Basic checks on seasonal maintenance service of the air-conditioner

In this chapter all the necessary information on maintenance service which is necessary to perform during a season of use for maintenance of the system of air-conditioning in a serviceable condition is given.

Attention: Before beginning of the works connected with the system of air-conditioning, it is necessary to familiarize with the safety precautions described in the first chapter of the second part of this book.

Productivity of the refrigerating system of the air-conditioner is much influenced by the requirements of maintenance service of seasonal and non-seasonal use.

Checking of the engine refrigerating system

Checking is made with once a year with the help of cleaner or radiator. They clean the refrigerating system and delete a scum. At serious pollution they make major overhaul.

They check the radiator fuse. When the fuse poorly operates at increase of pressure, cooling liquid begins to boil, especially they check if the valve is slightly opened due to the fact that between the air valve and rubber the dust has got.

They clean edges of a radiator, thus improving air ventilation.

Checking of the fan

Since at penetration of external air loading grows and the refrigerating system effectiveness is reduced, they check a degree of achievement of air-ventilator and an entrance aperture of external air (HEATER) and make sure, whether external air penetrates.

Checking of the heater’s water valve

Sensors and cable connected to the water valve are checked. They check and ascertain at the warm air appearance, because due to malfunction of sensor or cable, the heat regulator’s flap will not work, and as a result of this, effectiveness of the refrigerating systems will decrease.

Check of functional parts of the conditioner

Fastening.

They check a condition of fastening of each functional part (loosing, crack, damage, loss). In case of presence of cracks, damages, losses they are replaced with new details, at loosing – they are twist on the ordered moment.

Pipelines.

During non-seasonal use they check outflow of gas because of loosing connections, cracks of pipelines. At outflow of gas after correction and repair they fill the refrigerant up to necessary amount.

Attention: in case of full absence of the refrigerant in a contour because of outflow of gas, assuming, that inside there is a moisture, dust, sediment, they are deleted by the coolant. Then they replace a drier, pump out air from a contour and after full drying fill in a contour with the refrigerant.

Connections of pipes are screwed up after careful check of the processed part and wetting by pure compressor oil of a basic surface. It is necessary to carry out check carefully as over 90 % of the reasons of malfunctions of outflow of a gas - refrigerant arise in connecting parts.

The factor of deformation should be lower than 30%

At factor of deformation over 30 % the handicap of current of gas of refrigeration and because the site of deformation begins to play a role of a throttle, thus the surface of the pipeline freezes and the effect of cooling decreases.

В:А > 0.7

Wedge belt

The following 3 kinds of wedge belts are used. Belts 1 and 2 are belts used in radiators of cars, and 3 – buses.

After check of deterioration at extension of driven belts of the compressor and the fan of the refrigerating system, in case of their malfunctions, poor quality they are put in order or replaced.

Magnetic muff and a pulley of idling

They check whether there are extraneous noise or jingle because of the big backlash in bearings of a pulley of idling of magnetic muff. At malfunctions they are replaced.

1 – idler 2 – pulley 3 – ball bearing 4 – rotor 5 – nave 6 – tightening ring 7 – lock ring

Basic items which are necessary to take into account at maintenance service

To support safety of installation

Effective work of the refrigerating system is in correlation dependence on pressure of a pure refrigerant. During presence of a pure refrigerant in installation (including the specified amount of the compressor oil mixed with the refrigerant) it is necessary to take into account chemical stability.

If in installation foreign substances such as dust, air or moisture hit, they will change correlation dependence of pressure and refrigerant temperature. Therefore, this installation can not work any more at suitable values of pressure and temperatures, and its efficiency will decrease.

To support chemical safety

For maintenance of chemical safety in installation of conditioning it is necessary to observe the following requirements:

• If necessary to detach the parts of connections with the refrigerant, these places are always cleaned of dust and oil and do not let dust in a contour.
• That in both parts of connections foreign substances have not got, immediately it is necessary to close a cap or a fuse. Any air contains a moisture, therefore it is bad, when it gets into installation.
• Tools are cleaned and contained in dry. The structure of tools should include the complete set of measuring devices and spare parts.
• Vessel and tube for addition of oil should be clean and dry.
• If necessary to open the installation, it is necessary to prepare everything for fast end of work.
• When the system was open or installation is repeatedly closed, this installation is necessary to be completely emptied.

Attention: If in a contour of system of air-conditioning, the small amount of moisture will get, it will freeze to expansion valve and will prevent the flow or will close a way to the refrigerant, and becomes the reason of occurrence of rusts.

Connection with moisture in the system of air-conditioning

It is connected with the fact that if in freon-gas (CCl₂F₂) moisture (Н₂О) will get, the hydrochloric acid (HCl), which subjects to corrosion alloys of aluminium and copper, turns out. Therefore in rainy weather at the big humidity it is necessary to perform maintenance service of the conditioner, especially it is necessary to avoid work on filling by the refrigerant.