Insulating Refrigerant Pipes; Drain Piping Work; Electrical Work - Mitsubishi Electric CITY MULTI Series Installation Manual

Caution:
Cut the tip of the indoor unit piping, remove the gas, and then remove the
brazed cap.
[Fig. 5.3.1]
A
A Cut here

5.4. Insulating refrigerant pipes

Be sure to wind heat-resisting polyethylene form of more than 20 mm [13/16
in] 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. Incom-
plete insulation may cause excess condensation or heat losses. Pay careful at-
tention, particularly when insulating above the ceiling.
[Fig. 5.4.1]
B
A
D
E
A Locally procured insulating material for pipes
B Bind here using band or tape.
D Lap margin: more than 40 mm [1-19/32 in]
F Unit side insulating material

5.5. 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 [65 ft]. If the drain
piping is long, support it with metal brackets to prevent it from bending, warp-
ing, or vibrating.
• Connect the supplied drain hose to the discharge port on the unit body. Use
hard vinyl chloride pipes VP-25 (ø32 mm [1-1/4 in]) 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.
• Make sure to use the supplied hose band G to fix the drain hose in place.
Using a commercially available hose band may cause damage to the natural
drain discharge port when tightend too much, resulting in water leakage.

6. Electrical work

u Consult all related regulations and power companies beforehand.
Warning:
Electrical work should be handled by qualified electrical engineers in ac-
cordance with all related regulations and attached instruction manuals.
Special circuits should also be used. If there is a lack of power capacity or
a deficiency in electrical work, it may cause a risk of electric shock or fire.
u Connect all wires securely.
• Fix power source wiring to control box by using buffer bushing for tensile
force (PG connection or the like).
[Fig. 6.0.1]
B
A Control box
C ø21 mm [27/32 in] hole (closed rubber bushing)
D Transmission wiring
u Never connect the power cable to the terminal board for control cables.
(Otherwise it may be broken.)
u Be sure to wire between the control wire terminal boards for indoor
unit, outdoor unit and BC controller.
B
B Remove brazed cap
C
F
C Do not leave any opening.
E Insulating material (field-supplied)
A
C
D
B Power source wiring
[Fig. 5.5.1]
1
C
A B
A
B
A: 250 [9-27/32]
B: 1500-2000 [59-1/16-78-3/4]
A Downward pitch of more than 1/100
C Supporting bracket
E Drain hose (200 [7-7/8] long, accessory) F Tie band (accessory)
G Hose band (accessory)
• As shown in 3 , install a collecting pipe about 100 mm [3-15/16 in] 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 gen-
erated.
• 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. 5.5.2]
3
A
D
B
A BC controller
B Indoor unit
C Collecting pipe
D Please ensure this length is at least 100 mm [3-15/16 in].
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 wa-
ter 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.
Use non-polarized 2-wire as transmission cables.
Use 2-core shielding cables (CVVS, CPEVS) of more than 1.25 mm
diameter as transmission cables.
The switch capacity of the main power to BC controllers and the wire size are as
follows:
Switch (A)
Molded case
circuit breaker
Capacity Fuse
15 15 20 A
• For other detailed information, refer to the outdoor unit installation manual.
• Power supply cords of appliances shall not be lighter than design 245 IEC 53
or 227 IEC 53.
• A switch with at least 3 mm [1/8 in] contact separation in each pole shall be
provided by the Air conditioner installation.
Caution:
Do not use anything other than the correct capacity fuse and breaker. Us-
ing fuse, conductor or copper wire with too large capacity may cause a
risk of malfunction or fire.
Ensure that the outdoor units are put to the ground. 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.
(Unit: mm [in])
2
D
F
E
VP-25
G
B Insulating material
D Drain discharge port
VP-30
B
C
[AWG16] in
2
Earth leakage
Wire size
breaker
20 A 30 mA
1.5 mm [AWG15]
2
0.1 s or less
11