Central air conditioning equipment and systems are more expensive asset value, how to effectively play the role of air conditioning, it efficient, safe and economical operation, it is necessary for routine maintenance; regular central air conditioning maintenance can be discharged hidden faults reduce accidents, reduce operating costs, extend equipment life, while working to protect the normal timing. 1, air conditioning and refrigeration systems: ①, the system running for some time due to vibration of the compressor can cause cracking or weld pipe joints loose, resulting in leakage of refrigerant and refrigeration oil leak can cause a slight cooling effect is reduced, low pressure alarm. Serious when the compressor will not properly cooling and lubrication. Finally cause the compressor overheating, burn injury. ②, air conditioning compressor, after the initial running-in period of operation, due to mutual wear between the mechanical moving parts, the lubricant will be deposited under wear impurities, so that the lubricating effect of the lubricant oil decreases, the long-term use of the moving parts will exacerbate The wear and tear or injury, until the compressor burned. 2 ,, electrical system: ①, after a long-running air conditioning, due to the wires, components and other factors can cause fever joints loose, fall off, resulting in poor contact, phase; ②, AC contactor, thermal relay will appear poor contact, open circuit fault; if not exclude the above failures will cause the compressor phase or three-phase current imbalance was burned; failure ③, flow switch, low pressure switch, safety valve and other protective devices caused the accident. 3, air-conditioning ventilation system: ①, the system running for some time after the wind will accumulate dust filter online, increasing air resistance, thus causing air flow is reduced or blocked; reduce the amount of wind can cause the fan coil ineffective, blocked after no effect, affecting normal use. In particular, wind machines, variable air volume, combined air conditioner very easily lead to serious consequences motor burned; ②, fan coil due to the early effect filters can not filter down to the fine dust, therefore, after passing through the filter dust to accumulate in the fan fin surface heat exchanger coil, due to the fin heat transfer equipment only 2-3mm, therefore after a long accumulation can cause blockage, resulting effect is reduced, at the same time due to heat caused by the accumulation of dust fall can cause severe The above phenomenon. 4, air-conditioning water system: ①, cooling water system due to the open systems, cooling water through the cooling tower is sufficient contact with the air, being cooled at the same time a large amount of dust and other impurities in the air is introduced into the water system, deposited on the cooling towers, air conditioning units and plumbing in the formation of sludge, reducing the cycle of water, the impact of heat exchange. ②, the system put into use, due to the installation of residual slag in the system, iron, dirt, oil and other impurities will accumulate in the system; welding slag, iron and other hard materials will adhere to the surface of heat transfer equipment, affect heat transfer. ③, cooling water and air due to contact with the cooling tower and the pipeline will breed algae, bacteria and other microorganisms, their bodies after death and mud, oil and other debris adhered together, attached to the equipment and piping, affecting circulation water and heat, while the micro-organisms and sediment production, prompting the formation of concentration cell corrosion and corrosion under the scale of production, so that the corrosion rate of the metal increased. Chilled water systems are also often used because of the water by changing the water tank water, can also occur. ④, the higher the temperature of the cooling water system, and are using tap water to form carbonate scale back its Ca2 +, Me2 + ions heated, attached to the equipment and piping hot, because the thermal conductivity of the scale of 0.464 ~ 0.697W / MK, steel thermal coefficient of 46.4 ~ 52.2W / MK, only 1% of carbon steel, to reduce heat transfer equipment the heat transfer effect, causing an increase in running costs. Air conditioning effect, frequent alarms, electricity increases; it will cause severe clogging pipes and heat transfer equipment, equipment parts are corrosion perforation, causing damage to the unit components, shortening the life of equipment, attracted a great loss for the user. Therefore, regular water testing and chemical cleaning maintenance is necessary.