Hitachi RAS-18FSXNS2E - Charging Work

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PMML0628 rev.0 - 05/2023
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CHARGING WORK
PIPING WORK AND REFRIGERANT CHARGE
3.6.2 Triple Evacuaon Method
According to the following [Step 1] [Step 2] [Step 3] in order, conduct vacuum drying work.
Step 1
1 Vacuum unl the pressure reaches 2000 microns (2.0 mmHg).
2 Pressurize with nitrogen up to 0.3 MPaG (50 PSIG) for 15 minutes.
3 Release pressure unl reaching the atmosphere level, as low as 0.03 MPaG (5 PSIG).
Step 2
1 Vacuum unl the pressure reaches 1000 microns (1.0 mmHg).
2 Pressurize with nitrogen up to 0.3 MPaG (50 PSIG) for 15 minutes.
3 Release pressure unl reaching the atmosphere level, as low as 0.03 MPaG (5 PSIG).
Step 3
1 Vacuum unl the pressure reaches 500 microns (0.5 mmHg).
2 Stop vacuum pump.
3 Check that the vacuum 500 microns (0.5 mmHG) can maintain for one hour.
 NOTE
• If tool or measuring instruments come into contact with the refrigerant, use the tools or the
measuring instruments exclusively for R410A.
• Do not perform vacuuming pumping work with valves of the outdoor units open. Otherwise, the
refrigerant charged before shipment may leak and it may result in failure. If moisture remains
inside the pipes, the compressor may be damaged.
3.7 Charging work
Aer vacuum pumping work, check that the high/low pressure gas valve, low pressure gas valve
(low pressure gas valve is for heat recovery system only) and liquid stop valve are fully closed.
Charge the addional refrigerant from the check joint of liquid stop valve (acceptable error must
be within 0.5 kg).
Aer the refrigerant has been charged, fully open the liquid stop valve and the gas stop valves.
If it is impossible to charge the specied quanty of refrigerant, fully open the stop valve for the
gas line. For heat recovery system, both stop valves of high/low pressure and low pressure side.
Charge the correct refrigerant quanty according to Addional refrigerant charge calculaon. If
not, a compressor may be damaged due to an excess or insucient refrigerant charge.
Refrigerant charge from check joint of gas stop valve may lead to compressor failure. Be sure to