When install new air-conditioner or replaced new compressor or change new expansion valve,we need to evacuation or vacuum process.This is important to ensure no air inside the piping system.For easy understanding,this process is to vacuum the system to take out the air and moisture.
If air remain in the air-conditioner and refrigerant piping,it will affect the compressor performance,reduce the cooling capacity,clogged the cycle of refrigerant and could lead a malfunction.
This procedure very important to make sure air-conditioner running properly and can use for long period without breakdown.All maintenance person or electrical technician must know how to perform evacuation procedure.
Evacuation or vacuum procedures for Air-Condition
1) Firstly we need to ensure the unit already switch off before we start evacuation procedure.Connect manifold gauge to the system.The low pressure hose ( blue hose ) connect to service port 3 way valve and service hose ( yellow hose ) connect to vacuum pump.
2) Switch on the vacuum pump and open the valve for low side of manifold gauge.We can see the needle at pressure gauge move from 0 psi ( 0 cmHg ) to -14.5 psi ( -76 cmHg ).This process continue around 10 until 20 minute.
3) After that,Close the low side valve of manifold gauge first the switch off the vacuum pump.Now the system in the vacuum pressure.
4) Make sure the needle of low pressure gauge not move after approximately 10 minute.This procedure is to check refrigerant system from leaking.
5) After completed the leak tested,disconnected the manifold gauge hoses from vacuum pump.
6) Charges or refill the system with refrigerant ( refer name plate for types of refrigerant,e.g : R22,R134a,R407c ) until 43 psi.This process is to fill the system with 50% of refrigerant before we charge with full capacity.