Each specialist in the repair of HVAC equipment uses various devices for his work, from ordinary wrenches to a vacuum pump for an air conditioner. This device is designed to remove air, excess gases and water vapor from a closed loop system. In refrigeration, a vacuum pump is used when filling with freon.
If you do not evacuate before starting the air conditioner, air will accumulate in the pipeline, which, in turn, will adversely affect the operation of the compressor.
Based on the reviews, the process of its interaction with freon can also be attributed to the negative consequences of air accumulation. As a result, a small amount of acid is released, which reduces the insulation resistance of the electric motor.
Based on the purpose, vacuum pumps for installing an air conditioner are divided into several types: low-, medium-, high- and ultra-high vacuum. According to the principle of action, pumps of physicochemical and mechanical action are distinguished.
Varieties of vacuum pumps
The following types of vacuum pumps are distinguished:
- Lamellar-rotor. Maximum productivity - 63 liters per second. The highest residual pressure is 0.5 Pa. 2 varieties of this unit are adapted for a network with a voltage of 220 V, 2 more - for 380 V.
- Water ring. This vacuum pump is designed to pump air from the air conditioner. For the operation of such a unit, a water supply is required. A liquid ring pump creates a relatively small vacuum, and is also common and affordable in the price category.
- Membrane It is used mainly in industrial enterprises. Provides a shallow vacuum. The disadvantage is the need for frequent replacement of valves and membranes.
- Spool and oil sealed pumps are used for industrial purposes.
Pump selection for evacuation
The selection of the pump depends on the type of equipment with which to perform operations. For example, a small home or office appliance is serviced by a vacuum pump for an air conditioner with a small capacity. For industrial coolers, a powerful and high-performance pump is used, respectively.
When choosing equipment, you should pay attention to the following criteria:
- Residual pressure. This indicator affects the quality of the process (the lower the coefficient, the better the process).
- Engine power. This parameter is important when working with industrial plants.
- Performance. This parameter displays the rate of air outlet from the system (number of liters per unit time).
The device of the vacuum device for air conditioners
The vacuum pump for pumping air from the air conditioner can be one- or two-stage, depending on the type of air conditioner.
The most common is the device for use at home in the BBH series. It consists of:
- Engine.
- Mechanism for compressing gas (liquid ring).
- Drive (paddle wheel, which drives the ring).
- Housings.
- Branch pipes: for absorption and forcing.
Cast iron body consists of three cavities: for suction, discharge and working. Water is supplied through an opening in the lid.
The principle of the pump is as follows: vacuum is created by vacuum, due to this, water boils at low temperatures. Due to the fact that the boiling point of water decreases to the ambient air temperature, the process of liquid evaporation in the pipeline takes place. By evaporation, water is discharged from the system along with residual air.
Procedure for servicing cooling systems
Failure to follow the maintenance procedures for any equipment may result in personal injury or damage to the unit.
Therefore, each specialist must:
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Before starting operations, you should find out when the refueling was carried out.
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It should also be clarified with what capacity the chiller works. It may be necessary to remove air with a vacuum pump for the air conditioner before refueling.
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Connect pressure gauges, and trace the change in the system.
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Inspect pipelines for oil stains.
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After conducting an inspection and taking readings from the instruments, decide on one of the possible operations: refuel, refuel, diagnose or refuel with diagnostics.
System Air Removal Sequence
- First, a manifold with a vacuum gauge should be connected to the filling pipe.
- Then, a vacuum pump for the air conditioner is connected to the manifold, provided that the vacuum gauge indicates normal atmospheric pressure.
- The process of pumping air continues until the pressure is equal to 0.
- At the end of the process, the pump is not disconnected from the device for several hours.
- When the pressure approaches the mark of 1, you should leave the system for an hour without taking any action.
If the hand is in the “0” position for 20 minutes, the air is pumped out efficiently. In the case when the arrow rises, but does not approach 1, a reconnection of the pump is required.
Filling the cooling system without special appliances
There are cases when it is possible to install the air conditioner with your own hands without a vacuum pump. The new air conditioner contains about 50 grams more than the required amount of freon. Therefore, the first start-up of the cooling system can be made without activating the pump. To remove air, open the valve, which is placed on the fluid pipe (for no more than 10 seconds).
After this operation, it is necessary to check the tightness of the bolted connections and unscrew the valve again by opening the service port. To open the port, press its rod with a key. Further, service ports are closed, and air is removed from the gas pipe valve. Plugs are installed on the valves.
Homemade Air Removal Device
Due to the cost of the unit, many users have a question: how to replace a vacuum pump for vacuuming an air conditioner. Without additional investment, you can assemble a primitive vacuum model from improvised materials.
For this you will need: a cuffed automobile pump and a compressor for the aquarium. The assembly order is as follows:
- First, disassemble the car pump.
- Then the cuff through which air is pumped is turned through 180 °. This action will allow pumping gas in the opposite direction.
- At the end, a check valve should be installed (a plastic part from an aquarium compressor is installed as it). It is installed between the car pump and the hose.
