Connecting Refrigerant Pipes And Drain Pipes; Refrigerant Piping Work; Drain Piping Work; Electrical Wiring - Mitsubishi Electric CITY MULTI PFFY-P-VLRMM-E Manuel D'installation

6. Connecting refrigerant pipes and drain pipes

6.1. 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 brazing connection.
Caution:
• Install the refrigerant piping for the indoor unit in accordance with the
following.
1. Cut the tip of the indoor unit piping, remove the gas, and then remove the
brazed cap.
[Fig. 6.1.1] (P.3)
A Cut here
B Remove brazed cap
2. Pull out the thermal insulation on the site refrigerant piping, braze the unit
piping, and replace the insulation in its original position.
Wrap the piping with insulating tape.
Note:
• When blazing the refrigerant pipes, be sure to blaze, after covering a wet
cloth to the pipes of the units in order to prevent it from burning and
shrinking by heat.
[Fig. 6.1.2] (P.3)
A Cool by a wet cloth
• Pay strict attention when wrapping the copper piping since wrapping the
piping may cause condensation instead of preventing it.
[Fig. 6.1.3] (P.3)
A Thermal insulation
C Wrap with damp cloth
E Ensure that there is no gap here
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.

7. Electrical wiring

Precautions on electrical wiring
Warning:
Electrical work should be done by qualified electrical engineers in accord-
ance with "Engineering Standards For Electrical Installation" and supplied
installation manuals. Special circuits should also be used. If the power cir-
cuit lacks capacity or has an installation failure, it may cause a risk of elec-
tric shock or fire.
1. Be sure to take power from the special branch circuit.
2. Be sure to install an earth leakage breaker to the power.
3. Install the unit to prevent that any of the control circuit cables (remote control-
ler, transmission cables) is brought in direct contact with the power cable out-
side the unit.
4. Ensure that there is no slack on all wire connections.
5. Some cables (power, remote controller, transmission cables) above the ceiling
may be bitten by mouses. Use as many metal pipes as possible to insert the
cables into them for protection.
8
B Pull out insulation
D Return to original position
F Wrap with insulating tape
Warning:
Do not use refrigerant other than the type indicated in the manuals provided
with the unit and on the nameplate.
- Doing so may cause the unit or pipes to burst, or result in explosion or fire during
use, during repair, or at the time of disposal of the unit.
- It may also be in violation of applicable laws.
- MITSUBISHI ELECTRIC CORPORATION cannot be held responsible for mal-
functions or accidents resulting from the use of the wrong type of refrigerant.
Caution:
• Use refrigerant piping made of C1220 (Cu-DHP) phosphorus deoxidized
copper as specified in the JIS H3300 "Copper and copper alloy seamless
pipes and tubes". In addition, be sure that the inner and outer surfaces of
the pipes are clean and free of hazardous sulphur, oxides, dust/dirt, shav-
ing 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.
• 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.
• The refrigerant used in the unit is highly hygroscopic and mixes with
water and will degrade the refrigerator oil.

6.2. 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.
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. Put the supplied strainer at the bottom of the sub drain pan on the side of the
body frame, and connect the supplied drain hose to the end connection. Tighten
this end connection using the supplied hose hand.
4. Use a VP30 pipe or equivalent for collecting pipe if it is needed, and pipe it
giving a downward pitch of more than 1/100.
5. Provide sufficient insulation just as for refrigerant piping.
[Fig. 6.2.1] (P.3)
A Indoor unit
C Sub drain pan
E Drain hose (accessory)
Caution:
Pipe the drain piping to ensure that it discharges drain, and insulate it to
prevent dew condensation. A failure to the piping work may cause water
leakage and so wet your property.
6. Never connect the power cable to leads for the transmission cables. Otherwise
the cables would be broken.
7. Be sure to connect control cables to the indoor unit, remote controller, and the
outdoor unit.
8. Put the unit to the ground on the outdoor unit side.
9. Select control cables from the conditions given in page 9 .
Caution:
• Be sure to put the unit to the ground on the outdoor unit side. Do not
connect the earth cable to any gas pipe, water pipe, lightening rod, or
telephone earth cable. Incomplete grounding may cause a risk of electric
shock.
• If the supply cord is damaged, it must be replaced by the manufacturer,
its service agent or similarly qualified persons in order to avoid a hazard.
B Strainer (accessory)
D Hose band (accessory)