|
A binary pressure switch is a compressor safety device that has 2 distinct functions. The first function cuts the compressor off if the refrigerant charge is lost or too low to prevent the compressor from running dry and locking up. The second function cuts the compressor off if the head pressure reaches unsafe levels to prevent compressor damage or damage to other components such as a blown hose. Always install the binary switch on the liquid side of the a/c between the condenser and expansion valve.
Did you know?
The expansion valve is a refrigerant metering device that creates a temperature/pressure drop. It also divides the system into two zones, high pressure and low pressure.
When working with either PAG or Ester oils always be sure to keep the container capped when your not using. The chemical makeup of these types of oils will absorb moisture and can create a problem in the a/c system later.
Always use the correct oil viscosity according to the compressor manufacturers specifications. Never mix oils!
Remember to always check your newly purchased compressor for oil. Now many new and rebuilt compressors come without oil. Inadequate or excess oil in the system will cause loss of performance and compressor damage as well as other component damage.
Piston Compressors
There are two types of piston compressors currently in use, the opposed axial type, (also often referred to as the swash plate type), and the single row axial or wobble-plate type. Depending on design, these compressors may contain five, six, seven, or ten pistons.
With either type of piston compressor, the pumping action of the pistons draws low pressure/low temperature refrigerant vapor from the evaporator into the compressor through suction valves. The refrigerant exits the compressor through discharge valves as a high pressure/high temperature vapor. This happens because the pistons are pumping the refrigerant against a calibrated restriction in the system. Depending on the type of system, the calibrated restriction is contained in either the orifice tube or the expansion valve.
Each cylinder in the compressor contains one suction and one discharge flapper-type reed valve. As the piston moves away from the suction valve, the valve opens and refrigerant is drawn into the cylinder. After reversing direction, the piston compresses the low pressure/low temperature vapor into a high pressure/high temperature vapor. This vapor exits the cylinder through the discharge valve on its way to the condenser.
|
