What details do you need to pay attention to in refrigerator maintenance

A. Start with the test machine, the machine that can start and run normally is recommended for more than 1 hour, stop after operation, and open the process tube (also known as fluorinated tube) for a short time may not have refrigerant spray, especially the machine with 600a refrigerant, why? The refrigerant is being compressed under high pressure (condenser. Slowly evaporates to the low-pressure evaporator, so the shutdown of high and low pressure requires a certain amount of neutralizing pressure time, and the pipe cutting maintenance is generally carried out in the shutdown for more than 5 minutes to facilitate the preliminary determination of the amount of refrigerant in the machine.

B. Of course, all kinds of clogged machines occur, such as plugging dirty, and the downtime is longer, the refrigerant is not discharged or even aspirated into the cutting process pipe, and the high-pressure pipe must be cut before the refrigerant is sprayed out.

C. The formation of ice block is generally from the refrigerant, which is brought into the pressure, inhaled after leakage, the water contained in the compressor oil and the gas-liquid separation bottle is not excluded, and the system is exposed for too long, the refrigerant is not completely leaked after the test machine wet air pressure immediately, the evacuation is poor, the filter is not good, etc., and the control of ice block should treat the symptoms and add methanol is not advocated.

D. Capillaries generally advocate the original machine, so that the aperture and length can be maintained. Throttle, some of the capillaries purchased now are very poor, and they are broken with a few plays, but it is a little unrealistic to dig the original tube on the outside, and the length and diameter of the newly laid evaporator tube are changed, so the length and aperture of the capillary can not be completely compared to the original machine, the capillary is too long, the high pressure pressure is too high, and the low pressure is too low. If the reference pressure gauge pointer maintenance counterparts will continue to add refrigerant, shut down and then open the compressor is bound to protect, on the contrary, the same throttle is not allowed to cause poor refrigeration effect

E. This section often found that the effect can not be reached after the peer tube, the tube must reach the effective length in the box, the tube does not advocate 6 large thin copper tube laying evaporator, although the cost of the thin copper tube is relatively low and good to lay, but the performance has changed a lot, so why not do so, the tube must require the pipe close to the inner liner, so the pressure is obvious, Only effective endothermic refrigeration; The refrigerator evaporator pipe should be avoided or have a certain interval with the water, otherwise the water pipe is easy to freeze and block.

F. Just in contact with refrigeration product maintenance, it is recommended to use nitrogen when pressing and flushing pipes at pressure. Speed, performance, and effect of air can not be compared, used will know, of course, after experience can not use, there is no nitrogen humid weather heavy can be replaced with R22 high pressure refrigeration gas.

G. Evacuation at the same time can take heating compressor (oxygen welding), the inner box (hair dryer or light bulb) method, be sure to ensure that there is no air leakage between the evacuated pipe, the evacuation caused by air leakage will not appear bad.

H. Every time a new pipeline is laid and the joint is welded, the old pipeline installation and even burning red washing should be washed through high pressure gas, especially the filter before and after the welding head should be washed once to prevent dirty plugging (half plugging), and the filter does not need to burn red water before installation, which often causes too much oxide. Try not to deflate the bend of the pipe, so as not to produce secondary throttling, low pressure is abnormal, resulting in misjudgment;

I. Before welding the pipe, each contact of the small pipe should be extended into the large pipe about 1 cm, too short it is easy to weld (half blocked).

J. Refrigerant can also be added to select a quantitative bottle, measure the current, look back at the gas pipe condensation, etc.; The refrigerant is insufficient, the test time is very long and it is difficult to shut down (3 hours) under the normal condition of the thermostat, and the frost plate of the evaporator in the cold room of the test machine is not enough; Refrigerant leakage, open for a long time will cause the cold room or cold room to form transparent hard ice, serious no effect at all, the refrigerant is added too much, and the general chance to appear back pipe hanging frost (white frost); If the refrigerant is added too much, the refrigerant can not fully evaporate, which will also lead to insufficient cold capacity in the box; Less refrigerant can be directly added, more refrigerant according to the pressure gauge is positive pressure or negative pressure, positive pressure can be directly discharged for a few seconds, and then open for 10 minutes to see whether the gas pipe is dissolved frost, if it is negative pressure can be stopped to be discharged after positive pressure, but this delays the time, direct non-stop vacuum pump can be pumped for a few seconds, which is also good.

K. Sealing is generally used to boot, due to the low startup pressure close to atmospheric pressure, in the welding process due to the sealing clamp is not sealed so that the refrigerant spray welding is not strong.

L. Test machine time usually summer strong cold (set to the maximum) 3 hours without frozen products, back to the minimum (1), if shut down, and the return pipe cold dew is normal, 1.5 hours in winter, summer to shorten the test machine time can be used to blow fans or open air conditioning to reduce the test machine time.

M. Determine the material of the evaporator can be detected with a strong magnet liner.

N. Look for capillary outlets that can be fluoridated to see where to cool first.

O. Determine the exhaust performance of the compressor usually welded high and low pressure pipeline, power is blocked with your finger high pressure for a few seconds, can not be blocked as well.

P. Another way to determine the exhaust performance of the compressor is to install a 2.5 pressure gauge on the high pressure exhaust. If the pressure gauge can not rise to more than 2.5 or rise to 2.5 after stopping, the pointer immediately rebounds in the direction of 0.

Q. There is a type of refrigerator failure, in the compressor is not dumped and has not added oil, the engine oil intermittently from the high pressure, this time to consider the compressor problem.

R. Some compressors are found to be unable to start, the coil measurement is normal, and there may be unexpected gains in forcing a few compressors on the spot. This method is very effective for the compressor cylinder caused by low voltage; It is also a traditional method to connect a large capacitor to the starter.

S. There is a type of compressor can not start, if it is PTC, to consider whether the PTC resistance value increased.

T. The compressor starter can occasionally be used as a flexible substitute, such as heavy weight and PTC, of course, this is only a temporary substitute, 600a compressor is not allowed to install heavy weight starter.

U. When the conventional compressor starter is broken, the temporary test machine can insert the wire plug of the starter into the running pile head, and then use the driver to short connect the two points below the compressor (running and starting pile head) and release the driver, but not for a long time, because the temperature control will be stopped, and the compressor will not be easily damaged next time.

V. Old refrigerator door seal tube (also known as dew pipe) is easily perforated to leak refrigerant, maintenance is often get rid of not use, then the result of repair is that some machine door need to be very laborious.

W. Pipe out of the box part to use casing, otherwise easy to corrosion perforation.

X. The size of the replacement condenser is generally the size of the back of the original refrigerator.

Y. The high pressure and low pressure pipes connected to the compressor must be left room, a certain brand of a batch of freezer due to the low pressure pipe connected to the compressor is kept very straight, resulting in the vibration generated when the compressor is shut down, resulting in a number of compressor low pressure pipes are broken.

Z. Replace the clamp nut fixed in the pipeline as far as possible to use rust.