equal and does not exceed the rating of the input or group machine in the dashboard. Otherwise, the group switch will be the first to operate, de-energizing the entire apartment, including its lighting.
If this condition cannot be met with the existing group automaton, then it must be replaced with a more powerful one.
Since improper work on installing the machine in the floor panel of an apartment building can lead to failure of the electrical equipment not only for yours, but also for neighboring apartments, in this case, be sure to contact your management company or partnership
If it is impossible to install an air conditioner machine in the floor or apartment shields, then the rules allow installing it at a distance from them. In this case, the length of the wire from the shield to the machine should be no more than 6m, and to install the protective device, you will need to install an additional shield or box.
Installing the machine in a separate box is straightforward. This box is equipped with a built-in DIN rail and can be equipped with a zero bus. Install the box on the wall with suitable fasteners, fix the switch, connect the wires and close the cover
In the case of such an installation, the cross-section of the wire from the panel to the machine must be at least the cross-section of the wire from the machine to the air conditioner. Also, before installing a separate machine and a supply line to the air conditioner, make sure that the cross-sections of the supply line wires in the switchboard will withstand the additional load created by the split system.
Typical mistakes when installing the machine
The most common mistake when choosing and installing a machine to protect the purchased split systems is the overestimation of its current characteristics. Most often this happens due to the desire to hedge against "false" triggering.
This approach is really justified if the machine is installed in a room with a high temperature or is exposed to any kind of heating. In this case, the thermal release can trip at lower currents, and the heating factor must be taken into account when choosing a breaker, using a correction factor.
In all other cases, overstating the value of the machine is unacceptable, since it can lead to a delay in the disconnection of the line and its failure, up to a fire. The second mistake is the installation of the machine on a split system with a rated current equal to or higher than the current of the main machine in the panel. Such a discrepancy threatens a complete power outage in the apartment.
A common mistake during installation is insufficient stripping, partial insertion of wires into the terminal of the machine, or weak tightening. This is especially true for wires with a small cross section. Such a violation will lead to a large heating of the junction, as a result of which the insulation of the wire and the switch will melt, which may result in a fire.
A similar mistake when connecting wires is getting the 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 can 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 that 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 the location of the machine installation. As a result, it is not installed on a branch at the supply line, as prescribed by the rules, but in the immediate vicinity of the air conditioner. Such an installation does not at all protect the line from the panel to the machine from overloads, and the switch does not have a protective function, and only allows you to turn on and off the air conditioner.
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 dashboard:
The video tells how to install additional differential automata in the floor panel:
Video about the device and features of the machines:
It is better to connect the air conditioner in the apartment on a separate line with the installation of a circuit breaker. This will save you from a number of problems during the operation of electrical equipment and will make the use of the air conditioner safer.
The selection and installation of circuit breakers is a rather complicated process, on which the reliability of the operation of electrical equipment and the safety of people depend. Therefore, it is better to entrust these works to electricians and installers with the appropriate education and experience.
If you decide to do everything yourself, then the first thing to start with is to study the instructions for installing a split system. Often it contains direct instructions for choosing a machine and a wire.
