Toshiba HFC R-410A manual Selection of refrigerant piping

4. Selection of refrigerant piping

					Branching pipe	Header branching pipe
Slave	Slave	Slave	Master		Indoor unit connection piping
unit 3	unit 2	unit 1	unit
				Outdoor unit
				Balance pipe
				T-shape	Y-shape	Indoor unit
				branching joint
Outdoor unit					branching
connection				Main piping	joint
piping
		Main connection
		piping between		1st branching	Indoor unit
		outdoor units		section	connection piping

Indoor unit

Pipe size of outdoor unit (Table 1)

Model name	MMY-	Gas side	Liquid side
MAP0501T8	MAP0501HT8	Ø5/8”	Ø3/8”
MAP0601T8	MAP0601HT8	Ø3/4”	Ø3/8”
MAP0801T8	MAP0801HT8	Ø7/8”	Ø1/2”
MAP1001T8	MAP1001HT8	Ø7/8”	Ø1/2”
MAP1201T8	MAP1201HT8	Ø1-1/8”	Ø1/2”

Connecting pipe size between outdoor units (Table 2)

Total capacity code of	Gas side	Liquid side	Balance pipe
outdoor units downstream
14 to below 22	Ø1-1/8”	Ø5/8”	Ø3/8”
22 to below 26	Ø1-3/8”	Ø5/8”	Ø3/8”
26 to below 36	Ø1-3/8”	Ø3/4”	Ø3/8”
36 or more	Ø1-5/8”	Ø7/8”	Ø3/8”

Size of main pipe (Table 3)

Total capacity code of	Gas side	Liquid side
all outdoor units (*1)
Below 6	Ø5/8”	Ø3/8”
6 to below 8	Ø3/4”	Ø3/8”
8 to below 12	Ø7/8”	Ø1/2”
12 to below 14	Ø1-1/8”	Ø1/2”
14 to below 22	Ø1-1/8”	Ø5/8”
22 to below 26	Ø1-3/8”	Ø5/8”
26 to below 36	Ø1-3/8”	Ø3/4”
36 to below 46	Ø1-5/8”	Ø7/8”
46 or more	Ø1-5/8” (*5)	Ø7/8”

Determine thickness of the main pipe according to capacity of the outdoor units.

Pipe size between branching sections (Table 4)

Total capacity code of	Gas side	Liquid side
indoor units downstream (*1)
2.8 or less	Ø1/2”	Ø3/8”
2.8 to below 6.4	Ø5/8”	Ø3/8”
6.4 to below 12.2	Ø7/8”	Ø1/2”
12.2 to below 20.2	Ø1-1/8”	Ø5/8”
20.2 to below 25.2	Ø1-3/8”	Ø5/8”
25.2 to below 35.2	Ø1-3/8”	Ø3/4”
35.2 or more	Ø1-5/8”	Ø7/8”

If the total capacity code value of indoor units exceeds that of the outdoor units, apply the capacity code of the outdoor units.

Piping of indoor unit (Table 5)

Indoor unit size		Gas side	Liquid side
007 to 012	Actual length 15 m or less	Ø3/8”	Ø1/4”
	Actual length exceeds 15 m	Ø1/2”	Ø1/4”
015 to 018		Ø1/2”	Ø1/4”
024 to 056		Ø5/8”	Ø3/8”
072 to 096		Ø7/8”	Ø1/2”

Selection of branching section (Table 6)

		Total capacity code of indoor unit (*1)		Model
	Y-shape		Below 6.4	RBM-BY53E
branching joint			6.4 to below 14.2	RBM-BY103E
(*2)			14.2 to below 25.2	RBM-BY203E
			25.2 or more	RBM-BY303E
	Branching	For 4	Below 14.2	RBM-HY1043E
header		branching	14.2 to below 25.2	RBM-HY2043E
(*3)		For 8	Below 14.2	RBM-HY1083E
		branching	14.2 to below 25.2	RBM-HY2083E
	T-shape	1 set of 3 types of T-shape joint pipes as		RBM-BT13E
branching joint		described below:
(For connecting		The required quantity is arranged and
outdoor unit)		combined at the site.
		• Balance pipe (Corresponding difference
		Ø3/8”) × 1
		• Piping at liquid side (Corresponding
		difference Ø3/8” to Ø7/8”) × 1
		• Piping at gas side (Corresponding
		difference Ø5/8” to Ø1-5/8”) × 1

Minimum wall thickness for R-410A application (Table 7)

Soft	Half hard or hard	OD (Inch)	Minimum wall thickness (mm)
OK	OK	1/4”	0.80
OK	OK	3/8”	0.80
OK	OK	1/2”	0.80
OK	OK	5/8”	1.00
NG	OK (*4)	3/4”	1.00
NG	OK (*4)	7/8”	1.00
NG	OK (*4)	1-1/8”	1.00
NG	OK (*4)	1-3/8”	1.10
NG	OK (*4)	1-5/8”	1.25

*1 Code is determined according to the unit size. For details, refer to pages 7-9.

*2 When using Y-shape branching joint for 1st branching, select according to capacity code of outdoor unit.

*3 For one line after header branching, indoor units with a maximum of 6.0 capacity code in total can be connected. *4 If the pipe size is Ø3/4” or more, use a hard type or half hard type for material of the pipe.

*5 The maximum equivalent length of the main pipe should be 70 m or shorter.

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