Valeooscope - Air Conditioning System Thermal comfort loop

11. The components of the A/C Loop

11.9 Safety devices

11.9.1 The pressure switch (pressostat) The pressure switch monitors the A/C loop high pressure level; it enables or disables the compressor according to two pressure thresholds. One additional circuit controls the cooling fan; it secures the condensation process by forcing the air flow through the condenser.

Pressure sensor has a security function

P1 low

medium P3

P2 high

The pressure switch is a safety device for the A/C loop. The pressure switch is located on the High Pressure side of the loop.

Role: g It monitors the loop’s High Pressure g It detects too low a pressure P1 < 2 bars g It detects too high a pressure P2 > 27 to 32 bars g It includes one additional threshold to activate the maximum speed of the cooling fan P3 > 16 bars.

Pressure switch

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