Refrigerant Piping - Toshiba RAS-M18UAV-E Installation Manual

6 REFRIGERANT PIPING

How to remove the service valve cover
• Remove the three screws.
Pull the service valve cover in the direction of the arrow, and remove it.
•
Refrigerant piping connection
Flaring
1. Cut the pipe with a pipe cutter.
2. Deburr the inside of the pipe at its end.
Take steps to ensure that the removed burrs will not enter the pipe.
3. Remove the flare nuts provided with the indoor and outdoor units, and insert them
into the pipe.
4. Flare the pipe.
The projection margin of the pipe must be checked.
5. Check that the flare has the appropriate shape.
Die
Pipe
Pipe
Rigid
Outside
Thickness (clutch type)
diameter
R410A tool
mm mm mm
6.35 0.8 0 to 0.5
9.52 0.8 0 to 0.5
12.7 0.8 0 to 0.5
Pipe connection
1. Ensure that the same wires and pipes are used for connecting all the indoor and
outdoor units.
2. Align the centers of the connecting pipes and tighten the flare nut as much as
possible with your fingers. Then tighten the nut with a wrench and torque wrench
as shown in the table above.
• If the indoor units have different capacities, connect them in the sequence of A
and B starting with the unit which has the highest capacity.
• Do not remove the flare nuts in any of the rooms where an indoor unit is not
going to be connected.
• Do not leave the pipes with their flare nuts removed standing for a prolonged
period of time.
• When connecting a capacity class 16 pipe to the indoor unit, attach the
expander which is available as an optional accessory to the 9.52 mm diameter
service valve of the outdoor unit.
• When attaching the expander to the outdoor unit, be sure to fix the service valve
with a wrench.
EN
Service valve cover
Obliquity Roughness
A B Flare Nut
Imperial
(wing nut
C
type)
R410A tool
mm mm mm N•m
1.5 to 2.0 9.1 17 14 to 18
1.5 to 2.0 13.2 22 33 to 42
2.0 to 2.5 16.6 26 50 to 62
Air purge
Undertake the steps described below in each of the two rooms.
With respect to the preservation of the terrestrial environment, adopt "Vacuum pump"
to purge air (Evacuate air in the connecting pipes) when installing the unit.
* Hexagon wrench (4 mm) is required.
1. Connect the charge hose. *1
• Check that the handle Hi (manifold valve) is closed completely.
• Attach the connecting port of the charge hose on the end with a projection to
push the valve core (setting pin) to the service port of the set.
*1 When a control valve or charge valve is connected between the charge hose
and service port, the R410A refrigerant can definitely be prevented from being
discharged to the atmosphere during the air purging process.
2. Open Handle Lo fully. Turn ON the vacuum pump.
• Loosen the flare nut of the connected pipe (Gas side) a little to check that the air
Screw
passes through. Retighten the flare nut.
• If the air fails to enter, check whether the charge hose is connected securely to
the service port.
• Purge the air for 15 or more minutes, and check that a pressure level of
–101 kPa (–76 cmHg) is indicated on the compound pressure gauge.
• If the compound pressure gauge fails to indicate a pressure level of –101 kPa
(–76 cmHg), it may mean that air is infiltrating from an area where a pipe is
connected or other place. Check the areas where the pipes are connected.
3. Close Handle Lo completely. Turn OFF the vacuum pump.
• Leave the vacuum pump as it is for 1 or 2 minutes, and check that the indicator
of the compound pressure gauge does not return.
• No more refrigerant needs to be added if the total pipe length is no more than
20 meters.
• Add 20 g of refrigerant for every 1 m of piping that exceeds 21 m.
4. Disconnect the charge hose from the service port. Open the valve shaft fully with
a hexaganal wrench.
5. Tighten the service port cap and valve stem cap securely.
• Securely tighten these caps with torque in the following table.
6. Check the gas leaks after connection.
Service valve
Liquid side (6.35)
Warp
Gas side (9.52)
Tighten torque
kgf•m
1.4 to 1.8
3.3 to 4.2
5.0 to 6.2
Service port
(Valve core (Setting pin))
Service port cap
CAUTION
Install in rooms that are 5 m
room, an oxygen deficiency can occur.
5
Valve stem cap
N•m kgf•m
14 to 18 1.4 to 1.8
33 to 42 3.3 to 4.2
Compound pressure gauge
–101 kPa (–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Connecting pipe
Service valve at liquid side
Service valve at gas side
3
or larger. If a leak of refrigerant gas occurs inside the
Tighten torque
Service port cap
N•m kgf•m
– –
14 to 18 1.4 to 1.8
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Charge hose
(For R410A only)
Vacuum pump adapter for
counter-flow prevention (For
R410A only)
Vacuum
pump
4 mm
Valve stem cap