Suction pressure too high compared to the expected evaporation pressure.
Check the calibration of the suction pressure regulating valve. If the unit is equipped with a conventionally charged expansion valve and a suction pressure regulating valve is not present, check that the
expansion valve thermostatic bulb is securely attached to the suction piping and is properly lined. Check that the valve is correctly calibrated (overheating between 4 and 8 ºC) and is not overpowering. If the unit is equipped with an MOP-loaded expansion valve, excessive suction pressure may be caused by opening the same valve too much, because it is not properly calibrated (insufficient overheating) or because it is overpowering. Take appropriate action. If the unit is a capillary type, excessive suction pressure is caused by overloading.
