Additional Refrigerant Charge - Mitsubishi Electric City Multi PURY-HP-TNU-A Série Manuel D'installation

9-9. Additional refrigerant charge

Charge refrigerant in a liquid state.
- Charging refrigerant in the gaseous state will change the composition of the refrigerant and lead to a performance drop.
Do not use a charging cylinder when charging refrigerant.
- The use of a charging cylinder may change the composition of the refrigerant and lead to a performance drop.
The amount of refrigerant that is shown in the table below is factory-charged in the outdoor units. The amount necessary for extended piping is not
included and needs to be added on site.
Unit model Factory-charged amount [kg (oz)]
HP72
HP96
HP120
The amount of refrigerant that is shown in the table below is the maximum amount to be added on site.
Unit model Maximum amount to be added [kg (oz)]
HP72T/YNU
HP96T/YNU
HP120T/YNU
HP144T/YSNU
HP192T/YSNU
HP240T/YSNU
Both refrigerant overcharge and undercharge will cause problems. Charge the system with the proper amount of refrigerant.
Record the added refrigerant amount on the label attached to the control box panel for future servicing.
9-9-1. Calculation of the amount of additional refrigerant
・The amount of refrigerant to be added depends on the size and the total length of the high-pressure piping and liquid piping.
・Calculate the amount of refrigerant to be charged according to the formula below.
・Round up the calculation result to the nearest 0.1 kg (0.1 oz).
(1) Units "m" and "kg" (In an R2 system)
<Formula>
・When the piping length from the outdoor unit to the farthest indoor unit is 30.5 m (100 ft) or shorter
Amount of
High-pressure pipe ø28.58
additional charge =
total length × 0.36 (kg/m)
(kg)
Liquid pipe ø12.7 total
+
length × 0.12 (kg/m)
Main or sub BC
controller
J-type
+
JA-type
KA-type
KB-type
* In the case all connected indoor unit models are Case 1 or Case 2, do NOT add the refrigerant listed in table Ⓐ. Instead, add the following
amount of refrigerant.
Case 1: PLFY-EP06/18/36NEMU-E**
Case 2: PEFY-P06/24/36NMAU-E**
WT09112X02
8.0 (283)
10.8 (381)
10.8 (381)
25.5 (900)
30.7 (1083)
36.7 (1295)
42.5 (1500)
52.4 (1849)
68.4 (2413)
High-pressure pipe ø22.2
+
total length × 0.23 (kg/m)
Liquid pipe ø9.52 total
+
length × 0.06 (kg/m)
Total capacity of
Amount (kg/unit)
connected indoor units
1.5 27 or below
3.0 28 to 54
4.7 55 to 126
0.4 127 to 144
145 to 180
+
181 to 234
235 to 273
274 to 307
308 to 342
343 to 411
412 to 450
451 or above
GB-25
High-pressure pipe ø19.05 High-pressure pipe ø15.88
+ +
total length × 0.16 (kg/m) total length × 0.11 (kg/m)
Liquid pipe ø6.35 total
+
length × 0.024 (kg/m)
Amount (kg)
(to be added for
indoor unit)
2.0
2.5
3.0
3.5
4.5
+
5.0
6.0
8.0
9.0
10.0
12.0
14.0
Liquid pipe ø15.88 total
+
length × 0.2 (kg/m)
Ⓐ
Total capacity of
Amount (kg)
outdoor units
72 1.5
96 1.5
120 3.0
144 2.5
168 4.0
192 4.0
216 4.5
240 5.0
264 2.5
288 1.5
312 2.0
336 2.0