Refrigerant Piping Work; Insulating Refrigerant Pipes; Drain Piping Work - Mitsubishi Electric CITY MULTI CMB-P-V-E Serie Manuel D'installation

4.2. Refrigerant piping work

After connecting the refrigerant pipes of all indoor and outdoor units with
the outdoor units' stop valves remained fully closed, evacuate vacuum
from the outdoor units' stop valve service ports.
After completing the above, open the valve rods of the indoor 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:
• Before tightening the flare nut, apply refrigerating machine oil
lightly over the valve flare surface and its seating surface.
• Use a double spanner for pipe connection.
• After pipe connection, be sure to check that there is no gas leak-
age, using a leak detector or soap-and-water solution.
Warning:
Do not mix anything other than the specified refrigerant (R-22 or
R407C) into the refrigerating cycle when installing or moving. Mix-
ing air may cause the refrigerating cycle to get abnormally high
temperature, resulting in a burst.

4.3. Insulating refrigerant pipes

Be sure to wind heat-resisting polyethylene form of more than 10mm in
thickness onto both liquid and gas pipes and also put it into the joints
between indoor unit and insulating material so that there will be no gap.
Incomplete insulation may cause a risk of dew drop. Pay careful atten-
tion, particularly when insulating above the ceiling.
Connections between unit and locally procured pipe
B
A
D
E
A Locally procured insulating material for pipes
B Bind here using band or tape.
C Do not have any opening.
D Lap margin: more than 40
E Insulating material (field supply)
F Unit side insulating material
10
C
F
Insulating using accessory pipe cover
A
G
G Sealing tape
H Joint (Do not have any opening.)
I Supplied pipe cover
J Bind here using accessory band.
K Glue here using adhesive. Peel off separator for use.

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 down-
ward 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 20m. If the drain
piping is long, provide metal braces to prevent it from waving. Never
provide any air vent pipe. Otherwise drain may be ejected.
• 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 be removed for service later.)
• Do not have any odor trap around the discharge port.
K
I
J
F
H