Brochure

Parker Hannifin Corporation
Climate & Industrial Controls Group
Cleveland, OH
Catalog CIC-2003-1/US
Refrigeration Solenoid Valves
260
Pulse Width Modulating ValvesTypical Applications
Typical Applications
Superheat Control
Using appropriate temperature sensors, the tempera-
ture difference between the inlet and outlet of the
evaporator will define a temperature which is related di-
rectly to superheat. Flooding is present if the tempera-
ture difference is zero. Adjustments to actual superheat
must be made when the system has large evaporator
pressure drops.
Evaporator Temperature Control
In addition to the superheat control, the microcomput-
ers could include a sensor to control the evaporator
temperature or pressure.
Superheat can also be measured directly by sensing
the temperature and pressure at the evaporator outlet.
In this case the pressure sensor could be a pressure
transducer.
Superheat & Evaporator Temperature Control
Using Three Temperature Sensors
Superheat Control Using the
Temperature & Pressure of Evaporator Outlet
Superheat Control Using Two Temperature Sensors