Why is the inverter heating effect so poor?

A user in a certain area installed a frequency converter, and the user reported that the heating effect was poor. After eliminating the reasons related to usage: such as confirming that the mode, auxiliary heating, temperature and other usage methods are correct, it is necessary to conduct on-site inspection. What is going on? Let's take a look!

2. Case Analysis

1. On-site inspection: the ventilation and heat dissipation of the outdoor unit are very good. The room area is 13 square meters, the indoor temperature is 16°C, the room temperature rises to 20°C after the machine runs for 1 hour, the outlet temperature is detected to be 30°C, the system operating pressure is 2Mpa, the compressor current is 1.5A, and the opening degree of the electronic expansion valve is detected by the frequency conversion detector, which is 150 steps. The data is abnormal.

2. Based on the above data, the air outlet temperature is low, the heating operating pressure is low, the operating current is low, the opening of the electronic expansion valve is small, and the estimated exhaust temperature is not very high. After re-evacuating the refrigerant, adding liquid quantitatively, and adjusting the position of the electronic expansion valve coil, the heating effect is still poor.

3. The system is not short of refrigerant and has unlimited frequency reduction protection. Is it because of cross-flow of the four-way valve or the compressor has no suction or exhaust? Detect no suction or exhaust and finally determine that the compressor is faulty.

3. Case handling

After replacing the compressor and vacuuming and adding refrigerant, the outlet temperature was detected to be 58°C, the compressor working current was 7A, the system operating pressure was 33Mpa, and the heating effect was significantly improved.