RZQG71~140L + RZQSG100~140L
Split system air conditioners
4P339538-1A – 2014.03
Installation manual
12
Be sure to insulate the liquid and gas-side field piping.
(The highest temperature that the gas-side piping can reach is
around 120°C, so be sure to use insulating material which is
very resistant.)
1
Compressor
2
Indoor and outdoor field piping
3
Sealant, etc.
4
Insulation material
A
Wind heat insulation material around the piping section so
it is not exposed and then cover the insulation material with
vinyl tape.
10.3. Cautions for necessity of a trap
To avoid the risk of oil held inside the riser piping flowing back into the
compressor when stopped and causing liquid compression
phenomenon, or cases of deterioration of oil return, it will be
necessary to provide a trap at each difference in height of 10 m in the
riser gas piping.
Trap installation spacing.
(See figure 6)
A
Outdoor unit
B
Indoor unit
C
Gas piping
D
Liquid piping
E
Oil trap
H
Install trap at each difference in height of 10 m.
A trap is not necessary when the outdoor unit is installed at
higher position than the indoor unit.
11. Leak test and vacuum drying
When all piping work is complete and the outdoor unit is connected to
the indoor unit, it is necessary to:
check for any leakages in the refrigerant piping
to perform vacuum drying to remove all moisture in the
refrigerant piping.
If there is a possibility of moisture being present in the refrigerant
piping (for example, rainwater may have entered the piping), first
carry out the vacuum drying procedure below until all moisture has
been removed.
11.1. General guidelines
All piping inside the unit has been factory tested for leaks.
Use a 2-stage vacuum pump with a non-return valve which can
evacuate to a gauge pressure of –100.7 kPa (5 Torr absolute,
–755 mm Hg).
Connect the vacuum pump to
both
the service port of the gas
stop valve and the liquid stop valve to increase efficiency.
11.2. Setup
(See figure 8)
1
Pressure gauge
2
Nitrogen
3
Refrigerant
4
Weighing machine
5
Vacuum pump
6
Stop valve
11.3. Leak test
The leak test must satisfy specification EN378-2.
1
Vacuum leak test
1.1
Evacuate the system from the liquid and gas piping to
–100.7 kPa (5 Torr).
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 (refer to the paragraph
"Vacuum drying"
) 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.
2.3
Discharge all nitrogen gas.
NOTICE
Any exposed piping may cause condensation.
DANGER
Do not touch piping and internal parts.
1
3
4
A
2
NOTICE
Do not purge the air with refrigerants. Use a vacuum
pump to evacuate the installation. No additional
refrigerant is provided for air purging.
Make sure that the gas stop valve and liquid stop
valve are firmly closed before performing the leak test
or vacuum drying.
NOTICE
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).
