How to avoid chiller compressor coil burnout

Update:05 Jul 2019
Summary:

 How to avoid the burning of the compressor coil of the […]

 How to avoid the burning of the compressor coil of the chiller? Xiaobian below will analyze the main causes of the burning failure of this type of refrigeration compressor motor:

1. The power supply voltage is too low: When the power supply voltage is too low, the operation starts. At this time, the current flowing through the motor is very large, causing the thermal relay to frequently open and close, eventually causing the contact to melt and stick, causing the thermal relay to fail. When the motor is under the action of large current, the winding lashing wire is blown, and the outer insulating layer of the electromagnetic wire is burned, so that some windings are short-circuited, causing abnormal resistance of the winding. If the power supply voltage is too low, the power supply capacity is insufficient, and other high-powered electrical appliances on the power supply line, and the power line diameter selection is too thin or faulty, the refrigeration compressor may be faulty.

 2, motor power control loop failure: power switch, contactor is an important part of the compressor motor control loop, unreasonable selection and lack of maintenance can destroy the best refrigeration compressor, the correct selection of switches and contactors according to the load is extremely important.

3, three-phase current imbalance caused by motor failure: voltage is abnormal and lack of phase can easily destroy the motor. The imbalance of the three-phase voltage must not exceed 5%. The three-phase voltage imbalance can cause the three-phase current imbalance of the motor. One phase (or two phases) of the current is too large, so that the winding first generates heat and breaks down or blows. Other windings also sharply rise and burn the current. When the motor is running, the average value of the current value and the three-phase current of either phase must not exceed 10%. As a result of the voltage imbalance, an unbalanced voltage percentage in normal operation can cause a 4-10 times current imbalance of its percentage point.

4. The problem of the motor itself: The national standard has corresponding regulations and requirements for the manufacture of the motor, but the level of technical strength, testing instruments, production equipment, especially quality awareness of various production enterprises are mixed, especially those that do not. Products from small workshops with professional capabilities are difficult to avoid the inherent hidden dangers of the motor itself. It is not difficult to avoid this problem, because such products can often find some problems by visual inspection and general detection means (measured by megohmmeter).

5. Bad oil return in the refrigeration system: Due to poor oil return in the refrigeration system, the compressor will be short of oil and will not be able to deliver enough refrigeration oil to each lubrication part, so that the friction of each lubrication part (sleeve, piston) will be intensified in a short time. The piston and the crankshaft are stuck, causing the compressor motor current to rise sharply and burning the motor coil.