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Leak test
The leak test must satisfy specification EN 378-2.
1
Vacuum leak test
1.1 Evacuate the system from the liquid, gas and high pressure
piping to –100.7 kPa (5 Torr) for more than 2 hours.
1.2 Once reached, turn off the vacuum pump and check that
the pressure does not rise for at least 1 minute.
1.3 Should the pressure rise, the system may either contain
moisture (see vacuum drying below) or have leaks.
2
Pressure leak test
2.1 Break the vacuum by pressurizing with nitrogen gas to a
minimum gauge pressure of 0.2 MPa (2 bar).
Never set the gauge pressure higher than the maximum
operation pressure of the unit, i.e. 4.0 MPa (40 bar).
2.2 Test for leaks by applying a bubble test solution to all piping
connections.
Make sure to use a recommended bubble test
solution from your wholesaler.
Do not use soap water, which may cause
cracking of flare nuts (soap water may contain
salt, which absorbs moisture that will freeze
when the piping gets cold), and/or lead to
corrosion of flared joints (soap water may contain
ammonia which causes a corrosive effect
between the brass flare nut and the copper flare).
2.3 Discharge all nitrogen gas.
Vacuum drying
To remove all moisture from the system, proceed as follows:
1
Evacuate the system for at least 2 hours to a target vacuum of
–100.7 kPa.
2
Check that, with the vacuum pump turned off, the target vacuum
is maintained for at least 1 hour.
3
Should you fail to reach the target vacuum within 2 hours or
maintain the vacuum for 1 hour, the system may contain too
much moisture.
4
In that case, break the vacuum by pressurizing with nitrogen gas
to a gauge pressure of 0.05 MPa (0.5 bar) and repeat steps 1 to
3 until all moisture has been removed.
5
The outdoor stop valves can now be opened, and/or additional
refrigerant can be charged (see
refrigerant" on page
23).
NOTE
After opening the stop valve, it is possible that the
pressure in the refrigerant piping does not rise. This
might be caused by e.g. the closed state of the
expansion valve in the outdoor unit circuit, but does not
present any problem for correct operation of the unit.
NOTE
The connections to the indoor units and all indoor units
should also be leak and vacuum tested. Keep the stop
valves of the indoor units open as well.
Refer to the indoor unit installation manual for more
details.
Leak test and vacuum drying should be done before
the power supply is set to the unit. If not, see
"10.4. Leak test and vacuum drying" on page 16
more information.
EMRQ8~16ABY1
Daikin Altherma outdoor unit
4P501819-1 – 2017.08
"13.4. Method for adding
for
11. P
IPE INSULATION
After finishing the leak test and vacuum drying, the piping must be
insulated. Take into account the following points:
I
Make sure to insulate the connection piping and refrigerant
branch kits entirely.
I
Be sure to insulate liquid and discharge piping (for all units).
I
Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid piping and polyethylene foam
which can withstand a temperature of 120°C for gas piping.
I
Reinforce the insulation on the refrigerant piping according to
the installation environment.
Ambient temperature
≤30°C
>30°C
Condensation might form on the surface of the insulation.
I
If there is a possibility that condensation on the stop 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, this must be prevented by sealing up the connections. See
below.
1
Insulation material
2
Caulking, etc.
Humidity
Minimum thickness
75% to 80% RH
15 mm
≥80% RH
20 mm
2
1
Installation manual
18
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