Thermostat Setting for Two Compressor Systems
For controlling the operation of the two compressor packaged air conditioning system, two different thermostats can be connected to the two cooling systems. This will allow for the capacity control of both the compressors to ensure optimum running of the plant.
In many cases the thermostat is connected to the compressor of one cooling system only. In this case one compressors keeps on running at full capacity and the other compressor remains shut or runs at partial or full capacity depending on the cooling load. To ensure that one compressor won't wear and tear at the fast rate, the compressor running at the full capacity is interchanged from time-to-time.
The two compressor system is used for the cooling loads between 5 to tons 15 tons, for higher loads more than two units can be installed as per the requirements. There can be multiple air handling units in these systems sending the chilled air to different parts of the building. The compressor and the condenser units are housed in the same location of the building thus there is one common place for the return air. If these units have water cooled condenser, the hot water coming out from them is cooled in the single cooling tower.
During the full load all the compressors run at the full capacity, and when the load reduces one or more compressors are stopped manually or automatically, which makes the other compressors to run at the full load. When the compressor runs at full capacity it runs more efficiently. Whether the packaged air conditioner consists of single compressor or the multiple compressors, most of the components are assembled at the factory site, so the installation of the package AC is quite easy.