16
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Piping installation
Installer and user reference guide
86
LRYELRNUN5A7Y1
CO₂ Conveni-Pack outdoor unit
4P605460-1 – 2020.08
To check for leaks: Pressure leak test
1
Test for leaks by applying a bubble test solution to all piping connections.
2
Discharge all nitrogen gas.
3
Break the vacuum by pressurising with nitrogen gas to a minimum gauge
pressure of 0.2 MPa (2 bar).
▪
Never set the gauge pressure of the
high pressure section
of the system
higher than the maximum operation pressure of 12.0 MPa (120 bar).
▪
Never set the gauge pressure of the
low pressure section
of the system
higher than the maximum operation pressure of 9.0 MPa (90 bar). Contact
the manufacturer in advance for more information about the design
pressure of the indoor unit (field supply). Refer to the instruction label on
the front panel of the outdoor unit for the position of the service port.
NOTICE
ALWAYS use a recommended bubble test solution from your wholesaler.
NEVER use soap water:
▪
Soap water may cause cracking of components, such as flare nuts or stop valve
caps.
▪
Soap water may contain salt, which absorbs moisture that will freeze when the
piping gets cold.
▪
Soap water contains ammonia which may lead to corrosion of parts.
The system is ready for use if there is no pressure decrease within 24 hours. If
there is, check for and repair leaks.
16.4.5 To perform vacuum drying
1
Connect a vacuum pump to the charge ports of the gas stop valves (c) and
liquid stop valves (d). See
"16.4.3 Checking refrigerant piping: Setup"
2
Vacuum the unit for at least 2 hours and to –0.1 MPa or below.
3
Leave the unit for more than 1 hour with a vacuum pressure of –0.1 MPa or
less. On the vacuum gauge, check if the pressure does not increase. If the
pressure rises, the system has a leak or moisture remained into the piping.
In case of a leak
1
Find and repair the leak.
2
When done, vacuum again according to the procedure above.
In case of remaining moisture
When the unit is installed on rainy days, moisture may still remain in the piping
after a first vacuum drying is performed. If so, conduct the following procedure:
1
Pressurize the nitrogen gas up to 0.05 MPa (for vacuum destruction) and
vacuum for at least 2 hours.
2
Afterwards, vacuum dry the unit to –0.1 MPa or less for at least 1 hour.
3
Repeat vacuum destruction and vacuum drying if the pressure does not reach
–0.1 MPa or less.
4
Leave the unit for more than 1 hour with a vacuum pressure of –0.1 MPa or
less. On the vacuum gauge, check if the pressure does not increase.
