Mitsubishi Heavy Industries FDTCVA151HEN1R Technical Manual page 193

b) Give the drain piping a descending grade (1/50-1/100) and never create
a bump to go over or a trap.
c) In connecting drain pipes, care must be taken so as not to apply force
to the unit side piping and fix the pipe at a point as close to the unit as
possible.
d) Do not create an air vent under any circumstances.
e) When drain piping is implemented for more than one unit, provide a
collecting main about 100 mm below the units' drain outlets from which
it collects drain. Use a VP-30 or larger pipe for a collecting main.
f) Do not fail to provide heat insulation at the following two points because
they can cause dew condensation and a resultant water leak.
7) Drain socket
After a drain test is completed, apply a pipe cover (small: accessory) onto
the drain socket, cover the pipe cover (small), the clamp and part of the drain
hose with a pipe cover (large: accessory) and wrap it with a tape completely
without leaving any gaps.
(Cut pipe covers into appropriate shapes)
8) Hard PVC pipes laid indoor
a) Since a drain pipe outlet can be raised up to 700 mm from the ceiling,
use elbows, etc. to install drain pipes, it there are obstacles preventing
normal drain pipe arrangement. When the drain pipe is raised at a point
far from a unit, it can cause an overfl ow due to a back fl ow of drain upon
stoppage, so arrange piping to keep the dimensions specifi ed in the il-
lustration shown on the left.
b) Install the drain pipe outlet where no odor is likely to be generated.
c) Do not lead the drain pipe into a ditch where the generation of harmful
gas such as sulfuric gas or fl ammable gas is expected. A failure to observe
this instruction may cause such harmful or fl ammable gas to fl ow into the
room.
Drainage test
Check that water is draining thoroghly during test run, and that there are no water leaks from the joints and the drain pan.
The test has to be performed even if the unit is installed in the season when the unit is used for healting.
In a new house, perform the test before the ceiling is fitted.
• Using a water pump, pour about 1000 cc of water to the drain pan through
the blowing outlet.
• Check the transparent drain-out section of the drain hose for normal fl ow of
drainage.
* While observing the noise from the drain motor, test drain operation.
• Take off the drain plug to release the water. After the water is drained, place
the drain pulg back where it was.
* Be careful not to get splashed when pulling the drain plug.
Forced drain pump operation
♦ Set up from a unit side.
Turn power on after selecting the emergency operation mode with a setting on the indoor unit control PCB (SW9-3 ON) and
disconnecting the CnB connector on the board. Then, the drain pump will start a continuous operation 15 seconds later.
(Note: The blower will also start operation in tandem)
When a drain test is completed, reinstate the setting to cancel the emergency operation mode (SW9-3 OFF) and plug in the
CnB connector on the board.
(When electrical work is not completed, connect a convex joint to the drain pipe joint area, arrange an inlet and check leaks
and drain connections of the pipe)
192
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Suspension
1.5 m ~ 2 m
bolts
Insulation Desceding slope
material greater than 1/100
Air vent
Trapped air will
generate noises.
As wide as possible
(about 100 mm)
Desceding slope
VP30
greater than 1/100
295 ~ 325 mm 100 mm or less
Drain hose
Joint for VP-25
(not included)
Put the tip of the feed water pump
in the drain pan of the unit body
Drain plug
No bump
No trap
Not
touching
the water