Air Tight Test And Vacuum Drying - Daikin RZQ200MY1 Installation Manual

How to calculate the additional refrigerant to be
charged
Additional refrigerant to be charged: R(kg)
(R should be rounded off in units of 0.1 kg.)
( )
Total length of
R= liquid side piping ×0.12
size at Ø12.7
( )
Total length of
liquid side piping ×0.022
size at Ø6.4

7-8 Air tight test and vacuum drying

Preparation
[Tools required]
• To prevent entry of any impurities and insure
sufficient pressure resistance, always use the special
Multi-tube
tools dedicated for R410A.
pressure
gauge charge
• To connect to the service port of the stop valves or
hose valve
the refrigerant charge port, use the charge hose with
a pushing stick.
• Use a vacuum pump able to evacuate the system to
-100.7 kPa (5Torr, -755mmHg) or less for vacuum
drying.
Vacuum pump
• Take care the pump oil never flows backward into the
refrigerant pipe during the pump stops.
Check the following after piping connection is finished.
Air tight test
Always use nitrogen. (Refer to Stop valve operation procedure for
service port's position.)
[Procedure]
Pressurize the liquid side piping and the gas side piping to 4.0MPa
(do not exceed 4.0 MPa). If the pressure does not drop within 24
hours, the system passes the test.
If there is a pressure drop, check for leaks. (Discharge the nitrogen
after confirming there is no leakage.)
Vacuum drying
Use a vacuum pump able to evacuate the system to -100.7 kPa
(5Torr, -755mmHg) or less.
[Procedure]
Evacuate the system from the liquid side piping and gas side piping
using a vacuum pump for more than 2 hours to -100.7 kPa or less.
Keep the system under this condition for more than 1 hour, check if
the vacuum gauge indication rises or not.
(If it rises, the system may either contain moisture inside or have
gas leak.)
If moisture might enter the piping (e.g. if doing work during the
rainy season, if the actual work takes long enough that condensation
may form on the inside of the pipes, if rain might enter the pipes
during work, etc.)
After performing the vacuum drying for 2 hours, pressurize to
0.05 MPa (vacuum breakdown) with nitrogen gas, then depressurize
down to -100.7 kPa or less and hold for an hour using the vacuum
pump (vacuum drying).
(If the pressure does not reach -100.7 kPa even after depressurizing
for at least 2 hours, repeat the vacuum breakdown-vacuum drying
process.) After vacuum drying, maintain the vacuum for an hour and
make sure the pressure does not rise by monitoring with a vacuum
gauge.
( )
Total length of
liquid side piping ×0.059
+
size at Ø9.5
Gas side stop valve (close)
Liquid side stop valve (close)
Pressure-reducing valve
+
Vacuum pump
Note
Be sure to shut off the liquid side and gas side stop valves.
Otherwise, it may cause refrigerant leakage of the outdoor unit.
Stop valve operation procedure
Precautions to stop valve operation
• Name of each part should be know before operating the stop
valve (as show in the below figure ) When shipped, the stop
valve is left closed.
• Use proper tools.
Since the stop valve of this unit is not flaring sealed type,
remove it forcibly may result in damage to the valve body.
• When using the service port, adopt charge hose.
• After tightening the cap, check if the refrigerant leaks.
Service port
Shaft
Valve lid
Shut off valve operation procedure
Prepare two inner hexagon wrenches.
To open
1. Put the inner hexagon wrench to the valve shaft and turn it
counterclockwise.
2. Turn it until the shaft stops. The valve is opened.
To close
1. Put the inner hexagon wrench to the valve shaft and turn it
clockwise.
2. Turn it until the shaft stops. The valve is closed.
About valve lid
• Be sure to tighten the valve lid after valve operation is
completed.
About service port
• Operate with the charge hose with a pushing stick.
• Be sure to tighten the valve lid after operating.
Tightening torque
Look through the table below for the stop valve tightening torque.
[Specifications]
Liquid side stop valve
Gas side stop valve
Field piping
system
Outdoor
Indoor unit
unit
Valve
Stop valve service port
(open)
Charge hose
To open
To open
<Liquid side> <Gas side>
Ø9.5mm
Ø19.1mm
13