1-13. Example Of Tubing Size Selection And Refrigerant - Panasonic U-4LE1E5 Installation Instructions Manual

1-13. Example of Tubing Size Selection and
Refrigerant Charge Amount
Additional refrigerant charging
Based on the values in Tables 1-2, 1-3, 1-4 and 1-7, use the
liquid tubing size and length, and calculate the amount of
additional refrigerant charge using the formula below.
Required additional
refrigerant charge (kg)
(a): Liquid tubing Total length of ø9.52 (m)
(b): Liquid tubing Total length of ø6.35 (m)
● Charging procedure
Be sure to charge with R410A refrigerant in liquid form
1. After performing a vacuum, charge with refrigerant from
the liquid tubing side. At this time, all valves must be in the
"fully closed" position.
2. If it was not possible to charge the designated amount,
operate the system in Cooling mode while charging with
refrigerant from the gas tubing side. (This is performed at
the time of the test run. For this, all valves must be in the
"fully open" position.)
Charge with R410A refrigerant in liquid form.
With R410A refrigerant, charge while adjusting the
amount being fed a little at a time in order to prevent liquid
refrigerant from backing up.
● After charging is completed, turn all valves to the "fully open"
position.
● Replace the tubing covers as they were before.
Tightening torque for
valve stem cap:
19 – 21 N·m
3
Tightening torque:
34 – 42 N·m
2
Tightening torque for valve
stem cap: 28 – 32 N·m
CAUTION
1. R410A additional charging absolutely must be done
through liquid charging.
2. The R410A refrigerant cylinder has a gray base color,
and the top part is pink.
3. The R410A refrigerant cylinder includes a siphon tube.
Check that the siphon tube is present. (This is indicated
on the label at the top of the cylinder.)
4. Due to differences in the refrigerant, pressure, and
refrigerant oil involved in installation, it is not possible in
some cases to use the same tools for R22 and for R410A.
AMP Air Conditioning
= [56 × (a) + 26 × (b)] × 10
4
1
Tightening torque:
68 – 82 N·m
Example:
LA
Main tube
of unit
–3
1st branch
Unit distribution
tube
● Example of each tubing length
Main tubing
LA = 40 m
LB = 5 m
LC = 5 m
LD = 15 m
● Obtain charge amount for each tubing size
Note that the charge amounts per 1 meter are different for
each liquid tubing size.
ø9.52 → LA + LB + LC + LD : 65 m × 0.056 kg/m = 3.64 kg
ø6.35 → 1+ 2+ 3+ 4+ 5 : 23 m × 0.026 kg/m = 0.598 kg
Additional refrigerant charge amount is 4.238 kg.
CAUTION
Be sure to check the limit density for the room in which the
indoor unit is installed.
10
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L1
L2
LB LC LN
n
2 3
1 n–1
type type type type
22 28 36 45
Distribution joint tubing
Indoor side
1 = 5 m 4 = 6 m
2 = 5 m 5 = 5 m
3 = 2 m
type
56
Total 4.238 kg