Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 576

FDR-H
(d) When constructing drain piping for several units, posi-
tion the common pipe about 100mm below the drain out-
let of each unit as shown in the sketch. Use VP-30(11/4˝)
or thicker pipe for this purpose.
(e) Be sure to provide heat insulation to hard PVC pipes of
indoor placement.
(f) Do not ever provide an air vent.
(g) The height of the drain head can be elevated up to a point
600mm 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 higher
than 600mm, the back-flow quantity of drain at the event
of interruption of the operation gets too mush and it may
cause overflow at the at the drain pan. Therefore, make
the height of the drain pipe within the distance given in
the sketch below.
(h) Avoid positioning the drain piping outlet at a place where
generation of odor may be stimulated. Do not lead the
drain piping direct into a sewer from where sulfur gas
may generate.
Drainage Test
1 Conduct a drainage test after completion of the electrical work.
2 During the trial, make sure that drain flows properly through the piping and that no water leaks from connections.
3 In case of a new building, conduct the test before it is furnished with the ceiling.
4 Be sure to conduct this test even when the unit is installed in the heating season.
Procedures
1 Supply about 1000cc of water to the unit through the air outlet using a feed water pump.
2 Check the drain while cooling operation.
Remove grommet
Make sure to install
it back after test.
Drain situation can be checked with transparent socket.
574
Insert water supply hose
for 20 mm ~ 30 mm to
supply water.
( )
Insert hose facing
toward bottom.
Attached drain hose clamp
Main unit Drain piping
Secure the elevation as high as possible
(approx. 100 mm)
A downhill grade of
1/100 or less
290 ~ 325
Drain hose
Joint for VP25
(local procurement)
Pour water into a convex joint.
In the electrical work has not been completed, connect
a convex joint in the drain pipe connection to provide a
water inlet.
Then, check if water leaks from the piping system and
that drain flows through the drain pipe normally.
VP30
Unit: mm
100 or less
Right overhead