How to see if the compressor is variable frequency

To determine whether the compressor is variable frequency, you can observe and judge from the following aspects:

1. Check the product logo

1. Packaging box or product:

   • Inverter air conditioners usually clearly mark the words “inverter”, “Inverter” or “DC” on the packaging box or product.

2. Name plate information:

   • The nameplate of the compressor or air conditioner is usually marked with model, parameters and other information. The nameplate of the inverter air conditioner will be marked with the words “inverter” or “Inverter”, or the letters such as “BP” will be added to the model.
   • If the whole machine model has brackets, the first capital letter after brackets is “F”, which also means that the compressor is a variable frequency compressor.

2. Observe the appearance and structure of the compressor or air conditioner

1. Electronic control motherboard and start-up capacitor:

   • The outdoor unit where the frequency converter is located is usually equipped with an electronic control motherboard, which is used to control the frequency converter operation of the compressor. The outdoor unit where the fixed frequency compressor is located does not have an electronic control motherboard, but uses a starting capacitor to start the compressor.
   • So, if there is an electronic control motherboard on the outdoor unit, the compressor is likely to be frequency converter; if there is no electronic control motherboard but a starter capacitor, the compressor is frequency-fixed.

2. With terminals:

   • The coil of the variable frequency compressor is usually powered by three items, with three built-in windings, and the wire diameters and turns of the three windings are the same, so the resistance values ​​of the three windings are equal.
   • There are usually only two windings inside a fixed frequency compressor. Use multimeter resistor to measure the resistance value of the terminal. If three different results are obtained, and one of the maximum resistance values ​​is the sum of the resistance values ​​of the running winding plus the starting winding, the compressor is fixed frequency.

3. Check the product manual or technical parameters

1. Product manual:

   • The product manual of the air conditioner will introduce the technical parameters, usage methods and maintenance suggestions in detail. The instructions for inverter air conditioners will clearly mention the words “inverter” or “Inverter”, as well as the frequency conversion operation principle and characteristics of the compressor.

2. Technical parameters:

   • The technical parameters of variable frequency air conditioners will clearly indicate the type of compressor and the operating frequency range. Common types of variable frequency air conditioning compressors include DC variable frequency compressors and AC variable frequency compressors, and the operating frequency range is usually between 30 and 130 Hz.

4. Performance in actual operation

1. NoiseLevel:

   • Inverter compressors are usually relatively stable during operation and have relatively low noise. The fixed frequency compressor may produce more noise when starting and stopping.

2. Voltage change:

   • When the variable frequency air conditioner is running, the voltage will fluctuate significantly due to the variable frequency operation of the compressor. The voltage variation of fixed frequency air conditioners is small.

3. Temperature control:

   • Inverter air conditioners can automatically adjust the operating speed of the compressor according to changes in indoor temperature, so the indoor temperature changes are smaller and the comfort is higher. Fixed frequency air conditioners will frequently turn on and off during cooling or heating, resulting in large fluctuations in indoor temperature.

5. Summary

The most intuitive way to determine whether the compressor is variable frequency is to view the product logo and nameplate information. If this information is unclear or cannot be obtained, comprehensive judgment can be made by observing the appearance and structure of the compressor or air conditioner, consulting the product manual or technical parameters, and performing in actual operation. When purchasing or repairing an air conditioner, understanding the type of compressor is of great significance to selecting the right air conditioner product or performing repairs.