Selection, installation and operation of split systems. Part 3

Recommendation points

• Installation of an external block of a split system
• Split blocks connection to each other
• Drainage drain
• Vacuuming the freon line is a mandatory operation
• Documentation of the split system installation
• Split system commissioning sheet
• At the end

In this article: how to install an outdoor unit; characteristics of quality brackets; how the external and internal blocks are connected; construction of a drainage drain; after assembling the freon line, evacuation is performed; how to check the circuit for refrigerant leaks without using freon; installation acceptance sheet.

Often, split system installers prefer to perform their work at a low quality level, and it is difficult to identify this fact – specific knowledge is required, which is usually inaccessible to the average person. With the help of this material, you can find out how well the installation of the air conditioning system in your house is being carried out, protect yourself from possible imperfections on the part of the installers by issuing documents accompanying the installation work.

Installation of an external block of a split system

Let’s continue the description of the working stages performed during the installation of the split system, which began in the previous part of the material. It is much more difficult to expose the external unit of the air conditioner than the internal one, since it is heavy, the work is usually carried out at a high height and with minimal convenience – the installer is forced to protrude from the window opening more than half of his height, often it is necessary to perform installation operations in a head-down position. We list the possible installation locations for the street split block – an open balcony, roof and attic (it must be effectively ventilated, this is important) – then we examine its installation on the outer surface of the wall.

To place a weighty block, you will first need to put the brackets on the wall, keeping a distance between them equal to the distance between the mounting holes on the legs located on the underside of the block case. Before you start marking the positions of the two brackets on the wall and securing them, you need to carefully examine them. Ideally, the brackets should be from the factory, i.e. not handicraft-welded, but in this case, you should pay attention to:

• the type of paint applied – it must be a powder paint that forms a sufficiently strong coating in relation to mechanical damage. The enamel coating is easily chipped off by impacts, which cannot be completely avoided during installation, areas with exposed metal will rust and, over time, weaken the strength of the brackets. Accordingly, unpainted brackets are not suitable at all;
• mounting holes, drilled at the factory and usually oval in shape, which makes it possible to fix external blocks of splits of different depths in them, must be made before painting the brackets – again, due to rust;
• bracket type – make sure it is suitable for the weight of the unit and the material of the building wall. The brackets should be marked with this information.

The installation of the brackets on the walls is performed using dowel or anchor bolts, so it is safer – imagine the consequences of a street block falling on a car parked near your house or, even worse, on a bystander.

After finishing the installation of the brackets, the installers put the external block on them, place thick rubber gaskets between the mounts, called vibration isolators, which prevent the mounts from loosening due to vibration of the device during operation and suppress noise, then tighten the anchor bolts passed through the gaskets. The terminals of the air conditioner, located under the protective plastic cover, are connected to two obligatory cables – power and control, as well as, if necessary, grounding. In order to obtain a more reliable connection, the bare ends of the wires are crimped with ferrules.

Split blocks connection to each other

The copper pipes of the freon line are connected first to the external block, for this, union nuts are put on them, then the edges are processed with a rimmer, rolled and connected to the inlet fittings of the block. The tightening of the nuts is performed with special wrenches that allow the application of a limited force to them – for example, for? inch pipes, a wrench is required with a limitation of the force applied to it up to 160 kg / cm.

Cutting copper pipes for the purpose of shortening them is not performed – using a lever, spring or crossbow pipe bender, the “extra” length of pipes is rolled up in rings and laid behind the street split block. Then, insulation is put on along the entire length of the copper pipes, thermal tape is wound over it.

After completing the connection of communications with the inputs and terminals of the street unit, the installers proceed to their input into the indoor unit. The contacts of the cables are necessarily crimped with lugs, their connection to the terminals of the hair dryer must be done with special care, because if you mix up the contacts, then when the power is connected, the split system may fail. If the sheath of cables and wires inside them has a similar color – before connecting, you need to ring them with a tester.

Drainage drain

The operation of laying the drainage drainage tube can be performed both before the start of work on the construction of the refrigeration circuit (immediately after the installation of the indoor unit), and after them. To create drainage, only a special plastic tube with reinforcement is suitable – it bends easily, in a bent position, the gap inside it does not decrease, the inner walls are guaranteed not to contain shells and roughness, i.e. completely smooth.

In an attempt to simplify the task or slightly reduce the cost of installation, installers can use a plastic hose without reinforcement or a rubber tube – both options are not suitable, since the clearance at the bend decreases, and various microorganisms will settle on the rough inner walls, attracted by the moist atmosphere. As a result, a poor-quality drainage hose will become clogged and water will flow from the indoor unit of the split system, when approaching the hairdryer, households will feel unpleasant odors.

Drainage from the drainage tube will be most correct to discharge into the sewer, there are two reasons for this:

• in comfortable residential areas, the withdrawal of the drain to the street will be perceived with hostility by neighbors, as well as by homeowners association;
• with a drop in outdoor temperature below 0 ° C, the throughput of the drain tube will decrease in size due to freezing, condensed water will ooze from the hairdryer to the wall and floor of the room.

Vacuuming the freon line is a mandatory operation

After connecting the interblock communications of the split system, it is required to perform vacuuming, the purposes of which are as follows:

• complete elimination of air from the circuit. If atmospheric air partially remains in the copper pipes, it will increase the pressure in the circuit, which will cause an increased load on the compressor and reduce its performance;
• guaranteed absence of moisture. The air always contains moisture, which, when it penetrates into the freon line, when combined with freon, will change its chemical composition, form acid, lower the calculated insulation resistance of the compressor motor – as a result, the climatic device will become faulty.

The operation to evacuate the circuit is carried out using a special pump, which is connected to the split system through a manifold equipped with pressure gauges and several hoses. If it is not possible to eliminate air from the freon line during vacuumization, then this indicates its low tightness – vacuumization is carried out within 15 minutes, until complete confidence in the sealing of the circuit. Having found a leak in the system, the installers try to eliminate it by tightening the nuts on the inputs to the blocks, after which the vacuumization is repeated.

For complete confidence in the tightness of the freon line, a pressure test can be performed using a mixture of dehydrated nitrogen and refrigerant – a mixture of gases is naturally pumped into the previously evacuated circuit (the rarefied atmosphere inside the pipes will pull gas to equalize the internal pressure with the external one). Further, with the help of a leak detector, all connections are examined for leakage; if it is detected, the nuts are tightened. If it is not possible to eliminate the leak in this way, then the injected gas is vented, the connection is dismantled and rebuilt, after which it is again evacuated and checked for leaks with a mixture of gases or only with liquefied and dehydrated nitrogen..

After making sure that there is no leak, the installers of the split system release the gas, completely removing its residues by vacuumization. The next step is to enter the refrigerant into the created freon line. The compressor of the new split is filled with the necessary portion of freon of the proper brand at the factory, and if the length of the circuit does not exceed that specified in the technical documentation for the air conditioner, then it is not necessary to refuel it additionally, you just need to open the valves on the external unit. Otherwise, refueling is carried out – the required portion of freon is calculated using electronic scales and a charging cylinder. It is important that the volume of freon circulating in the air conditioning system is strictly calculated – its pressure in the circuit should not be lower or higher than the factory setting. With a longer line length, opening the valves on the street block, which allows you to combine the refrigeration circuit into one whole, is done only after refueling.

Important: during the installation of the split system, you cannot ignore the vacuumization stage, because otherwise, a high leakage of freon from the system cannot be avoided!

Please note that some installers of air conditioners declare that there is no need for this operation – they say, it will be enough to displace the air by supplying freon under pressure. However, the effectiveness of this method is based only on luck (maybe you will be lucky!), So I recommend that you immediately refuse the services of such “masters”.

At the end of the work, the power cable leading to the outlet is equipped with a plug – this is where the installation is over, the line for commissioning, i.e. checking the air conditioning system for operability.

Documentation of the split system installation

Upon completion of the installation work, the team of installers that performed them expects to receive a calculation and retire to a new facility – no matter how it is, before you or your more knowledgeable representative must fill in all the points of the table on commissioning, drawn up in two copies, indicating the names, addresses, contact phones and, if necessary, passport data. Be sure to make sure that the information entered in the table corresponds to the real situation, check each subparagraph. Please note that the simplest way to check the split installation – with the help of your palm, placed under the air flow coming from the split hair dryer and verbal conclusion “cools” or “warms” – is not suitable, because it is important to make sure that the split system will work for many years to come.

Split system commissioning sheet

In the “Results” column, confirm the checked parameter (indicated on the left) with a tick or a digit, if it is measurable. If the parameters differ from the data given in the column “What is checked”, the contractor must identify the cause of the discrepancy and correct it.

At the end

In addition to the described installation work, I recommend that you equip the external split unit with a protective visor – you never know what can fall on top of it. The next, final part of the article will be devoted to the operation and prevention of split systems.