Daikin VRV RXYQ72XBYC Series Installation Manual page 32

NOTE
• If the power of some units is turned off, the charging procedure can-
not be finished properly.
• In case of a multiple outdoor system, turn on the power of all out-
door units.
• Make sure to turn ON the power 6 hours before starting the opera-
tion. This is necessary to warm the crankcase by the electric heater.
• 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.
• Before starting charging procedures, check if the segment display
indication of the main printed circuit board (A1P) is as normal (see
functions of the push button switches which are located on the main
printed circuit board (A1P) on page 24). If a malfunction code is
present, see 15.5. Malfunction code list on page 40.
• Make sure all connected indoor units are recognized (see
15.2. Monitoring function and field settings on page 31).
• 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.
14.3.2. Charging method
As explained during vacuum drying method, once vacuum drying is
finished, additional refrigerant charging can start.
A flow chart is available which gives an overview of the possibilities
and actions to be taken (see 14.3.1. Flow chart on page 28).
To speed up the process of pre-charging refrigerant for large systems,
it is recommended to first charge a portion of the refrigerant before
performing refrigerant charging operation of outdoor unit. This step is
included in below procedure. This step can be skipped, but charging
will take longer in such a case.
Follow the steps as described below.
1 Calculate the additional amount of refrigerant to be added using
the formula mentioned in 14.2. Calculating the additional refriger-
ant charge on page 26.
2 The first 22 lbs. (10 kg) of additional refrigerant can be charged
without outdoor unit operation.
If the additional refrigerant amount is smaller than 22 lbs. (10 kg),
perform the pre-charging procedure as explained in step 3 and 4a
below.
If the additional refrigerant charge is larger than 22 lbs. (10 kg),
perform step 3 till the end of the procedure.
3 Pre-charging can be done without compressor running by con-
necting the refrigerant tank only to the liquid stop valve service port
(open valve A). Make sure that all outdoor unit stop valves, as well
as valve B are closed.
6
1
A
4
B
2 3 5
1 Pressure reducing valve
2 Nitrogen
3 Measuring instrument
29
9 9 9
7
8
10
14
11
12
13
4 Refrigerant R410A tank (siphon system)
5 Vacuum pump
6 Charge hose
7 Gas pipe stop valve
8 Liquid pipe stop valve
9 Outdoor unit
10 To indoor unit
11 Stop valve
12 Field piping
13 Gas flow
14 Stop valve service port
A Valve A
B Valve B
4 a) If the calculated additional refrigerant amount is reached by
above pre-charging procedure, close valve A.
b) If the total amount of refrigerant could not be charged by pre-
charging, then close valve A and go to step 5.
INFORMATION
If the total additional refrigerant amount was reached in step 4 (by
pre-charging only), record the amount of refrigerant that was added
on the additional refrigerant charge label provided with the unit and
attach it on the back side of the front panel. Perform the test procedure
as described in 15.4. Test operation on page 39.
5 After pre-charging, perform the refrigerant charge operation as
shown below and charge the remaining refrigerant of the additional
charging amount through valve B.
Open all outdoor units stop valves. Valves A and B must remain
closed!
NOTE
In order to ensure uniform refrigerant distribution, it may take the com-
pressor ±10 minutes to start up after the unit has started operation.
This is not a malfunction.
6 The remaining additional refrigerant charge can be charged by
operating the outdoor unit by means of the refrigerant charge
operation mode:
• Turn on the power of the indoor units and outdoor unit.
• Take all the precautions mentioned in start-up and configura-
tion into account.
• Activate outdoor unit setting [2-20]=1 to start refrigerant charge
mode. Refer to page 32 for details.
Result: The unit will start operation. Valve A can be opened.
Charging of remaining additional refrigerant can be done.
When the remaining calculated additional refrigerant amount is
added, close valve A and push BS3 to stop the refrigerant charg-
ing procedure.
English