Tips for checking and maintaining bus air conditioners during the winter deactivation period

Winter has arrived in the northern hemisphere, the temperature has plummeted, entering the winter bus hvac system out of service period. In order to ensure that all parts of the air conditioner to get good lubrication maintenance, we recommend that you choose a higher temperature period every month to turn on the cooling run 15 minutes (low temperature operation process, the evaporative core will exist frost, frost air conditioning system will enter the frost mode, at this time the compressor will stop, the panel shows the frost symbol, as a normal phenomenon, until the end of the frost compressor will restart), running engine idle speed, air conditioning wind speed Adjust to the maximum, open the air outlet. When the temperature is low, press the snow key for 3 seconds after opening the air conditioner to enter the forced cooling mode. Remind you to do a good job of daily cleaning of the ventilation and running parts of the bus air conditioning. This article provides the specific operation methods.


 

Check items before running the bus hvac system

1、 Take out the dust screen inside the air return grille and clean it (clean it with water and neutral detergent and dry it in a cool place), it is recommended to clean it once in winter.
2、 Make sure that there is no loosening and oil leakage in each pipeline interface in the air return grille, no loosening of the electric control box insurance and module, and clean the dust on the electric control box.
3、 Open the engine hatch, check the compressor harness plug, pressure switch harness, air conditioner insurance fixed point and pipeline interface, no loose and oil leakage.
4、 Check whether there are oil stains on the surface of compressor and shaft seal, if there are oil stains, please drain the compressor oil discharge pipe first (the fixed height of the end of the oil pipe cannot be higher than 3/4 of the shaft seal end cover), and clean the oil on the surface of the compressor, then follow the steps below to determine whether it is normal.
① compressor oil window oil level is not less than 1/4 position is normal, below belongs to the lack of oil.
②The air return grille inside the sight glass is normal for occasional bubbles after 15 minutes of refrigeration operation, and a large number of bubbles belong to the lack of refrigerant (specific according to the professional pressure gauge test data shall prevail).
Special reminder: the above two items are judged to be normal, indicating that the air conditioning system and components are good, please wipe the surface of the components with a soft cloth to keep it clean.
5、 Press the compressor to the middle of the engine belt by hand, 8-10mm is normal, press more than 10mm need to adjust the tension.


 

Safety precautions

Before inspection, one person is responsible for the vehicle and air conditioning on and off, the other person is responsible for the inspection, to avoid other people in ignorance of the danger caused by starting the vehicle.
During the inspection, if the vehicle and bus air conditioner are in the starting state, please pay attention to keep a safe distance from the inspection parts to avoid causing personal injury; it is strictly forbidden for the inspector to ascend the roof of the vehicle for inspection without protection, and to use a hand ladder for aerial inspection to ensure safety protection.
After inspection, ensure that all parts are restored to their original position to avoid damage and loss of parts caused by running on.