Addition Of Refrigerant - Mitsubishi Electric MXZ-8B48NA Manual De Instalación

5. Installing the refrigerant piping
5.3. Addition of refrigerant
* When the unit is stopped, charge the unit with the additional refrigerant through
the liquid stop valve after the pipe extensions and indoor unit have been vacu-
umized.
When the unit is operating, add refrigerant to the gas check valve using a safe-
ty charger. Do not add liquid refrigerant directly to the check valve.
Refer to the "1.5. Using R410A refrigerant air conditioners" for more information.
Table 1
Total piping length 41-50m 51-70m 71-90m 91-115m
bl+b2+al +a2+a3+a4+a5+a6+a7+a8
(135-164ft.) (165-230ft.) (231-295ft.) (296-377ft.)
Additional refrigerant charging amount 0.6 kg 1.4 kg 2.2 kg 3.2 kg
(21 oz) (49 oz) (78 oz) (113 oz)
If connecting an indoor unit with _9.52 mm (3/8 inch) liquid pipes (model number
24 or more for M- and S-Series and model number 18 or more for P-Series'_. the
additional refrigerant charging amount in Table 1 must be corrected (add the follow-
ing AR value from the value given in Table 1 ).
Additional refrigerant charging correction amount
AR = 0.01 [kg/m] x _9.52 (3/8 inch) branch pipe (liquid pipe) total length [m]
(0.107 [oz/ft] x _a9.52 (3/8 inch) branch pipe (liquid pipe) total length [ft])
Example) bl = 20 m (66 ft.). b2 = 25 m (82 ft.)
Indoor unitA _9.52 (3/8) Liquid pipe a1=12 m (39 ft.)
Indoor unit B _6.35 (1/4) Liquid pipe a2=11 m (36 ft.)
Indoor unit C _6.35 (1/4) Liquid pipe a6=14 m (46 ft.)
Indoor unit D _9.52 (3/8) Liquid pipe a7=13 m (43 ft.)
Total piping length : b1+b2+a1+a2+a6+a7=95 m (312 ft.)
--_ According to Table 1, the additional refrigerant charging amount is 3.2 kg (113 oz).
Because indoor units with _a9.52 (3/8) liquid pipes are connected (indoor units A and
D in this example), the additional refrigerant charging amount must be corrected.
Additional refrigerant charging correction amount
AR = 0.01 [kg/m] x _9.52 (3/8) branch pipe (liquid pipe) total length (al +a7)
= 0.01 x (12+13 m) [0.107 x(39+43 ft.)]
= 0.25 kg (9 oz)
Therefore the additional refri(]erant charaina amount is
3.2 kg + 0.25 kg = 3.45 kg [113 oz + 9 oz =122 oz].
• in case of using 1-branch box
Flare connection employed. (No. brazing)
Branch box
0
• in case of using 2-branch boxes
2 branches pipe (joint)
(1) Valve size for outdoor unit
(2) Valve size for branch box
Branch box #2
Fig. 5-2
mm (3/8 inch)
__)
Liquid pipe _a6.35 mm (1/4 inch)
A_ UNIT
Gas pipe _a9.52 mm (3/8 inch)
Liquid pipe _a6.35 mm (1/4 inch)
a_ UNIT
Gas pipe _a9.52 mm (3/8 inch)
Liquid pipe _a6.35 mm (1/4 inch)
UNIT
Gas pipe _a9.52 mm (3/8 inch)
Liquid pipe _a6.35 mm (1/4 inch)
UNIT
Gas pipe _a9.52 mm (3/8 inch)
Liquid pipe _a6.35 mm (1/4 inch)
UNIT
Gas pipe _a12.7 mm (1/2 inch)
* 3-branch type : only [A],1_. [] unit
Conversion formula
/('_'_ f--'_ _B_ 1/4 F _6.35 (1/4)
3/8 F _9.52 (3/8)
1/2 F _12.7 (1/2)
5/8 F _15.88 (5/8)
r,u'-:-.
5-3
3/4 F _19.05 (3/4)
t
5.4. Selecting pipe size (Fig. 5-2)
Conversion formula
The piping connection size differs ac-
_9.52 mm cording to the type and capacity of indoor
Liquid units. Match the piping connection size of
(3/8 inch) branch box with indoor unit.
If the piping connection size of branch
box does not match the piping connection
size of indoor unit, use optional different-
_15.88 mm
Gas diameter (deformed) joints to the branch
(5/8 inch) box side. (Connect deformed joint directly
to the branch box side.)
Different-diameter joint (optional parts) (Fig. 5-3)
iiiiiiii
MAC-A454JP _a9.52 (3/8) --_ _a12.7 (1/2) _9.52 (3/8) _a12.7 (1/2)
MAC-A455JP _a12.7 (1/2) --_ _a9.52 (3/8) _12.7 (1/2) _a9.52 (3/8)
MAC-A456JP _a12.7 (1/2) --_ _a15.88 (5/8) _12.7 (1/2) _a15.88 (5/8)
PAC-493PI _a6.35 (1/4) --_ _a9.52 (3/8) _6.35 (1/4) _a9.52 (3/8)
PAC-SG78RJ-E _a9.52 (3/8) --_ _a15.88 (5/8) _9.52 (3/8) _a15.88 (5/8)
Piping preparation
Table below shows the specifications of pipes commercially available.
: i_i_
6.35 (1/4) 8 (5/16)
9.52 (3/8) 8 (5/16) Heat resisting foam plastic 0.045
12.7 (1/2) 8 (5/16) specific gravity
15.88 (5/8) 8 (5/16)
) Ensure that the 2 refrigerant pipes are insulated to prevent condensation.
Refrigerant pipe bending radius must be 4" (100 ram) or more.
z_ Caution
Be sure to use the insulation of specified thickness. Excessive thickness
may cause incorrect installation of the indoor unit and branch box, and
lack of thickness may cause dew drippage.
2-branch pipe (Joint) : Optional parts (According to the connection method,
you can choose the favorite one.
MSDD-50AR-E flare
MSDD-50BR-E brazing
• installation procedure (2 branches pipe (Joint))
Refer to the installation manuals of MSDD-50AR-E and MSDD-50BR-E.
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