250B8W1B
Split system air conditioner
4PW25544-1A
Installation manual
8
7.10. Checking of unit and installation conditions
Be sure to check the following:
1
Make sure there is no faulty power wiring or loosing of a nut.
See
2
Make sure there is no faulty transmission wiring or loosing of a
nut. See
3
Make sure there is no faulty refrigerant piping. See
"7. Refrigerant piping" on page 4
4
Make sure piping size is correct. See
5
Make sure insulation work is done. See
6
Make sure insulation resistance of main power circuit is not
deteriorated.
Using a megatester for 500
V, check that the insulation
resistance of 2 M
Ω
or more is attained by applying a voltage of
500 V DC between power terminals and earth. Never use the
megatester for the transmission wiring (between outdoor and
indoor unit, outdoor and COOL/HEAT selector, etc.).
7.11. Stop valve operation procedure
Introduction
Confirm the sizes of the stop valves connected to the system
referring to the table below.
Opening stop valve
1.
Remove the cap and turn the valve counterclockwise with the
hexagon wrench.
2.
Turn it until the shaft stops.
Do not apply excessive force to the stop valve. Doing so may break
the valve body, as the valve is not a backseat type. Always use the
special tool.
3.
Make sure to tighten the cap securely.
Closing stop valve
1.
Remove the cap and turn the valve clockwise with the hexagon
wrench.
2.
Securely tighten the valve until the shaft contacts the main body seal.
3.
Make sure to tighten the cap securely.
For the tightening torque, refer to the table below.
CAUTION
■
Always use a charge hose for service port connection.
■
After tightening the cap, check that no refrigerant leaks are
present.
7.12. Additional refrigerant charge
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.
Do not open the stop valve until the steps
"7.10. Checking of unit and installation conditions" on
page 8
are completed. If the stop valve is left open without
turning on the power, it may cause refrigerant to buildup in
the compressor, leading to insulation degradation.
Model
Liquid line stop valve
Gas line stop valve
RZQ200
Ø9.5
Ø22.2
RZQ250
Ø12.7
Ø22.2
Tightening torque (N•m) (Turn clockwise to close)
stop
valve
size
Shaft (valve body)
Cap
(valve lid)
Service
port
Flare nut
Gas line
piping
attached
to unit
Ø9.5
5.4~6.6
Hexagonal
wrench
4 mm
13.5~16.5
11.5~13.9
33~40
—
Ø12.7
8.1~9.9
18~22
50~60
Ø15.9
13.5~16.5
Hexagonal
wrench
6 mm
23~27
62~75
Ø22.2
27~33
Hexagonal
wrench
10 mm
36~44
—
22~28
Ø25.4
1
Service port
2
Cap
3
Hexagon hole
4
Shaft
5
Seal
When performing service on the unit requiring the
refrigerant system to be opened, refrigerant must be
evacuated according to local regulations.
