Drain Piping - Hitachi airCore 700 Operation Installation Maintenance Manual

(4) Evacuation and refrigerant charging procedures should be performed according to "Installation &
Maintenance Manual" of the outdoor unit.

6. Drain Piping

(1) The position of the drain piping connection is shown in Fig.6.1.
(2) Prepare polyvinyl chloride pipe with a 32mm outer diameter.
(3) Fasten the tube to the drain hose with the adhesive agent and the factory-supplied clamp. The drain
piping must be performed with a DOWN-SLOPE pitch of 1/25 to 1/100.
(4) Insulate the drain pipe after connecting the drain hose.
NOTE:
•
When the relative humidity of inlet or ambient air exceeds 80%, apply an (field-supplied) auxiliary drain
pan beneath the indoor unit as shown in Fig.6.2.
(1) Do not create an upper-slope or rise for the drain piping, since drain water can flow back to the unit
and leakage to the room will occur when the unit operation is stopped.
(2) Do not connect the drain pipe with sanitary or sewage piping or any other drainage piping.
(3) When the common drain piping is connected with other indoor units, the connected position of each
indoor unit must be higher than the common piping. The pipe size of the common drain pipe must
be large enough according to the unit size and number of units.
(4) After performing drain piping work and electrical wiring, check to ensure that water flows smoothly
as in the following procedure.
(5) Checking with the Float Switch.
(a) Switch ON the power supply.
(b) Pour 2 or 2.5 liters of water into the drain pan.
(c) Check to ensure that the water flows smoothly or whether water leakage occurs. When water
cannot be found at the end of the drain piping, pour another 2 liters of water into the drain.
Drain Hose
1/25 to 1/100
Down-Slope
Incorrect
Incorrect: Upward Slope
Unit
Rising Part
Fig.6.1 Drain Piping
Indoor Unit
Auxiliary Drain Pan
(Field-Supplied)
Fig.6.2 Auxiliary Drain Pan
Thermal Insulation
(Field-Supplied)
Seal
(Adhesive)
Thermal
Clamp
Insulation
Polyvinyl
Chloride Tube
(Field-Supplied)
Correct
Drain Piping
Connection
1/25 to 1/100 Down-Slope
Common Drain Piping
This drain pipe shall be
separating from other pipes.
To the Atmosphere
-14-
6. Drain Piping