Your questions need more information as to what you are working on but in general for a vehicle its is as follows..
Using a set of a/c gauges put the blue hose on the low side (suction side) and the red hose on the high side (discharge side) and make sure that there is no freon in the system and if you have freon in the system then you will have to go to an automotive a/c shop and have them reclaim it for you..
Put the yellow hose on your vacuum pump and let it run for about 1 hour and then let it sit for 1 hour so that you can see if it will at least hold the vacuum pulled.
If so then let it run for an additional hour and then start the recharging process remembering to keep the low side readings between 30 to 40psi and the high side between 200 to 250psi depending on the outside temperature…………….
Restricting liquid refrigerant during charging helps prevent the compressor from being flooded with liquid, which could cause damage. It allows the refrigerant to enter the system as a vapor, which is more efficient for the compressor to handle. Properly charging the system with vapor also ensures that the refrigerant circulates effectively throughout the system.
Refrigerant pressure decreases in a refrigerant cylinder while charging with vapor because vapor has a lower density compared to liquid refrigerant. As vapor is introduced into the cylinder, it displaces the liquid refrigerant, causing the pressure to drop as the overall density of the refrigerant in the cylinder decreases.
Ensure the charging cylinder is in an upright position to prevent liquid refrigerant from escaping. Slowly open the cylinder valve to let refrigerant flow into the system in a controlled manner. Monitor the pressure and temperature while charging to avoid overfilling the system.
Restricting liquid refrigerant when charging a refrigeration system means controlling the flow of refrigerant to ensure only vapor enters the system. This is important because introducing liquid refrigerant can lead to compressor damage or poor system performance. The proper method is to add refrigerant in vapor form to prevent liquid slugging and ensure efficient operation.
It means charging the A/C system with the proper kind and amount of refrigerant + oil. Overcharging the system will damage the compressor.
Lighter, as the refrigerant is boiled off, and colder, as it has absorbed heat, and has a lesser pressure to reflect the current temperature / pressure relationship for the type of refrigerant
They are more difficult to use when charging refrigerant into a system and more calculations are necessary to determine the amount of refrigerant charged.
Charging an R404A unit involves connecting a charging hose from a refrigerant cylinder to the low-pressure side of the system. The refrigerant is then added slowly, while monitoring the system's pressure and temperature to ensure proper charging levels are reached. It is recommended to consult a professional technician to ensure correct charging procedures are followed.
Liquid refrigerant charging of a system is normally accomplished in the liquid line. For example, when a system is out of refrigerant, liquid refrigerant can be charged into the king valve on the liquid line or receiver.
Must be recovered
926.5
Must be recovered