Refrigerant Piping Work; Insulating Refrigerant Pipes; Drain Piping Work - Mitsubishi Electric CMB-PW202V-J Installationshandbuch

4.2. Refrigerant piping work

After connecting the refrigerant pipes of all indoor and outdoor units with the out-
door units' stop valves remained fully closed, evacuate vacuum from the outdoor
units' stop valve service ports.
After completing the above, open the outdoor units' stop valves. This connects the
refrigerant circuit (between outdoor and BC controller) completely.
How to handle stop valves is described on each outdoor unit.
Notes:
• After pipe connection, be sure to check that there is no gas leakage,
using a leak detector or soap-and-water solution.
• Before brazing the refrigerant piping, always wrap the piping on the main
body, and the thermal insulation piping, with damp cloths to prevent heat
shrinkage and burning the thermal insulation tubing. Take care to ensure
that the flame does not come into contact with the main body itself.
• Do not use leak-detection additives.
Warning:
Do not mix anything other than the specified refrigerant (R410A) into the
refrigerating cycle when installing or moving. Mixing air may cause the re-
frigerating cycle to reach abnormally high temperature, resulting in burst
pipes.
Caution:
Cut the tip of the indoor unit piping, remove the gas, and then remove the
brazed cap.
[Fig. 4.2.1] (P.4)
A Cut here

4.3. Insulating refrigerant pipes

Be sure to wind heat-resisting polyethylene form of more than 20 mm in thickness
onto both liquid and gas pipes and also put it onto the joints between indoor unit
and insulating material so that there will be no gaps. Incomplete insulation may
cause excess condensation or heat losses. Pay careful attention, particularly when
insulating above the ceiling.
Note:
Be sure to mount the insulation so that the slit is on the top.
[Fig. 4.3.1] (P.4)
A Locally procured insulating material for pipes
B Bind here using band or tape.
D Lap margin: more than 40
F Unit side insulating material
B Remove brazed cap
C Do not leave any opening.
E Insulating material (field supply)

4.4. Drain piping work

1. Drain piping work
• Ensure that the drain piping is downward (pitch of more than 1/100) to the
outdoor (discharge) side. If it is impossible to take any downward pitch, use an
optionally available drain-up mechanism to obtain a downward pitch of more
than 1/100.
• Ensure that any cross-wise drain piping is less than 20 m. If the drain piping is
long, support it with metal brackets to prevent it from bending, warping, or
vibrating.
• Connect the supplied drain hose to the discharge port on the unit body. Use
hard vinyl chloride pipes VP-25 (ø32) for drain piping (2). Tighten the supplied
drain hose onto the discharge port using the supplied hose band. (For this, do
not use any adhesive because the drain hose will need to be removed for
servicing at a later date.)
• Do not use any odor trap around the discharge port.
[Fig. 4.4.1] (P.4)
A: 25 cm
B: 1.5 – 2 m
A Downward pitch of more than 1/100
B Insulating material
D Drain discharge port
F Tie band (accessory)
• As shown in 3, install a collecting pipe about 10 cm below the drain ports and
give it a downward pitch of more than 1/100. This collecting pipe should be of
VP-30.
• Set the end of drain piping in a place without any risk of odor generation.
• Do not put the end of drain piping into any drain where ionic gases are gener-
ated.
• Drain piping may be installed in any direction. However, please be sure to
observe the above instructions.
• When using an optionally available drain-up mechanism, follow its instruction
manual regarding its installation and use.
[Fig. 4.4.2] (P.4)
A BC controller
C Collecting pipe
2. Discharge test
After completing drain piping work, open the BC controller panel, and test drain
discharge using a small amount of water. Also, check to see that there is no water
leakage from the connections.
3. Insulating drain pipes
Provide sufficient insulation to the drain pipes just as for refrigerant pipes.
Caution:
Be sure to provide drain piping with heat inslation in order to prevent excess
condensation. Without drain piping, water may leak from the unit causing
damage to your property.
C Supporting bracket
E Drain hose (200 mm long, accessory)
G Hose band (accessory)
B
Indoor unit
D
Please ensure this length is at least 10 cm.
9