Focus ZTS L4-2.0L DOHC VIN 3 (2001)
Refrigerant Pressure Sensor / Switch: Description and Operation
Air Conditioning System Low Pressure Switch
Air Conditioning System - Low Pressure Switch
Control
When the air conditioning is switched on, the clutch only receives 12 V if the low pressure switch is closed. When the pressure falls below 1.6 bar, the
low pressure switch is opened and the supply of current to the compressor clutch is interrupted.
Installation position
On the low-pressure line between the evaporator and the wheel housing.
Function
The air conditioning low-pressure switch has the following functions:
-
Protecting the evaporator against icing
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Protects the air conditioning system when the pressure is too low or the system is empty in the event of leaks.
Operation
The low-pressure switch functions as a de-icing switch and controls the compressor clutch on/off switch.
The pressures in the low-pressure line and evaporator are practically equal. As the pressure in the low-pressure line drops, the temperature in the
evaporator approaches freezing point. There is a risk that the evaporator will ice up and loose its cooling power. The low-pressure switch opens the
compressor clutch when the pressure drops to a certain level and will not close it again until the pressure has risen to a suitable level.
