How to charge new refrigerant on scroll and screw compressors: 

Due to the characteristics of the new refrigerant, it must be charged in liquid phase so that there is no change in the refrigerant's properties, 

so it should be charging in liquid even at high pressure side(70%) and low pressore side(30%). 

This causes a fatal risk to the compressor due to frequent operation of the low-pressure switch when the amount of suction refrigerant is low in the process of condensing, expanding, evaporating, or sucking due to the characteristics of the scroll compressor or screw compressor. 

Of course, there is a delay time for the compressor in the medium and large size, so it is a little bit relieved, but in the case of the small size, there is often no such delay, which causes compressor failure. (In the case of air conditioners, the fixed amount of refrigerant is measured with a scale and injected. 

This is because the amount of refrigerant is determined by the manufacturer, so the amount of refrigerant is added as much as the additional length of the pipe) In the case of walk-in Freezer,

it charges about 0.75Kg to 1.0Kg per 1HP. 

Instructions recommended by the compressor manufacturer:

•Recharge the refrigerant from the high pressure side with liquid refrigerant in the container to suppress the composition change. Since the composition of the refrigerant changes when charging with gas, performance may deteriorate or normal operation may not be possible.

•Do not charge liquid refrigerant to the low pressure side. If the liquid refrigerant is charged to the low pressure side, there is a risk of malfunction of the compressor, so use a dedicated manifold between the container and the refrigerator.

•If the refrigerant charge is too small or the refrigerant gas is insufficient due to gas leakage, the low pressure pressure will drop and the cooling capacity and oil return will deteriorate. It can also lead to overheating.

Recharge the refrigerant from the high pressure side with liquid refrigerant in the container to suppress the composition change. Since the composition of the refrigerant changes when charging with gas, performance may deteriorate or normal operation may not be possible.

•Do not charge liquid refrigerant to the low pressure side. If the liquid refrigerant is charged to the low pressure side, there is a risk of malfunction of the compressor, so use a dedicated manifold between the container and the refrigerator.

•If the refrigerant charge is too small or the refrigerant gas is insufficient due to gas leakage, the low pressure pressure will drop and the cooling capacity and oil return will deteriorate. It can also lead to overheating.

•The minimum amount of refrigerant required is the optimal amount of refrigerant in the system when the temperature in the warehouse is lowered to a predetermined temperature, the condensation temperature is kept as steady as possible, and the flash gas (bubbles) disappears from the liquid pipe level gauge.

How to rechargein by low pressore side(Be careful.): not recommended

When the compressor is stopped, the refrigerant is very slowly charged up to 1kg in liquid form.

And start the compressor after 1Kg enters. 

Slowly add the remaining refrigerant as well.

For example, for 4 HP, 3Kg to 4Kg of refrigerant is required.

If you put too little or too much, it may cause the compressor to overheat, and you may not be able to set the desired temperature for a malfunction or cold room. 

Precautions:

1. After tubbing work is completed, fill with nitrogen and perform a soap bubble test for leaks. At this time, it must be in the open state by applying electricity to the solenoid valve.

2. If there is no airtight leakage, a sufficient vacuum must be performed using a vacuum pump. 

If air is sucked in together, it may cause overheating of the compressor or malfunction of the expansion valve. 

EGPIS INDUSTRIAL MACHINERY TRADING/First EGPIS Merchandise,

Manila 02)8809-2084, Pampanga 045)457-6394, 0927-321-8556