Water Cooler: Parts and Working | Appliances | Electrical Engineering

In this article we will discuss about:- 1. Parts of a Water Cooler 2. Working Principle of the Water Cooler 3. Electrical Circuit.

Parts of a Water Cooler:

The various parts of a water cooler are:

1. Compressor

2. Motor

3. Receiver

4. Condenser

5. Expansion valve

6. Evaporator coils surrounding the water tank

7. Water tank

8. Cover

9, 10. Pressure gauges

11. Insulator (glass wool etc.)

12. Feeler bulb.  

Working Principle of the Water Cooler:

The working principle of the water cooler is based upon the vapour compression refrigeration cycle. The refrigerant is compressed by the compressor and is delivered to the condenser which is cooled by a fan. The high pressure liquid after being cooled by a condenser is collected in a receiver from where it goes to the expansion valve. The expansion valve takes the required quantity of the refrigerant depending upon the load on the evaporator.

As the refrigerant passed through the expansion valve, its temperature falls down considerably (up to – 10°C). Its pressure also falls down. Then this liquid refrigerant passes through the evaporator coils, which surround the water tank (water may be stored in it). The liquid refrigerant in the coils absorbs its latent heat from the water, leaving it cooled.

The liquid refrigerant as it flows through the evaporator coils is converted into vapour and by the time it leaves the coils, it is almost converted into dry vapour. This vapour is again compressed through the compressor. This way this cycle is repeated again and again. The cooled water may be drained out and the fresh water may be added to the tank for cooling.

Electrical Circuit in Water Cooler:

In water cooler, two single phase induction motors are used. One is fan motor and other is compressor motor. The fan motor is a capacitor start motor but its capacitor (C_F) remains in the circuit during running also.

The function of fan motor is to cool the condenser by forced circulation by a fan. The compressor circulated by a fan. The compressor motor is a capacitor start, capacitor run motor. The capacitor (C_C) used in compressor motor is of large capacity as compared to fan motor. The capacitor improves the power factor and starting torque of the motor.

The overload protection and thermostat are also used in water cooler. When the water attains desired temperature the thermostat dipped in water chamber operates and disconnects the power supply to the motor.