Drain Piping Work; Duct Work; Electrical Wiring; Types Of Control Cables - Mitsubishi Electric CITY MULTI PEFY-P-NMHSU-E Manuel D'installation

7.2. Drain piping work

• 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)
• Ensure that any cross-wise drain piping is less than 20 m [65 ft] (excluding the
difference of elevation). If the drain piping is long, provide metal braces to pre-
vent it from waving. Never provide any air vent pipe. Otherwise drain may be
ejected.
• Use a hard vinyl chloride pipe VP-25 (with an external diameter of 32 mm
[1-5/16 in]) for drain piping.
• Ensure that collected pipes are 10 cm [3-15/16 in] lower than the unit body's
drain port as shown in 2.
• Do not provide any odor trap at the drain discharge port.
• Put the end of the drain piping in a position where no odor is generated.
• Do not put the end of the drain piping in any drain where ionic gases are
generated.
• When 2 drains are necessary, attach the drain hose to the adjacent drain pip-
ing not in use.
• When the drain piping connection is one place, please do not use the drain
piping closed with the rubber cork.
[Fig. 7.2.1] (P. 3)
A Downward slope 1/100 or more
B Drain hose (Accessory)
C Indoor unit
D Collective piping
E Maximize this length to approx. 10 cm [3-15/16 in]

8. Duct work

• When connecting ducts, insert a canvas duct between the main body and the
duct.
• Use non-combustible duct components.
• Install sufficient thermal insulation to prevent condensation forming on air inlet
and air outlet duct flanges, and air outlet ducts.
[Fig. 8.0.1] (P. 3)
A Air inlet
C Duct
E Access door
G Ensure sufficient length to prevent short cycling
H Air outlet
I Keep duct-work length 850 mm [33-1/2 in] or more

9. 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.
B Air filter (supplied at site)
D Canvas duct
F Ceiling
1. Insert the drain hose (accessory) into the drain port.
(The drain hose must not be bent more than 45° to prevent the hose from
breaking or clogging.)
The connecting part between the indoor unit and the drain hose may be dis-
connected at the maintenance. Fix the part with the accessory band, not be
adhered.
2. Attach the drain pipe (O.D. ø32 PVC TUBE, field supply).
(Attach the pipe with glue for the hard vinyl chloride pipe, and fix it with the
band (small, accessory).)
3. Perform insulation work on the drain pipe (O.D. ø32 PVC TUBE) and on the
socket (including elbow).
[Fig. 7.2.2] (P. 3)
A Indoor unit
B Hose band (accessory)
C Tie band (accessory)
D Band fixing part
E Insertion margin
F Drain hose (accessory)
G Drain pipe (O.D. ø32 PVC TUBE, field supply)
H Insulating material (field supply)
I Max.145 ± 5 mm [5-3/4 ± 3/16 in]
Caution:
Inlet duct is 850 mm [33-1/2 in] or more necessary to construct.
Always install horizontal.
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 10 .
Caution:
Be sure to put the unit to the ground on the outdoor unit side. Do not con-
nect the earth cable to any gas pipe, water pipe, lightening rod, or telephone
earth cable. Incomplete grounding may cause a risk of electric shock.

Types of control cables

1. Wiring transmission cables
• Types of transmission cables
Design wiring in accordance with the following table <Table 1>.
• Cable diameter
2
More than 1.25 mm [AWG16]
9