Additional Refrigerant Charge - Mitsubishi Electric CITY MULTI PUMY-SP125VKM Installationshandbuch

4. Installing the refrigerant piping
(1)
F
B
C
A
G
H
I
E
D
H Double spanner section
A Valve
B Unit side
C Cap
I Seal section
D Local pipe side
E Pipe cover
F Service port
G Wrench hole
Fig. 4-12
B
C
Fig. 4-14

4.6. Additional refrigerant charge

Additional refrigerant charge
Refrigerant for the extended piping is not included in the outdoor unit when the unit is
shipped from the factory. Therefore, charge each refrigerant piping system with addi-
tional refrigerant at the installation site. In addition, in order to carry out service, enter
the size and length of each liquid pipe and additional refrigerant charge amounts in
the spaces provided on the "Refrigerant amount" plate on the outdoor unit.
Calculation of additional refrigerant charge
• Calculate the additional charge using the liquid pipe size and length of the ex-
tended piping.
• Calculate the additional refrigerant charge using the procedure shown to the
right, and charge with the additional refrigerant.
• For amounts less than 0.1 kg, round up the calculated additional refrigerant
charge.
(For example, if the calculated charge is 32.92 kg, round up the charge to 33.0
kg.)
14
(2)
F
B
C
A
G
H
I
E
D
(Do not apply a spanner other than to this section. Doing
so would cause coolant leaks.)
(Seal the end of the heat insulation material at the pipe
connection section with whatever seal material you
have on hand so that water does not infiltrate the heat
insulation material.)
Fig. 4-13
* The figure to the left is an example
only. The stop valve shape, service port
A
position, etc., may vary according to the
model.
* Turn section A only.
(Do not further tighten sections A and
B together.)
D
C Charge hose
D Service port
4.5. Stop valve opening method
The stop valve opening method varies according to the outdoor unit model. Use the
appropriate method to open the stop valves.
(1) Gas side (Fig. 4-12)
Remove the cap and turn the valve rod counterclockwise as far as it will go with
1
the use of a 5 mm hexagonal wrench. Stop turning when it hits the stopper.
(ø15.88: Approximately 13 revolutions)
Make sure that the stop valve is open completely and rotate the cap back to its
2
original position.
(2) Liquid side (Fig. 4-13)
Remove the cap and turn the valve rod counterclockwise as far as it will go with
1
the use of a 4 mm hexagonal wrench. Stop turning when it hits the stopper.
(ø9.52: Approximately 10 revolutions)
Make sure that the stop valve is open completely, push in the handle and rotate
2
the cap back to its original position.
Refrigerant pipes are protectively wrapped
• The pipes can be protectively wrapped up to a diameter of ø90 before or after con-
necting the pipes. Cut out the knockout in the pipe cover following the groove and
wrap the pipes.
Pipe inlet gap
• Use putty or sealant to seal the pipe inlet around the pipes so that no gaps remain.
(If the gaps are not closed, noise may be emitted or water and dust will enter the
unit and breakdown may result.)
Warning:
When installing the unit, securely connect the refrigerant pipes before starting
the compressor.
Precautions when using the charge valve (Fig. 4-14)
Do not tighten the service port too much when installing it, otherwise, the valve core
could be deformed and become loose, causing a gas leak.
After positioning section B in the desired direction, turn section A only and tighten it.
Do not further tighten sections A and B together after tightening section A.
<Additional Charge>
Calculation of refrigerant charge
Pipe size Pipe size
Liquid pipe Liquid pipe
+
ø6.35 ø9.52
(m) × 19.0 (g/m) (m) × 50.0 (g/m)
Included refrigerant amount when shipped from the factory
Included refrigerant amount
3.5 kg
Calculation example (Please see the lower half of Fig. 4-1.)
Outdoor model : SP140 A : ø9.52 [3/8"]/ø15.88 [5/8"] : 30 m
1: P100 (11.2 kW) a : ø9.52 [3/8"]/ø15.88 [5/8"] : 15 m
2: P40 (4.5 kW) b : ø6.35 [1/4"]/ø12.7 [1/2"] : 10 m
The total length of each pipe size is as follows:
ø9.52 [3/8"]/ø15.88 [5/8"] : A = 30 m
ø9.52 [3/8"]/ø15.88 [5/8"] : a = 15 m
ø6.35 [1/4"]/ø12.7 [1/2"] : b = 10 m
The total capacity of connected indoor unit is as follows:
11.2 + 4.5 = 15.7
Therefore, the additional charge is as follows:
19.0 50.0
= 10 × + (30 + 15) ×
1000 1000
= 5.0 kg
Total capacity of Amount for the
connected indoor units indoor units
+
~ 8.0 kW 1.5 kg
8.1 ~ 16.0 kW 2.5 kg
16.1 ~ 20.4 kW 3.0 kg
For these
piping
lengths
+ 2.5