Motor, Compressor, High Side Valve, Condenser, Accumulator, Valve, Filter, Dryer, Sight Glass, THX, Evaporator, Oil Dryer, Accumulator, Suction Line, Suction Line Valve
The Thermostat is the Control Device used in all Heating and Cooling Systems and requires a low voltage of electricity to function properly. Older models have a vial of mercury attached to a spring that when placed in the proper position produce a low voltage of electricity called micro voltage and in the heating cycle this electricity will travel through wires attached to the R and W post at the thermostat to open the gas valve and produce a spark that will ignite the gas burner producing heat that will rise inside of the combustion chambers and make hot metal panels called clam shells and will also at that moment (at temperature)and through the G post at the thermostat will be connected to transformer and to the fan coil switch inside the space where the clam shells are producing high voltage turning on a blower motor that will push air through the duct work and over the Clam Shells sending the air throughout the space needing heat.
In the cooling cycle the R, G and Y post are utilized and the R and G posts remain connected to the Blower Motor and the Y post is connected to the normally open relay closing it pulling in a contactor that will allow line voltage coming from a circuit breaker and panel box to pass through turning on the motor compressor and the condenser fan that removes the heat from the line set that connects to the condenser nearby transforming the refrigerant from a hot gas back to a cool liquid and sending the cool liquid gas back to the evaporator usually a Slant or A Coil made of copper tubing and aluminum fins inside of the furnace and the space that needs to be cooled and as the warm air passes over the refrigerant inside it turns to gas and is sucked down the line by the action of the motor compressor also situated near the condenser and the condensing fan outside of the space that needs to be cooled and any liquid or oil will be deposited in the accumulator before it reaches the motor compressor as liquid and oil will damage the valve reeds inside that prevent back feed that will reduce compression of the gas to a superheated gas capable of absorbing the heat from the air around us and crazily that superheated gas after absorbing the heat around us through copper tubing turns to a cool liquid inside of the copper tubing.
With the application at the various valves immediately after the Motor – Compressor but before the Condenser at the High Side Valve of temperature and pressure gauges there should be a difference of about 20 to 30 pounds of pressure in the + column versus temperature or 80 Degrees Fahrenheit the outside air temperature there should be about 110 pounds of pressure inside the copper tubing carrying the refrigerant when using R-22 single blend and most toxic, R-12 double blend and less toxic or R-124 triple blend and non toxic refrigerant gas the usual arrangement in most residential and light commercial applications.