Mitsubishi Heavy Industries FDC112KXEN6 Technical Manual page 220

4) When constructing drain piping for several units, position the common pipe about 100 mm below the drain outlet of each
unit as shown in the sketch below. Use VP-30 or thicher pipe for this purpose.
5) Be sure to provide heat insulation to hard PVC pipes of indoor placement.
6) Do not ever provide an air vent.
7) The height of the drain head may be elevated up to a point 600 mm from the bottom of unit and, when an obstacle exists
in the ceiling space, elevate the piping to avoid the obstacle using an elbow or corresponding gadget. When doing this, if
the stretch for the needed height is too high, the back-flow quantity of drain at the time of interruption of the operation gets
too much and it may cause overflow at the drain pan. Therfore, make the height of the drain pipe withing the distance
given in the drawing below.
8) Avoid positioning the drain piping outlet at a place where generation of odor may stimulated. Do not lead the drain piping
direct into a sewer from where sulfur gas may generate.
9) Drainage test
a) During trial operation, make sure that drainage is properly execued and check that leakage is not found at connections.
b) Be sure to carry out a drainage test when installing the system during a heating season.
c) When installing the system in a building under construction, carry out the drainage test before ceiling tiles are in-
stalled.
1 Supply approx 1000cc of water through the outlet of the unit using a feed water pump.
2 Make sure that drainage is proceeding properly at the see-through outlet of the unit.
* Also confirm the revolving sound of the condensate motor when checking the drainage.
3 Then remove the drain plug at lower section of the unit to drain water off. After making sure water is not left, restore
the drain plug to the original position.
Secure the elevation as high as possible
(approx. 100 mm)
A downhill grade of
1/100 or more
295 ~ 325
Drain hose
Joints for VP-20
Insert a water filing hose by approx 50 mm and feed water.
(Be sure to insert the water filing hose in a downward direction.)
Remove the grommet.
Be sure to restro it to the original
position after the test is over.
216
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VP30
Unit : mm
Right above