Mitsubishi Electric MXZ-8B48NA Manual De Instalación página 7

5. Installing the refrigerant piping
5.3. Addition of refrigerant
¢ Additional charging is not necessary for this unit if the total pipe length
(b1+b2+a1+a2+a3+a4+a5+a6+a7+a8) does not exceed 40 m (131 ft.).
CM MMe elie tae Caoece- MMe im merle mm mdi!
additional R410A refrigerant according to the permitted pipe lengths in
the chart below.
* 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 vaive using a safe-
ty charger. Do not add liquid refrigerant directly to the check vaive.
* After charging the unit with refrigerant, note the added refrigerant
amount on the service label (attached to the unit).
Refer to the "1.5. Using R410A refrigerant air conditioners" for more information.
Table 1
Total piping length
(b1+b2+a1+a2+a3+a4+a5+a6+a7+a8) 41-50 m] 51-70 m]|77- 90 m]91-4115m
(136 - 164 ft) | (485 -230 ft) | (234 - 295 #.) | (296 - 377 ft)
Additional refrigerant charging amount | 0.6 kg
(21 oz)
1.4 kg
(49 oz)
2.2 kg
(78 oz)
3.2 kg
(113 oz)
If connecting an indoor unit with 29.52 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 foz/ft] x @9.52 (3/8 inch) branch pipe (liquid pipe) total length [ft])
Example) b1 = 20 m (66 ft.), b2 = 25 m (82 ft.)
Indoor unit A 29.52 (3/8) Liquid pipe a1=12 m G9 ft.)
Indoor unit B 26.35 (1/4) Liquid pipe a2=11 m G6 ft.)
Indoor unit © 26.35 (1/4) Liquid pipe a6=14 m (46 ft.)
Indoor unit D 29.52 (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 #9.52 (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 (a1+a7)
= 0.01 x (12+13 m) [0.107 x(39+43 ft.)]
= 0.25 kg (9 0z)
Therefore, the additional refrigerant charging amount is
3.2 kg + 0.25 kg = 3.45 kg [113 02 + 9 oz =122 oz].
Hi In case of using 1-branch box
Flare connection employed. (No. brazing)
Branch box
ea
5.4. Selecting pipe size (Fig. 5-2)
Conversion formula
The piping connection size differs ac-
cording to the type and capacity of indoor
units. Match the piping connection _ size of
branch box with indoor unit.
If the piping connection size of branch
29.52 mm
(3/8 inch)
Hi In case of using 2-branch boxes
2 branches pipe (joint)
: optional parts.
Branch box #1
Branch box #2
Fig. 5-2
(1) Valve size for outdoor unit
For liquid
For gas
29.52 mm (3/8 inch)
215.88 mm (5/8 inch)
(2) Valve size for branch box
* 3-branch type : only [Al, ], [Cl unit
Conversion formula
— 1/4 F | 06.35 (1/4)
get BN. Ger perr an)
Siz.
A LI
B
5/8 F | #15.88 (5/8)
Fig. 5-3 3/4 F | @19.05 (3/4)
box does not match the piping connection
size of indoor unit, use optional different
215.88 mm | . o s
Gas 5/8 inch 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)
MAC-A454JP
MAC-A455JP
29.52 > 012.7 (1/2
012.7 (1/2) — 99 52
MAC-A456JP | 012.7 (1/2) — 015.88 (5/8
PAC-493P| 96.35 (1/4) — 99 52
PAC-SG76RJ-E | 09.52 — 015.88 (5/8
Piping preparation
@ Table below shows the specifications of pipes commercially available.
Outside diameter Insulation Inickness
29.52
12.7 (1/2
12.7 (1/2
96.35 (1/4
29.52
12.7 (1/2
9.52 (3/8
215.88 (5/8
29.52 (3/8
215.88 (5/8
Insulation maternal
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 mm) 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.
Connection method
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.