3315455 - 5040BA Check operation of four stage pressure switch
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Check 1st stage (approx. 2.5 bar):
- Disconnect the pressure switch from its pipe (see op.) and check that the circuit between pins 1 and 2 is open.
- Reconnect the pressure switch to its pipe: the contact between pins 1 and 2 closes.
- Reconnect the electrical connection of the pressure switch and start up the air conditioner.
- Wait a few minutes, making sure that the compressor switches on normally.
- The calibration of the 1st stage is: contact opens 2.10-1.80 bar and contact closes max. 3.5 bar.
Check 2nd stage (approx. 15 bar):
- Operate the system with the car stopped. Wait a few more minutes: the contact between pins 3 and 4 closes. At the same time make sure that the fan comes on at the first speed.
- The calibration of the 2nd level is: contact closes 14-16 bar and contact opens 9-13 bar.
Checking 3rd level (approx. 20 bar):
- Again operate the system with the car stopped. Wait a few minutes: the contact between pins 6 and 4 closes. At the same time make sure that the fan changes from the first to the second speed.
- The calibration of the 3rd stage is: contact closes 18.8-21.2 bar and contact opens 13.8-18.2 bar.
Check 4th stage (approx. 28 bar):
- It is advisable not to allow the pressure of the circuit to increase to that value, which is too close to the safety limits.
 | The calibration of this level cannot therefore be checked on the car. |