Toshiba MMU-AP0091H Owner's Manual Installation And Operation page 44

5
REFRIGERANT PIPING
Addition of refrigerant
After vacuuming work, exchange the vacuum pump with the refrigerant bomb and then start the additional charging
work of refrigerant.
Calculation of additional refrigerant charge amount
Refrigerant charge amount at shipment from the factory does not include the refrigerant for pipe at the local site.
For refrigerant to be charged in pipe at the local site, calculate the amount and charge it additionally.
NOTE) If the additional refrigerant amount indicates minus as the result of calculation, use the air conditioner
without addition of refrigerant.
Outdoor unit Model
Charging amount (kg)
Additional refrigerant
charge amount at local site
Example : Additional charge amount R (kg) = {(L1 × 0.025kg/m) + (L2 × 0.055kg/m) + (L3 × 0.105kg/m)} × 1.3
Table-1
Liquid Additional refrigerant
pipe dia. amount/1m liquid pipe
(mm) (kg/m)
6.4 0.025
9.5 0.055
12.7 0.105
15.9 0.160
19.1 0.250
22.2 0.350
Charging of refrigerant
• Keeping valve of the outdoor unit closed, be sure to charge the liquid refrigerant into service port at liquid side.
• If the specified amount of refrigerant cannot be charged, open fully valves of outdoor unit at liquid and discharge/
suction gas sides, balance side operate the air conditioner in COOL mode under condition that valve at suction
gas side is a little returned to close side, and then charge refrigerant into service port at suction gas side. In this
time, choke the refrigerant slightly by operating valve of the bomb to charge liquid refrigerant.
The liquid refrigerant may be charged suddenly, therefore be sure to charge refrigerant gradually.
• When refrigerant leaks and refrigerant shortage occurs in the system, recover the refrigerant in the system and
recharge refrigerant newly up to the correct level.
<Entry of refrigerant charge amount>
• Fill the additional refrigerant record column of the wiring diagram indication plate with the additional refrigerant
amount at installation work, total refrigerant amount and the name of the service man who charged refrigerant
at installation time.
• The total refrigerant amount means the total value of the refrigerant amount at shipment and the additional
refrigerant amount at installation time. The refrigerant amount at the shipment is one described on the "Unit
nameplate".
MMY-MAP0802FT8

Real length Additional refrigerant charge
= ×

of liquid pipe amount per 1m liquid pipe (Table 1)
L1 : Real total length of liquid pipe Ø6.4 (m)
L2 : Real total length of liquid pipe Ø9.5 (m)
L3 : Real total length of liquid pipe Ø12.7 (m)
System : 10HP
Table-2
Combined
(HP)
8
10
12
16
18
20
24
26
28
30
REQUIREMENT
MMY-MAP1002FT8
11.5
Combined outdoor unit
(HP)
8
10
12
8 8
10 8
10 10
8 8 8
10 8 8
10 10 8
10 10 10
41
MMY-MAP1202FT8

× 1.3

C (Corrected refrigerant amount)
(kg)
2.0
2.5
3.0
–1.5
0.0
2.0
–4.5
–3.0
–1.5
0.0