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Replacing a Filter Dryer (Welding)
Prerequisites
- A filter dryer needs to be replaced.
- A spare welded filter dryer of the same model is available and functional.
- Tools: welding equipment, refrigerant reclaiming device (configured based on local conditions), Phillips insulated torque screwdriver, nitrogen cylinder, refrigerant tank, vacuum pump, pressure gauge, rubber hose, protective gloves
- Preparation: Power off the indoor unit and reclaim the refrigerant in the system.
Context
- Reclaim or dispose of the refrigerant in accordance with local laws and regulations. During the reclaim process, the R410A refrigerant composition may change. Therefore, you are not advised to refill the reclaimed R410A refrigerant to the cooling system.
Figure 11-27 shows the position of the filter dryer.
Procedure
- Tap Shutdown on the home screen of the display module. Turn off the active power switch QF1, standby power switch QF2 (you do not need to turn off QF2 for the model with a single power supply), and drive switch QF3.
Exercise caution because the device is still energized after it is shut down on the home screen of the display module.
- Reclaim the refrigerant and ensure that the system has no pressure.
If a refrigerant reclaiming pump is used, the requirements for using the pump must be met.
- Connect the refrigerant reclaiming pump to the outdoor unit needle valve and (if a low temperature component is deployed) the needle valve at the outdoor unit liquid pipe port of the low temperature component. When the pressure decreases to the atmospheric pressure and becomes stable, shut down the refrigerant reclaiming pump.
- Connect the refrigerant reclaiming pump to the low-pressure needle valve of the indoor unit. When the pressure decreases to the atmospheric pressure and becomes stable, shut down the refrigerant reclaiming pump. Ensure that there is no pressure in the system and the refrigerant is completely reclaimed.
- Remove the filter dryer, as shown in Figure 11-28.
- During welding, use a silver copper welding rod containing 5% silver. Check that the welding joints are in good condition, without poor welding.
- To avoid burning the internal components, other pipes, thermal insulation foam, power cables, and labels, take protective measures, such as spreading wet cloth, around the welding joints.
- Do not use face-down bonding when welding.
- Remove the hold hoop (3 in Figure 11-27) from the filter dryer using a Phillips insulated torque screwdriver.
- Weld off the entrance below the filter dryer, as shown by (4) welding point B in Figure 11-27.
- Weld off the filter dryer assembly from the top of the filter dryer, as shown by (1) welding point A in Figure 11-27, and remove the filter dryer.
- Weld off the lower part of the removed filter dryer assembly.
- Install a new filter dryer, as shown in Figure 11-29.
- Weld the entrance elbow and the new filter dryer to form an assembly, and then weld the assembly to the original position. Note that the arrow direction on the filter dryer identifies the flow direction of the refrigerant.
- Do not use face-down bonding when welding.
- Remove the rubber plug from the port of the filter dryer.
- Weld the removed straight pipe (step 4 in Figure 11-28) to the new filter dryer to form a new filter dryer assembly. Install the filter dryer in the smart cooling product.
- Reinstall the hold hoop.
- Perform a leakage test with nitrogen again. Refer to 3.11 Leakage Test with Nitrogen for Refrigerant Pipes.
- After checking that the smart cooling product does not leak, vacuumize the smart cooling product, and charge refrigerant. Refer to 4.1 Vacuumizing and Precharging Refrigerant.
- Power on the device and tap Start on the home screen. Ensure that the smart cooling product is running normally without any alarms.
