Refrigerant Pipe, Drain Pipe And Filling Port; Request For Refrigerant Piping Connection; Connecting Refrigerant Pipes And Drain Pipes; Refrigerant Piping Work - Mitsubishi Electric City Multi PEFY-P-VMM-E Manuel D'installation

6.2. Refrigerant pipe, drain pipe and filling
port
[Fig. 6.2.1] (P.2)
A Electrical parts box
C Refrigerant piping (gas)
6.3. Request for refrigerant piping connec-
tion
Connecting refrigerant piping
• After connecting refrigerant piping, insulate the joints (flared joints) with ther-
mal insulation tubing as shown below.

7. Connecting refrigerant pipes and drain pipes

7.1. Refrigerant piping work

This piping work must be done in accordance with the installation manuals for both
outdoor unit and BC controller (simultaneous cooling and heating series R2).
• Series R2 is designed to operate in a system that the refrigerant pipe from an
outdoor unit is received by BC controller and branches at the BC controller to
connect between indoor units.
• For constraints on pipe length and allowable difference of elevation, refer to
the outdoor unit manual.
• The method of pipe connection is flare connection.
Cautions On Refrigerant Piping
s s s s s Be sure to use non-oxidative brazing for brazing to ensure that no for-
eign matter or moisture enter into the pipe.
s s s s s Be sure to apply refrigerating machine oil over the flare connection seat-
ing surface and tighten the connection using a double spanner.
s s s s s Provide a metal brace to support the refrigerant pipe so that no load is
imparted to the indoor unit end pipe. This metal brace should be pro-
vided 50 cm away from the indoor unit's flare connection.
Warning:
When installing and moving the unit, do not charge it with refrigerant other
than the refrigerant specified on the unit.
- Mixing of a different refrigerant, air, etc. may cause the refrigerant cycle to mal-
function and result in severe damage.
Caution:
• Use refrigerant piping made of phosphorus deoxidized copper as speci-
fied. In addition, be sure that the inner and outer surfaces of the pipes are
clean and free of hazardous sulphur, oxides, dust/dirt, shaving particles,
oils, moisture, or any other contaminant.
• Never use existing refrigerant piping.
- The large amount of chlorine in conventional refrigerant and refrigerator oil
in the existing piping will cause the new refrigerant to deteriorate.

8. Duct work

• In connecting duct, insert canvas duct between unit and duct.
• Use incombustible material for duct parts.
• Provide full insulation to inlet duct flange and outlet duct to prevent condensa-
tion.
• Be sure to change the position of air filter to the position where it can be serv-
iced.
[Fig. 8.0.1] (P.3)
<A> In case of rear inlet
<B> In case of bottom inlet
A Duct
C Access door
E Ceiling surface
G Leave distance enough to prevent short cycle
B Refrigerant piping (liquid)
D Drain piping
B Air inlet
D Canvas duct
F Air outlet
[Fig. 6.3.1] (P.2)
A Thermal insulation tubing 1
B Caution:
Pull out the thermal insulation on the refrigerant piping at the site, insert the
flare nut to flare the end, and replace the insulation in its original position.
Take care to ensure that condensation does not form on exposed copper
piping.
C Liquid end of refrigerant piping
E Site refrigerant piping
G Thermal insulation tubing 2
I Pull
K Return to original position
M Plate on main body
O Inside
Q Ensure that there is no gap here. Place joint upwards.
• Store the piping to be used during installation indoors and keep both
ends of the piping sealed until just before brazing.
- If dust, dirt, or water gets into the refrigerant cycle, the oil will deteriorate and
the compressor may fail.
• Use Suniso 4GS or 3GS (small amount) refrigerator oil to coat the flare
and flange connection part. (For models using R22)
• Use ester oil, ether oil or alkylbenzene (small amount) as the refrigerator
oil to coat flares and flange connections. (For models using R410A or
R407C)
- The refrigerant used in the unit is highly hygroscopic and mixes with water
and will degrade the refrigerator oil.

7.2. Drain piping work

1. Ensure that the drain piping is downward (pitch of more than 1/100) to the
outdoor (discharge) side. Do not provide any trap or irregularity on the way. 1
2. Ensure that any cross-wise drain piping is less than 20 m (excluding the differ-
ence of elevation). 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.
3. Use a hard vinyl chloride pipe VP-25 (with an external diameter of 32 mm) for
drain piping.
4. Ensure that collected pipes are 10 cm lower than the unit body's drain port as
shown in 2.
5. Do not provide any odor trap at the drain discharge port.
6. Put the end of the drain piping in a position where no odor is generated.
7. Do not put the end of the drain piping in any drain where ionic gases are gen-
erated.
[Fig. 7.2.1] (P.3)
A Downward slope 1/100 or more
C Indoor unit
E Maximize this length to approx. 10 cm
• Procedure for changing the rear inlet to the bottom inlet.
1. Remove air filter. (First remove filter lock screw.)
2. Remove the bottom plate and flange.
3. Fit the bottom plate to the rear of the body.
4. Fit filter to the underside of the body with screws.
[Fig. 8.0.2] (P.3)
A Flange
C Bottom plate
Caution:
Inlet duct of 850 mm or more should be construted.
To connect the air conditioner main body and the duct for potential equaliza-
tion.
D Gas end of refrigerant piping
F Main body
H Thermal insulation
J Flare nut
L Ensure that there is no gap here
N Outside
P Tie
B Connection dia. 25A external thread
D Collective piping
B Filter
D Screws for filter fitting
7