An air conditioner or a refrigeration system has the same four main components. Compressor, condenser, expansion valve and eveporator. But compressor is called the heart of a refrigeration or air conditioning cycle.
Compressor delivers the refrigerant to condenser at a high temperature and high pressure. So working load is maximum on this part except the other three components. Because of being an expensive part a compressor is protected by some safety accossories installed in the refrigeration cycle. All the safety accessories like HP LP switches, overload relays, overheating protector etc are connected in series connection so that if there is any problem in the system, whole system could shut down.
1. LP Switch :- LP switch means Low pressure switch. This switch is installed on the suction side of the compressor on the copper pipe. LP switch senses the pressure in system and if due to any reason like leakage of refrigerant, low gas charge etc, it will cut the system which is called tripping. These switches has a range of pressure according to the capacity of the refrigeration or air conditioner.
2. HP Switch :- HP switch stands for High pressure switch. This switch is fixed on the discharge line of the compressor where pressure and temperature is high. It works opposite to LP switch and when the pressure goes high in the system it will shut down the entire unit.
LP & HP Switches works on pressure only and dont sense the temperature. An air conditioner or a refrigeration system is always equiped with these switches to protect the compressor.
3. Relays :- Relays are also used to protect compressor and fan motors ( Blower and condenser fan motors). These relays are connected with PCB that senses the flow of amperes and voltage. If there is any problem with the motor of fans or high amps of compressor these relays disconnect the entire system. The relay which is mounted on the body of compressor is called overload relay and this relay senses the temperature of compressor body if the temperature is too high then this relay will shut down the system.
4. Crank case heater :- A crank case heater is fixed on the compressor body to protect the compressor. The lubricant which is used in crank case of compressors of high capacity has the heaters to heat up the lubricant before starting the unit. At the time of start the crank case heaters are switched on before half an hour of starting the entire system as recommended. If the crank case heater is not switched on before half an our the lubricant will start to freeze because of low temperature of refrigerant and this may demage the compressor.
5. Timer relay :- Timer switches are installed in the large capacity units which have two or more circuits in single unit. These switches startes system's circuits step by step like at the time when a system with tree compressors is switched on these three compressors don't start work at same time. This happens because of these timer switches. After start of first circuit the other circuit will start at time interval adjusted mannually as per recommended of manufacturer.
Compressor delivers the refrigerant to condenser at a high temperature and high pressure. So working load is maximum on this part except the other three components. Because of being an expensive part a compressor is protected by some safety accossories installed in the refrigeration cycle. All the safety accessories like HP LP switches, overload relays, overheating protector etc are connected in series connection so that if there is any problem in the system, whole system could shut down.
1. LP Switch :- LP switch means Low pressure switch. This switch is installed on the suction side of the compressor on the copper pipe. LP switch senses the pressure in system and if due to any reason like leakage of refrigerant, low gas charge etc, it will cut the system which is called tripping. These switches has a range of pressure according to the capacity of the refrigeration or air conditioner.
2. HP Switch :- HP switch stands for High pressure switch. This switch is fixed on the discharge line of the compressor where pressure and temperature is high. It works opposite to LP switch and when the pressure goes high in the system it will shut down the entire unit.
LP & HP Switches works on pressure only and dont sense the temperature. An air conditioner or a refrigeration system is always equiped with these switches to protect the compressor.
3. Relays :- Relays are also used to protect compressor and fan motors ( Blower and condenser fan motors). These relays are connected with PCB that senses the flow of amperes and voltage. If there is any problem with the motor of fans or high amps of compressor these relays disconnect the entire system. The relay which is mounted on the body of compressor is called overload relay and this relay senses the temperature of compressor body if the temperature is too high then this relay will shut down the system.
4. Crank case heater :- A crank case heater is fixed on the compressor body to protect the compressor. The lubricant which is used in crank case of compressors of high capacity has the heaters to heat up the lubricant before starting the unit. At the time of start the crank case heaters are switched on before half an hour of starting the entire system as recommended. If the crank case heater is not switched on before half an our the lubricant will start to freeze because of low temperature of refrigerant and this may demage the compressor.
5. Timer relay :- Timer switches are installed in the large capacity units which have two or more circuits in single unit. These switches startes system's circuits step by step like at the time when a system with tree compressors is switched on these three compressors don't start work at same time. This happens because of these timer switches. After start of first circuit the other circuit will start at time interval adjusted mannually as per recommended of manufacturer.
