Drainage Piping Work; Gas Pipe Insulation (Large); Liquid Pipe Insulation (Small); Drain Socket - Mitsubishi Electric PSA-RP71GA Manuel D'installation

4. Installing the refrigerant piping
b
a
c
e
f
Fig. 4-4
2
a
1
b
3
d
c
3
e
Fig. 4-5

5. Drainage piping work

a
Fig. 5-1
a
Fig. 5-2
6
a Air intake grill
b Pipe support
c Hanger
d Side panel
e Screw
f 4 × 10 tapping screw
c
d
a Liquid pipe
b Gas pipe
c Frame
d Square hole
e Pass the band through the square hole in the
frame to hold the refrigerant pipes in place.
1 Gas pipe insulation
2 Liquid pipe insulation
3 Band
b
a Drain hose
b Drain socket
c
c Drain pipe VP20 (obtain locally)
c
b
a Heat exchanger
d
b Side plate
c Water
d Inside wall
e e Drain pan
Refrigerant piping connection (Fig. 4-4)
1. Remove the screw from the air intake grill handle and then remove the air intake
grill by pulling it up and forward.
2. Remove the tapping screw that holds the pipe support in place and then remove
the pipe support.
• After finishing this work, always reassemble the unit.
• When reassembling, hook the air intake grill hangers c onto the holes in the sides
of the panels.
Insulate flare joints 1 and 2 of the gas and refrigerant pipes completely. If any part
of the joints are exposed, condensation can drip down. (Fig. 4-5)
• Fasten the gas pipe insulation 1 and the liquid pipe insulation 2 at both ends so
that they will not slip and align with one another.
• After the insulation is installed, use a band 3 to fasten the refrigerant pipe to the
frame (below the pipe joint section). This will prevent the refrigerant pipe from lifting
up off of the frame.
(When the refrigerant pipe is off of the frame, the grille cannot be installed.)
• After connecting the refrigerant piping to the indoor unit, be sure to test the pipe
connections for gas leakage with nitrogen gas. (Check that there is no refrigerant
leakage from the refrigerant piping to the indoor unit.)
Conduct the airtightness test before connecting the outdoor unit stop valve and the
refrigerant pipe.
If the test is conducted after the valve and pipe are connected, gas, which is used
for checking the airtightness, will leak from the stop valve and flow into the outdoor
unit, resulting in abnormal operation.
5.1. Drainage Piping Work (Fig. 5-1)
• Install the drain pipe so that it slopes downward (1/100 or more).
• Use VP20 (O.D. ø26 PVC TUBE) for the drain pipes.
• The drain hose can be cut with a knife to match on-site requirements.
• When connecting to the VP20, use the accessory drain socket b. Securely fasten
the socket to the pipe with vinyl chloride type adhesive so that it doesn't leak.
• Do not insert the drain pipe directly into a location where sulfur-containing gas is
likely to be generated (i.e. a sewer).
• Make sure that no water leaks from the drain pipe joint.
• If the drain pipe passes through an indoor area, wrap commercially available insu-
lation (polyethylene foam of specific gravity 0.03 with a thickness of 9 mm or more)
around it and cover the surface with tape. This will prevent air from entering and
condensation from forming.
5.2. Drainage check (Fig. 5-2)
• After installing the pipes, make sure that the waste water is being drained out prop-
erly and that water is not leaking from the joints (also perform these checks if instal-
lation is done during the heating season).
• Insert a water supply pump from the right side of the air outflow port and pump
about 1L of water into the unit.
* Pump gently, toward the heat exchanger side plate or the unit inside wall.
* Always pump from the right side of the air outflow port.
* If the unit has a heater, the heater will be attached to the front surface of the heat
exchanger, make sure that water does not get onto the heater.