Mitsubishi Electric PLFY-WP VBM-E, Data Book

Page: 180 / 192

3 - 27
3. Piping Design
S.D. WR2
MEE15K052
3-3. Refrigerant charging calculation
<Amount of refrigerant to be added>
The amount of refrigerant that is shown in the table below is factory-charged to the heat source units.
The amount necessary for extended pipe (field piping) is not included and must be added on site.
Round up the calculation result to the nearest 0.1kg. (Example: 18.04kg to 18.1kg)
× 2
Heat source
unit model
Amount of pre-charged refrigerant Amount of pre-charged refrigerant
in the heat source unit (kg)
Heat source
unit model
in the heat source unit (kg)
P200YLM 5.0 P400YLM 6.0
P250YLM 5.0 P450YLM 6.0
P300YLM 5.0 P500YLM 6.0
P350YLM 6.0
■ Calculation formula
The amount of refrigerant to be added depends on the size and the length of field piping. (unit in m[ft])
1) When the distance between HBC and heat source unit is longer than 30.5m:
Amount of added refrigerant (kg) = (0.21xL
1
)+(0.14xL
2
)+(0.1xL
3
)+α
1
2) When the distance between HBC and heat source unit is 30.5m or shorter:
Amount of added refrigerant (kg) = (0.23xL
1
)+(0.16xL
2
)+(0.11xL
3
)+α
1
L
1
: Length of ø22.20 [7/8"] high pressure pipe (m)
L
2
: Length of ø19.05 [3/4"] high pressure pipe (m)
L
3
: Length of ø15.88 [5/8"] high pressure pip (m)
α
1
: Refer to the table below.
Use of one HBC controller
Heat source unit index Diameter of high-pressure pipe
P200 ø15.88
P250 ø19.05
P300 ø19.05
P350 ø19.05
Amount for the HBC controller
α1 (kg) α1 (kg)
3.0
Use of two HBC controllers
Heat source unit index Diameter of high-pressure pipe
P300 ø19.05
P350 ø19.05
P400 ø22.20
P450 ø22.20
Amount for the HBC controller
3.0
P500 ø22.20
Example
■ Sample calculation
A
Heat source unit
(~P350)
HBC controller
Indoor unit
(15 ~ 50)
Indoor unit
(15 ~ 50)
Indoor unit
(15 ~ 50)
Indoor unit
(15 ~ 50)
A
B
C
D
Heat source unit
(P300~)
HBC controller
HBC controller
Indoor unit
(15 ~ 50)
Indoor unit
(15 ~ 50)
Indoor unit
(15 ~ 50)
Indoor unit
(15 ~ 50)
Indoor 1: 50 A: ø19.05 42 m
2: 50
3: 50
4: 40
Heat source P250
The total length of each liquid line is as follows:
ø19.05: A = 42 m, α
1
= 3.0
Therefore,
<Calculation example>
Additional refrigerant charge
= 42 × 0.14 + 3.0
= 8.88 kg
* All pipe work except A is water pipe work.
Indoor 1: 50 A:ø22.20 18 m
2: 50 B:ø15.88 5 m
3: 50 C:ø15.88 10 m
4: 50 D:ø15.88 8 m
Heat source P400
The total length of each liquid line is as follows:
ø22.20: A = 18 m, ø15.88: B + C + D = 23m, α
1
= 3.0 × 2
Therefore,
<Calculation example>
Additional refrigerant charge
= 18 × 0.23+ (5 + 10 + 8) × 0.11 + 3.0 × 2
= 12.67 kg
* All pipe work except A, B, C, D is water pipe work.
= 8.9 kg
= 12.7 kg
0000003907.BOOK 27 ページ ２０１６年２月１８日 木曜日 午前１０時５３分