Mitsubishi Heavy Industries V Multi 100VNX Technical Manual Download

Page: 222 / 592

221

'13 • PAC-T-197

212

'12 • PAC-T-173

④

Installation of indoor unit (continued)

6. Make sure to install the indoor unit horizontally. Confirm the

levelness of the indoor unit with a level gauge or transparent

hose filled with water. Keep the height difference at both ends of

the indoor unit within 3mm.

7. Tighten four upper nuts and fix the unit after height and levelness

adjustment.

Caution



Do not adjust the height by adjusting upper nuts. It will cause unexpected stress on the indoor unit

and it will lead to deformation of the unit, failure of attaching a panel, and generating noise from the

fan.



Make sure to install the indoor unit horizontally and set the gap between the unit underside and

the ceiling plane properly. Improper installation may cause air leakage, dew condensation, water

leakage and noise.



Even after decorative panel attached, still the unit height can be adjusted finely. Refer to the

installation manual for decorative panel for details.



Make sure there is no gap between decoration panel and ceiling surface, and between decoration

panel and the indoor unit. The gap may cause air leakage, dew condensation and water leakage.



In case decorative panel is not installed at the same time, or ceiling material is installed after the

unit installed, put the cardboard template for installation attached on the package (packing material

of cardboard box) on the bottom of the unit in order to avoid dust coming into the indoor unit.

⑤

Refrigerant pipe

Caution



Use the new refrigerant pipe.

When re-using the existing pipe system for R22 or R407C, pay attention to the following items.



Change the flare nuts with the attached ones (JIS category 2), and reprocess the flare parts.



Do not use thin-walled pipes.



Use phosphorus deoxidized copper alloy seamless pipe (C1220T specified in JIS H3300) for

refrigeration pipe installation.

In addition, make sure there is no damage both inside and outside of the pipe, and no harmful

substances such as sulfur, oxide, dust or a contaminant stuck on the pipes.



Do not use any refrigerant other than R410A.

Using other refrigerant except R410A (R22 etc.) may degrade inside refrigeration oil. And air getting

into refrigeration circuit may cause over-pressure and resultant it may result in bursting, etc.



Store the copper pipes indoors and seal the both end of them until they are brazed in order to avoid

any dust, dirt or water getting into pipe. Otherwise it will cause degradation of refrigeration oil and

compressor breakdown, etc.



Use special tools for R410A refrigerant.

Work procedure

1. Remove the flare nut and blind flanges on the pipe of the indoor unit.

Make sure to loosen the flare nut with holding the nut on pipe side with a spanner and giving

torque to the nut with another spanner in order to avoid unexpected stress to the copper pipe,

and then remove them.

(Gas may come out at this time, but it is not abnormal.)



Pay attention whether the flare nut pops out. (as the indoor unit is sometimes pressured.)

2. Make a flare on liquid pipe and gas pipe, and connect the refrigeration pipes on the indoor unit.

Bend the pipe with as big radius as possible and do not bend the pipe repeatedly. In addition, do

not twist and crush the pipes.

Do a flare connection as follows:



Make sure to loosen the flare nut with holding the nut on pipe side with a spanner and giving

torque to the nut with another spanner in order to avoid unexpected stress to the copper pipe,

and then remove them.



When fastening the flare nut, align the refrigeration pipe with the center of flare nut, screw the

nut for 3-4 times by hand and then tighten it by spanner with the specified torque mentioned

in the table below. Make sure to hold the pipe on the indoor unit securely by a spanner when

tightening the nut in order to avoid unexpected stress on the copper pipe.

3. Cover the flare connection part of the indoor unit with attached insulation material after a gas

leakage inspection, and tighten both ends with attached straps.



Make sure to insulate both gas pipes and liquid pipes completely.

Incomplete insulation may cause dew condensation or water dropping.

4. Refrigerant is charged in the outdoor unit.

As for the additional refrigerant charge for the indoor unit and piping, refer to the installation manual

attached to the outdoor unit.

Pipe diameter

Tightening torque N·m

6.35

14 to 18

9.52

34 to 42

12.7

49 to 61

15.88

68 to 82

19.05

100 to 120

⑥

Drain pipe (continued)

Work procedure

1. Make sure to insert the drain hose (the end mode of soft PVC) to the end of the step part of drain

socket.

Attach the hose clamp to the drain hose around 10mm from the end, and fasten the screw within

5mm left to the nut.



Do not apply adhesives on this end.

Drain socket

The step part

Drain hose

No adhesive allowed

Drain socket

Metal plate

10mm

Hose clamp

Fasten the screw within 5 mm left to the nut.

Drain hose

2. Prepare a joint for connecting VP-20 pipe, adhere and connect the joint to the drain hose (the end

made of rigid PVC), and adhere and connect VP-20 pipe (prepare on site).

As for drain pipe, apply VP-20 made of rigid PVC which is on the market.



Make sure that the adhesive will not get into the supplied drain hose.
It may cause the flexible part broken after the adhesive is dried up and gets rigid.



Do not bend or make an excess offset on the drain hose as shown in the picture.
Bend or excess offset will cause drain leakage.

Over 20mm

3. Make sure to make descending slope of greater than 1/100 and do not make up-down bend and/or

trap in the midway.



Pay attention not to give stress on the pipe on the indoor unit side, and support and fix the pipe
as close place to the unit as possible when connecting the drain pipe.



Do not set up air vent.

Supporting metal

No bump

No trap

Not touching the water

Trapped air will

generate noises.

Air vent

Insulation material

1.5m ~ 2m

Descending slope greater than 1/100



When sharing a drain pipe for more than one
unit, lay the main pipe 100mm below the drain
outlet of the unit. In addition, select VP-30 or
bigger size for main drain pipe.

4. Insulate the drain pipe.



Be sure to insulate the drain socket and rigid PVC pipe installed indoors otherwise it may cause
dew condensation and water leakage.

After drainage test implementation, cover the drain socket part with pipe cover (small size),

then use the pipe cover (big size) to cover the pipe cover (small size), clamps and part of the
drain hose, and fix and wrap it with tapes to wrap and make joint part gapless.

Drain up



The position for drain pipe outlet can be raised up to 600mm above the ceiling. Use elbows for
installation to avoid obstacles inside ceiling. If the horizontal drain pipe is too long before vertical
pipe, the backflow of water will increase when the unit is stopped, and it may cause overflow of
water from the drain pan on the indoor unit. In order to avoid overflow, keep the horizontal pipe
length and offset of the pipe within the limit shown in the figure below.

Drain hose

600mm or less

Joint for VP-20

(Prepare on site)

295 to 325mm

100 or less

⑥

Drain pipe

Caution



Install the drain pipe according to the installation manual in order to drain properly.

