Servicing of the system of air-conditioning with the help of the bench equipment

• Automatic programming of operations
• Sequence of operations (ACT-4500)

After having read this chapter, you will learn how as to carry out correctly checking and maintenance service of the system of air-conditioning with the help of the gas-filling device.

In this mode the operator enters the time of underpressure, time of the vacuum maintenance, refrigerant and amount of the cooling liquid necessary for servicing of the automobile. The air-conditioning system of the automobile is connected with high and low pressure hoses to the given equipment and before the cycle of air exhaust it is necessary to enter first the cycle of the refrigerant return on regeneration.

Upon termination of work on return on regeneration (RECLAIM) the vacuum cycle is carried out during the time entered by the user.

At the vacuum cycle, on the left and right index panels there appear numerical values of vacuum / pressure (continuously varied values) related to the low and high side of pressure. Upon termination of the vacuum cycle the equipment supports (HOLD) vacuum during the entered time. During preservation of vacuum (VACUUM HOLD) on the left index panel the remaining time of the vacuum maintenance is shown in minutes, and on the first - the degree of underpressure (continuously varied values) of the automobile installation. It proceeds after the termination of the vacuum of time entered for maintenance before excess of an allowable level of a degree of underpressure of 2 m.hg. If the degree of underpressure exceeds the allowed level, the buzzer sounds and the alarm lamp of maintenance of vacuum (HOLD LED) informing the user on presence of malfunctions in a contour of vacuum lights up.

Thus, if in the index the value of underpressure degree decreases, it means presence of outflow on any site of the system of air-conditioning of the automobile. In this case the user stops operation of the equipment, eliminates at first defects and after end of repair again carries out testing for outflow. At absence of reduction of the underpressure degree, filling of the automobile installation is necessary. At receipt of the refrigerant into the system of air-conditioning of the automobile on both indexes continuously there are given values up to achievement of the digital value of volume of refuelling entered by the user.

After programming of automatic performance during refuelling, on the index appearance of inscription ERROR CODE "ERR7" is possible. It specifies equality of pressure between installation of the system of air-conditioning of the automobile and MRC, in other words, emptiness of a tank. Thus, MRC enters into the mode of temporary stop (HOLD) and it will show a type of the supplying tank R-134a. If a user wants to choose other capacity delivering R-134a it may take use the buttons "upwards" and "downwards" and if he is going to renew refuelling, he may use the button of repeated start (RESTART).

Attention: At presence of the installation in the mode of automatic performance, it is impossible to press the button of automatic performance. By repeated pressing, automatic performance will start again from the very beginning.

The exact method looks as follows:

• Press the button of automatic performance. If to press this button once, on indexes LCD all values (VALVE) will specify "О&qout; and if to hold the button pressed more than 5 seconds., the values programmed earlier will appear.
• With the help of buttons "upwards" and "downwards", enter desirable numerical value. If these buttons to hold in the pressed condition, it is possible to increase speed of changes. The value adjusted here is put by pressing the button ENTER into the device of memory. During the cycle it is impossible to press the button of automatic performance. Through introduction of "О" for unnecessary functions and determined value for the necessary functions included into the mode of automatic performance, it is possible to choose and start the necessary function individually. For example, wishing to carry out testing only on outflow.
• Set up and enter the time of maintenance of vacuum of 5-95 minutes, and time of underpressure or amount of the refrigerant — "O".
• When performing only refuelling of R-l34a, the appropriate amount of the refrigerant, and time of underpressure, time of maintenance of vacuum and amount of oil - "О" are entered.