250C7Y1B
Split system air conditioner
4PW34720-1G – 07.2010
Installation manual
9
Precaution for servicing
This unit requires additional charging of refrigerant according to the
length of pipe connected at the site. Charge the refrigerant to the
liquid pipe in its liquid state through the serviceport of the liquid stop
valve. Since R410A is a mixed refrigerant, its composition changes if
charged in a state of gas and normal system operation would no
longer be assured.
On this model it is not necessary to charge additionaly if the standard
pipe size in pair combination is used and if the total piping length
≤
30 m.
Additional charging of refrigerant
Installations with total piping lengths
≤
30 m do not require additional
charging of refrigerant.
For total piping lengths over 30 m, calculate the required additional
refrigerant in function of the calculated length and pipe diameters like
explained in the following procedure.
1
Add up the total piping length.
•
In case the result is
≤
30 m, your installation does not require
any additional charge.
•
In case the result is over 30 m, proceed as explained from
step 2 onwards.
2
Subtract 30 m from the calculated total piping length. Take note
of this rest value and, starting from the outdoor unit, check the
exact position in the refrigerant flow where you reach this rest
value.
3
Determine the pipe diameter at that position in the refrigerant
flow.
4
From that same position on, add up the remaining pipe lengths
of that same pipe diameter downstream to the indoor unit(s).
5
Determine the required additional refrigerant charge in function
of the calculated pipe length of that pipe diameter by multiplying
that length by the appropriate calculation coefficient.
Take note of the calculated weight.
6
Repeat step 5 for other pipe diameters in function of other pipe
diameter pipe lengths downstream to the indoor units and add
up all calculated weights.
7
The sum of all calculated weights is the total required additional
refrigerant charge for your installation.
The final result must be rounded to 100 g.
8
Calculation coefficients
9
See the examples below for a clear understanding.
When performing service on the unit requiring the
refrigerant system to be opened, refrigerant must be
evacuated according to local regulations.
Ø
Coefficient
12.7
0.09
9.5
0.05
6.4
0.03
Example 1
L=80 m
Ø12.7
Chargeless length = 30 m
Additional refrigerant charge = (80–30)x0.09 = 50x0.09 = 4.5 kg
Example 2
L2=7 m
100 type
Ø9.5
200 type
L1=35 m
indoor
Ø9.5
L3=5 m
100 type
Ø9.5
Chargeless length = 30 m
Additional refrigerant charge
= ((35+7+5)–30)x0.05 = 17x0.05 = 0.85 kg = 0.9 kg
Example 3
L2=7 m
60 type
Ø6.4
200 type
L1=5 m
L3=17 m
60 type
Ø9.5
Ø6.4
L4=10
m
60 type
Ø6.4
Chargeless length = 30 m
Ø9.5
(30–5) = 25 m
Ø6.4
25–(7+17+10) = –9 m
Additional refrigerant charge = 9x0.03 = 0.27 kg = 0.3 kg
Example 4
L4=10 m
60 type
Ø6.4
L2=5 m
Ø9.5
L5=7 m
60 type
Ø6.4
250 type
L1=25 m
Ø12.7
L6=7 m
60 type
Ø6.4
L3=5 m
Ø9.5
L7=5 m
60 type
Ø6.4
Chargeless length = 30 m
Ø12.7 (30–25) = 5 m
Ø9.5
5–(5+5) = –5 m
Ø6.4
10+7+7+5 = 29 m
Additional refrigerant charge = (5x0.05)+(29x0.03) = 1.12 kg = 1.1 kg
In case of complete recharge of the refrigerant, please first
execute vacuuming. Vacuuming must be executed using
the both 2 service ports situated on the piping inside the
airconditioning outdoor unit simultaneously.
Make sure that both stop valves are open for vacuuming.
Vacuuming can not be executed completely using the ports
on the stop valves.
