JC3.5 hydraulic controller and its wiring a

Refrigerator oil pressure controller is also called oil pressure difference relay . It is
a safety protection device that automatically stops the operation of the refrigerator when the lubricating oil pressure of the refrigerator is lower than a certain value of the crankcase pressure . There are many types of hydraulic controllers, but the control principles
are the same.
  Figures 5 and 8 show the JC3.5 oil pressure controller circuit. It is a relay that operates on pressure difference .