Mitsubishi Electric ECOV-X37VA Manuel D'installation page 31

8. Air tightness test/Vacuum drying
8-1. Air tightness test
8-1-1. Purpose of air tightness test
Check for any refrigerant leakage in the refrigerant pipes and the indoor unit.
The condensing unit has been subjected to an air tightness test prior to shipping.
8-1-2. Air tightness test pressure
When the refrigerant piping is completed, perform the air tightness test before insulating the pipes. The condensing unit has
been tested prior to shipping.
The air tightness test pressure must be at or higher than the design pressure. Refer to 8-1-3.Air tightness test procedure for
details.
The pressure used for the air tightness test must not exceed 8.0 MPa to protect the unit.
The design pressure for the refrigerant pipes and the indoor unit is shown in the table below.
Design pressure for refrigerant pipes and
indoor unit
8.0 MPa
Test procedure
Complete refrigerant
piping work.
8-1-3. Air tightness test procedure
1.
The air tightness test is performed by pressurizing the
refrigerant pipes up to the unit's design pressure with
nitrogen gas. Connect the devices to the check joint
upstream of the refrigerant service valve (ball valve)
<suction> and the high-pressure check joint. See the
figure on the right for connections.
The check joints are all designed to be connected with
Swagelok fittings.
Air tightness test inside the condensing unit is not nec-
essary.
2. Fully open the refrigerant service valve (three-way
valve) <liquid> and open the refrigerant service valve
(ball valve) <suction>. For usage of the refrigerant ser-
vice valves, refer to sections 8-2-6. (Page 35).
3. Do not pressurize the system up to the design pressure at once. Increase the pressure in small increments.
Pressurize the system to 0.5 MPa, stop increasing the pressure for at least 5 minutes, and check that the pres-
sure does not drop.
4. Pressurize the system to 1.5 MPa, stop increasing the pressure for at least 5 minutes, and check that the pres-
sure does not drop.
5. Write down the outside air temperature and pressure after pressurizing the system to the design pressure.
(24 hours)
Pressurize with nitrogen gas.
Check for leaks and repair.
31
Check for pressure drop.
High pressure CJ
Refrigerant service valve
(three-way valve) <liquid>
Pass the test
Refrigerant service valve
(ball valve) <suction>
Check joint
WT09614X03_GB