Analysis and treatment of over-current causes of high and low temperature test chamber compressors <br>Excessive operation current in refrigeration system means that the operating current of the compressor is too large. Simply put, there are three reasons for the overcurrent of the compressor: Wenzhou Deli Machinery Equipment Co., Ltd. , https://www.sungoodtech.com
The condensing pressure of the refrigeration system is too high; there is too much refrigerant in the refrigeration system; the compressor lacks refrigeration oil;
First, the external heat dissipation is bad (1) The external machine is back and exhausted: if the external machine is installed in a closed balcony, in a narrow aisle, in a house where there is no ventilation, there is an obstruction in front of the tuyere. (2) The external air volume is small, and the heat dissipation speed is slow: if the external condenser is too dirty or blocked by dust and oil, the fan motor rotates slowly, the fan capacitance becomes small, and the temperature around the external machine is high.
Second, the external power supply voltage factor:
The power supply voltage is low or high, and both cases will cause the compressor operating current to be high, while the domestic voltage is low, especially during peak hours.
1. If the power supply voltage (ie, the voltage before starting) is too low, the user should re-wire. If the voltage is around 190V, consider adding a voltage regulator. If it is too low, it will be invalid.
2. Measure the pressure drop after starting. Under normal conditions, the pressure drop is only ten volts, and the pressure drop is too large (the recommended voltage drop is more than 20V and the voltage after the compressor is started is 190V). The power cord should be bolded or re-sold. Wiring, and eliminating faults such as poor line contact.
Third, the refrigeration system failure:
1. Air in the refrigeration system: If air is mixed into the system, the air tends to accumulate in the upper part of the condenser because it cannot pass through the accumulator. Whether there is air in the system can generally be determined by the jitter of the system pressure. If there is air in the system, it should be vacuumed and added with fluorine.
2. Too much fluorine: The compressor is overloaded for a long time, which will cause the compressor to over-current. In this case, part of the fluorine should be released to the standard range (the suction pressure is about 0.5 MPa at an ambient temperature of 35 ° C).
Fourth, the shell / internal temperature is high:
1. Poor lubrication of the compressor: the indoor and external machine height difference is more than 5 meters without returning the oil bend, or only the oil bend is made on one of the pipes, the system can not smoothly return the oil, and the compressor is in the process of running due to lack of lubrication. Slowly rise, and finally lead to overheating and jumping. For example, the outdoor unit is underneath, heating operation. Under such working conditions, the gaseous working fluid flows upward in the thick pipe, and the liquid working fluid flows downward in the thin pipe, so the oil return is poor. The outdoor unit is on the top, the heating is turned, the gaseous working medium flows downward in the thick tube, and the liquid working medium flows upward in the thin tube, so the oil return is better. In the case of cooling, the oil return bend has two types: U-shaped and S-shaped. The S-shaped can be added to the middle part of the connecting pipe. The U-shape is generally close to the machine, and the radius should be as small as possible.
2. Impurities in the system, too much water: The lubricant is degraded and carbonized, and the normal effect cannot be exerted, resulting in a sharp rise in the temperature of the compressor and overheating.
This kind of situation usually occurs on a repaired machine or a machine that has been used for a long time. If the substance in the inspection system is black, this situation must exist. At this time, the nitrogen cleaning system is applied, the compressor is replaced, the capillary assembly is re-evacuated. Add fluoride.
3. The air conditioner is often used in an environment below 0 degrees: when the compressor starts, the lubricating oil will foam, so that a large amount of lubricating oil will flow out of the compressor instantaneously. At this time, the system design is no good, and the oil is returned. The speed is much lower than the oil discharge speed, and the compressor lacks lubrication to cause temperature rise and overheat protection. In this case, an oil heater (40W---60W, 220V) should be installed on the compressor. When the compressor is stopped, the oil heater is continuously energized. The connection is to connect the oil heater to the contactor. On the normally closed switch, the fire and neutral wires of the power supply are connected.
5. The compressor cooling effect is not good. The system has too little fluorine. The temperature of the compressor is very high. The high temperature coil is cooled by the inhaled refrigerant. If the fluorine is too small, the system flow is small and cannot meet the evaporator 100%. The load causes the suction superheat to increase, and the compressor suction flow rate is small, and the cooling efficiency is greatly reduced, so that long-term operation can cause thermal protection of the compressor.