3. Indoor unit installation
①. Hanging code production and selection
Cut the material after determining the length of the boom according to the hoisting height of the indoor unit and the height of the floor.
②. Indoor unit installation
a. Use an infrared locator to determine the installation position of the indoor unit suspender, mark it, and drill holes with an electric drill.
b. The hoisting position of the indoor unit should ensure that the condensed water of the air conditioner can be discharged, and the air duct is easy to install and the air supply is smooth.
c. The fully threaded suspender must be used, and the indoor unit must be fixed with double nuts to ensure that the machine is hung firmly.
d. After the indoor unit is hoisted, the level must be adjusted.
e The throttling parts must be installed vertically upwards and horizontally. It is forbidden to tilt or invert, and pay attention to the connection direction when connecting.
f. The indoor unit is wrapped with a dust cover to prevent a large amount of dust from entering the inside of the machine and affecting the operation of the machine.
g. Ensure that there is enough space for installation and maintenance around the indoor unit, and the air flow of the return air is organized reasonably.
4. Refrigerant pipe construction
①. Bracket installation
The distance between the racks should not be too large, and the installed racks must be arranged neatly.
②. Refrigerant piping installation
a. Use a cutter to cut the copper tube of the corresponding specification length.
b. Clean up the burrs at the port and the copper pipe shavings in the pipe.
③. Refrigerant pipe protection
a. If the piping cannot be connected to the outdoor unit in time, it must be sealed to prevent the intrusion of dust and water.
b. When the piping passes through the wall, it is necessary to add a casing for sealing protection in time.
④. Branch pipe installation
a. The branch pipe cannot be replaced by a tee, it can only be installed horizontally or vertically.
b. The horizontal straight pipe section between the turning point of the copper pipe and the adjacent branch pipe is ≥1M.
c. The horizontal distance between two adjacent branch pipes is 1M. d. The distance between the branch pipe and the horizontal straight pipe section connected to the indoor unit is ≥0.5M.
⑤. Expansion tube connection
The connection of the copper pipe diameter refrigerant pipe must adopt the expansion method, and it is forbidden to use the flare connection method.
⑥. Expand the bell mouth
a. Expand the bell mouth with a flarer, the tube mouth should be flat and free of burrs, and the bell mouth should be free of deformation and cracks.
b. Nut connection must be operated with two adjustable wrenches.
⑦. Nitrogen-filled welding of refrigerant pipes
a. To ensure construction safety, the nitrogen cylinder needs to be connected to a pressure reducing valve, and the nitrogen pressure is controlled at 0.2-0.3KGF/CM² during welding.
b. Determine the nitrogen path, insert the nitrogen pipe into the inlet of the refrigerant pipe to be welded and seal it, open the valve of the nitrogen cylinder, adjust the flow of nitrogen through the pressure reducing valve, and finally perform welding.
⑧. Refrigerant pipe air tightness test
Connect the gas-liquid pipes together, lead out a pressure gauge, and seal and weld this interface. R22 uses 28KG/CM nitrogen to keep the pressure (R410A system uses 40KGF/CM²), pay attention to the pressure correction before and after the pressure test, there will be a pressure change of +0.1KGF/CM² for every +1°, the temperature during the pressure test and the confirmed temperature are the same Keep records.
⑨. Refrigerant pipe blowing
In principle, top-down or horizontal blowing is adopted, and the blowing pressure is 5KG/CM² to ensure that there are no impurities in the system. Use the following method to blow the pollution: a. Hold a suitable plugging material against the main nozzle of the gas side of the indoor unit; b. Use nitrogen to gradually pressurize the inside of the tube, and when the pressure increases beyond resistance, release the nozzle suddenly; c. Repeat steps a and b to repeat blowing.
⑩. Refrigerant pipeline insulation
a. Use a paper knife to cut the thermal insulation material with a larger gap, and glue the end face of the thermal insulation pipe.
b. Pull the two ports apart, insert the insulation material, and paste the joints with glue.
5. Condensate pipe installation
①. The condensate pipe should be installed with a slope of 1/100.
②. When setting the air vent, two elbows must be added to make the air vent face down, so as to prevent dust and other dirt from falling into the pipe and blocking the pipe.
③. The horizontal exhaust pipe must avoid hedging to avoid poor drainage.
④ For models with a lift pump, the height of the riser pipe cannot exceed the maximum value specified by the equipment, and no air vents can be installed in the lift section.
⑤. The support interval of horizontal pipes is generally 0.8~1.2m, which should not be too large, otherwise it will cause radial curvature and form air pockets.
⑥. For indoor units with high negative pressure at the drain outlet of the water storage pan, the drain pipe must be a water trap. After the installation is completed, the full water test must be done.
6. Pipeline system insulation installation
①.The insulation material of the refrigerant pipeline should use closed-cell foam insulation material, flame retardant B1 grade, and heat resistance exceeding 120 ℃. When the outer diameter of the copper pipe is D≤12.7MM, the thickness of the insulation layer is &=15MM or more; when the outer diameter of the copper pipe is D≥15.88MM, the thickness of the insulation layer is &=20MM or more.
②. The condensed water pipe should be insulated with flame-retardant B1 grade rubber and plastic insulation cylinder, and the thickness of the insulation layer is usually 10MM.
③. The pipe must be sleeved when passing through the wall.
7. Signal line installation
①. A special power supply line must be installed, and the allowable fluctuation range of the power supply voltage is ±10% of the rated voltage; the power supply capacity must be sufficient, the cable diameter meets the requirements, and there are corresponding circuit breaker protection devices; the grounding system must be reliable, such as the air conditioner external unit installed in Attention should be paid to lightning protection at the highest point of the building;
②. The signal wire must use three-core shielded wire, and the shielding layer of the signal wire must be connected to the sheet metal grounding of the electric control box.
8. Vacuum drying
Vacuum must be drawn from both sides of the vapor and liquid at the same time; the ultimate vacuum degree of the vacuum pump must reach -756MMHG or below, and its displacement must reach 4 liters/second or above; the vacuum pump used for the R410A system must be equipped with a check valve, or use a belt Vacuum pump with check valve.
9. Additional refrigerant
According to the actual size and length of the liquid pipe, use the formula to calculate the additional amount of refrigerant, and record the additional amount of refrigerant in the outdoor unit refrigerant additional table; it is absolutely impossible to estimate the amount of refrigerant by measuring the operating current and pressure.
10. Debugging
Confirm whether the number of indoor unit connections is consistent with the number displayed on the digital tube of the outdoor unit; start the operation, check whether the drainage is smooth, whether there is any fault in the electric control board of the indoor unit, whether the operating current of the unit and the temperature of the inlet and outlet air are within the allowable range.
Ten forbidden areas for multi-line engineering installation
1. It is forbidden to use different power supply for indoor units of the same system.
2. It is forbidden to use carbon tetrachloride to clean the pipeline.
3. It is forbidden to weld the pipeline without nitrogen protection.
4. It is forbidden to install the branch pipelines of indoor and outdoor units not horizontally.
5. It is forbidden to use "copper-aluminum connecting pipes" instead of copper pipes for air-conditioning system installation.
6. It is forbidden to heat the vapor-liquid two-phase pipeline together.
7. It is forbidden to install the external unit in a place where the wind is not smooth.
8. It is forbidden to install the multi-line in the computer room and other places.
9. It is forbidden to bundle control lines (communication lines) and power lines (strong electricity) together.
10. It is forbidden to choose cables that do not comply with the wire diameter requirements of the technical manual.
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