Refrigerant Pressure Sensor / Switch: Description and Operation

A/C Pressure Switch -F129-

Functions







- At low or high pressure in the refrigerant circuit the low/high pressure switch (switch between terminals 1 and 2) switches the compressor off (via A/C Control Head -E87-).
- Switching pressures (in bar high pressure):
- Switch open (compressor off):
Low pressure switch (opens at 1.2 bar and closes at 1.8 bar).
High pressure switch (opens at 30 bar and closes at 14.5 bar).
- Switch closed (compressor on):
1.2 (1.8) bar to 30 (14.5) bar.
- Coolant Fan -V7- is switched to second speed via the high pressure switch (switch between contact 3 and 4).
- Switching pressures (in bar high pressure):
- Second speed of coolant fan engages at 16 bar (switch closes).
- Second speed of coolant fan is switched off at 12.5 bar (switch opens).