English
18
8-1 Preparations
<Required tools>
<The system for air tight test and vacuum drying>
• Referring to figure 28.1 and 28.2, connect on nitrogen tank and a
vacuum pump to the outdoor unit.
•
Heat Pump series (RQ(C)YQ)
(Refer to figure 28.1)
1.
Gauge manifold
2.
Nitrogen
3.
Vacuum pump
4.
Charge hose
5.
Valve A
6.
Liquid side shutoff valve
7.
Gas side shutoff valve
8.
Refrigerant charge port
9.
Outdoor unit
10.
To indoor unit
11.
Interunit piping
12.
Flow of the gas
13.
Service port
•
Heat Recovery series (RQCEQ)
(Refer to figure 28.2)
1.
Gauge manifold
2.
Nitrogen
3.
Vacuum pump
4.
Charge hose
5.
Valve A
6.
Liquid side shutoff valve
7.
Suction gas side shutoff valve
8.
HP/LP gas side shutoff valve
9.
Refrigerant charge port
10.
Outdoor unit
11.
To indoor unit
12.
Interunit piping
13.
Flow of the gas
14.
Service port
Note
• The airtightness test and vacuum drying
should be done using the liquid side and
gas side shutoff valve service ports.
See the [R410A] Label attached to the front
plate of the outdoor unit for details on the
location of the service port (see figure at
right).
• See
[Shutoff valve operation procedure]
in
“11-1 Before working” for details on handling
the shutoff valve.
• The refrigerant charge port is connected to
unit pipe.
When shipped, the unit contains the refrigerant, so use caution
when attaching the charge hose.
8-2 Air tight test and vacuum drying method
After finished piping work, carry out air tight test and vacuum drying.
<Air tight test>
Pressurize the liquid and gas pipes to 3.3MPa (33bar) (do not
pressurize more than 3.3MPa (33bar)). If the pressure does not
drop within 24 hours, the system passes the test.
If there is a pressure drop, check for leaks, make repairs and per-
form the airtight test again.
<Vacuum drying>
Evacuate the system from the liquid and gas pipes by using a vac-
uum pump for more than 2 hours and bring the system to
–100.7kPa or less. After keeping the system under that condition
for more than 1 hour, check if the vacuum gauge rises or not. If it
rises, the system may either contain moisture inside or have
leaks.
Note
If moisture might enter the piping, follow belows.
(I.e., 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.)
(1) After performing the vacuum drying for two hours, pressurize to
0.05 MPa (i.e., vacuum breakdown) with nitrogen gas, then
depressurize down to –100.7 kPa for an hour using the vacuum
pump (vacuum drying).
(2) If the pressure does not reach –100.7 kPa even after depressur-
ization for at least two hours, repeat the vacuum breakdown - vac-
uum 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.
9.
PIPE INSULATION
• Insulation of pipes should be done after performing “
8. AIR TIGHT
TEST AND VACUUM DRYING
”.
• Especially the HP/LP gas side piping is required to be insulated
as suction gas side piping in cooling operation. (Heat Recovery
series.)
• Always insulate the liquid side piping, gas side piping, HP/LP gas
side piping and suction gas piping in the interunit piping and
refrigerant branching kit. Failing to insulate the pipes could cause
leaking or burns. (The HP/LP gas side and gas side piping can
reach temperatures of 120°C. Be sure the insulation used can
withstand such temperatures.)
• Reinforce the insulation on the refrigerant piping according to the
installation environment. Condensation might form on the surface
of the insulation.
Ambient temperature: 30°C, humidity: 75% to 80% RH: min.
thickness: 15 mm.
If the ambient temperature exceeds 30°C and the humidity
80% RH, then the min. thickness is 20 mm.
• If there is a possibility that condensation on the shutoff valve
might drip down into the indoor unit through gaps in the insulation
and piping because the outdoor unit is located higher than the
indoor unit, etc., this must be prevented by caulking the connec-
tions, etc.
(Refer to figure 29.1, 29.2)
• The piping lead-out hole lid should be attached after opening a
knock hole.
(Refer to figure 30)
• If small animals and the like might enter the unit through the pip-
ing lead-out hole, close the hole with blocking material (procured
onsite) after completion of “
11. ADDITIONAL REFRIGERANT
CHARGE AND CHECK OPERATION
”.
(Refer to figure 30)
•
Heat Pump series (RQ(C)YQ)
(Refer to figure 29.1)
1.
Gas side shutoff valve
2. RQYQ is not used
3.
Liquid side shutoff valve
4.
Indoor interunit piping
5.
Insulation material
6.
Use caulking or similar sealant
•
Heat Recovery series (RQCEQ)
(Refer to figure 29.2)
1.
HP/LP gas side shutoff valve
2.
Suction gas side shutoff valve
3.
Liquid side shutoff valve
4.
Indoor interunit piping
5.
Insulation material
6.
Use caulking or similar sealant
(Refer to figure 30)
1.
Piping lead-out hole lid
2.
Open a knock hole at “
”
3.
Block “
”
Note
• After knocking out the holes, we recommend you remove burrs in
the knock holes (see figure 30) and paint the edges and areas
around the edges using the repair paint.
Gauge manifold,
Charge hose
valve
• To prevent entry of any impurities and insure suffi-
cient pressure resistance, always use the special
tools dedicated for R410A.
• Use a charge hose that has pushing stick for con-
necting to service port of shutoff valves or refriger-
ant charge port.
Vacuum pump
• The vacuum pump for vacuum drying should be
able to lower the pressure to –100.7kPa
(5 Torr –755mm Hg).
• Take care the pump oil never flow backward into the
refrigerant pipe during the pump stops.
[R410A] Label
01_EN_3P226891-14T.fm Page 18 Tuesday, September 30, 2014 7:48 PM
