Description and operating principle of air conditioning (Focus 1)

Contents: Cooler circuit ↳ Compressor A/C Ford FVS 090 variable… ↳

The air conditioning (A/C) system has an evaporator jet, controlled by a low pressure relay. The refrigerant used is R134a.

Cooler circuit

Pos.	Spare Part No	Name
1	-	Capacitor core
2	-	Air conditioning (A/C) compressor
3	-	Suction tank
4	-	Blower fan electric motor
5	-	Evaporator core
6	-	Evaporator jet
7	-	Condenser Fan Motor
8	-	High pressure side, liquid form and warm state
9	-	Low pressure side, liquid form and cold state
10	-	Low pressure side, gaseous form and cold state
11	-	High pressure side, gaseous form and hot state

The A/C compressor (2) is driven by the engine. The A/C compressor draws refrigerant gas from the suction accumulator (3) and compresses it. The refrigerant is heated and forced into the condenser core (1) under high pressure.

At this point, heat from the refrigerant is removed by the air forced through the cooling fins. This loss of heat causes the refrigerant to liquefy and leave the condenser core.

The evaporator orifice (6), which separates the high-pressure refrigerant from the low-pressure refrigerant, is located between the condenser core and the evaporator core (5). This evaporator orifice slows down the flow of refrigerant from the A/C compressor, causing pressure to build up in the condenser core.

After passing through the evaporator jet, the liquid refrigerant expands in a circuit directed toward the evaporator core. In the evaporator core, the liquid refrigerant returns to a gaseous state again, and this causes heat to be released from the air entering the vehicle. Therefore, the air is cooled and releases the moisture it contains in the evaporator core. The refrigerant stream leaving the evaporator core enters the suction accumulator and is pumped again by the A/C compressor.

The system is protected by a high pressure switch, which prevents damage due to excessive pressure (e.g. due to overfilling). If the pressure exceeds the maximum permissible level, the high pressure switch switches off the A/C compressor.

The A/C compressor cycles are controlled by a low pressure switch based on the low pressure level in the suction accumulator. The low pressure switch shuts off the A/C compressor when the pressure drops below a set value (for example, if there is a leak).