Carrier 17/19EX Refrigeration Cy cle (Figure 4)

Motor Starter ( Purchased Separa tely)
The starter allows for the proper starting and disc onn ecting of the electrical energy for the
compressor-motor, oil pump, oil heater, and control panels.
Utility Vessel
During normal operation , this vessel function s as an ec on omizer, returning fla sh gas to the
second stage of the compressor and increasing the efficiency of the refrigeration cycle. During
periods of shutdown an d s er v ic e , the utility vessel can se r v e as a s to rage tank for the
refrigerant.
Refrigeration Cy cle (Figure 4)
The machine com pressor continuou sly draws large quantities of re frigerant vapor from the
cooler, at a rate determ ine d by the amount of guide vane op ening. This compress or s uc t ion
reduces the pressure within the cooler, al lowing the liquid ref rigerant to boil vigorou sly at a fairly
low temperature (typically 38 to 42 F [3 to 6 C]).
The liquid refrigera nt obtains the energy ne eded to vaporize by remov ing heat from the water
or brine in the cooler tube s. The cold water or brine can then be used in air conditioni ng and/or
other processes.
After removing heat from the wat er or br in e, the refrigerant vapor enter s th e first stage of the
compressor, is compressed and flows into the compressor seco nd stage. Here it is mixed with
flash-economizer gas and is further compressed.