Mitsubishi Heavy Industries FDE40ZMXVG Technical Manual page 102

• If an existing pipe system is used, a required refrigerant charge volume will very depending on the liquid pipe size.
For further information, please see "5. UTILIZATION OF EXISTING PIPING."
Formula to calculate the volume of additional refrigerant required
Additional charge volume (kg) = { Main length (m) – Factory charged volume 15 (m) } x 0.02 (kg/m)
* When an additional charge volume calculation result is negative, it is not necessary to charge refrigerant additionally.
• For an installation measuring 15m or shorter in pipe length, please charge the refrigerant volume charged for
shipment at the factory, when you recharge refrigerant after servicing etc.
8) Heating and condensation prevention
(1) Dress refrigerant pipes (both gas and liquid pipes) for heat insulation and prevention of dew condensation.
• Improper heat insulation/anti-dew dressing can result in a water leak or dripping causing damage to household effects, etc.
(2) Use a heat insulating material that can withstand 120 C or a higher temperature. Poor heat insulating capacity can cause heat insulation problems or cable
deterioration.
• All gas pipes must be securely heat insulated in order to prevent damage from dripping water that comes from the condensation formed on them during a cooling
operation or personal injury from burns because their surface can reach quite a high temperature due to discharged gas flowing inside during a heating operation.
• Wrap indoor units' flare joints with heat insulating parts (pipe cover) for heat insulation (both gas and liquid pipes).
• Give heat insulation to both gas and liquid side pipes. Bundle a heat insulating material and a pipe tightly together so that no gaps may be left between them and
wrap them together with a connecting cable by a dressing tape.
• Both gas and liquid pipes need to be dressed with 20mm or thicker heat insulation materials above the ceiling where relative humidity exceeds 70%.
3. DRAIN PIPING WORK
• Execute drain piping by using a drain elbow and drain grommets
supplied separately as accessories, where water drained from
the outdoor unit is a problem.
• Water may drip where there is a larger amount of drain water.
Seal around the drain elbow and drain grommets with putty or
adequate caulking material.
• Condensed water may flow out from vicinity of service valve or
connected pipes.
• Where you are likely to have several days of sub-zero
temperatures in a row, do not use a drain elbow and drain
grommets. (There is a risk of drain water freezing inside and
blocking the drain.)
CAUTION
Do not put a grommet on
this hole.
This is a supplementary
drain hole to discharge
drain water, when a large
quantity of it is gathered.
Drain elbow
Drain hose
(To be procured on the installer's part)
Grommet
• In charging refrigerant, always charge a calculated volume by using a scale to measure the charge
volume.
• When refrigerant is charged with the unit being run, complete a charge operation within 30minutes.
Running the unit with an insufficient quantity of refrigerant for a long time can cause a compressor failure.
Put down the refrigerant volume calculated from the pipe length onto the caution label attached
NOTE
on the service panel.
Band (procured locally)
Wires for connecting indoor
and outdoor units
• When condensed water needs to be led to a drain, etc., install the unit
on a flat base (supplied separately as an optional part) or concrete
blocks.
Then, please secure space for the drain elbow and the drain hose.
Pipe cover (procured locally)
Exterior tape
Gas piping
Liquid piping
Insulation
Clearance
Are the existing units our pr
YES
Does the existing pipe system to reuse sat
(1) The pipe length is 30m or less.
(2) The pipe size conforms to the table of p
(3) The elevation difference between the in
conforms to the following restrictions.
Where the outdoor unit is above: 15m
Where the outdoor unit is below: 15m
YES
Is the unit to install in the existing
twin-triple-double-twin model?
NO
Is the existing pipe system to reuse free of co
NO
Is the existing pipe system to reuse free o
(Check whether refrigerant charge was req
the system before)
NO
Are there any branch pipes with no indo
NO
Are heat insulation materials of the existin
reuse free of peel-offs or deterioration?
(Heat insulation is necessary for both gas
NO
Are not there any loose pipe
No loose pipe supports
The existing pipe system
INSTALLATION
POINTS
Check the following points again
installation, and before turning o
again and ensure that the unit op
Explain to the customer how to u
of the unit following the instructi