Mitsubishi Electric PURY-WP-YJM-A, Data Book

Page: 203 / 220

3. Piping Design
SYSTEM DESIGN 4 - 32
System
3-3. Refrigerant charging calculation
Sample connection
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
Amount of factory charged refrigerant
Sample calculation
Outdoor unit
Model
WP200
WP250
Charged amount
11.8 kg
Indoor 1: 50 A: ø19.05 42 m
At the
conditions
on the right:
2: 50
3: 50
4: 40
Outdoor WP250
The total length of each liquid line is as follows:
ø19.05: A = 42 m
Therefore,
<Calculation example>
Additional refrigerant charge
= 42 × 0.16 + 3.0
= 9.72 kg
* All pipe work except A is water pipe work.
•
•
•
[WP200, WP250YJM]
A
Outdoor unit
HBC controller
Indoor unit
(20 ~ 50)
Additional refrigerant
charge
=
High-pressure
pipe size
Total length of ø19.05
×0.16
+
High-pressure
pipe size
Total length of ø15.88
×0.11
(kg) (m)×0.16 (kg/m) (m)×0.11 (kg/m)
+
Total Outdoor Unit
Model Name
HBC controller
WP200, 250 3.0 kg
Indoor unit
(20 ~ 50)
Indoor unit
(20 ~ 50)
Indoor unit
(20 ~ 50)