AZQS100~1Y1B
Split system air conditioners
4P332194-1B – 2015.01
Installation manual
10
10.1. Preventing foreign objects from entering
Plug the pipe through-holes with putty or insulating material
(procured locally) to stop up all gaps, as shown in the figure.
1
Putty or insulating material
(produced locally)
If there is any possibility that small animals
enter the system through the knock-out holes,
plug the holes with packing materials (field
supplied).
Insects or small animals entering the outdoor unit may cause a short
circuit in the electrical box.
Seal knock-out holes to avoid snow and humidity entering.
10.2. Precautions when connecting field piping and
regarding insulation
Be careful not to let the indoor and outdoor piping come into
contact with the compressor terminal cover.
If the liquid-side piping insulation might come into contact with it,
adjust the height as shown in the figure below. Also, make sure
the field piping does not touch the bolts or outer panels of the
compressor.
When the outdoor unit is installed above the indoor unit the
following can occur:
The condensed water on the stop valve can move to the indoor
unit. To avoid this, please cover the stop valve with sealing
material.
If the temperature is higher than 30°C and the humidity is higher
than RH 80%, then the thickness of the sealing materials should
be at least 20 mm in order to avoid condensation on the surface
of the sealing.
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.)
(See figure 3)
.
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 7)
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
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).
