Daikin VRV IV i Series Installation And Operation Manual Download

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14 Piping installation

Installation and operation manual

RK RKXYQ8T7Y1B

VRV IV compressor unit for indoor installation

4P499900-1B – 2021.12

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 flared joints (between the brass flare nut
and the copper flare).

14.3.5

To perform vacuum drying

To remove all moisture from the system, proceed as follows:

Evacuate the system for at least 2 hours to a target vacuum of
–⁠100.7 kPa (–⁠1.007 bar)(5 Torr absolute).

Check that, with the vacuum pump turned off, the target
vacuum is maintained for at least 1 hour.

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. In that case, break the vacuum by pressurising
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.

Depending  on  whether  you  want  to  immediately  charge
refrigerant through the refrigerant charge port or first pre-charge
a  portion  of  refrigerant  through  the  liquid  line,  either  open  the
compressor  unit  stop  valves,  or  keep  them  closed.  See

"14.4.3 To charge refrigerant"

[

25] for more information.

14.3.6

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

▪ If there is a possibility that condensation on the stop valve might

drip down into the indoor unit or into the heat exchanger unit
through gaps in the insulation and piping because the compressor
unit is located higher than the indoor unit or higher than the heat
exchanger unit, this must be prevented by sealing up the
connections. See below figure.

Insulation material

Caulking etc.

14.4

Charging refrigerant

14.4.1

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 (GWP) 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
compressor unit, heat exchanger unit and indoor units are
turned on, the compressor will not operate before the
communication is established in a correct way between the
compressor unit, heat exchanger unit and indoor units.

NOTICE

Before starting charging procedures:

▪ In case of 5 HP: Check if the 7‑LEDs display is as

normal (see

"16.1.4 To access mode 1 or 2"

[

30]),

and there is no malfunction code on the user interface
of the indoor unit. If a malfunction code is present, see

"19.1 Solving problems based on error codes"

[

38].

▪ In case of 8 HP: Check if the 7‑segment display