Mitsubishi Electric PURY-WP-YJM-A Data Book page 203

3. Piping Design
3-3. Refrigerant charging calculation
Sample connection
[WP200, WP250YJM]
Outdoor unit
A
Indoor unit
(20 ~ 50)
Amount of additional refrigerant to be charged
Refrigerant for extended pipes (field piping) is not factory-charged to the outdoor unit. Add an appropriate amount of refrigerant for each
pipe on site.
Record the size of each high pressure pipe and liquid pipe, and the amout of refrigerant that was charged on the outdoor unit for future
reference.
Calculating the amount of additional refrigerant to be charged
• Calculate the amount of additional charge based on the length of the piping extension and the size of the refrigerant line.
• Use the table below as a guide for calculating the amount of additional charging and then charge the system accordingly.
• Always round up the calculation to the next 0.1 kg. For example, if the result of the calculation was 6.72 kg,
round the result up to 6.8 kg.
<Amount of additional refrigerant to be charged>
Calculating the amount of additional refrigerant to be charged
High-pressure
Additional refrigerant
charge Total length of ø19.05
=
(kg) (m)×0.16 (kg/m)
Total Outdoor Unit
HBC controller
+ Model Name
WP200, 250
Amount of factory charged refrigerant
Outdoor unit
Charged amount
Model
WP200
11.8 kg
WP250
Sample calculation
Indoor 1: 50 A: ø19.05
2: 50
3: 50
4: 40
Outdoor WP250
HBC controller
Indoor unit
(20 ~ 50)
High-pressure
pipe size pipe size
Total length of ø15.88
+
×0.16 ×0.11
(m)×0.11 (kg/m)
3.0 kg
The total length of each liquid line is as follows:
42 m ø19.05: A = 42 m
Therefore,
At the
<Calculation example>
conditions
Additional refrigerant charge
on the right:
= 42 × 0.16 + 3.0
= 9.72 kg
* All pipe work except A is water pipe work.
SYSTEM DESIGN
Indoor unit
(20 ~ 50)
Indoor unit
(20 ~ 50)
4 - 32