5 Installation
Installation and operation manual
12
5TMV1B
VRV IV-S system air conditioner
4P399985-1B – 2015.06
5.5
To insulate the refrigerant piping
After finishing the leak test and vacuum drying, the piping must be
insulated. Take into account the following points:
▪ Make sure to insulate the connection piping and refrigerant branch
kits entirely.
▪ Be sure to insulate the liquid and gas piping (for all units).
▪ 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.
▪ Reinforce the insulation on the refrigerant piping according to the
installation environment.
Ambient
temperature
Humidity
Minimum thickness
≤30°C
75% to 80% RH
15 mm
>30°C
≥80% RH
20 mm
Condensation might form on the surface of the insulation.
▪ 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 figure.
b
a
a
Insulation material
b
Caulking etc.
5.6
Charging refrigerant
5.6.1
Precautions when charging refrigerant
WARNING
▪ Only use R410A as refrigerant. Other substances may
cause explosions and accidents.
▪ R410A contains fluorinated greenhouse gases. Its
global warming potential value is 2087.5. Do NOT vent
these gases into the atmosphere.
▪ When charging refrigerant, always use protective
gloves and safety glasses.
NOTICE
If the power of some units is turned off, the charging
procedure cannot be finished properly.
NOTICE
Be sure to turn on the power 6 hours before operation in
order to have power running to the crankcase heater and
to protect the compressor.
NOTICE
If operation is performed within 12 minutes after the indoor
and outdoor units are turned on, the compressor will not
operate before the communication is established in a
correct way between outdoor unit(s) and indoor units.
NOTICE
Before starting charging procedures, check if the 7‑LEDs
display is as normal (see
"6.1.4 To access mode 1 or 2" on
page 16
), and there is no malfunction code on the user
interface of the indoor unit. If a malfunction code is
present, see
"8.1 Solving problems based on error
codes" on page 22
.
NOTICE
Make sure all connected indoor units are recognised
(setting [1‑5]).
NOTICE
Close the front panel before any refrigerant charge
operation is executed. Without the front panel attached the
unit cannot judge correctly whether it is operating properly
or not.
NOTICE
In case of maintenance and the system (outdoor unit+field
indoor units) does not contain any refrigerant any
more (e.g., after refrigerant reclaim operation), the unit has
to be charged with its original amount of refrigerant (refer
to the nameplate on the unit) and the determined additional
refrigerant amount.
5.6.2
To determine the additional refrigerant
amount
INFORMATION
For final charge adjustment in a test laboratory, contact
your dealer.
Additional refrigerant to be charged=R (kg). R should be rounded off
in units of 0.1 kg.
R=[(X
1
×
Ø9.5
)×0.059+(X
2
×
Ø6.4
)×0.022]
X
1...2
=Total length (m) of liquid piping size at
Øa
INFORMATION
Piping length is considered the distance from the outdoor
unit to the farthest indoor unit.
When using metric piping, please take into account following table
concerning the weight factor to be allocated. It should be substituted
in the formula for R.
Inch piping
Metric piping
size (Ø) (mm)
Weight factor
size (Ø) (mm)
Weight factor
6.4
0.022
6
0.018
9.5
0.059
10
0.065
5.6.3
To charge refrigerant
To speed up the refrigerant charging process, it is in case of larger
systems recommended to first pre-charge a portion of refrigerant
through the liquid line before proceeding with the manual charging. It
can be skipped, but charging will take longer then.
Pre-charging refrigerant
Pre-charging can be done without compressor operation, by
connecting the refrigerant bottle to the service port of the liquid stop
valve.
1
Connect as shown. Make sure that all outdoor unit stop valves,
as well as valve A are closed.
