At present, our common water source heat pump, ground source heat pump and some air source heat pump central air conditioning host are using screw compressors, then in the use of these equipment, what are the common failures of screw compressors? Next central air conditioning maintenance editor often to share with you, let's have a look!

First, the compressor suddenly stops during operation

1. The reasons for the sudden shutdown of the compressor during operation are

(1) The suction pressure is too low, lower than the low pressure lower limit of the pressure relay;

(2) The exhaust pressure is too high, causing the high-voltage relay to operate and power off;

(3) Oil pressure is too low, oil pressure relay action relay;

(4) motor overload, thermal relay action relay;

2. The elimination method of sudden stop of compressor in operation

(1) Check the reasons, belong to the pipeline blockage to unblock the pipeline, such as the system refrigerant is insufficient to supplement;

(2) Check the cooling capacity of the condenser or cooling air volume;

(3) Check the pipelines and oil pumps of the oil transmission system;

(4) Check whether the power supply voltage is low or the cooling load is too large;

Second, the exhaust compression is too high

1. The causes of excessive exhaust compression are

(1) The cooling water of the water-cooled condenser is insufficient or the cooling air of the air-cooled condenser is insufficient;

(2) The scale on the surface of the condenser tube cluster is too thick or the oil is too thick, causing heat dissipation difficulties;

(3) There is air in the refrigeration system;

(4) Excessive refrigerant injection;

(5) The valve in the exhaust pipe fails, resulting in too high pressure;

2. Exclusion method of excessive exhaust compression

(1) Check whether the valve is fully open, increase the water supply or check whether the motor voltage, speed, and transmission belt are too loose;

(2) Clean the scale, scrub the oil, so that the surface of the condenser tube cluster is clean;

(3) Let off the air;

(4) Discharge excess refrigerant;

(5) Check and correct the valve;

Three, the wet stroke of the compressor

1. The reasons for the wet stroke of the compressor are as follows

(1) Thermal expansion valve failure, open too large;

(2) The solenoid valve fails, and a large amount of refrigerant enters the evaporation tube after shutdown, and enters the compressor when starting up again;

(3) Excessive perfusion refrigeration dose of the system;

(4) The thermal expansion valve temperature sensing bag is loose and not tied, resulting in an increase in the opening degree of the thermal expansion valve;

2. The method of eliminating the wet stroke of the compressor

(1) Close the liquid supply valve and overhaul the thermal expansion valve;

(2) Repair the solenoid valve;

(3) Release excess refrigerant;

(4) Check the bundling of the temperature sensing bag;

Four, the compressor is stuck

1. The compressor is stuck for the following reasons

(1) There are dirty impurities in lubricating oil;

(2) The oil pump pipeline is blocked, so that the cylinder is short of oil piston stuck;

(3) The handle pin in the main gear of the oil pump inserted into the crank is twisted off, causing the oil system to cut off oil;

2. Troubleshooting method of compressor stuck

(1) Replace the new lubricating oil;

(2) Repair oil pump pipeline;

(3) Repair and replace the main gear shaft of the oil pump;

Five, there is noise in the cylinder

1. The reasons for the noise in the cylinder are as follows

(1) the dead center clearance in the cylinder is too small;

(2) The bushing gap between the piston pin and the connecting rod size is too large;

(3) The valve plate is broken;

(4) The oil percussion sound caused by the oil splashing of the crankshaft crank or connecting rod head;

2. There are different sound processing methods in the cylinder

(1) Adjust the thickened cylinder gasket;

(2) Replace the piston pin or bushing;

(3) Stop immediately to replace the valve disc;

(4) No need to stop for a short time, such as stopping for inspection after a few minutes;

Six, crankcase sound

1. The crankcase sounds for the following reasons

(1) Connecting rod nut is loose;

(2) connecting rod big head bearing bush clearance is too large;

2. Sound elimination method in crankcase

(1) Stop and re-tighten;

(2) Replace the tile;

Seven, the compressor can not start up

1. The compressor can not start for the following reasons

(1) Power failure fuse contact is poor, burnt;

(2) The vertical contact point of the starter is in poor contact;

(3) The temperature controller is out of whack or faulty;

(4) The setting discomfort of the pressure relay;

2. The elimination method that the compressor can not start up

(1) Check the power supply and fuse;

(2) Check the starter and wipe the contact with gauze;

(3) Check the temperature indicating position and check the components;

(4) Check the pressure relay components or setting values;

Eight, the compressor refrigeration capacity is insufficient

1. The reasons for the insufficient refrigeration capacity of the compressor are

(1) piston ring wear or piston and cylinder clearance due to wear is too large;

2. The elimination method of insufficient refrigeration capacity of compressor

(1) Replace the new piston ring or repair the new parts;

Nine, compressor and motor coupling noise

1. Compressor and motor coupling noise causes are

(1) improper combination of compressor and motor coupling;

(2) The key and keyway of the coupling are not properly matched;

(3) The elastic ring of the coupling is loose or damaged;

(4) the belt is too loose;

(5) The inner hole of the coupling is loose with the shaft;

2. Compressor and motor coupling noise elimination method

(1) Reassemble according to the correct assembly requirements;

(2) Adjust the coordination between the key and the keyway, and replace the new key;

(3) Tighten elastic rings or replace new parts;

(4) Adjust and tighten the belt;

(5) Adjust the coupling.

The above content is a small series to share with you about the common faults and maintenance methods in the maintenance of central air conditioning screw compressor, if you encounter the same problem, it is recommended that you still ask Kunshan central air conditioning maintenance professional maintenance personnel to repair, to avoid more trouble because of our improper operation. If you have this need, you can contact our customer service in time.