Daikin VRV III REYQ8PY1B, Service Manual

Page: 170 / 472

SiBE37-701 Test Operation
Test Operation 159
<Air tight test>
Pressurize the liquid pipe, suction gas pipe, HP/LP gas pipe and equalizer pipe from the
service ports of each shutoff valve to 4.0MPa (40bar) (do not pressurize more than 4.0MPa
(40bar)). 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 perform the airtight test again.
<Vacuum drying>
Evacuate the system from the liquid and gas pipes by using a vacuum 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 below.
(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 depressurizing for at least two 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.
1.2.4 Pipe Insulation
„
Insulation of pipes should be done after performing “1.2.3. Air Tight Test and Vacuum
Drying” .
„
Always insulate the liquid piping, the HP/LP gas piping, the gas piping, the equalizer pipe
(between the outdoor units for the outdoor multi system) and these pipe connections.
Failing to insulate the pipes may cause leaking or burns.
Especially, be sure to insulate the HP/LP gas piping as withstanding as the suction pipe
because the suction gas follows in the HP/LP gas piping when the system is whole cooling
mode.
And be sure to use the insulation which can withstand such temperatures of 120°C or more
for the HP/LP gas piping, the equalizer pipe and the gas piping because the HP/LP gas
follows in these pipings.
„
Reinforce the insulation on the refrigerant piping according to the installation environment.
Condensation might form on the surface of the insulation. Refer to the below.
•
Ambient temperature : 30°C, humidity : 75% to 80% RH : min. thickness : 15mm.
• If the ambient temperature exceeds 30°C and the humidity 80% RH, then the min.
thickness is 20mm.
See the Engineering data book for detail.
„
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 connections, etc.
(Refer to next
figure)
„
The piping lead-out hole lid should be attached after opening a knock hole. (Refer to next
figure)
„
If small animals and the like might enter the unit through the piping lead-out hole, close the
hole with blocking material (procured on site) after completion of
“1.2.5 Additional
Refrigerant Charge and Check Operation”. (Refer to next figure)