Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 870

FDC-HKX
(d) Drain piping
1) Drain piping should always be in a downhill grade (1/50-1/100) and avoid riding across an elevation or makeing traps.
● Good piping
Suspension
bolts
1.5 m ~ 2m
Heat
A downhill grade
insulation
of 1/100 or more
2) When connecting the drain pipe to the unit, pay suffcient attention not to apply excess force to the piping on the unit side.
Also, fix the piping at a point as close as possible to the unit.
3) For drain pipe, use hard PVC general purpose pipe VP-25 which can be purchased
locally. When connecting, insert a PVC pipe end securely into the drain socket before
tightening securely using the attached drain hose and clamp. Adhesive must not be used
connection of the drain socket and drain hose ( accessory).
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.
868
● Improper piping
Air vent
Pipe cover (large)[insulation]
Main
unit
Drain socket
Pipe cover (small)[insulation]
(accessory)
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-25
Avoid riding across an elevation
Keep free from traps
Do not pipe under water
Drain socket
Joint for VP-25
(local procurement)
(accessory)
Drain hose
Clamp
(accessory)
(accessory) Pipe cover [insulation]
Adhesion
(local procurement)
VP30
Right above
Level difference part
Drain hose
VP-25
(local procurement)